Drill core extractor

Abstract

A system for extracting drill cores from a borehole. The system enables a semi-resilient sleeve-inserted in a housing—to be sealed about the circumference of a drill rod thereby allowing for upward backpressure against the drill core when activated. The system comprises: a housing assembly having sleeve retaining annular rings with edge treatment that forces outward displacement of the central region of the sleeve so as to ensure utmost clearance from a drill rod, which traverses said sleeve. The system thereby allows extraction of drill core samples without the time-consuming fishing method therefore increasing productivity by a substantial margin.

Description

FIELD OF THE INVENTION

The present invention relates to a system for extracting drill cores from a borehole. The system enables a semi-resilient sleeve-inserted in a housing—to be sealed about the circumference of a drill rod thereby allowing for upward backpressure against the drill core when activated. The system comprises: a housing assembly having sleeve retaining annular rings with edge treatment that forces outward displacement of the central region of the sleeve so as to ensure utmost clearance from a drill rod, which traverses said sleeve. The system thereby allows extraction of drill cores without the time-consuming fishing method therefore increasing productivity by a substantial margin.

BACKGROUND OF THE INVENTION

One of the many facets of hard rock mining is exploration drilling comprising generally of boring core samples in bed rock to obtain a clearer picture within the ore body. This in presently accomplished by boring through an ore body using a hollow drill bit and drill rods; leaving a central core within an annular cut in the ore body. Cores are left is the center of a core tube within the hollow drill rod for intermittent extraction. Presently, the core tube retrieval process is much like fishing; involving a long wire cable having latching means to a mating receiving portion at the upper end of the core tube. Once latched, the cable is then pulled upward along with the core tube, which contains the core sample. The process is repeated intermittently until the desired core depth is achieved. This retrieval process accounts for nearly 50% of the available drilling time.

The inventor sought to provide miners with a device and system that greatly reduces core retrieval time so as to increase actual drilling time per work shift.

The applicant failed in finding attempts in prior art that provide similar methodologies for core extraction.

While attempts have been made to refine core-extraction systems, no prior art provides sleeve sealing of drill rods as a means to use water backpressure to extract core samples at a much speedier rate.

SUMMARY OF THE INVENTION

It is thus the object of the present invention to provide the hard rock mining industry with a core extraction system-using sleeve sealing of drill rods as a means to utilize water backpressure to extract core samples.

In one aspect of the invention, the sleeve may comprise any suitable semi-resilient material type, which has low friction quality.

In another aspect of the invention, inner diameter of the sleeve is directly proportional to the outer diameter of the traversing rod.

Accordingly, the device of the present invention therefore provides the hard rock mining industry with a core extraction system-using sleeve sealing of drill rods as a means to utilize water backpressure to extract core samples.

The utility of the present invention includes but is not limited to rock drill-cores.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other advantages of the invention will become apparent upon reading the following brief description and upon referring to the drawings in which:—

FIG. 1 is a perspective exploded view of the seal assembly of the present invention.

FIG. 2 is a partially cross-sectioned view of the seal assembly of the present invention.

FIG. 3 is a cross-sectioned view of the seal assembly of the present invention shown with the rod seal in a rested position.

FIG. 4 is a cross-sectioned view of the seal assembly of the present invention shown with the rod seal in a compressed position.

FIG. 5 is a cross-sectional view selected from FIG. 3 of the seal assembly of the present invention shown prior to full tightening of the assembly.

FIG. 6 is a cross-sectional view selected from FIG. 3 of the seal assembly of the present invention shown after full tightening of the assembly.

FIG. 7 is a cross-sectioned elevation view of the seal assembly of the present invention shown installed ready for drilling.

FIG. 8 is a cross-sectioned elevation view of the seal assembly of the present invention shown installed ready for core extraction.

While the invention is described in conjunction with preferred illustrated embodiments, it will be understood that it is not intended to limit the invention to such embodiments. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

In the following description, similar features in the drawings have been given similar reference numerals.

Although exploration drilling is generally oriented to a downward and upward vertical axis, mild angles are at times used. However, for clarity and illustration of the present invention, the specification will depict the common downward vertical orientation.

