METHOD OF HIGH POWER LASER-MECHANICAL DRILLING

There is provided a laser-mechanical method for drilling boreholes that utilizes specific combinations of high power directed energy, such as laser energy, in combination with mechanical energy to provide a synergistic enhancement of the drilling process.

Skip to: Description  ·  Claims  · Patent History  ·  Patent History
Description

This application: (i) claims, under 35 U.S.C. §119(e)(1), the benefit of the filing date of Feb. 24, 2011 of U.S. provisional application Ser. No. 61/446,041; (ii) claims, under 35 U.S.C. §119(e)(1), the benefit of the filing date of Feb. 24, 2011 of U.S. provisional application Ser. No. 61/446,312; (iii) claims, under 35 U.S.C. §119(e)(1), the benefit of the filing date of Feb. 24, 2011 of U.S. provisional application Ser. No. 61/446,040; (iv) claims, under 35 U.S.C. §119(e)(1), the benefit of the filing date of Feb. 24, 2011 of U.S. provisional application Ser. No. 61/446,043; (v) claims, under 35 U.S.C. §119(e)(1), the benefit of the filing date of Feb. 24, 2011 of U.S. provisional application Ser. No. 61/446,042; (vi) is a continuation-in-part of U.S. patent application Ser. No. 12/544,038 filed Aug. 19, 2009, which claims under 35 U.S.C. §119(e)(1) the benefit of the filing date of Feb. 17, 2009 of U.S. provisional application Ser. No. 61/153,271, the benefit of the filing date of Oct. 17, 2008 of U.S. provisional application Ser. No. 61/106,472, the benefit of the filing date of Oct. 3, 2008 of U.S. provisional application Ser. No. 61/102,730, and the benefit of the filing date of Aug. 20, 2008 of U.S. provisional application Ser. No. 61/090,384; (vii) is a continuation-in-part of U.S. patent application Ser. No. 12/543,968 filed Aug. 19, 2009; and (viii) is a continuation-in-part of U.S. patent application Ser. No. 12/543,986 filed Aug. 19, 2009, which claims under 35 U.S.C. §119(e)(1) the benefit of the filing date of Feb. 17, 2009 of U.S. provisional application Ser. No. 61/153,271, the benefit of the filing date of Oct. 17, 2008 of U.S. provisional application Ser. No. 61/106,472, the benefit of the filing date of Oct. 3, 2008 of U.S. provisional application Ser. No. 61/102,730, and the benefit of the filing date of Aug. 20, 2008 of U.S. provisional application Ser. No. 61/090,384, the entire disclosures of each of which are incorporated herein by reference.

This invention was made with Government support under Award DE-AR0000044 awarded by the Office of ARPA-E U.S. Department of Energy. The Government has certain rights in this invention.

BACKGROUND OF THE INVENTION Field of the Invention

The present inventions relate to high power laser energy tools and systems and methods.

As used herein, unless specified otherwise, “high power laser energy” means a laser beam having at least about 1 kW (kilowatt) of power. As used herein, unless specified otherwise “great distances” means at least about 500 m (meter). As used herein the term “substantial loss of power,” “substantial power loss” and similar such phrases, mean a loss of power of more than about 3.0 dB/km (decibel/kilometer) for a selected wavelength. As used herein the term “substantial power transmission” means at least about 50% transmittance.

As used herein, unless specified otherwise, the term “earth” should be given its broadest possible meaning, and includes, the ground, all natural materials, such as rocks, and artificial materials, such as concrete, that are or may be found in the ground, including without limitation rock layer formations, such as, granite, basalt, sandstone, dolomite, sand, salt, limestone, rhyolite, quartzite and shale rock.

As used herein, unless specified otherwise, the term “borehole” should be given it broadest possible meaning and includes any opening that is created in a material, a work piece, a surface, the earth, a structure (e.g., building, protected military installation, nuclear plant, offshore platform, or ship), or in a structure in the ground, (e.g., foundation, roadway, airstrip, cave or subterranean structure) that is substantially longer than it is wide, such as a well, a well bore, a well hole, a micro hole, slimhole, a perforation and other terms commonly used or known in the arts to define these types of narrow long passages. Wells would further include exploratory, production, abandoned, reentered, reworked, and injection wells. Although boreholes are generally oriented substantially vertically, they may also be oriented on an angle from vertical, to and including horizontal. Thus, using a vertical line, based upon a level as a reference point, a borehole can have orientations ranging from 0° i.e., vertical, to 90°,i.e., horizontal and greater than 90° e.g., such as a heel and toe and combinations of these such as for example “U” and “Y” shapes. Boreholes may further have segments or sections that have different orientations, they may have straight sections and arcuate sections and combinations thereof; and for example may be of the shapes commonly found when directional drilling is employed. Thus, as used herein unless expressly provided otherwise, the “bottom” of a borehole, the “bottom surface” of the borehole and similar terms refer to the end of the borehole, i.e., that portion of the borehole furthest along the path of the borehole from the borehole's opening, the surface of the earth, or the borehole's beginning. As used herein unless specified otherwise, the terms “side” and “wall” of a borehole should to be given their broadest possible meaning and include the longitudinal surfaces of the borehole, whether or not casing or a liner is present, as such, these terms would include the sides of an open borehole or the sides of the casing that has been positioned within a borehole. Boreholes may be made up of a single passage, multiple passages, connected passages and combinations thereof, in a situation where multiple boreholes are connected or interconnected each borehole would have a borehole bottom. Boreholes may be formed in the sea floor, under bodies of water, on land, in ice formations, or in other locations and settings.

Boreholes are generally formed and advanced by using mechanical drilling equipment having a rotating drilling tool, e.g., a bit. For example and in general, when creating a borehole in the earth, a drilling bit is extending to and into the earth and rotated to create a hole in the earth. In general, to perform the drilling operation the bit must be forced against the material to be removed with a sufficient force to exceed the shear strength, compressive strength or combinations thereof, of that material. Thus, in conventional drilling activity mechanical forces exceeding these strengths of the rock or earth must be applied. The material that is cut from the earth is generally known as cuttings, e.g., waste, which may be chips of rock, dust, rock fibers and other types of materials and structures that may be created by the bit's interactions with the earth. These cuttings are typically removed from the borehole by the use of fluids, which fluids can be liquids, foams or gases, or other materials know to the art.

As used herein, unless specified otherwise, the term “advancing” a borehole should be given its broadest possible meaning and includes increasing the length of the borehole. Thus, by advancing a borehole, provided the orientation is not horizontal, e.g., less than 90° the depth of the borehole may also be increased. The true vertical depth (“TVD”) of a borehole is the distance from the top or surface of the borehole to the depth at which the bottom of the borehole is located, measured along a straight vertical line. The measured depth (“MD”) of a borehole is the distance as measured along the actual path of the borehole from the top or surface to the bottom. As used herein unless specified otherwise the term depth of a borehole will refer to MD. In general, a point of reference may be used for the top of the borehole, such as the rotary table, drill floor, well head or initial opening or surface of the structure in which the borehole is placed.

As used herein, unless specified otherwise, the terms “ream”, “reaming”, a borehole, or similar such terms, should be given their broadest possible meaning and includes any activity performed on the sides of a borehole, such as, e.g., smoothing, increasing the diameter of the borehole, removing materials from the sides of the borehole, such as e.g., waxes or filter cakes, and under-reaming.

As used herein, unless specified otherwise, the terms “drill bit”, “bit”, “drilling bit” or similar such terms, should be given their broadest possible meaning and include all tools designed or intended to create a borehole in an object, a material, a work piece, a surface, the earth or a structure including structures within the earth, and would include bits used in the oil, gas and geothermal arts, such as fixed cutter and roller cone bits, as well as, other types of bits, such as, rotary shoe, drag-type, fishtail, adamantine, single and multi-toothed, cone, reaming cone, reaming, self-cleaning, disc, three cone, rolling cutter, crossroller, jet, core, impreg and hammer bits, and combinations and variations of the these.

Mechanical bits cut rock with shear stresses created by rotating a cutting surface against the rock and placing a large amount of weight-on-bit (“WOB”). Mechanical bits cut rock by applying crushing (compressive) and/or shear stresses created by rotating a cutting surface against the rock and placing a large amount of WOB. In the case of a bit made of the material polycrystalline diamond compact (“PDC”), e.g., a PDC bit, this action is primarily by shear stresses and in the case of roller cone bits this action is primarily by crushing (compression) and shearing stresses. For example, the WOB applied to an 8¾″ PDC bit may be up to 15,000 lbs, and the WOB applied to an 8¾″ roller cone bit may be up to 60,000 lbs. When mechanical bits are used for drilling hard and ultra-hard rock excessive WOB, rapid bit wear, and long tripping times result in an effective drilling rate that is essentially economically unviable. The effective drilling rate is based upon the total time necessary to complete the borehole and, for example, would include time spent tripping in and out of the borehole, as well as, the time for repairing or replacing damaged and worn bits.

As used herein, unless specified otherwise, the term “drill pipe” should be given its broadest possible meaning and includes all forms of pipe used for drilling activities; and refers to a single section or piece of pipe. As used herein the terms “stand of drill pipe,” “drill pipe stand,” “stand of pipe,” “stand” and similar type terms are to be given their broadest possible meaning and include two, three or four sections of drill pipe that have been connected, e.g., joined together, typically by joints having threaded connections. As used herein the terms “drill string,” “string,” “string of drill pipe,” string of pipe” and similar type terms are to be given their broadest definition and would include a stand or stands joined together for the purpose of being employed in a borehole. Thus, a drill string could include many stands and many hundreds of sections of drill pipe.

As used herein, unless specified otherwise, the term “tubular” should be given its broadest possible meaning and includes drill pipe, casing, riser, coiled tube, composite tube, vacuum insulated tubing (“VIT), production tubing and any similar structures having at least one channel therein that are, or could be used, in the drilling industry. As used herein the term “joint” is to be given its broadest possible meaning and includes all types of devices, systems, methods, structures and components used to connect tubulars together, such as for example, threaded pipe joints and bolted flanges. For drill pipe joints, the joint section typically has a thicker wall than the rest of the drill pipe. As used herein the thickness of the wall of tubular is the thickness of the material between the internal diameter of the tubular and the external diameter of the tubular.

SUMMARY

There has been a long-standing need for rapidly and efficiently drilling boreholes into hard and very hard materials, and to do so with minimal damage to the drilling bit. The present inventions, among other things, solve these and other needs by providing the articles of manufacture, devices and processes taught herein.

Thus, there is provided herein a method of directed energy mechanical drilling having the steps of: providing directed energy to a surface of a material; providing mechanical energy to that surface; so that the ratio of directed energy to mechanical energy is greater than about 5; and, in this manner a borehole is advance through the surface of the material.

Further, there is provided a method directed energy mechanical drilling having steps including: providing directed energy to a surface of a material; providing mechanical energy to the surface; so that the ratio of directed energy to mechanical energy is greater than about 10; and, in this manner a borehole is advance through the surface of the material.

Moreover, there is provided a method of directed energy mechanical drilling including the following: providing directed energy to a surface of a material; providing mechanical energy to the surface; so that the ratio of directed energy to mechanical energy is greater than about 20; and, in this manner a borehole is advance through the surface of the material.

Still further, there is provided a method of providing directed energy to a surface of a material and providing mechanical energy to the surface; in a manner where the ratio of directed energy to mechanical energy is greater than about 40; and, in this manner a borehole is advance through the surface of the material.

Further still, there is provided directed energy mechanical drilling by directing directed energy to a surface of a material and directing mechanical energy to the surface in a ratio of directed energy to mechanical energy that is greater than about 2 and this manner a borehole is advance through the surface of the material.

Additionally, there is provided a method of directed energy mechanical drilling having the steps of: providing high power laser directed energy to a surface of a material; providing mechanical energy to the surface; and, so that the ratio of high power laser directed energy to mechanical energy is greater than about 5; and, in this manner a borehole is advance through the surface of the material.

Yet still additionally, there is provided a directed energy mechanical drilling method of providing high power laser directed energy to a surface of a material; providing mechanical energy to the surface; in the ratio of high power laser directed energy to mechanical energy that is greater than about 10; and, thus advancing a borehole through the surface of the material.

Additionally, there is provided a method of directed energy mechanical drilling by providing high power laser directed energy to a surface of a material, providing mechanical energy to the surface, so that the ratio of high power laser directed energy to mechanical energy is greater than about 20; and, in this manner a borehole is advance through the surface of the material.

Still further, there is provided a method of directed energy mechanical drilling having steps including: providing high power laser directed energy to a surface of a material; providing mechanical energy to the surface; and, so that the ratio of high power laser directed energy to mechanical energy is greater than about 40; and, in this manner a borehole is advance through the surface of the material.

Yet additionally, there is provided a directed energy mechanical drilling method by providing high power laser directed energy to a surface; providing mechanical energy to the surface; in a ratio of directed energy to mechanical energy that is greater than about 2 and, thus advancing a borehole through the surface of the material are utilized.

Still further, the methods may also include steps, conditions and parameters in which: the directed energy is high power laser energy and in which the high power laser directed energy has a power of at least about 40 kW; the surface is not substantially melted by the laser energy; the mechanical energy is provided by a bit having a weight-on-bit less than about 2000 pounds; the mechanical energy is provided by a bit having a weight-on-bit less than about 1000 pounds; the mechanical energy is provided by a bit having a weight-on-bit less than about 2000 pounds so that the borehole is advanced at a rate of penetration of at least about 10 feet per hour; the mechanical energy is provided by a bit having a weight-on-bit less than about 2000 pounds so that the borehole is advanced at a rate of penetration of at least about 10 feet per hour; the high power laser directed energy has a power of at least about 20 kW and the mechanical energy is provided by a bit having a weight-on-bit less than about 2000 pounds so that the borehole is advanced at a rate of penetration of at least about 20 feet per hour; the high power laser directed energy has a power of at least about 20 kW and the mechanical energy is provided by a bit having a weight-on-bit less than about 2000 pounds so that the borehole is advanced at a rate of penetration of at least about 20 feet per hour; the high power laser directed energy has a power of at least about 20 kW and the mechanical energy is provided by a bit having a weight-on-bit less than about 2000 pounds so that the borehole is advanced at a rate of penetration of at least about 20 feet per hour; the high power laser directed energy has a power of at least about 50 kW and the mechanical energy is provided by a bit having a weight-on-bit less than about 2000 pounds so that the borehole is advanced at a rate of penetration of at least about 20 feet per hour; the mechanical energy is provided by a bit having a weight-on-bit less than about 2000 pounds so that the borehole is advanced at a rate of penetration the rate of penetration of at least about 20 feet per hour through material having an average hardness of about 20 ksi (kilopound per square inch) or greater; the borehole is advanced for greater than about 500 feet; and the borehole is advanced for greater than about 5,000 feet.

