Downhole Robotic Micro-Drilling System
The invention relates to the completion and enhancement of oil and gas wells. The invention provides for a downhole tool which: enters vertical or horizontal wells located adjacent to the oil and gas bearing formation, parts the casing and extends outward forming micro-boreholes necessary to remove residual oil and gas which remain in place. After the initial fluid production has been harvested, the invention can be employed on new or old wells and can operate in all conditions which wells encounter during the standard drilling process. The process of micro-holes can replace the process known as “fracking”. Fracking is being employed; however the process is being reviewed due to safety of human life. The invention employs special alloys and procedures to form the extended reach micro-boreholes.
[The application is a non-provisional, and claims priority benefit, of U.S. Provisional Patent Application Ser. No. 61/630,205 filed Dec. 6, 2011 which is incorporated herein by specific reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENTNot applicable.
NAMES OF PARTIES TO A JOINT RESEARCH AGREEMENTNot applicable.
REFERENCE TO APPENDIXNot applicable.
BACKGROUND OF THE INVENTION1. Field of the Invention
The invention disclosed and taught herein relate to the producing of oil and gas wells. The invention provides a method to place micro-boreholes into an oil and gas formation employing a robotic micro-drilling method.
2. Description of the Related Art
U.S. Provisional Patent Application Ser. No. 61/630,205 discloses the micro-drilling system herein a radius turn is required to transform the vertical borehole to a horizontal borehole.
U.S. Provisional Patent Application Ser. No. 61/630,205 discloses the method in which the casing is parted and the radius micro-boreholes are provided.
The invention disclosed and taught herein is directed to an improved method to provide micro boreholes employing a robotic control system.
BRIEF SUMMARY OF THE INVENTIONThe oil and gas industry has found new production in areas, which are considered “harsh”. The areas of new discovery are the Arctic, deepwater, and areas prone to citizens unrest. Recently, the formations known as “shale” are being developed employing a process know as “fracking” for completion purposes. This process, for the most part, is not controlled and the process is being reviewed as a system, which will affect the health of humans.
The invention described in the application relates to a method to enhance oil and gas formations to yield high production rates. The system also replaces the fracking process with a safe and controllable method of completion. The invention allows boreholes to be placed in a controlled location and extends from the main borehole to a required length. The micro-holes are designed to provide individual channels to reach the oil and gas reserves.
Studies have indicated that the size of the micro-hole can be provided to release a certain portion of reserves. High concentration of the boreholes allow for greater inflow of production. The invention is based on placing micro-holes in a lateral mode extending from the main borehole. The invention also requires that the micro-holes are made at a rapid pace and that 20 micro-holes can be provided with only one trip into the main borehole.
It is also the intention of the invention to provide composite inserts in the casing string to allow rapid entry into the formation and that the mill/bit's effective life is extended due to the carbon fiber material properties. The casing inserts also provide landing nipples to position the micro-hole boring tool. The landing nipples are located to allow the micro-holes to be provided employing a robotic system. The invention further describes a method where the micro-hole can be separated from other holes and can be programmed to open or close on demand. The micro-holes can be directed in any direction.
Due to the formation strength, different methods of formation cutting may be chosen. In soft to medium strength formations, the micro-hole can be jetted employing high-pressure fluids. In harder formations, the micro-holes are made using special cutters, designed to cut the hardness of the materials.
The basic purpose of the invention provides for the manufacturing of micro-boreholes into oil and gas formations for enhancement of the oil and gas production. The preferred embodiment is described as follows:
The invention's purpose is to provide cluster micro-holes 10 as illustrated in
The downhole tools are controlled via the system mounted on the control console unit 36 of
The drilling of the micro-boreholes is supported by a power swivel 47 of
The fluid enters the work string 59 from the power swivel 47 at a location above the drill floor, as seen in
Above the downhole tool is an extension tube 60, which has a length between 30′ and 1000′. The extension tube 60 has flush internal connections which allow a constant outside diameter. The upper extension tube is connected to the lower extension tube 61. The lower extension tube 61 is constructed of a special alloy material. The lower extension tube 61 has lateral spherical supports, which are welded to the tubes via an electron-beam welding process. The lateral support spheres cause the extension tube 61 to have greater compression strength to conduct the drilling process. The extension tube is connected via a thread to the mill/bit unit 62.
Metallic particles are often present in the main borehole. Metallic particles can be harmful to the downhole tool.
The casing insert mill/bit is illustrated in
Electron-beam welding prevents major heat changes to occur with regards to the alloy tube. Heat changes will distort the use of the extension and can cause failure in the heat effective zone.
Operational Procedures of the Invention
The micro-borehole process allows enhancement of oil and gas wells. The process can be employed in different well conditions throughout the world. The oil and gas reserves throughout the world have harvested approximately 25% of the oil found. Hence, there is 75% of the discovered oil remaining to be harvested. The quest is to produce the “locked in” oil and gas is being conducted throughout the world. In the recent time period certain formation “shales” are being produced in vast quantities. In order to produce the shale formation, a fracking process is required, which is deemed to be harmful to humans.
The invention being considered allows the production of “shale” and other “tight” formations to be produced at an efficient level. The invention teaches a method to control the enhancement process. The following procedure is employed in the manufacture of micro-boreholes:
Procedure 1
The well to be considered is prepared for the micro-borehole installation. Production tubing is pulled, the well internal surfaces are cleaned and residual fluids are pumped out. The well bore is gauged and the casing collars are identified via well logs.
Procedure 2
A well plan is formulated to install the micro-borehole in a specific area and direction about the borehole.
Procedure 3
The invention (downhole tool) is prepared to accommodate the requirements of the well enhancement. (Steel casing application)
Procedure 4
In new wells, the carbon fiber inserts are inserted into the casing string as per the specifications. (New well conditions with inserts)
Procedure 5
The downhole tool is lowered to the production zone within the well. By instruments (gamma ray technology), the oil-bearing areas are identified and located.