Turning now to FIG. 1, a perspective exploded view of the seal assembly 2 of the present invention generally comprising; a male casing adapter 10, a grip ring 20, a sleeve housing 30, a retainer ring 40, an upper oil seal 45, a lower oil seal 48, a sleeve 50, a form ring 52, a water inlet 60, a water outlet 70, and an oil inlet.

Turning to FIG. 2, a partially cross-sectioned view of the seal assembly of the present invention further comprising:—a male casing adapter 10 having a rigid tubular body threaded at a lower end to mate with a female casing adapter, and a forming end 12, water ports 14, and an attachment flange 16 about the full circumference of the tubular adapter 10 wherein said flange further comprises a plurality of fastener perforations therethrough,—a semi-resilient grip ring 20 having a plurality of fastener perforations therethrough and in direct alignment with those of the male casing adapter 10, and a plurality of grip slots 21 arrayed about the grip ring's 20 outer circumference for use to apply a wrench therein for rotable insertion and removal of the assembly 2 on and off a female casing adapter,—a sleeve housing 30 having a round tubular body with a lower flange 22 having a plurality of fastener perforations therethrough in direct alignment with those of the male casing adapter 10 and the grip ring 20, and an upper flange 23 also having a plurality of fastener perforations therethrough in direct alignment with those of a retainer ring 40, a water inlet 60 angularly and threadedly engaged above the base of the sleeve housing 30 and in direct alignment with a first water port 14 within the male casing adapter 10, a water outlet 70 also angularly and threadedly engaged above the base of the sleeve housing 30 distal from the inlet 60 and also in direct alignment with a second water port 14 within the male casing adapter 10, an outwardly raised continuous annular depression 81 located centrally within the sleeve housing 30 through which an oil inlet 81 is adapted,—a retainer ring 40 comprising a annular flanged body with a raised central diameter adapted to engage frictionally within an opening of the upper portion of the sleeve housing 30 and said flanged body also having a plurality of fastener perforations therethrough in direct alignment with those of the upper flange 23 of the sleeve housing 30,—an upper oil seal 45 frictionally retained within a seal slot at the upper inner portion of the sleeve housing 30, which said upper oil seal 45 also engages frictionally against the outer circumference of the raised central portion of the retainer ring 40 thus forming a positive seal therebetween,—a lower oil seal 48 also frictionally retained within a seal slot at the lower inner portion of the sleeve housing 30, which said upper oil seal 48 also engages frictionally against the outer circumference of the male casing adapter 10 also forming a positive seal therebetween,—a sleeve 50 fabricated of a semi-resilient rubber-like compound, which said sleeve 50 having an outer diameter generally equal to that of the inner diameter of the sleeve housing 30 and a length slightly greater than the distance between a form ring 52 and the forming end 12 at the uppermost portion of the male casing adapter,—a form ring 52 having an annular body wherein its upper face is planar and its inner face is adapted with two circumferential peaks,—an oil inlet 80 threadedly engaged through the sleeve housing 30 wherein the oil inlet 80 is in communication with the outwardly raised continuous annular depression 81 located centrally within said sleeve housing 30, and fasteners 85 securedly holding the assembly as one.

Turning to FIG. 3, a cross-sectioned view of the seal assembly 2 of the present invention shown with the sleeve 50 in a rested position wherein a drill rod 35 traverses the assembly 2 and said rod 35 is free to rotate within the assembly 2. This configuration is thus used during the drilling process where water is pumped at a lower rate through and down the drill rod, out the drill bit, up the drill rod then ejected out the water outlet 70 to provide cooling of the drill bit down the bore. Conversely, the water inlet 60 may be adapted to alternate in use between inlet and outlet.

Turning now to FIG. 4, a similar cross-sectioned view of the seal assembly 2 of the present invention shown with the sleeve 50 in a compressed position wherein—rotation of the drill rod is halted and hydraulic oil is compressed at a high rate via the oil inlet. The oil then pressurizes the space between the inner surface of the sleeve housing 30 and the sleeve 50. The sleeve's 50 end seal is maintained by being compressed between the form ring 52 above said sleeve 50 and the forming end 12 at the uppermost portion of the male casing adapter 10 thereby creating an annular pinch valve about the circumference of the drill rod.