Moreover, there is provided a method of advancing borehole in the earth using high power laser mechanical drilling techniques, the method involving: directing laser energy, in a moving pattern, to a bottom surface of a borehole in the earth; heating the earth with the directed laser energy to a point below the melting point; providing mechanical energy to the heated earth; so that the ratio of laser energy to mechanical energy is greater than about 2; and, in this manner the borehole is advanced

Furthermore, the methods may also include steps, conditions and parameters in which: the laser energy has a power of about 20 kW or greater; the power/area of the laser energy on the surface of the bottom of the borehole is about 50 W/cm2 or greater; the power/area of the laser energy on the surface of the bottom of the borehole is about 75 W/cm2 or greater; the power/area of the laser energy on the surface of the bottom of the borehole is about 100 W/cm2 or greater; the laser energy on the surface of the bottom of the borehole is about 200 W/cm2 or greater; the power/area of the laser energy on the surface of the bottom of the borehole is about 300 W/cm2 or greater; the mechanical energy is provided by a bit having a weight-on-bit less than about 2000 pounds; the mechanical energy is provided by a bit having a weight-on-bit less than about 1000 pounds; the mechanical energy is provided by a bit having a weight-on-bit less than about 2000 pounds and so that the borehole is advanced at a rate of penetration of at least about 10 feet per hour; the mechanical energy is provided by a bit having a weight-on-bit, so that the weight-on-bit is less than about 2000 pounds and so that the borehole is advanced at a rate of penetration of at least about 20 feet per hour; the mechanical energy is provided by a bit having a weight-on-bit less than about 2000 pounds and so that borehole is advances at a rate of penetration of at least about 10 feet per hour through material having an average hardness of about 20 ksi or greater; the mechanical energy is provided by a bit having a weight-on-bit less than about 2000 pounds and so that the borehole is advanced at a rate of penetration of at least about 20 feet per hour through material having an average hardness of about 20 ksi or greater; and the borehole is advanced for greater than about 1,000 feet, greater than about 2,000 feet, and greater than then about 5,000 feet and greater than about 10,000 feet.

Moreover, there is provided a method of laser-mechanical drilling a borehole in a formation having at least 500 feet of material having a hardness greater than about 30 ksi by: providing a laser-mechanical bit into a borehole, the laser-mechanical bit in optical communication with a high power laser beam source; rotating the laser-mechanical bit against a surface of the borehole while propagating a laser beam against the borehole surface; with an RPM of from about 240 to about 720, a WOB of less than about 2,000 lbs, a DE Power/Area of about 90 W/cm2 to about 560 W/cm2, and an ME Power/Area of about 4 W/cm2 to about 250 W/cm2; and in this manner the borehole is advanced at an ROP of at least about 10 ft/hr.

Further, there is provided a method of laser-mechanical drilling a borehole in a formation having at least 500 feet of material having a hardness greater than about 30 ksi by: providing a laser-mechanical bit into a borehole, the laser-mechanical bit in optical communication with a high power laser beam source; rotating the laser-mechanical bit against a surface of the borehole while propagating a laser beam against the borehole surface; with an RPM of from about 600 to about 800, a WOB of less than about 5,000 lbs, a DE Power/Area of about 40 W/cm2 to about 250 W/cm2, and an ME Power/Area of about 200 W/cm2 to about 3000 W/cm2; and, in this manner the borehole is advanced at an ROP of at least about 15 ft/hr.

Additionally, there is provided a method of laser-mechanical drilling a borehole in a formation having at least 500 feet of material having a hardness greater than about 20 ksi by: providing a laser-mechanical bit into a borehole, the laser-mechanical bit in optical communication with a high power laser beam source; rotating the laser-mechanical bit against a surface of the borehole while propagating a laser beam against the borehole surface; with an RPM of from about 600 to about 1250, a WOB of from about 500 to about 5,000 lbs, a DE Power/Area of about 90 W/cm2 to about 570 W/cm2, and an ME Power/Area of about 40 W/cm2 to about 270 W/cm2; and in this manner the borehole is advanced at an ROP of at least about 10.

Yet additionally, there is provided a method of laser-mechanical drilling a borehole in a formation having at least 500 feet of hard rock material, having a hardness greater than about 20 ksi by: providing a laser-mechanical bit into a borehole, the laser-mechanical bit in optical communication with a high power laser beam source; rotating the laser-mechanical bit against a surface of the borehole with an RPM of about 250, a WOB of from about 1,000 lbs, a DE Power/Area of about 370 W/cm2, and an ME Power/Area of about 40 W/cm2; and, in this manner the borehole is advanced at an ROP of at least about 20 ft/hr.

Yet still further, there is provided a method of laser-mechanical drilling a borehole in a formation having at least 500 feet of hard rock material, having a hardness greater than about 20 ksi, the method having the steps of: providing a laser-mechanical bit into a borehole, the laser-mechanical bit in optical communication with a high power laser beam source; rotating the laser-mechanical bit against a surface of the borehole with an RPM of from about 720, a WOB of from about 2,000 lbs, a DE Power/Area of about 190 W/cm2, and an ME Power/Area of about 250 W/cm2; and, in this manner the borehole is advanced at an ROP of at least about 50 ft/hr.

Further still, there is provided a method of laser-mechanical drilling a borehole in a formation having at least 500 feet of hard rock material, having a hardness greater than about 20 ksi by: providing a laser-mechanical bit into a borehole, the laser-mechanical bit in optical communication with a high power laser beam source; rotating the laser-mechanical bit against a surface of the borehole with an RPM of from about 720, a WOB of from about 2,000 lbs, a DE Power/Area of about 370 W/cm2, and an ME Power/Area of about 250 W/cm2; and, in this manner the borehole is advanced at an ROP of at least about 50 ft/hr.

Still further, there is provided a method of laser-mechanical drilling a borehole in a formation having at least 500 feet of hard rock material, having a hardness greater than about 20 ksi by: providing a laser-mechanical bit into a borehole, the laser-mechanical bit in optical communication with a high power laser beam source; rotating the laser-mechanical bit against a surface of the borehole with an RPM of from about 720, a WOB of from about 5,000 lbs, a DE Power/Area of about 290 W/cm2, and an ME Power/Area of about 240 W/cm2; and, in this manner the borehole is advanced at an ROP of at least about 20 ft/hr.

Moreover, there is provided a method of laser-mechanical drilling a borehole in a formation having at least 500 feet of hard rock material, having a hardness greater than about 20 ksi, this method includes: providing a laser-mechanical bit into a borehole, the laser-mechanical bit in optical communication with a high power laser beam source; rotating the laser-mechanical bit against a surface of the borehole with an RPM of from about 1,200, a WOB of from about 500 lbs, a DE Power/Area of about 470 W/cm2, and an ME Power/Area of about 100 W/cm2; and, in this manner the borehole is advanced at an ROP of at least about 30 ft/hr.

Still further, a method of laser-mechanical drilling a borehole in a formation having at least 500 feet of hard rock material, having a hardness greater than about 20 ksi, by: providing a laser-mechanical bit into a borehole, the laser-mechanical bit in optical communication with a high power laser beam source; rotating the laser-mechanical bit against a surface of the borehole with an RPM of from about 720, a WOB of from about 2,000 lbs, a DE Power/Area of about 470 W/cm2, and an ME Power/Area of about 250 W/cm2; and, in this manner the borehole is advanced at an ROP of at least about 30 ft/hr.

Furthermore, there is also provided a method of laser-mechanical drilling a borehole in a formation by: providing a laser-mechanical bit into a borehole, the laser-mechanical bit in optical communication with a high power laser beam source; applying from the high power laser beam source a high power laser beam to a surface of the borehole, so that the high power laser beam generates an intensity ranging from about 150 to about 250 W/cm2 on a surface of the borehole for an elapsed time sufficient to cause a surface temperature rise in the range from about 400 degrees C. to about 1,000 degrees C. and thus forming a laser applied surface; and applying a mechanical force to the laser applied surface, so that the mechanical force generates an intensity ranging from about 30 to about 250 W/cm2 to remove the laser applied surface of the borehole.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective view of an embodiment of a fixed cutter laser-mechanical bit in accordance with the present invention.

FIG. 1B is a bottom view of the bit of FIG. 1A.

FIG. 1C is a cross section view of the bit of FIGS. 1A and 1B taken along line 1C-1C.

FIG. 2 is a schematic of an embodiment of a high power laser drilling, workover and completion unit in accordance with the present invention.

FIG. 3 is a chart showing various directed energy regimes.

FIG. 4 is schematic of chips of basalt.

FIG. 5 is a schematic of chips of dolomite.

 DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present inventions relate to directed energy mechanical drilling methods that utilize high power directed energy in conjunction with mechanical forces. These methods may find uses in many different types of materials and structures, such as metal, stone, composites, concrete, the earth, and structures in the earth. In particular, these methods may find preferable uses in situations and environments where advancing a borehole with conventional, e.g., non-directed energy technology, was difficult or impossible, because, for example, the remoteness of the area where the borehole was to be advanced, difficult environmental conditions or other factors that placed great, and at times insurmountable burdens on conventional drilling or boring technologies. These methods also find preferable uses in situations where reduced noise and vibrations, compared to conventional technologies, are desirable or a requisite.

In general, the present methods involve the application of directed energy and mechanical forces to a surface, e.g., the bottom of a borehole, to remove material and advance the borehole. The directed energy and mechanical forces are preferably applied in a rotating or revolving manner, so that they are so moved about or on the surface to be drilled (i.e., the drilling surface), e.g., the bottom of a borehole. “Directed energy” would include, for example, optical laser energy, non-optical laser energy, microwaves, sound waves, plasma, electric arcs, flame, flame jets, steam and combinations of the foregoing, as well as, water jets (although a water jet may be viewed as having a mechanical interaction with the drilling surface, for the purpose of this specification it will be characterized amongst the group of directed energies, based upon the following specific definition of mechanical energy), and other forms of energy that are not “mechanical energy” as defined in these specifications. “Mechanical energy,” as used herein, is limited to energy that is transferred to the drilling surface by the interaction or contact of a solid object, e.g., a drill bit cutter, roller cone, or a saw blade, with the drilling surface.

These methods provide for the application of unique combinations of directed energy and mechanical force to obtain a synergism. This synergism enables these methods to advance boreholes through very hard materials, such as hard rocks and ultra hard rocks, with very low WOB, e.g., less than about 5,000 lbs, less than about 2000 lbs and preferably about 1000 lbs or less. This reduction in WOB has the potential benefit of providing for substantially longer drilling bit life, longer drilling times where the bit can remain in the borehole, and reduced tripping, which in turn has the potential to greatly reduce the cost of drilling a borehole. In addition to reducing WOB, in other processes, such as in a cutting application, the associated mechanical forces that are needed may similarly be greatly reduced.

In general, and using drilling a borehole in the earth as an illustrative example, as the bit is rotated in the bottom of the borehole, the directed energy is propagated at the bottom surface (and potentially side and gauge surfaces). The directed energy weakens (and may also partially remove, and remove) the material so contacted, i.e., directed energy affected material. The mechanical devices, e.g., cutters, then rotate in the borehole, contacting and removing the directed energy affected material (and potentially some additional material). However, it is preferable, as shown by the examples below, that the mechanical cutter, and the mechanical energy that it delivers, is only sufficient to remove the directed energy affected material. In this way the life of the cutters is preserved, damage is minimized, and the amount of heat built up from friction is controlled and preferably in some embodiments kept to a minimum.

Preferably, in these methods the source of directed energy is a high power laser beam. Thus, and more preferably the laser beam, or beams, may have 10 kW, 20 kW, 40 kW, 80 kW or more power; and have a wavelength in the range of from about 445 nm (nanometers) to about 2100 nm, preferably in the range of from about 800 to 1900 nm, and more preferably in the ranges of from about 1530 nm to 1600 nm, from about 1060 nm to 1080 nm, and from about 1800 nm to 1900 nm. Further, the types of laser beams and sources for providing a high power laser beam may be the devices, systems, optical fibers and beam shaping and delivery optics that are disclosed and taught in the following US patent applications and US Patent Application Publications: Publication No. US 2010/0044106, Publication No. US 2010/0044105, Publication No. US 2010/0044103, Publication No. US 2010/0044102, Publication No. US 2010/0215326, Publication No. 2012/0020631, Ser. No. 13/210,581, and Ser. No. 61/493,174, the entire disclosures of each of which are incorporated herein by reference. The source for providing rotational movement may be a string of drill pipe rotated by a top drive or rotary table, a down hole mud motor, a down hole turbine, a down hole electric motor, and, in particular, may be the systems and devices disclosed in the following US patent applications and US Patent Application Publications: Publication No. US 2010/0044106, Publication No. US 2010/0044104, Publication No. US 2010/0044103, Ser. No. 12/896,021, Ser. No. 61/446,042 and Ser. No. 13/211,729, the entire disclosures of each of which are incorporated herein by reference. The high power lasers for example may be fiber lasers or semiconductor lasers having 10 kW, 20 kW, 50 kW or more power and, which emit laser beams with wavelengths preferably in about the 1064 nm range, about the 1070 nm range, about the 1360 nm range, about the 1455 nm range, about the 1550 nm range, about the 1070 nm range, about the 1083 nm range, or about the 1900 nm range (wavelengths in the range of 1900 nm may be provided by Thulium lasers). Thus, by way of example, there is contemplated the use of four, five, or six, 20 kW lasers to provide a laser beam in a bit having a power greater than about 60 kW, greater than about 70 kW, greater than about 80 kW, greater than about 90 kW and greater than about 100 kW. One laser may also be envisioned to provide these higher laser powers.