Procedure 6
In wells with inserts, the placement of the inserts defines the area in which the micro-holes will be provided. In wells without inserts, the gamma ray tool will locate the exit points within the main well bore to provide micro-boreholes.
Procedure 7
Once the tool is anchored within the casing, the process can start. Pump pressure is elevated to a level of 3500 psi. The pressure releases the lock assembly allowing the extension tube and guide tube to be free of the tool body.
Procedure 8
The pump pressure is elevated to 20,000# psi. The power swivel is engaged to the desired speed and torque.
Procedure 9
The advancement of the mill/bit is started from the surface controls. Depending on the formation strength, the rate of penetration is set.
Procedure 10
As the advancement of the mill/bit occurs and surface indication illustrates that the mill/bit has departed the stowed location.
Procedure 11
The mill/bit advances outward with the guide tube which is set at 5°/foot angle. As the guide shoe extends outward, a borehole radius is formed. Once the guide tube is extended outward to its limit (30′-0″), the guide tube is disconnected from the extension tube.
Procedure 12
Once the guide tube is disconnected from the extension tube, the rate of penetration is increased to meet the drilling plan rate of penetration.
Procedure 13
Once the micro-hole is formed due to the length limitation, the movement of the extension tube is stopped. Fluid is pumped to remove any material from the micro-borehole.
Procedure 14
Once the pumping is completed, the pressure is reduced to 3500 psi. The rotation remains active throughout the process.
Procedure 15
The extension tube is extracted from the micro-borehole. Once the automatic disconnect is re-engaged, the guide tube and extension tube moves up the hole together.
Procedure 16
Once the extension tube and guide tube reach the stowed position, a surface indication allows the operator to know that the process is complete and that a micro-hole has been completed.
Procedure 17
The operator must follow the drilling plan. The anchor is unlocked and repositioned at a new location. A minimum of 20 micro-boreholes can be provided in one trip into the main borehole.
Procedure 18
In the event that the carbon fiber inserts are not employed, the steel casing can be parted. Due to the steel, material between 3 and 4 micro-holes can be provided considering one trip into the hole.
The general extension and guide tube procedures are identical in both the carbon fiber insert method and the steel casing method.
Claims
1. A downhole drilling system for drilling micro-holes in earth formations comprising: a surface control unit which programs the action of the downhole tool and provides high-pressure fluid pressure to the downhole tool which in turn, by robotic action, parts the casing and drills a micro-hole to a general location, which is pre-programmed from the surface for the enhancement of oil and gas production.
2. A method of claim 1 to extend a micro-borehole outward into an oil and gas formation allowing the general attitude of the borehole to be as planned and to rotate the vertical borehole to a horizontal borehole in a distance less than 30′-0″.
3. A system of claim 1 of casing inserts which are mounted into the standard protective casing allowing the inserts to be placed in a planned location allowing the casing string to be parted employing a mill/bit, which, due to the insert material, allows many cycles to occur without replacement of the mill/bit downhole.
4. A method in which a hex-shaped guide tube is allowed to exit the casing into the formation cased into the formation allowing a pre-determined radius to be formed by the mill/bit, which extends into the oil and gas formation and the radius is formed via the bent section located at the end section of the extension tube.
5. A guide tube as set forth in claim 4, which is constructed of a carbon fiber material or the like, which has strength qualities in torsion resistance of a high magnitude and the axial bending is of very low resistance thereby allowing the guide tube to retain its tolerance when loaded by torsional forces and will bend an axial load at a very low magnitude of force.
6. The extension tube is equipped with a disconnect assembly which allows the tube to assist in providing a 90° turn and by a robotic event allows the drilling string to go forward into the formation at a given angle to a pre-determined distance and return to the guide tube all allowing retraction of the guide tool into the downhole tool.
7. A mill/bit to be employed for the purpose of parting the casing and extending outward into the formation causing a micro-borehole to be found at a specific distance from the protection casing.
8. A mill/bit extension tube as set forth in claim 6 is provided to allow the rotating assembly to bend to the shape and direction of the guide tube by employing a special alloy such as NiTi material having a small tube diameter resulting in a small section modulus and having mounted along the axis spherical guides which supports the small diameter tube and provides lateral stability of the extension tube which is loaded by compression forces.
9. A system which allows the extension tube as set forth in claim 6 to be disconnected from the guide tube in an automatic and robotic fashion and once the guide tube is disconnected, the extension tube is allowed to travel to the designated distance and once the extension tube has completed its travel, it is extracted causing the extension tube to reenter the tool casing causing the guide tube to also be retracted into the tool casing.
10. A system which allows the downhole tool to be located at different intervals along the axis of the casing employing the landing nipples to be engaged thereby locating the micro-hole formation and to anchor the tool to avoid any axial movement.
11-13. (canceled)
14. A drilling system, which provides completion fluids to be cleaned from solids at a level lower than 5 microns thereby allowing the formation to be clear of any particles, which are introduced from the completion fluids.
15. A drilling system, as set forth in claim 8 which indicates the cycle milestones, which have been completed, and identifies the completion of the drilling event.
16. (canceled)
17. A drilling system as described in claim 9, which allows the placement of clusters of micro-boreholes to replace oil and gas formation fracking process with a controlled and predictable program employing micro-boreholes.
Type: Application
Filed: Dec 6, 2012
Publication Date: Mar 6, 2014
Inventor: Herman Joseph Schellstede (New Iberia, LA)
Application Number: 13/707,529
International Classification: E21B 43/112 (20060101); E21B 17/10 (20060101); E21B 21/06 (20060101); E21B 17/00 (20060101);