Referring now to FIG. 5, depicting a better cross-sectional view selected from FIG. 3 of the seal assembly of the present invention shown prior to full tightening of the fasteners of the assembly wherein an upper oil seal 45 frictionally retained within a seal slot at the upper inner portion of the sleeve housing 30, which said upper oil seal 45 also engages frictionally against the outer circumference of the raised central portion of the retainer ring 40 thus forming a positive seal therebetween. A closer look at the contacting area adjacent each end of the sleeve 50 is also depicted wherein a form ring 52 having an annular body wherein its upper face is planar and its inner face is adapted with two circumferential peaks 55 & 56. The innermost peak 55 extending toward the sleeve more so than the outer peak 56, which said peak 56 is rather slightly recessed. This arrangement is simply mirrored at the sleeve's 50 opposing end with the exception that the peak formation at the opposing end is integral with the uppermost edge of the male casing adapter. Conversely, the upper form ring 52 may be integral to the retainer ring 40.

FIG. 6, also a cross-sectional view selected from FIG. 3 of the seal assembly of the present invention shown after full tightening of the assembly wherein once the assembly is fully assembled and tightened, the sleeve 50 becomes compressed while the offset peaks 55 & 56 encourage an outward central bulge tendency at the sleeve's circumference thereby ensuring maximum clearance between the sleeve's inner surface and the drill rod's outer surface as best illustrated in FIG. 3.

Turning now to FIG. 7, a cross-sectioned elevation view of the seal assembly of the present invention as shown installed and ready for drilling wherein the configuration entails: an ore body 90 in which a pit 91 is bored so as to insert a female casing 92 set in place within the pit 91 using grout 93 so as to seal and immobilize the casing 92 with the ore body 90. The seal assembly 2 is threadedly engaged with the female casing 92, and a drilling rig attached to the drill rod 35 as per current practice.

In the drilling process, the sleeve 50 is depressurized, allowing it to retract away from the drill rod 35 with sufficient clearance so as to prevent friction against the rotating drill rod 35. Water is pumped down through the center of the drill rod 35 where it reaches the drill bit 36 to cool said bit 36. The water then exits the bit end through a plurality of slots at the bit's lower periphery where said water finds its way up the drilled bore wall where it is forcedly directed to one or more water outlets 60 & 70.

Let's turn to FIG. 8, a cross-sectioned elevation view of the seal assembly of the present invention shown installed ready for core extraction wherein the configuration similarly entails: an ore body 90 in which a pit 91 is bored so as to insert a female casing 92 set in place within the pit 91 using grout 93 so as to seal and immobilize the casing 92 with the ore body 90. The seal assembly 2 is threadedly engaged with the female casing 92, and a drilling rig attached to the drill rod 35.

In the core extraction process, rotation of the drill rod 35 is halted and only the drill head is removed. Hydraulic oil is compressed at a high rate via the oil inlet 80; pressurizing the space between the inner surface of the sleeve housing 30 and the sleeve 50 creating an annular pinch valve about the circumference of the drill rod 35. Water is now pumped into the water inlet 60 down along the drill rod 35 outer wall within the bore where it reaches the drill bit 36. The pressurized water then enters the bit end through a plurality of slots at the bit's lower periphery where said water finds its way up the drill rod's 35 center applying upward force against the base of the core sample 100 thereby extracting the core 100 longitudinally up the drill rod 35. Once surfaced, the core sample is collected. Water pressure is then removed at the drill head re-installed onto the drill core for yet another drilling cycle.

Upon referring to the drawing figures and the above specification, it can now be understood how pinch-sealing the immobilized drill rod can afford miners the ability to reverse the water flow to use existing systems along with the present invention to speed the core retrieval process.