Preferably, the source of mechanical energy is a fixed cutter drill bit or roller cone used as part of a laser-mechanical bit. In general, the components of a laser mechanical bit may be made from materials that are known to those of skill in the art for such applications or components, or that are later developed for such applications. For example, the bit body may be made from steel, preferably a high-strength, weldable steel, such as SAE 9310, or cemented carbide matrix material. The blades may be made from similar types of material. The blades and the bit body may be made, for example by milling, from a single piece of metal, or they may be separately made and affixed together. The cutters may be made from for example, materials such as polycrystalline diamond compact (“PDC”), grit hotpressed inserts (“GHI”), and other materials known to the art or later developed by the art. Cutters are commercially available from for example US Synthetic, MegaDiamond, and Element 6. The roller cone arms may be made from steel, such as SAE 9310. Like the blades, the arms and the bit body may be made from a single piece of metal, or they may be made from separate pieces of metal and affixed together. Roller cone inserts, for example, may be made from sintered tungsten carbide insert (“TCI”) or the roller cones may be made with milled teeth (“MTs”). Roller cones, roller cone inserts, and roller cones and leg assemblies, may be obtained commercially from Varel International, while TCI may be obtained from for example Kennametal or ATI Firth Sterling. It is preferred that the inner surface of the beam path be made of material that does not absorb the laser energy, and thus, it is preferable that such surfaces be reflective or polished surfaces. It is also preferred that any surfaces of the bit that may be exposed to reflected laser energy, reflections, also be non-absorptive, minimally absorptive, and preferably be polished or made reflective of the laser beam.

An example of such a bit and system to provide the high power laser energy and mechanical energy are set forth in FIGS. 1A to C, and in FIG. 2.

In FIGS. 1A, 1B and 1C there is shown views of an embodiment of a fixed cutter type laser-mechanical bit. Thus, there is provided a laser-mechanical bit 100 having a body section 101 and a bottom section 102. The bottom section 102 has mechanical blades 103, 104, 105, 106, 107, 108, 109, and 110.

The bit body 101 may have a receiving slot for each mechanical blade. For example, in FIG. 1A receiving slots, 111, 112, 113, are 114 are identified. Note that with respect to blades, of the type shown as blades 108, 109 and 110, the receiving slots may be joined or partially joined, into a unitary opening. The bit body 101 has side surfaces or areas, e.g., 115a, 115b, 117 in which the blade receiving slots are formed. The bit body 101 has surfaces or areas, e.g., 116a, 116b for supporting gauge pads, e.g., 141. The bit body 101 further has surfaces 119a, 119b, 119c, 119d, that in this embodiment are substantially normal to the surfaces 115a, 115b, 116a, 116b, which surfaces 115a, 115b, have part of the blade receiving slots formed therein. The surface 119 a, 119b, 119c, 119d are connected to surfaces 115a, 115b, 116a, 116b by angled surfaces or areas 118a, 118b, 118c, 118d.

The bit is further provided with beam blades, 120, 121, 122, 123. In this embodiment the beam blades are positioned along essentially the entirely of the width of the bit 100 and merge at the end 126 of beam path slot 125 into a unitary structure. The inner surfaces or sides of the beam blades form, in part, slot 125. The outer surfaces or sides of the beam blades also form a sidewall for the junk slots, e.g., 170. Thus, the beam blades are positioned in both the bit body section 101 and the bottom section 102. Other positions and configurations of the beam blades are contemplated. In the embodiment of FIGS. 1A and 1B the bottom of the beam blades is located at about the same level as the depth of cut limiters, e.g., 146, that are located on blades 103, 107, i.e. depth of cut blades, and slightly below the bottom of the cutters, e.g., 134. As used herein “bottom” refers to the section of the bit that is intended to engage or be closest to the bottom of a borehole, and top of the bit refers to the section furthers away from the bottom. The distance between the top and the bottom of the bit would be the bit length, or longitudinal dimension; and the width would be the dimension transverse to the length, e.g., the outside diameter of the bit, as used herein unless specified otherwise.

The longitudinal position of the bottom of the beam blades with respect to the cutters and any depth of cut limiters, e.g., the beam blades relative proximity to the bottom of the borehole, may be varied in each bit design and configuration and will depend upon factors such as the power of the laser beam, the type of rock or earth being drilled, the flow of and type of fluid used to keep the beam path clear of cuttings and debris. In general it is preferable that the longitudinal positioning of the bottoms of the beam blades, any depth of cut limiter blades and the cutter blades all be relatively close, as shown in FIG. 1A, although other positions and configurations are envisioned.

A beam path 124 is formed in the bit, and is bordered, in part, by the inner surfaces or sides of the beam blades 120, 121, 122, 123 and the inner ends of blades 103, 105, 107 and 109. In this embodiment the beam path extends through the center axis 161 of the bit and divides the bit into two separate sections, as more clearly seen in FIG. 1B. Thus, it is preferable that the structures and their configuration on one side of the beam path 124, be similar, and more preferably the same, as the structures on the other side of the beam path 124, which is the case for this embodiment. This positioning and configuration is preferred, although other positions and configurations are contemplated. The beam path 124 should be close to, but preferably not touch the beam blades or the beam blade inner surfaces. When using high power laser energy, and in particular laser energy greater than 5 kW, 10 kW, 20 kW, 40 kW, 80 kW and greater, if the beam path, and, in particular, the laser beam 160, which is propagated along the beam path, contacts a blade it will melt or otherwise remove that section of the blade in the beam path, and potentially damage the remaining section of the blade, bit, or other bit structure or component that is struck.

The beam path in this embodiment also serves as a fluid path for a fluid, such as air, nitrogen, or a transmissive, or substantially transmissive liquid to the laser beam. This fluid is used to keep the laser beam path clear and also to remove or help remove cuttings from the borehole. Configurations, systems and methods for providing and removing such fluids in laser drilling, and for keeping the beam path clear, as well as, the removal of cuttings from the borehole, during laser drilling are provided in the following US patent applications and US Patent Application Publications: Publication No. US 2010/0044102, Publication No. US 2010/0044103, Publication No. US 2010/0044104, Ser. No. 12/896,021, Ser. No. 13/211,729, Ser. No. 13/210,581 and Ser. No. 13/222,931, the entire disclosures of each of which are incorporated herein by reference.

The beam blades 120, 121, 122 and 123 form a beam path slot 125, which slot has ends, e.g., 126a, 126b. In this embodiment, although other configurations and positions are contemplated, the beam path slot 125 extends from the bottom section 102 partially into the bit body section 101. The beam path slot 125 may also have end sections 126a, 126b, these end sections 126a, 126b, are angled, such that they do not extend into the beam path. The beam pattern, e.g., the shape of the area of illumination by the laser upon the bottom of the borehole, or at any cross section of the beam as it is traveling toward the area to be cut, e.g., a borehole surface, when the bit is not in rotation, in this embodiment is preferably a narrow ellipse or rectangular type of pattern, and more preferably may be such a generally elliptical rectangular pattern where less energy or on laser energy is provided to center of pattern. (In FIG. 1B the laser beam 160 is shown as having a beam pattern that is substantially rectangular.) The beam path for this pattern expands from the optics, not shown, until it strikes the bottom of the borehole (see and compare, FIG. 1C showing a cross section of the laser beam 160 and the beam path 161, with FIG. 1B showing the bottom view of the laser beam pattern, and thus, the shape of the area of illumination of the bottom surface of the borehole by the laser beam when the beam is not rotating). It should additionally be noted that in this embodiment the beam path is such that the area of illumination of the bottom of the borehole surface is wider, i.e., a larger diameter, than the diameter of the bit, put about the same as the outer diameter of the gauge cutters. It is contemplated that the area of illumination may be equal to the bit diameter (excluding or including gauge cutters and/or gauge reamers as forming the outer diameter of the bit), substantially the same as the bit diameter (excluding or including gauge cutters and/or gauge reamers as forming the outer diameter of the bit), greater than the bit diameter (excluding or including gauge cutters and/or gauge reamers as forming the outer diameter of the bit). The bottom of the end section 126 also defines the end of the slot 125 with respect to the outer surface of the bit body. In this embodiment the end of the slot 125 is at about the same longitudinal position as the end of the blades, e.g., 127.

The slot, beam slot or beam path slot refers to the opening or openings, e.g., a slot, in the sides, or side walls, of the bit that permit the beam path and the laser beam to extend out of, or from the side of the bit, as illustrated, by way of example, in FIG. 1C.

In the embodiment of FIGS. 1A-C there are provided gauge cutters, 128, 129, 130, 131. The gauge cutters are located on blades 105, 106, 109 and 110. Blades 106 and 110 only support gauge cutters 128, 130. Blades 105, 109 support gauge cutters 131, 129, as well as, bottom cutters 132, 133, 134, 138, 139, 140, which cutters remove material from the bottom of the borehole, after it has been softened, or otherwise weakened, e.g., laser-affected material, by the laser beam 160. Depending upon the configuration and shape of the laser beam, the gauge cutters may also be removing laser-affected rock or material. Gauge pads, e.g., 141 are positioned in surfaces of the bit body, e.g., 116a. In this embodiment gauge reamers 142, 143, 144, 145 are positioned in blades 104, 105 (and also similarly positioned in blades 108, 109 although not seen in FIG. 1A). Blades 103 and 107 have depth of cut limiters, e.g., 146. The blades, and in particular the blades having cutters, may have internal passages for cooling, e.g., vents or ports, such as, e.g., 147, 148, 149 (it being noted that the actual openings for vents 148, 149, are not seen in the view of FIG. 1A).

As best illustrated in FIG. 1B, the cutters are positioned with respect to each other, such that they each take a slightly different path along the bottom of the borehole, in this way each cutter is assisting in the removal of laser-affected rock, and preferably does not encounter any rock that has not first been affected by the laser. In this embodiment the distance of travel by a cutter before it contacts laser-affected rock is shown by arc 162. Arc 162 defines an angle between the laser beam path, and in this embodiment the laser beam, and the plane of the blade supporting the cutters. This angle, which may be referred to as the “beam path angle,” can be from about 90 degrees to about 140 degrees, about 100 degrees to about 130 degrees, and about 110 degrees to about 120 degrees. Beam path angles of less than 90 degrees may be employed, but are not preferred, as they tend to not give enough time for the heat deposited by the laser to affect the rock before the cutter reaches the area of laser affected rock. (Greater angles than 140 degrees may be employed, however, at greater angles space and strength of component issues can become significant, as the blades have very little space in which to be positioned.) Additionally, when multiple blades are used, each blade could have the same, substantially the same, or a different angle (although care should be taken when using different angles to make certain that the cutters and overall engagement with the borehole surface is properly balanced.) In the embodiment of FIG. 1B this angle, defined by arc 162, is 135 degrees.

This angle between the laser beam (and the beam path, since generally in a properly functioning bit they are coincident) and the cutter position has a relationship to, and can be varied and selected to, address and maximize, efficiency based upon several factors, including for example, the laser power that is delivered to the rock, the reflectivity and absorptivity of the rock to the laser beam, the rate and depth to which the laser beam's energy is transmitted into the rock, the thermal properties of the rock, the porosity of the rock, and the speed, i.e., RPM at which the bit is rotated. Thus, as the laser is fired, e.g., a laser beam is propagated, along its beam path from optics to the surface of the borehole, a certain amount of time will pass from when the laser first contacts a particular area of the surface of the borehole until the cutter revolves around and reaches that point. This time can be referred to as soak time. Depending upon the above factors, the soak time can be adjusted, and optimized to a certain extent by the selection of the cutter-laser beam angle.

The bit 100 has channels, e.g., junk slots, 170, 171 that provide a space between the bit 100 and the wall or side surface 150 of the borehole, for the passage of cuttings up the borehole. The relationship of the gauge cutters 129, 128, 131, 130 as well as other components of the bit 100 to the wall of the borehole 150 can been seen in FIG. 1B.

The blades that support the cutters, 104, 105, 106, 108, 109, 110, i.e., the cutter blades, in the embodiment of FIGS. 1A-C, are essentially right angle shaped. Thus, the bottom section of the blades, i.e., the lower end holding the cutters that engage the bottom and/or gauge of the borehole, and also the associated bottom of the cutters positioned in that end (e.g., cutters 134,133, 132,129), are along an essentially straight line that forms a right angle with the side section of the blades, i.e., the side end holding the cutters that engage the side and/or gauge of the borehole, and also the associated side of the cutters positioned in that end (e.g., cutters 142, 144, 129) form a right angle. This right angle configuration of all of the cutter blades, as shown in the embodiment of FIG. 1, is referred to as a flat bottom configuration, or a flat bottom laser-mechanical bit. Thus, the lower ends of the blades, as well as their associated cutters, are essentially co-planar and thus provided the flat bottom of the bottom section 102 of the bit 100. Accordingly, in laser mechanical-bits, having fixed cutters, it is preferable that the bottom of the bit, as primarily defined by the end of the cutter blades, and the position of the cutters in those ends, is essentially flat and more preferably flat, and as such will engage the borehole in an essentially even manner, and more preferably an even manner, and will in general provide a borehole with an essentially flat bottom and more preferably a flat bottom.

In the bit of FIG. 1 the cutters, e.g., 134, 133, 132, gauge cutters, e.g., 129, and gauge reamers, e.g., 144, 142, may be PDC; and the gauge pads, e.g., 141, may be carbide inserts, which provides for impact resistance, enhanced wear, as well as bit stability.

Further examples of laser-mechanical bits, beam paths, beam patterns including split beam patterns, hybrid-laser-mechanical bits, beam path angles and related processes and systems are disclosed and taught in the following U.S. patent applications Ser. No. 61/446,043 and co-filed patent application having attorney docket no. 13938/79 (Foro s13a), the entire disclosures of each of which are incorporated herein by reference.

Thus, in general, and by way of example, there is provided in FIG. 2 a high efficiency laser drilling system 1000 for creating a borehole 1001 in the earth 1002. FIG. 2 provides a cut away perspective view showing the surface of the earth 1030 and a cut away of the earth 1002 below the surface 1030. In general and by way of example, there is provided a source of electrical power 1003, which provides electrical power by cables 1004 and 1005 to a laser 1006 and a chiller 1007 for the laser 1006. The laser provides a laser beam, i.e., laser energy, that can be conveyed by a laser beam transmission means 1008 to a spool of tubing 1009. A source of fluid 1010 is provided. The fluid is conveyed by fluid conveyance means 1011 to the spool of tubing 1009.

The spool of tubing 1009, e.g., coiled tubing, composite tubing or other conveyance device, is rotated to advance and retract the tubing 1012. Preferred examples of such conveyance means are disclosed and taught in the following US patent applications and US Patent Application Publications: Publication No. US 2010/0044106, Publication No. US 2010/0044104, Publication No. US 2010/0044105, Publication No. US 2010/0044103, Publication No. US 2010/0215326, Publication No. 2012/0020631, Ser. No. 13/210,581, Ser. No. 13/366,882 and Ser. No. 13/211,729, the entire disclosures of each of which are incorporated herein by reference. Thus, the laser beam transmission means 1008 and the fluid conveyance means 1011 are attached to the spool of tubing 1009 by means of rotating coupling means 1013. The tubing 1012 contains a means to transmit the laser beam along the entire length of the tubing, i.e., “long distance high power laser beam transmission means,” to the bottom hole assembly, 1014. The tubing 1012 also contains a means to convey the fluid along the entire length of the tubing 1012 to the bottom hole assembly 1014.

Additionally, there is provided a support structure 1015, which holds an injector 1016, to facilitate movement of the tubing 1012 in the borehole 1001. Further other support structures may be employed, for example, such structures could be derrick, crane, mast, tripod, or other similar type of structure or hybrid and combinations of these. As the borehole is advance to greater depths from the surface 1030, the use of a diverter 1017, a blow out preventer (BOP) 1018, and a fluid and/or cutting handling system 1019 may become necessary. The tubing 1012 is passed from the injector 1016 through the diverter 1017, the BOP 1018, a wellhead 1020 and into the borehole 1001.

The fluid is conveyed to the bottom 1021 of the borehole 1001. At that point the fluid exits at or near the bottom hole assembly 1014 and is used, among other things, to carry the cuttings, which are created from advancing a borehole, back up and out of the borehole. Thus, the diverter 1017 directs the fluid as it returns carrying the cuttings to the fluid and/or cuttings handling system 1019 through connector 1022. This handling system 1019 is intended to prevent waste products from escaping into the environment and separates and cleans waste products and either vents the cleaned fluid to the air, if permissible environmentally and economically, as would be the case if the fluid was nitrogen, or returns the cleaned fluid to the source of fluid 1010, or otherwise contains the used fluid for later treatment and/or disposal.

The BOP 1018 serves to provide multiple levels of emergency shut off and/or containment of the borehole should a high-pressure event occur in the borehole, such as a potential blow-out of the well. The BOP is affixed to the wellhead 1020. The wellhead in turn may be attached to casing. For the purposes of simplification the structural components of a borehole such as casing, hangers, and cement are not shown. It is understood that these components may be used and will vary based upon the depth, type, and geology of the borehole, as well as, other factors.

The downhole end 1023 of the tubing 1012 is connected to the bottom hole assembly 1014. The bottom hole assembly 1014 contains optics for delivering the laser beam 1024 to its intended target, in the case of FIG. 1, the bottom 1021 of the borehole 1001. The bottom hole assembly 1014, for example, also contains means for delivering the fluid.

Thus, in general this system operates to create and/or advance a borehole by having the laser create laser energy in the form of a laser beam. The laser beam is then transmitted from the laser through the spool and into the tubing. At which point, the laser beam is then transmitted to the bottom hole assembly where it is directed toward the surfaces of the earth and/or borehole.

Without being bound by the following theory providing an explanation for the synergistic effects the present method obtains, and without being bound by the following theory of energy-rock interaction, physics and thermodynamics, the following theory is offered by way of illustration and to assist in the understanding of, and explanation for, the surprising and never before obtained results of these methods.

Thus, this process can be viewed as a hybrid thermal/mechanical process in which thermally-induced compressive stresses are generated in a thin skin of rock at the drilling surface. These thermally induced stresses create fractures parallel to the surface of the rock and give rise to rock removal from the borehole via chips of material. Mechanical cutter action is present primarily to ensure continuous removal of the fractured material, which in the presence of laser energy only might not be completely expelled from the surface. The physics of the process and experimental and theoretical results indicate that higher rates of penetration can be achieved by increases in laser power delivered to the drilling surface.

When laser power is absorbed by a rock, the response depends on both the intensity of the impinging laser power, as well as, the illumination time. As shown in the chart of FIG. 3, the material response can generally include several regimes, which may be generally classified as: an ultrafast regime 310, a heating regime 320, a melting regime 330, and a vaporization regime 340. Various processes may occur along these regimes, such as shock hardening 341, drilling 342, glazing 331, cutting 332, welding 333, cladding 334, stereo lithography 321, and transformation hardening 322. At laser intensities and times below the melting of rock, regime 340, lies the regime in which spallation or rock fragmentation occur, as shown in regime area 350. The spallation regime 350 is the preferred area in which it is presently believed that the greatest synergistic benefit for the tailored directed energy mechanical energy process may occur.

When laser power is absorbed by the rock, a thin layer of rock near the surface of the sample is rapidly heated. The thickness of the layer is determined both by the quantity of absorbed laser power, and the thermal properties of the rock. Rock is a naturally insulating material, which means that the propagation of heat into the rock is slow, and the heated region may by necessity be very near the surface. In an unconstrained rock sample, laser absorption would cause the heated region to expand in volume. However, in a drilling environment, the heated rock is constrained on all sides by the surrounding rock mass, and the result is a thermally induced stress state in the heated section that is compressive in nature.

When the magnitude of the thermally induced stress reaches a level comparable to the compressive strength of the rock, it induces fracture in the direction of the maximum compressive stress (i.e., parallel to the heated surface). Under sufficiently large stress, these fractures can extend to very long distances until they intersect with the surface, resulting in the formation of chips, in a process known as “spallation”. Turning to FIG. 4, these chips 401, 402, 403, 404 are characterized by a high aspect ratio, e.g., the lateral dimensions 1.48″ arrow 411, and 1.87″ arrow 412 are much greater than the thickness 0.140″ of chip 404. These chips, e.g., 401 of FIG. 4 are basalt. Similar characteristics of dolomite chips are shown in FIG. 5. Thus, chips 501, 502, 503, 504, 505, 506, 507, 508, 509, 510, and 511 are characterized by a high aspect ratio, e.g., the lateral dimensions 1.06″ arrow 521, and 1.52″ arrow 522, are much greater than the thickness 0.182″ of chip 511.

However, spallation without a mechanical removal mechanism may be and at time has been shown to be an unreliable drilling solution. Not every rock type spalls (e.g., a spallable limestone is believed to have never been identified, for example), and macroscopic fractures in the rock mass can inhibit the spallation process. Although the generation of thermal stress and stress-induced fracture is likely a universal rock response, the explosive release of spalled chips is presently believed to be material specific.

The introduction of mechanical action to a primarily thermal process, then, can increase robustness in a synergistic manner by removing the thermally fractured and damaged material without relying on explosive spallation for rock removal. For a combined thermal/mechanical process, a laser represents an ideal directed energy source, as a high flux of energy can be delivered to the rock over a precisely controlled area designed to minimize heat loads on the mechanical cutters. In the preferred method of operation the role of the mechanical cutters is to provide a minimum amount of pressure sufficient to remove the damaged material; and so that they do not otherwise contribute substantially to the rate of material removal.

The surface temperature of the rock during the process may generally be around 250-650° C., which is the temperature rise sufficient to generate compressive stresses comparable to the strength of the rock; broader ranges are provide in the table of examples and may prove advantageous for various tailored drilling conditions and parameters, Under intense laser power, the surface temperature rise may be sufficient to melt rock directly under the laser beam. This melting would reduce or eliminate the thermal stresses responsible for laser processing, and is therefore preferably a condition to be avoided for this method of processing. Processes whereby the rock surface is melted allowed to cool and then scraped off are contemplated. Such processes do not rely upon a spallation regime and thus may have a broader application to different materials and in particular materials that do not exhibit spallation. Thus, this directed energy mechanical energy process is not material specific.

The methods provided herein can further be understood by the exemplary conditions and parameters set forth in the examples of Table 1. As used in the Table 1, the headings have the following meanings:

WOB: Weight on bit. Force applied by the bit. Units of pounds.

ROP: Rate of penetration. This is the speed of advancement of the drilling surface. Units of feet per hour.

RPM: Rotation speed of the bit in revolutions per minute.

Torque: the degree of twist applied by the bit. Units of foot-pounds.

Mechanical power: The power transmitted to the rock by the bit, given by the equation torque*RPM. Units of kilowatts.

Ratio of DE/ME: The ratio of directed energy or directed laser energy to mechanical energy is the delivered directed laser energy (DE) divided by the delivered mechanical energy (ME). Dimensionless number.

DE Power/Area: The directed energy laser power per unit of drilling surface area. Units are Watts per square centimeter.

ME Power/Area: The delivered mechanical energy power per unit of drilling surface area. Units are Watts per square centimeter.