Claims

1. A drill core extractor comprising:

a. a seal assembly having: i. a male casing adapter comprising: a rigid tubular body threaded at a lower end to mate with a female casing, a forming end, water ports, an attachment flange about the full circumference of the tubular adapter wherein said flange further comprises a plurality of fastener perforations therethrough, ii.—a grip ring having a plurality of fastener perforations therethrough and in direct alignment with those of the male casing adapter, and a plurality of grip slots arrayed about the grip ring's outer circumference for use to apply a wrench therein for rotable insertion and removal of the assembly on and off a female casing adapter, iii.—a sleeve housing having a round tubular body with a lower flange having a plurality of fastener perforations therethrough in direct alignment with those of the male casing adapter and the grip ring, and an upper flange also having a plurality of fastener perforations therethrough in direct alignment with those of a retainer ring, a water inlet angularly and threadedly engaged above the base of the sleeve housing and in direct alignment with a first water port within the male casing adapter, a water outlet also angularly and threadedly engaged above the base of the sleeve housing distal from the inlet and also in direct alignment with a second water port within the male casing adapter, an outwardly raised continuous annular depression located centrally within the sleeve housing inner wall through which an oil inlet is adapted, iv.—a retainer ring comprising a annular flanged body with a raised central diameter adapted to engage frictionally within an opening of the upper portion of the sleeve housing and said flanged body also having a plurality of fastener perforations therethrough in direct alignment with those of the upper flange of the sleeve housing, v.—an upper oil seal frictionally retained within a seal slot at the upper inner portion of the sleeve housing, which said upper oil seal also engages frictionally against the outer circumference of the raised central portion of the retainer ring thus forming an impermeable seal therebetween, vi.—a lower oil seal also frictionally retained within a seal slot at the lower inner portion of the sleeve housing, which said upper oil seal also engages frictionally against the outer circumference of the male casing adapter also forming an impermeable seal therebetween, vii.—a sleeve fabricated of a semi-resilient rubber-like compound, which said sleeve having an outer diameter generally equal to that of the inner diameter of the sleeve housing and a length slightly greater than the distance between a form ring and the forming end at the uppermost portion of the male casing adapter, viii.—a form ring having an annular body wherein its upper face is planar and its inner face is adapted with two circumferential peaks, ix.—an oil inlet threadedly engaged through the sleeve housing wherein the oil inlet is in communication with the outwardly raised continuous annular depression located centrally within said sleeve housing, and fasteners securedly holding the assembly as one.

b. a method of extracting drill core samples comprising the steps of: i. de-energizing the drill to halt rotation, ii. removing drill head from drill rod, iii. pressurizing hydraulic sleeve seal about the periphery of the drill rod, iv. activating water pump and directing high-pressure water into the water inlet, V. allow core sample to attain a height sufficient enough to surface above drill rod, vi. grasp core sample for retrieval from drill rod, vii. re-assemble drill head, reconfigure water flows, de-pressurize sleeve seal and continue drilling.

2. The drill core extractor of claim 1 wherein the present seal assembly can be adapted with current water cooling hard rock drilling rig systems without the addition of specialized tools.

3. The drill core extractor of claim 1 wherein the direction of water-flow through the drill rod is reversed during the core extraction process.

4. The drill core extractor of claim 1 wherein the male casing adapter is further adapted with a forming end having two circumferential offset peaks oriented such that the peaks pressuredly contact with the circumferencial end surface of a tubular sleeve, wherein the central-most peak extends toward the sleeve more so than the outer peak, which said outer peak is rather slightly recessed thereby encouraging an outward central bulge tendency at the sleeve's circumference.

5. The drill core extractor of claim 1 wherein the retainer ring is further adapted with a forming end having two circumferential offset peaks oriented such that the peaks pressuredly contact with the circumferencial end surface of a tubular sleeve, wherein the central-most peak extends toward the sleeve more so than the outer peak, which said outer peak is rather slightly recessed thereby encouraging an outward central bulge tendency at the sleeve's circumference.

6. The drill core extractor of claim 5 wherein the forming end of the retainer ring is oriented in mirror image of the forming end of the male casing adapter.

7. The drill core extractor of claim 1 wherein the outwardly raised continuous annular depression located centrally within the sleeve housing inner wall enables a body circumferential communication of compressed fluid to exert equal for against the sleeve's outer wall so as to ensure the sleeve's inner wall mates evenly about the outer diameter of an immobilized drill rod.