TABLE 1 Compressive Sonic Velocity Hole Diameter Example # Rock Type Strength (ksi) (m/s) Porosity (%) Laser Power (kW) RPM (inches) WOB 1 Sandstone 35 4800 3.8% 5 120 3.25 200 2 Sandstone 35 4800 3.8% 5 240 3.25 1000 3 Sandstone 35 4800 3.8% 5 360 3.25 200 4 Sandstone 35 4800 3.8% 5 720 3.25 2000 5 Sandstone 35 4800 3.8% 10 120 3.25 200 6 Sandstone 35 4800 3.8% 10 240 3.25 1000 7 Sandstone 35 4800 3.8% 10 360 3.25 200 8 Sandstone 35 4800 3.8% 10 720 3.25 2000 9 Sandstone 35 4800 3.8% 10 1200 3.25 500 10 Sandstone 35 4800 3.8% 15 120 3.25 200 11 Sandstone 35 4800 3.8% 15 240 3.25 1000 12 Sandstone 35 4800 3.8% 15 360 3.25 200 13 Sandstone 35 4800 3.8% 15 720 3.25 2000 14 Sandstone 35 4800 3.8% 15 1200 3.25 500 15 Sandstone 35 4800 3.8% 20 120 3.25 200 16 Sandstone 35 4800 3.8% 20 240 3.25 1000 17 Sandstone 35 4800 3.8% 20 360 3.25 200 18 Sandstone 35 4800 3.8% 20 720 3.25 2000 19 Sandstone 35 4800 3.8% 20 1200 3.25 500 20 Sandstone 35 4800 3.8% 25 240 3.25 1000 21 Sandstone 35 4800 3.8% 25 360 3.25 200 22 Sandstone 35 4800 3.8% 25 720 3.25 2000 23 Sandstone 35 4800 3.8% 25 1200 3.25 500 24 Sandstone 35 4800 3.8% 30 240 3.25 1000 25 Sandstone 35 4800 3.8% 30 360 3.25 200 26 Sandstone 35 4800 3.8% 30 720 3.25 2000 27 Sandstone 35 4800 3.8% 30 1200 3.25 500 28 Sandstone 35 4800 3.8% 10 240 6 1500 29 Sandstone 35 4800 3.8% 10 360 6 3000 30 Sandstone 35 4800 3.8% 10 720 6 2000 31 Sandstone 35 4800 3.8% 10 1200 6 500 32 Sandstone 35 4800 3.8% 20 120 6 500 33 Sandstone 35 4800 3.8% 20 240 6 1500 34 Sandstone 35 4800 3.8% 20 360 6 3000 35 Sandstone 35 4800 3.8% 20 720 6 2000 36 Sandstone 35 4800 3.8% 20 1200 6 500 37 Sandstone 35 4800 3.8% 30 120 6 500 38 Sandstone 35 4800 3.8% 30 240 6 1500 39 Sandstone 35 4800 3.8% 30 360 6 3000 40 Sandstone 35 4800 3.8% 30 720 6 2000 41 Sandstone 35 4800 3.8% 30 1200 6 500 42 Sandstone 35 4800 3.8% 40 120 6 500 43 Sandstone 35 4800 3.8% 40 240 6 1500 44 Sandstone 35 4800 3.8% 40 360 6 3000 45 Sandstone 35 4800 3.8% 40 720 6 2000 46 Sandstone 35 4800 3.8% 40 1200 6 500 47 Sandstone 35 4800 3.8% 50 120 6 500 48 Sandstone 35 4800 3.8% 50 240 6 1500 49 Sandstone 35 4800 3.8% 50 360 6 3000 50 Sandstone 35 4800 3.8% 50 720 6 2000 51 Sandstone 35 4800 3.8% 50 1200 6 500 52 Sandstone 35 4800 3.8% 60 240 6 1500 53 Sandstone 35 4800 3.8% 60 360 6 3000 54 Sandstone 35 4800 3.8% 60 720 6 2000 55 Sandstone 35 4800 3.8% 60 1200 6 500 56 Sandstone 35 4800 3.8% 70 240 6 1500 57 Sandstone 35 4800 3.8% 70 360 6 3000 58 Sandstone 35 4800 3.8% 70 720 6 2000 59 Sandstone 35 4800 3.8% 70 1200 6 500 60 Sandstone 35 4800 3.8% 80 360 6 3000 61 Sandstone 35 4800 3.8% 80 720 6 2000 62 Sandstone 35 4800 3.8% 80 1200 6 500 63 Sandstone 35 4800 3.8% 15 240 8.5 2000 64 Sandstone 35 4800 3.8% 15 360 8.5 3500 65 Sandstone 35 4800 3.8% 15 720 8.5 5000 66 Sandstone 35 4800 3.8% 15 1200 8.5 1000 67 Sandstone 35 4800 3.8% 30 120 8.5 1000 68 Sandstone 35 4800 3.8% 30 240 8.5 2000 69 Sandstone 35 4800 3.8% 30 360 8.5 3500 70 Sandstone 35 4800 3.8% 30 720 8.5 5000 71 Sandstone 35 4800 3.8% 45 120 8.5 1000 72 Sandstone 35 4800 3.8% 45 240 8.5 2000 73 Sandstone 35 4800 3.8% 45 360 8.5 3500 74 Sandstone 35 4800 3.8% 45 720 8.5 5000 75 Sandstone 35 4800 3.8% 45 1200 8.5 1000 76 Sandstone 35 4800 3.8% 60 120 8.5 1000 77 Sandstone 35 4800 3.8% 60 240 8.5 2000 78 Sandstone 35 4800 3.8% 60 360 8.5 3500 79 Sandstone 35 4800 3.8% 60 720 8.5 5000 80 Sandstone 35 4800 3.8% 60 1200 8.5 1000 81 Sandstone 35 4800 3.8% 75 120 8.5 1000 82 Sandstone 35 4800 3.8% 75 240 8.5 2000 83 Sandstone 35 4800 3.8% 75 360 8.5 3500 84 Sandstone 35 4800 3.8% 75 720 8.5 5000 85 Sandstone 35 4800 3.8% 75 1200 8.5 1000 86 Sandstone 35 4800 3.8% 90 120 8.5 1000 87 Sandstone 35 4800 3.8% 90 240 8.5 2000 88 Sandstone 35 4800 3.8% 90 360 8.5 3500 89 Sandstone 35 4800 3.8% 90 720 8.5 5000 90 Sandstone 35 4800 3.8% 90 1200 8.5 1000 91 Sandstone 35 4800 3.8% 105 120 8.5 1000 92 Sandstone 35 4800 3.8% 105 240 8.5 2000 93 Sandstone 35 4800 3.8% 105 360 8.5 3500 94 Sandstone 35 4800 3.8% 105 720 8.5 5000 95 Sandstone 35 4800 3.8% 105 1200 8.5 1000 96 Sandstone 35 4800 3.8% 120 240 8.5 2000 97 Sandstone 35 4800 3.8% 120 360 8.5 3500 98 Sandstone 35 4800 3.8% 120 720 8.5 5000 99 Sandstone 35 4800 3.8% 120 1200 8.5 1000 100 Dolomite 30 5400 3.2% 5 240 3.25 1000 101 Dolomite 30 5400 3.2% 5 360 3.25 200 102 Dolomite 30 5400 3.2% 5 720 3.25 2000 103 Dolomite 30 5400 3.2% 10 120 3.25 200 104 Dolomite 30 5400 3.2% 10 240 3.25 1000 105 Dolomite 30 5400 3.2% 10 360 3.25 200 106 Dolomite 30 5400 3.2% 10 720 3.25 2000 107 Dolomite 30 5400 3.2% 10 1200 3.25 500 108 Dolomite 30 5400 3.2% 15 120 3.25 200 109 Dolomite 30 5400 3.2% 15 240 3.25 1000 110 Dolomite 30 5400 3.2% 15 360 3.25 200 111 Dolomite 30 5400 3.2% 15 720 3.25 2000 112 Dolomite 30 5400 3.2% 15 1200 3.25 500 113 Dolomite 30 5400 3.2% 20 120 3.25 200 114 Dolomite 30 5400 3.2% 20 240 3.25 1000 115 Dolomite 30 5400 3.2% 20 360 3.25 200 116 Dolomite 30 5400 3.2% 20 720 3.25 2000 117 Dolomite 30 5400 3.2% 20 1200 3.25 500 118 Dolomite 30 5400 3.2% 25 120 3.25 200 119 Dolomite 30 5400 3.2% 25 240 3.25 1000 120 Dolomite 30 5400 3.2% 25 360 3.25 200 121 Dolomite 30 5400 3.2% 25 720 3.25 2000 122 Dolomite 30 5400 3.2% 25 1200 3.25 500 123 Dolomite 30 5400 3.2% 30 120 3.25 200 124 Dolomite 30 5400 3.2% 30 240 3.25 1000 125 Dolomite 30 5400 3.2% 30 360 3.25 200 126 Dolomite 30 5400 3.2% 30 720 3.25 2000 127 Dolomite 30 5400 3.2% 30 1200 3.25 500 128 Dolomite 30 5400 3.2% 10 240 6 1500 129 Dolomite 30 5400 3.2% 10 360 6 3000 130 Dolomite 30 5400 3.2% 10 720 6 2000 131 Dolomite 30 5400 3.2% 10 1200 6 500 132 Dolomite 30 5400 3.2% 20 120 6 500 133 Dolomite 30 5400 3.2% 20 240 6 1500 134 Dolomite 30 5400 3.2% 20 360 6 3000 135 Dolomite 30 5400 3.2% 20 720 6 2000 136 Dolomite 30 5400 3.2% 20 1200 6 500 137 Dolomite 30 5400 3.2% 30 120 6 500 138 Dolomite 30 5400 3.2% 30 240 6 1500 139 Dolomite 30 5400 3.2% 30 360 6 3000 140 Dolomite 30 5400 3.2% 30 720 6 2000 141 Dolomite 30 5400 3.2% 30 1200 6 500 142 Dolomite 30 5400 3.2% 40 120 6 500 143 Dolomite 30 5400 3.2% 40 240 6 1500 144 Dolomite 30 5400 3.2% 40 360 6 3000 145 Dolomite 30 5400 3.2% 40 720 6 2000 146 Dolomite 30 5400 3.2% 40 1200 6 500 147 Dolomite 30 5400 3.2% 50 120 6 500 148 Dolomite 30 5400 3.2% 50 240 6 1500 149 Dolomite 30 5400 3.2% 50 360 6 3000 150 Dolomite 30 5400 3.2% 50 720 6 2000 151 Dolomite 30 5400 3.2% 50 1200 6 500 152 Dolomite 30 5400 3.2% 60 120 6 500 153 Dolomite 30 5400 3.2% 60 240 6 1500 154 Dolomite 30 5400 3.2% 60 360 6 3000 155 Dolomite 30 5400 3.2% 60 720 6 2000 156 Dolomite 30 5400 3.2% 60 1200 6 500 157 Dolomite 30 5400 3.2% 70 120 6 500 158 Dolomite 30 5400 3.2% 70 240 6 1500 159 Dolomite 30 5400 3.2% 70 360 6 3000 160 Dolomite 30 5400 3.2% 70 720 6 2000 161 Dolomite 30 5400 3.2% 70 1200 6 500 162 Dolomite 30 5400 3.2% 80 120 6 500 163 Dolomite 30 5400 3.2% 80 240 6 1500 164 Dolomite 30 5400 3.2% 80 360 6 3000 165 Dolomite 30 5400 3.2% 80 720 6 2000 166 Dolomite 30 5400 3.2% 80 1200 6 500 167 Dolomite 30 5400 3.2% 15 120 8.5 1000 168 Dolomite 30 5400 3.2% 15 240 8.5 2000 169 Dolomite 30 5400 3.2% 15 360 8.5 3500 170 Dolomite 30 5400 3.2% 15 720 8.5 5000 171 Dolomite 30 5400 3.2% 15 1200 8.5 1000 172 Dolomite 30 5400 3.2% 30 120 8.5 1000 173 Dolomite 30 5400 3.2% 30 240 8.5 2000 174 Dolomite 30 5400 3.2% 30 360 8.5 3500 175 Dolomite 30 5400 3.2% 30 720 8.5 5000 176 Dolomite 30 5400 3.2% 45 120 8.5 1000 177 Dolomite 30 5400 3.2% 45 240 8.5 2000 178 Dolomite 30 5400 3.2% 45 360 8.5 3500 179 Dolomite 30 5400 3.2% 45 720 8.5 5000 180 Dolomite 30 5400 3.2% 60 120 8.5 1000 181 Dolomite 30 5400 3.2% 60 240 8.5 2000 182 Dolomite 30 5400 3.2% 60 360 8.5 3500 183 Dolomite 30 5400 3.2% 60 720 8.5 5000 184 Dolomite 30 5400 3.2% 75 120 8.5 1000 185 Dolomite 30 5400 3.2% 75 240 8.5 2000 186 Dolomite 30 5400 3.2% 75 360 8.5 3500 187 Dolomite 30 5400 3.2% 75 720 8.5 5000 188 Dolomite 30 5400 3.2% 75 1200 8.5 1000 189 Dolomite 30 5400 3.2% 90 120 8.5 1000 190 Dolomite 30 5400 3.2% 90 240 8.5 2000 191 Dolomite 30 5400 3.2% 90 360 8.5 3500 192 Dolomite 30 5400 3.2% 90 720 8.5 5000 193 Dolomite 30 5400 3.2% 90 1200 8.5 1000 194 Dolomite 30 5400 3.2% 105 120 8.5 1000 195 Dolomite 30 5400 3.2% 105 240 8.5 2000 196 Dolomite 30 5400 3.2% 105 360 8.5 3500 197 Dolomite 30 5400 3.2% 105 720 8.5 5000 198 Dolomite 30 5400 3.2% 105 1200 8.5 1000 199 Dolomite 30 5400 3.2% 120 120 8.5 1000 200 Dolomite 30 5400 3.2% 120 240 8.5 2000 201 Dolomite 30 5400 3.2% 120 360 8.5 3500 202 Dolomite 30 5400 3.2% 120 720 8.5 5000 203 Dolomite 30 5400 3.2% 120 1200 8.5 1000 204 Granite 20 4700 1.5% 5 240 3.25 1000 205 Granite 20 4700 1.5% 5 360 3.25 200 206 Granite 20 4700 1.5% 5 720 3.25 2000 207 Granite 20 4700 1.5% 5 1200 3.25 500 208 Granite 20 4700 1.5% 10 120 3.25 200 209 Granite 20 4700 1.5% 10 240 3.25 1000 210 Granite 20 4700 1.5% 10 360 3.25 200 211 Granite 20 4700 1.5% 10 720 3.25 2000 212 Granite 20 4700 1.5% 15 240 3.25 1000 213 Granite 20 4700 1.5% 15 360 3.25 200 214 Granite 20 4700 1.5% 15 720 3.25 2000 215 Granite 20 4700 1.5% 20 720 3.25 2000 216 Granite 20 4700 1.5% 25 720 3.25 2000 217 Granite 20 4700 1.5% 25 1200 3.25 500 218 Granite 20 4700 1.5% 30 720 3.25 2000 219 Granite 20 4700 1.5% 30 1200 3.25 500 220 Granite 20 4700 1.5% 10 120 6 500 221 Granite 20 4700 1.5% 10 240 6 1500 222 Granite 20 4700 1.5% 10 360 6 3000 223 Granite 20 4700 1.5% 10 720 6 2000 224 Granite 20 4700 1.5% 20 120 6 500 225 Granite 20 4700 1.5% 20 240 6 1500 226 Granite 20 4700 1.5% 20 360 6 3000 227 Granite 20 4700 1.5% 20 720 6 2000 228 Granite 20 4700 1.5% 20 1200 6 500 229 Granite 20 4700 1.5% 30 240 6 1500 230 Granite 20 4700 1.5% 30 360 6 3000 231 Granite 20 4700 1.5% 30 720 6 2000 232 Granite 20 4700 1.5% 30 1200 6 500 233 Granite 20 4700 1.5% 40 240 6 1500 234 Granite 20 4700 1.5% 40 360 6 3000 235 Granite 20 4700 1.5% 40 720 6 2000 236 Granite 20 4700 1.5% 40 1200 6 500 237 Granite 20 4700 1.5% 50 360 6 3000 238 Granite 20 4700 1.5% 50 720 6 2000 239 Granite 20 4700 1.5% 50 1200 6 500 240 Granite 20 4700 1.5% 60 720 6 2000 241 Granite 20 4700 1.5% 60 1200 6 500 242 Granite 20 4700 1.5% 70 720 6 2000 243 Granite 20 4700 1.5% 70 1200 6 500 244 Granite 20 4700 1.5% 80 1200 6 500 245 Granite 20 4700 1.5% 15 120 8.5 1000 246 Granite 20 4700 1.5% 15 240 8.5 2000 247 Granite 20 4700 1.5% 15 360 8.5 3500 248 Granite 20 4700 1.5% 15 720 8.5 5000 249 Granite 20 4700 1.5% 30 120 8.5 1000 250 Granite 20 4700 1.5% 30 240 8.5 2000 251 Granite 20 4700 1.5% 30 360 8.5 3500 252 Granite 20 4700 1.5% 30 720 8.5 5000 253 Granite 20 4700 1.5% 30 1200 8.5 1000 254 Granite 20 4700 1.5% 45 120 8.5 1000 255 Granite 20 4700 1.5% 45 240 8.5 2000 256 Granite 20 4700 1.5% 45 360 8.5 3500 257 Granite 20 4700 1.5% 45 720 8.5 5000 258 Granite 20 4700 1.5% 45 1200 8.5 1000 259 Granite 20 4700 1.5% 60 240 8.5 2000 260 Granite 20 4700 1.5% 60 360 8.5 3500 261 Granite 20 4700 1.5% 60 720 8.5 5000 262 Granite 20 4700 1.5% 75 240 8.5 2000 263 Granite 20 4700 1.5% 75 360 8.5 3500 264 Granite 20 4700 1.5% 75 720 8.5 5000 265 Granite 20 4700 1.5% 90 360 8.5 3500 266 Granite 20 4700 1.5% 90 720 8.5 5000 267 Granite 20 4700 1.5% 105 720 8.5 5000 268 Granite 20 4700 1.5% 120 720 8.5 5000 269 Basalt 40 5100 2.1% 5 120 3.25 200 270 Basalt 40 5100 2.1% 5 240 3.25 1000 271 Basalt 40 5100 2.1% 5 360 3.25 200 272 Basalt 40 5100 2.1% 5 720 3.25 2000 273 Basalt 40 5100 2.1% 10 240 3.25 1000 274 Basalt 40 5100 2.1% 10 360 3.25 200 275 Basalt 40 5100 2.1% 10 720 3.25 2000 276 Basalt 40 5100 2.1% 10 1200 3.25 500 277 Basalt 40 5100 2.1% 15 720 3.25 2000 278 Basalt 40 5100 2.1% 15 1200 3.25 500 279 Basalt 40 5100 2.1% 20 720 3.25 2000 280 Basalt 40 5100 2.1% 20 1200 3.25 500 281 Basalt 40 5100 2.1% 10 240 6 1500 282 Basalt 40 5100 2.1% 10 360 6 3000 283 Basalt 40 5100 2.1% 10 720 6 2000 284 Basalt 40 5100 2.1% 10 1200 6 500 285 Basalt 40 5100 2.1% 20 240 6 1500 286 Basalt 40 5100 2.1% 20 360 6 3000 287 Basalt 40 5100 2.1% 20 720 6 2000 288 Basalt 40 5100 2.1% 20 1200 6 500 289 Basalt 40 5100 2.1% 30 360 6 3000 290 Basalt 40 5100 2.1% 30 720 6 2000 291 Basalt 40 5100 2.1% 30 1200 6 500 292 Basalt 40 5100 2.1% 40 720 6 2000 293 Basalt 40 5100 2.1% 40 1200 6 500 294 Basalt 40 5100 2.1% 50 1200 6 500 295 Basalt 40 5100 2.1% 15 120 8.5 1000 296 Basalt 40 5100 2.1% 15 240 8.5 2000 297 Basalt 40 5100 2.1% 15 360 8.5 3500 298 Basalt 40 5100 2.1% 15 720 8.5 5000 299 Basalt 40 5100 2.1% 15 1200 8.5 1000 300 Basalt 40 5100 2.1% 30 120 8.5 1000 301 Basalt 40 5100 2.1% 30 240 8.5 2000 302 Basalt 40 5100 2.1% 30 360 8.5 3500 303 Basalt 40 5100 2.1% 30 720 8.5 5000 304 Basalt 40 5100 2.1% 45 240 8.5 2000 305 Basalt 40 5100 2.1% 45 360 8.5 3500 306 Basalt 40 5100 2.1% 45 720 8.5 5000 307 Basalt 40 5100 2.1% 45 1200 8.5 1000 308 Basalt 40 5100 2.1% 60 360 8.5 3500 309 Basalt 40 5100 2.1% 60 720 8.5 5000 310 Basalt 40 5100 2.1% 60 1200 8.5 1000 311 Basalt 40 5100 2.1% 75 720 8.5 5000 312 Basalt 40 5100 2.1% 75 1200 8.5 1000 313 Basalt 40 5100 2.1% 90 720 8.5 5000 314 Basalt 40 5100 2.1% 90 1200 8.5 1000 315 Basalt 40 5100 2.1% 105 1200 8.5 1000 Surface Temp. Mechanical DE Power/Area ME Power/Area Example # ROP (ft/hr) Rise (DegC.) Torque (ft-lbs) Power (kW) Ratio of DE/ME (W/cm{circumflex over ( )}2) (W/cm{circumflex over ( )}2) 1 5.5 434 13.1 0.22 22.3 93.4 4.2 2 6.6 341 65.7 2.24 2.2 93.4 41.8 3 5.7 341 13.1 0.67 7.4 93.4 12.6 4 15.9 170 131.4 13.44 0.4 93.4 251.0 5 10.6 651 13.1 0.22 44.7 186.8 4.2 6 12.4 504 65.7 2.24 4.5 186.8 41.8 7 11.7 467 13.1 0.67 14.9 186.8 12.6 8 19.4 308 131.4 13.44 0.7 186.8 251.0 9 13.1 338 32.9 5.60 1.8 186.8 104.6 10 14.5 866 13.1 0.22 67.0 280.3 4.2 11 17.1 660 65.7 2.24 6.7 280.3 41.8 12 16.8 592 13.1 0.67 22.3 280.3 12.6 13 24.4 416 131.4 13.44 1.1 280.3 251.0 14 19.2 410 32.9 5.60 2.7 280.3 104.6 15 17.5 1081 13.1 0.22 89.3 373.7 4.2 16 20.9 814 65.7 2.24 8.9 373.7 41.8 17 21.2 717 13.1 0.67 29.8 373.7 12.6 18 29.1 514 131.4 13.44 1.5 373.7 251.0 19 24.9 481 32.9 5.60 3.6 373.7 104.6 20 24.0 968 65.7 2.24 11.2 467.1 41.8 21 24.9 841 13.1 0.67 37.2 467.1 12.6 22 33.4 608 131.4 13.44 1.9 467.1 251.0 23 30.0 550 32.9 5.60 4.5 467.1 104.6 24 26.6 1121 65.7 2.24 13.4 560.5 41.8 25 28.1 965 13.1 0.67 44.7 560.5 12.6 26 37.2 700 131.4 13.44 2.2 560.5 251.0 27 34.8 619 32.9 5.60 5.4 560.5 104.6 28 3.7 311 182.0 6.20 1.6 54.8 34.0 29 6.5 217 364.0 18.60 0.5 54.8 102.0 30 5.6 204 242.6 24.80 0.4 54.8 136.0 31 3.4 257 60.7 10.34 1.0 54.8 56.7 32 6.6 575 60.7 1.03 19.4 109.6 5.7 33 7.4 451 182.0 6.20 3.2 109.6 34.0 34 9.7 362 364.0 18.60 1.1 109.6 102.0 35 9.2 312 242.6 24.80 0.8 109.6 136.0 36 7.2 322 60.7 10.34 1.9 109.6 56.7 37 9.6 754 60.7 1.03 29.0 164.5 5.7 38 10.8 582 182.0 6.20 4.8 164.5 34.0 39 13.1 480 364.0 18.60 1.6 164.5 102.0 40 12.9 398 242.6 24.80 1.2 164.5 136.0 41 11.0 381 60.7 10.34 2.9 164.5 56.7 42 12.2 933 60.7 1.03 38.7 219.3 5.7 43 13.8 711 182.0 6.20 6.5 219.3 34.0 44 16.3 591 364.0 18.60 2.2 219.3 102.0 45 16.4 478 242.6 24.80 1.6 219.3 136.0 46 14.6 439 60.7 10.34 3.9 219.3 56.7 47 14.3 1112 60.7 1.03 48.4 274.1 5.7 48 16.5 839 182.0 6.20 8.1 274.1 34.0 49 19.2 699 364.0 18.60 2.7 274.1 102.0 50 19.8 555 242.6 24.80 2.0 274.1 136.0 51 18.1 497 60.7 10.34 4.8 274.1 56.7 52 18.9 966 182.0 6.20 9.7 328.9 34.0 53 21.8 805 364.0 18.60 3.2 328.9 102.0 54 22.9 630 242.6 24.80 2.4 328.9 136.0 55 21.5 554 60.7 10.34 5.8 328.9 56.7 56 21.0 1093 182.0 6.20 11.3 383.7 34.0 57 24.2 910 364.0 18.60 3.8 383.7 102.0 58 25.8 705 242.6 24.80 2.8 383.7 136.0 59 24.7 611 60.7 10.34 6.8 383.7 56.7 60 26.3 1015 364.0 18.60 4.3 438.6 102.0 61 28.5 780 242.6 24.80 3.2 438.6 136.0 62 27.8 668 60.7 10.34 7.7 438.6 56.7 63 2.7 274 343.8 11.71 1.3 41.0 32.0 64 4.5 195 601.6 30.75 0.5 41.0 84.0 65 14.6 94 859.4 87.85 0.2 41.0 240.0 66 2.6 224 171.9 29.28 0.5 41.0 80.0 67 4.9 481 171.9 2.93 10.2 81.9 8.0 68 5.5 385 343.8 11.71 2.6 81.9 32.0 69 7.0 313 601.6 30.75 1.0 81.9 84.0 70 14.5 188 859.4 87.85 0.3 81.9 240.0 71 7.4 616 171.9 2.93 15.4 122.9 8.0 72 8.2 485 343.8 11.71 3.8 122.9 32.0 73 9.7 405 601.6 30.75 1.5 122.9 84.0 74 15.5 274 859.4 87.85 0.5 122.9 240.0 75 8.4 330 171.9 29.28 1.5 122.9 80.0 76 9.6 750 171.9 2.93 20.5 163.9 8.0 77 10.7 582 343.8 11.71 5.1 163.9 32.0 78 12.3 490 601.6 30.75 2.0 163.9 84.0 79 17.4 349 859.4 87.85 0.7 163.9 240.0 80 11.2 375 171.9 29.28 2.0 163.9 80.0 81 11.6 884 171.9 2.93 25.6 204.9 8.0 82 13.0 678 343.8 11.71 6.4 204.9 32.0 83 14.7 572 601.6 30.75 2.4 204.9 84.0 84 19.6 416 859.4 87.85 0.9 204.9 240.0 85 14.0 419 171.9 29.28 2.6 204.9 80.0 86 13.3 1018 171.9 2.93 30.7 245.8 8.0 87 15.1 774 343.8 11.71 7.7 245.8 32.0 88 17.0 652 601.6 30.75 2.9 245.8 84.0 89 21.9 479 859.4 87.85 1.0 245.8 240.0 90 16.7 463 171.9 29.28 3.1 245.8 80.0 91 14.9 1152 171.9 2.93 35.9 286.8 8.0 92 17.0 869 343.8 11.71 9.0 286.8 32.0 93 19.1 731 601.6 30.75 3.4 286.8 84.0 94 24.2 539 859.4 87.85 1.2 286.8 240.0 95 19.3 506 171.9 29.28 3.6 286.8 80.0 96 18.8 964 343.8 11.71 10.2 327.8 32.0 97 21.1 810 601.6 30.75 3.9 327.8 84.0 98 26.3 598 859.4 87.85 1.4 327.8 240.0 99 21.8 549 171.9 29.28 4.1 327.8 80.0 100 5.1 207 65.7 2.24 2.2 93.4 41.8 101 4.1 218 13.1 0.67 7.4 93.4 12.6 102 21.7 79 131.4 13.44 0.4 93.4 251.0 103 7.7 406 13.1 0.22 44.7 186.8 4.2 104 9.2 310 65.7 2.24 4.5 186.8 41.8 105 8.3 295 13.1 0.67 14.9 186.8 12.6 106 21.6 159 131.4 13.44 0.7 186.8 251.0 107 9.7 211 32.9 5.60 1.8 186.8 104.6 108 10.6 536 13.1 0.22 67.0 280.3 4.2 109 12.7 406 65.7 2.24 6.7 280.3 41.8 110 12.1 371 13.1 0.67 22.3 280.3 12.6 111 22.9 232 131.4 13.44 1.1 280.3 251.0 112 14.1 256 32.9 5.60 2.7 280.3 104.6 113 12.9 666 13.1 0.22 89.3 373.7 4.2 114 15.6 500 65.7 2.24 8.9 373.7 41.8 115 15.4 446 13.1 0.67 29.8 373.7 12.6 116 25.4 298 131.4 13.44 1.5 373.7 251.0 117 18.3 300 32.9 5.60 3.6 373.7 104.6 118 14.7 796 13.1 0.22 111.6 467.1 4.2 119 18.0 593 65.7 2.24 11.2 467.1 41.8 120 18.2 521 13.1 0.67 37.2 467.1 12.6 121 28.0 358 131.4 13.44 1.9 467.1 251.0 122 22.1 342 32.9 5.60 4.5 467.1 104.6 123 16.2 926 13.1 0.22 134.0 560.5 4.2 124 20.0 686 65.7 2.24 13.4 560.5 41.8 125 20.7 596 13.1 0.67 44.7 560.5 12.6 126 30.5 416 131.4 13.44 2.2 560.5 251.0 127 25.6 384 32.9 5.60 5.4 560.5 104.6 128 2.9 187 182.0 6.20 1.6 54.8 34.0 129 8.2 106 364.0 18.60 0.5 54.8 102.0 130 6.4 100 242.6 24.80 0.4 54.8 136.0 131 2.5 161 60.7 10.34 1.0 54.8 56.7 132 4.7 359 60.7 1.03 19.4 109.6 5.7 133 5.5 278 182.0 6.20 3.2 109.6 34.0 134 9.0 203 364.0 18.60 1.1 109.6 102.0 135 8.0 179 242.6 24.80 0.8 109.6 136.0 136 5.2 203 60.7 10.34 1.9 109.6 56.7 137 6.9 468 60.7 1.03 29.0 164.5 5.7 138 8.0 359 182.0 6.20 4.8 164.5 34.0 139 11.0 282 364.0 18.60 1.6 164.5 102.0 140 10.4 237 242.6 24.80 1.2 164.5 136.0 141 7.9 240 60.7 10.34 2.9 164.5 56.7 142 8.8 577 60.7 1.03 38.7 219.3 5.7 143 10.2 438 182.0 6.20 6.5 219.3 34.0 144 13.1 353 364.0 18.60 2.2 219.3 102.0 145 12.9 288 242.6 24.80 1.6 219.3 136.0 146 10.5 276 60.7 10.34 3.9 219.3 56.7 147 10.5 685 60.7 1.03 48.4 274.1 5.7 148 12.2 516 182.0 6.20 8.1 274.1 34.0 149 15.2 420 364.0 18.60 2.7 274.1 102.0 150 15.3 337 242.6 24.80 2.0 274.1 136.0 151 13.1 311 60.7 10.34 4.8 274.1 56.7 152 11.9 792 60.7 1.03 58.1 328.9 5.7 153 14.0 593 182.0 6.20 9.7 328.9 34.0 154 17.0 486 364.0 18.60 3.2 328.9 102.0 155 17.5 384 242.6 24.80 2.4 328.9 136.0 156 15.5 346 60.7 10.34 5.8 328.9 56.7 157 13.1 900 60.7 1.03 67.7 383.7 5.7 158 15.6 670 182.0 6.20 11.3 383.7 34.0 159 18.8 551 364.0 18.60 3.8 383.7 102.0 160 19.6 430 242.6 24.80 2.8 383.7 136.0 161 17.9 381 60.7 10.34 6.8 383.7 56.7 162 14.2 1008 60.7 1.03 77.4 438.6 5.7 163 17.1 747 182.0 6.20 12.9 438.6 34.0 164 20.3 615 364.0 18.60 4.3 438.6 102.0 165 21.6 476 242.6 24.80 3.2 438.6 136.0 166 20.1 415 60.7 10.34 7.7 438.6 56.7 167 1.5 215 171.9 2.93 5.1 41.0 8.0 168 2.2 162 343.8 11.71 1.3 41.0 32.0 169 5.5 94 601.6 30.75 0.5 41.0 84.0 170 19.7 46 859.4 87.85 0.2 41.0 240.0 171 2.1 133 171.9 29.28 0.5 41.0 80.0 172 3.5 301 171.9 2.93 10.2 81.9 8.0 173 4.1 236 343.8 11.71 2.6 81.9 32.0 174 6.3 176 601.6 30.75 1.0 81.9 84.0 175 19.8 92 859.4 87.85 0.3 81.9 240.0 176 5.3 384 171.9 2.93 15.4 122.9 8.0 177 6.1 299 343.8 11.71 3.8 122.9 32.0 178 8.0 239 601.6 30.75 1.5 122.9 84.0 179 19.7 138 859.4 87.85 0.5 122.9 240.0 180 7.0 465 171.9 2.93 20.5 163.9 8.0 181 7.9 359 343.8 11.71 5.1 163.9 32.0 182 9.8 294 601.6 30.75 2.0 163.9 84.0 183 19.7 183 859.4 87.85 0.7 163.9 240.0 184 8.4 546 171.9 2.93 25.6 204.9 8.0 185 9.6 418 343.8 11.71 6.4 204.9 32.0 186 11.5 345 601.6 30.75 2.4 204.9 84.0 187 20.1 228 859.4 87.85 0.9 204.9 240.0 188 10.2 262 171.9 29.28 2.6 204.9 80.0 189 9.7 627 171.9 2.93 30.7 245.8 8.0 190 11.2 476 343.8 11.71 7.7 245.8 32.0 191 13.2 395 601.6 30.75 2.9 245.8 84.0 192 20.9 270 859.4 87.85 1.0 245.8 240.0 193 12.1 289 171.9 29.28 3.1 245.8 80.0 194 10.9 708 171.9 2.93 35.9 286.8 8.0 195 12.6 534 343.8 11.71 9.0 286.8 32.0 196 14.7 444 601.6 30.75 3.4 286.8 84.0 197 21.9 310 859.4 87.85 1.2 286.8 240.0 198 14.0 316 171.9 29.28 3.6 286.8 80.0 199 11.9 789 171.9 2.93 41.0 327.8 8.0 200 13.9 592 343.8 11.71 10.2 327.8 32.0 201 16.1 493 601.6 30.75 3.9 327.8 84.0 202 23.1 348 859.4 87.85 1.4 327.8 240.0 203 15.8 342 171.9 29.28 4.1 327.8 80.0 204 7.3 481 65.7 2.24 2.2 93.4 41.8 205 5.2 507 13.1 0.67 7.4 93.4 12.6 206 47.9 177 131.4 13.44 0.4 93.4 251.0 207 7.4 331 32.9 5.60 0.9 93.4 104.6 208 8.7 1097 13.1 0.22 44.7 186.8 4.2 209 11.5 800 65.7 2.24 4.5 186.8 41.8 210 10.2 748 13.1 0.67 14.9 186.8 12.6 211 48.4 354 131.4 13.44 0.7 186.8 251.0 212 14.7 1099 65.7 2.24 6.7 280.3 41.8 213 14.0 985 13.1 0.67 22.3 280.3 12.6 214 48.7 530 131.4 13.44 1.1 280.3 251.0 215 48.8 706 131.4 13.44 1.5 373.7 251.0 216 48.8 883 131.4 13.44 1.9 467.1 251.0 217 26.2 898 32.9 5.60 4.5 467.1 104.6 218 48.7 1060 131.4 13.44 2.2 560.5 251.0 219 29.5 1030 32.9 5.60 5.4 560.5 104.6 220 2.8 606 60.7 1.03 9.7 54.8 5.7 221 4.4 423 182.0 6.20 1.6 54.8 34.0 222 18.5 232 364.0 18.60 0.5 54.8 102.0 223 14.3 197 242.6 24.80 0.4 54.8 136.0 224 5.7 951 60.7 1.03 19.4 109.6 5.7 225 7.4 701 182.0 6.20 3.2 109.6 34.0 226 18.4 464 364.0 18.60 1.1 109.6 102.0 227 14.4 393 242.6 24.80 0.8 109.6 136.0 228 7.0 465 60.7 10.34 1.9 109.6 56.7 229 10.0 953 182.0 6.20 4.8 164.5 34.0 230 18.5 695 364.0 18.60 1.6 164.5 102.0 231 15.9 570 242.6 24.80 1.2 164.5 136.0 232 10.3 580 60.7 10.34 2.9 164.5 56.7 233 12.2 1199 182.0 6.20 6.5 219.3 34.0 234 19.2 917 364.0 18.60 2.2 219.3 102.0 235 18.1 730 242.6 24.80 1.6 219.3 136.0 236 13.4 692 60.7 10.34 3.9 219.3 56.7 237 20.4 1130 364.0 18.60 2.7 274.1 102.0 238 20.3 882 242.6 24.80 2.0 274.1 136.0 239 16.3 801 60.7 10.34 4.8 274.1 56.7 240 22.3 1029 242.6 24.80 2.4 328.9 136.0 241 19.0 910 60.7 10.34 5.8 328.9 56.7 242 24.2 1173 242.6 24.80 2.8 383.7 136.0 243 21.5 1019 60.7 10.34 6.8 383.7 56.7 244 23.8 1127 60.7 10.34 7.7 438.6 56.7 245 2.1 503 171.9 2.93 5.1 41.0 8.0 246 3.5 347 343.8 11.71 1.3 41.0 32.0 247 12.6 193 601.6 30.75 0.5 41.0 84.0 248 43.5 110 859.4 87.85 0.2 41.0 240.0 249 4.5 770 171.9 2.93 10.2 81.9 8.0 250 5.7 573 343.8 11.71 2.6 81.9 32.0 251 12.5 387 601.6 30.75 1.0 81.9 84.0 252 43.9 219 859.4 87.85 0.3 81.9 240.0 253 5.8 381 171.9 29.28 1.0 81.9 80.0 254 6.5 1028 171.9 2.93 15.4 122.9 8.0 255 7.9 767 343.8 11.71 3.8 122.9 32.0 256 13.0 573 601.6 30.75 1.5 122.9 84.0 257 44.1 328 859.4 87.85 0.5 122.9 240.0 258 8.4 477 171.9 29.28 1.5 122.9 80.0 259 9.9 955 343.8 11.71 5.1 163.9 32.0 260 14.2 744 601.6 30.75 2.0 163.9 84.0 261 44.3 437 859.4 87.85 0.7 163.9 240.0 262 11.6 1138 343.8 11.71 6.4 204.9 32.0 263 15.6 906 601.6 30.75 2.4 204.9 84.0 264 44.5 546 859.4 87.85 0.9 204.9 240.0 265 17.0 1062 601.6 30.75 2.9 245.8 84.0 266 44.6 655 859.4 87.85 1.0 245.8 240.0 267 44.6 764 859.4 87.85 1.2 286.8 240.0 268 44.6 874 859.4 87.85 1.4 327.8 240.0 269 4.0 1122 13.1 0.22 22.3 93.4 4.2 270 4.8 868 65.7 2.24 2.2 93.4 41.8 271 4.2 849 13.1 0.67 7.4 93.4 12.6 272 12.1 432 131.4 13.44 0.4 93.4 251.0 273 8.8 1339 65.7 2.24 4.5 186.8 41.8 274 8.4 1219 13.1 0.67 14.9 186.8 12.6 275 14.3 803 131.4 13.44 0.7 186.8 251.0 276 9.7 851 32.9 5.60 1.8 186.8 104.6 277 17.6 1107 131.4 13.44 1.1 280.3 251.0 278 14.1 1061 32.9 5.60 2.7 280.3 104.6 279 20.6 1388 131.4 13.44 1.5 373.7 251.0 280 17.9 1265 32.9 5.60 3.6 373.7 104.6 281 2.7 782 182.0 6.20 1.6 54.8 34.0 282 4.9 549 364.0 18.60 0.5 54.8 102.0 283 4.2 501 242.6 24.80 0.4 54.8 136.0 284 2.4 613 60.7 10.34 1.0 54.8 56.7 285 5.4 1185 182.0 6.20 3.2 109.6 34.0 286 7.1 949 364.0 18.60 1.1 109.6 102.0 287 6.8 798 242.6 24.80 0.8 109.6 136.0 288 5.3 798 60.7 10.34 1.9 109.6 56.7 289 9.5 1286 364.0 18.60 1.6 164.5 102.0 290 9.5 1041 242.6 24.80 1.2 164.5 136.0 291 8.1 971 60.7 10.34 2.9 164.5 56.7 292 12.0 1270 242.6 24.80 1.6 219.3 136.0 293 10.8 1141 60.7 10.34 3.9 219.3 56.7 294 13.3 1309 60.7 10.34 4.8 274.1 56.7 295 1.5 856 171.9 2.93 5.1 41.0 8.0 296 1.9 674 343.8 11.71 1.3 41.0 32.0 297 3.4 482 601.6 30.75 0.5 41.0 84.0 298 11.1 244 859.4 87.85 0.2 41.0 240.0 299 1.9 527 171.9 29.28 0.5 41.0 80.0 300 3.5 1262 171.9 2.93 10.2 81.9 8.0 301 4.0 991 343.8 11.71 2.6 81.9 32.0 302 5.1 805 601.6 30.75 1.0 81.9 84.0 303 11.1 488 859.4 87.85 0.3 81.9 240.0 304 5.9 1282 343.8 11.71 3.8 122.9 32.0 305 7.1 1065 601.6 30.75 1.5 122.9 84.0 306 11.7 719 859.4 87.85 0.5 122.9 240.0 307 6.2 826 171.9 29.28 1.5 122.9 80.0 308 8.9 1309 601.6 30.75 2.0 163.9 84.0 309 12.9 924 859.4 87.85 0.7 163.9 240.0 310 8.3 957 171.9 29.28 2.0 163.9 80.0 311 14.4 1112 859.4 87.85 0.9 204.9 240.0 312 10.3 1086 171.9 29.28 2.6 204.9 80.0 313 15.9 1292 859.4 87.85 1.0 245.8 240.0 314 12.2 1213 171.9 29.28 3.1 245.8 80.0 315 14.1 1339 171.9 29.28 3.6 286.8 80.0

In these examples of drilling conditions and parameters, the laser power is to be delivered to the rock surface. The examples are for use with air as the fluid for drilling, and may be utilized with, by way of example, the bits and systems that are described in FIGS. 1A-C and 2 of this specification and with the bits and systems disclosed and taught in U.S. patent applications Ser. No. 61/446,043 and co-filed patent application having attorney docket no. 13938/79 (Foro s13a).

Thus, from the forgoing examples, which provide various illustrative laser-mechanical drilling conditions and parameters, there is contemplated generally, and by way of further example, a method of laser-mechanical drilling a borehole in a formation having at least 500 feet, at least about 1,000 ft, at least about 5,000 and at least about 10,000 feet of material having a hardness greater than about 15 ksi, greater than about 20 ksi, greater than about 30 ksi, and greater than about 40 ksi and at drilling rates, e.g., ROP, of at least about 10 ft/hr, at least about 20 ft/hr, at least about 30 ft/hr and at least about 40 ft/hr. Such methods in generally would include, by way of example, drilling under the following conditions and parameters: (i) an RPM of from about 240 to about 720, a WOB of less than about 2,000 lbs, a DE Power/Area of about 90 W/cm2 to about 560 W/cm2, and an ME Power/Area of about 4 W/cm2 to about 250 W/cm2; (ii) an RPM of from about 600 to about 800, a WOB of less than about 5,000 lbs, a DE Power/Area of about 40 W/cm2 to about 250 W/cm2, and an ME Power/Area of about 200 W/cm2 to about 3000 W/cm2; (iii) an RPM of from about 600 to about 1250, a WOB of from about 500 to about 5,000 lbs, a DE Power/Area of about 90 W/cm2 to about 570 W/cm2, and an ME Power/Area of about 40 W/cm2 to about 270 W/cm2; (iv) an RPM of about 250, a WOB of from about 1,000 lbs, a DE Power/Area of about 370 W/cm2, and an ME Power/Area of about 40 W/cm2; (v) an RPM of from about 720, a WOB of from about 2,000 lbs, a DE Power/Area of about 190 W/cm2, and an ME Power/Area of about 250 W/cm2; (vi) an RPM of from about 720, a WOB of from about 2,000 lbs, a DE Power/Area of about 370 W/cm2, and an ME Power/Area of about 250 W/cm2; (vii) an RPM of from about 720, a WOB of from about 5,000 lbs, a DE Power/Area of about 290 W/cm2, and an ME Power/Area of about 240 W/cm2; (viii) an RPM of from about 1,200, a WOB of from about 500 lbs, a DE Power/Area of about 470 W/cm2, and an ME Power/Area of about 100 W/cm2; (ix) an RPM of from about 720, a WOB of from about 2,000 lbs, a DE Power/Area of about 470 W/cm2, and an ME Power/Area of about 250 W/cm2; and, combinations and variations of these.

Many other uses for the present inventions may be developed or realized and thus, the scope of the present inventions is not limited to the foregoing examples, uses conditions, and applications. For example, in addition to the forgoing examples and embodiments, the implementation of these directed/mechanical energy processes may find applications in down hole tools, and may also be utilized in holes openers, perforators, reamers, whipstocks, and other types of boring tools.

The present inventions may be embodied in other forms than those specifically disclosed herein without departing from their spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive.

Claims

1. A method of directed energy mechanical drilling comprising:

a. providing directed energy to a surface of a material;
b. providing mechanical energy to the surface; and,
c. wherein the ratio of directed energy to mechanical energy is greater than about 5; and,
d. whereby a borehole is advance through the surface of the material.

2. A method directed energy mechanical drilling comprising:

a. providing directed energy to a surface of a material;
b. providing mechanical energy to the surface; and,
c. wherein the ratio of directed energy to mechanical energy is greater than about 10; and,
d. whereby a borehole is advance through the surface of the material.

3. A method of directed energy mechanical drilling comprising:

a. providing directed energy to a surface of a material;
b. providing mechanical energy to the surface; and,
c. wherein the ratio of directed energy to mechanical energy is greater than about 20; and,
d. whereby a borehole is advance through the surface of the material.

4. A method of directed energy mechanical drilling comprising:

a. providing directed energy to a surface of a material;
b. providing mechanical energy to the surface; and,
c. wherein the ratio of directed energy to mechanical energy is greater than about 40; and,
d. whereby a borehole is advance through the surface of the material.

5. A directed energy mechanical drilling comprising:

a. providing directed energy to a surface;
b. providing mechanical energy to the surface; and,
c. wherein the ratio of directed energy to mechanical energy is greater than about 2; and,
d. whereby a borehole is advance through the surface of the material.

6. A method of directed energy mechanical drilling comprising:

a. providing high power laser directed energy to a surface of a material;
b. providing mechanical energy to the surface; and,
c. wherein the ratio of high power laser directed energy to mechanical energy is greater than about 5; and,
d. whereby a borehole is advance through the surface of the material.

7. A method directed energy mechanical drilling comprising:

a. providing high power laser directed energy to a surface of a material;
b. providing mechanical energy to the surface; and,
c. wherein the ratio of high power laser directed energy to mechanical energy is greater than about 10; and,
d. whereby a borehole is advance through the surface of the material.

8. A method of directed energy mechanical drilling comprising:

a. providing high power laser directed energy to a surface of a material;
b. providing mechanical energy to the surface; and,
c. wherein the ratio of high power laser directed energy to mechanical energy is greater than about 20; and,
d. whereby a borehole is advance through the surface of the material.

9. A method of directed energy mechanical drilling comprising:

a. providing high power laser directed energy to a surface of a material;
b. providing mechanical energy to the surface; and,
c. wherein the ratio of high power laser directed energy to mechanical energy is greater than about 40; and,
d. whereby a borehole is advance through the surface of the material.

10. A directed energy mechanical drilling comprising:

a. providing high power laser directed energy to a surface;
b. providing mechanical energy to the surface; and,
c. wherein the ratio of directed energy to mechanical energy is greater than about 2; and,
d. whereby a borehole is advance through the surface of the material.

11. The method of claim 6, wherein the high power laser directed energy has a power of at least about 40 kW.

12. The method of claim 8, wherein the surface is not substantially melted by the laser energy.

13. The method of claim 8, wherein the mechanical energy is provided by a bit having a weight-on-bit less than about 2000 pounds.

14. The method of claim 9, wherein the mechanical energy is provided by a bit having a weight-on-bit less than about 1000 pounds.

15. The method of claim 11, wherein the mechanical energy is provided by a bit having a weight-on-bit less than about 1000 pounds.

16. The methods of claim 9, wherein the mechanical energy is provided by a bit having a weight-on-bit less than about 2000 pounds and wherein the borehole is advanced at a rate of penetration of at least about 10 feet per hour.

17. The methods of claim 11, wherein the mechanical energy is provided by a bit having a weight-on-bit less than about 2000 pounds and wherein the borehole is advanced at a rate of penetration of at least about 10 feet per hour.

18. The methods of claim 6, wherein the high power laser directed energy has a power of at least about 20 kW and the mechanical energy is provided by a bit having a weight-on-bit less than about 2000 pounds and wherein the borehole is advanced at a rate of penetration of at least about 20 feet per hour.

19. The methods of claim 8, wherein the high power laser directed energy has a power of at least about 20 kW and the mechanical energy is provided by a bit having a weight-on-bit less than about 2000 pounds and wherein the borehole is advanced at a rate of penetration of at least about 20 feet per hour.

20. The methods of claim 10, wherein the high power laser directed energy has a power of at least about 20 kW and the mechanical energy is provided by a bit having a weight-on-bit less than about 2000 pounds and wherein the borehole is advanced at a rate of penetration of at least about 20 feet per hour.

21. The methods of claim 8, wherein the high power laser directed energy has a power of at least about 50 kW and the mechanical energy is provided by a bit having a weight-on-bit less than about 2000 pounds and wherein the borehole is advanced at a rate of penetration of at least about 20 feet per hour.

22. The methods of claim 6, wherein the mechanical energy is provided by a bit having a weight-on-bit less than about 2000 pounds and wherein the borehole is advanced at a rate of penetration the rate of penetration of at least about 20 feet per hour through material having an average hardness of about 20 ksi or greater.

23. The method of claim 6, wherein the borehole is advanced for greater than about 500 feet.

24. The methods of claim 9, wherein the borehole is advanced for greater than about 5,000 feet.

25. A method of advancing a borehole in the earth using high power laser mechanical drilling techniques, the method comprising:

a. directing laser energy, in a moving pattern, to a bottom surface of a borehole in the earth;
b. heating the earth with the directed laser energy to a point below the melting point;
c. providing mechanical energy to the heated earth;
d. wherein the ratio of laser energy to mechanical energy is greater than about 2; and,
e. whereby the borehole is advanced

26. The method of claim 25, wherein the laser energy has a power of about 20 kW or greater.

27. The method of claim 25, wherein the power/area of the laser energy on the surface of the bottom of the borehole is about 50 W/cm2 or greater.

28. The method of claim 25, wherein the power/area of the laser energy on the surface of the bottom of the borehole is about 75 W/cm2 or greater.

29. The method of claim 25, wherein the power/area of the laser energy on the surface of the bottom of the borehole is about 100 W/cm2 or greater.

30. The method of claim 25, wherein the power/area of the laser energy on the surface of the bottom of the borehole is about 200 W/cm2 or greater.

31. The method of claim 25, wherein the power/area of the laser energy on the surface of the bottom of the borehole is about 300 W/cm2 or greater.

32. The method of claim 29, wherein the mechanical energy is provided by a bit having a weight-on-bit less than about 2000 pounds.

33. The method of claim 30, wherein mechanical energy is provided by a bit having a weight-on-bit less than about 1000 pounds.

34. The method of claim 28, wherein the mechanical energy is provided by a bit having a weight-on-bit less than about 2000 pounds and wherein the borehole is advanced at a rate of penetration of at least about 10 feet per hour.

35. The method of claim 28, wherein the mechanical energy is provided by a bit having a weight-on-bit, wherein the weight-on-bit is less than about 2000 pounds and wherein the borehole is advanced at a rate of penetration of at least about 20 feet per hour.

36. The method of claim 30, wherein the mechanical energy is provided by a bit having a weight-on-bit less than about 2000 pounds and wherein borehole is advances at a rate of penetration of at least about 10 feet per hour through material having an average hardness of about 20 ksi or greater.

37. The method of claim 30, wherein the mechanical energy is provided by a bit having a weight-on-bit less than about 2000 pounds and wherein the borehole is advanced at a rate of penetration of at least about 20 feet per hour through material having an average hardness of about 20 ksi or greater.

38. The method of claim 36, wherein the borehole is advanced for greater than about 1,000 feet.

39. A method of laser-mechanical drilling a borehole in a formation having at least 500 feet of material having a hardness greater than about 30 ksi, the method comprising:

a. providing a laser-mechanical bit into a borehole, the laser-mechanical bit in optical communication with a high power laser beam source;
b. rotating the laser-mechanical bit against a surface of the borehole while propagating a laser beam against the borehole surface; with an RPM of from about 240 to about 720, a WOB of less than about 2,000 lbs, a DE Power/Area of about 90 W/cm2 to about 560 W/cm2, and an ME Power/Area of about 4 W/cm2 to about 250 W/cm2;
c. whereby the borehole is advanced at an ROP of at least about 10 ft/hr.

40. A method of laser-mechanical drilling a borehole in a formation having at least 500 feet of material having a hardness greater than about 30 ksi, the method comprising:

a. providing a laser-mechanical bit into a borehole, the laser-mechanical bit in optical communication with a high power laser beam source;
b. rotating the laser-mechanical bit against a surface of the borehole while propagating a laser beam against the borehole surface; with an RPM of from about 600 to about 800, a WOB of less than about 5,000 lbs, a DE Power/Area of about 40 W/cm2 to about 250 W/cm2, and an ME Power/Area of about 200 W/cm2 to about 3000 W/cm2;
c. whereby the borehole is advanced at an ROP of at least about 15 ft/hr.

41. A method of laser-mechanical drilling a borehole in a formation having at least 500 feet of material having a hardness greater than about 20 ksi, the method comprising:

a. providing a laser-mechanical bit into a borehole, the laser-mechanical bit in optical communication with a high power laser beam source;
b. rotating the laser-mechanical bit against a surface of the borehole while propagating a laser beam against the borehole surface; with an RPM of from about 600 to about 1250, a WOB of from about 500 to about 5,000 lbs, a DE Power/Area of about 90 W/cm2 to about 570 W/cm2, and an ME Power/Area of about 40 W/cm2 to about 270 W/cm2;
c. whereby the borehole is advanced at an ROP of at least about 10.

42. A method of laser-mechanical drilling a borehole in a formation having at least 500 feet of hard rock material, having a hardness greater than about 20 ksi, the method comprising:

a. providing a laser-mechanical bit into a borehole, the laser-mechanical bit in optical communication with a high power laser beam source;
b. rotating the laser-mechanical bit against a surface of the borehole with an RPM of about 250, a WOB of from about 1,000 lbs, a DE Power/Area of about 370 W/cm2, and an ME Power/Area of about 40 W/cm2; and,
c. whereby the borehole is advanced at an ROP of at least about 20 ft/hr.

43. A method of laser-mechanical drilling a borehole in a formation having at least 500 feet of hard rock material, having a hardness greater than about 20 ksi, the method comprising:

a. providing a laser-mechanical bit into a borehole, the laser-mechanical bit in optical communication with a high power laser beam source;
b. rotating the laser-mechanical bit against a surface of the borehole with an RPM of from about 720, a WOB of from about 2,000 lbs, a DE Power/Area of about 190 W/cm2, and an ME Power/Area of about 250 W/cm2; and,
c. whereby the borehole is advanced at an ROP of at least about 50 ft/hr.

44. A method of laser-mechanical drilling a borehole in a formation having at least 500 feet of hard rock material, having a hardness greater than about 20 ksi, the method comprising:

a. providing a laser-mechanical bit into a borehole, the laser-mechanical bit in optical communication with a high power laser beam source;
b. rotating the laser-mechanical bit against a surface of the borehole with an RPM of from about 720, a WOB of from about 2,000 lbs, a DE Power/Area of about 370 W/cm2, and an ME Power/Area of about 250 W/cm2; and,
c. whereby the borehole is advanced at an ROP of at least about 50 ft/hr.

45. A method of laser-mechanical drilling a borehole in a formation having at least 500 feet of hard rock material, having a hardness greater than about 20 ksi, the method comprising:

a. providing a laser-mechanical bit into a borehole, the laser-mechanical bit in optical communication with a high power laser beam source;
b. rotating the laser-mechanical bit against a surface of the borehole with an RPM of from about 720, a WOB of from about 5,000 lbs, a DE Power/Area of about 290 W/cm2, and an ME Power/Area of about 240 W/cm2; and,
c. whereby the borehole is advanced at an ROP of at least about 20 ft/hr.

46. A method of laser-mechanical drilling a borehole in a formation having at least 500 feet of hard rock material, having a hardness greater than about 20 ksi, the method comprising:

a. providing a laser-mechanical bit into a borehole, the laser-mechanical bit in optical communication with a high power laser beam source;
b. rotating the laser-mechanical bit against a surface of the borehole with an RPM of from about 1,200, a WOB of from about 500 lbs, a DE Power/Area of about 470 W/cm2, and an ME Power/Area of about 100 W/cm2; and,
c. whereby the borehole is advanced at an ROP of at least about 30 ft/hr.

47. A method of laser-mechanical drilling a borehole in a formation having at least 500 feet of hard rock material, having a hardness greater than about 20 ksi, the method comprising:

a. providing a laser-mechanical bit into a borehole, the laser-mechanical bit in optical communication with a high power laser beam source;
b. rotating the laser-mechanical bit against a surface of the borehole with an RPM of from about 720, a WOB of from about 2,000 lbs, a DE Power/Area of about 470 W/cm2, and an ME Power/Area of about 250 W/cm2; and,
c. whereby the borehole is advanced at an ROP of at least about 30 ft/hr.

48. A method of laser-mechanical drilling a borehole in a formation, the method comprising:

a. providing a laser-mechanical bit into a borehole, the laser-mechanical bit in optical communication with a high power laser beam source;
b. applying from the high power laser beam source a high power laser beam to a surface of the borehole, wherein the high power laser beam generates an intensity ranging from about 150 to about 250 W/cm2 on a surface of the borehole for an elapsed time sufficient to cause a surface temperature rise in the range from about 400 degrees C. to about 1,000 degrees C., whereby a laser applied surface is formed;
c. applying a mechanical force to the laser applied surface, wherein the mechanical force generates an intensity ranging from about 30 to about 250 W/cm2 to remove the laser applied surface of the borehole.
Patent History
Publication number: 20120261188
Type: Application
Filed: Feb 23, 2012
Publication Date: Oct 18, 2012
Inventors: Mark S. Zediker (Castle Rock, CO), Brian O. Faircloth (Evergreen, CO), Erik C. Allen (Minneapolis, MN)
Application Number: 13/403,132
Classifications
Current U.S. Class: Rotating The Heating Tool (175/15); Electrically Produced Heat (175/16)
International Classification: E21B 7/15 (20060101); E21B 7/00 (20060101);