Downhole tool piston assembly
A piston assembly may comprise a housing with a wall, and at least one chamber formed in the wall. A piston may be disposed within the chamber and at least one passageway may pass through the piston. At least one pin may be disposed within the passageway and attached to the chamber, and the piston may be free to translate relative to the pin.
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Notice: More than one reissue application has been filed for the reissue of U.S. Pat. No. 9,085,941. The reissue applications are application Ser. Nos. 15/164,663 and 16/150,875 (the present application). The present application is a divisional reissue of U.S. Pat. No. 9,085,941 and application Ser. No. 15/164,663 is a reissue of U.S. Pat. No. 9,085,941.
CROSS-REFERENCE TO RELATED APPLICATIONSThis application is a divisional reissue application of U.S. patent application Ser. No. 15/164,663, filed May 25, 2016, which is a reissue of U.S. Pat. No. 9,085,941, issued on Jul. 21, 2015. This application is also a reissue application of U.S. Pat. No. 9,085,941, issued on Jul. 21, 2015.
BACKGROUND OF THE INVENTIONThe present invention relates to the fields of downhole oil, gas, and/or geothermal exploration and more particularly to piston assemblies for actuating downhole tools. There exists in the art a variety of downhole tools comprising piston assemblies configured to actuate downhole tools to protrude and retract. One such downhole tool may be a directional steering mechanism. In directional drilling operations, a piston may extend a pad that contacts a formation and causes the drill string to move in a direction. Other such tools include expandable tools configured to enlarge the diameter of a wellbore and/or stabilize a drill string. The expandable tools may contain arms or blades which extend from the sides of the drill string and contact the formation. Examples from the prior art of such piston assemblies used in downhole tools are given below.
U.S. Patent Publication No. 2010/0071962 to Beuershausen, which is herein incorporated by reference for all that it contains, discloses a drill bit that includes at least one blade profile having a side section and an adjustable pad on the side section that is configured to extend from the side section to cause the drill bit to alter a drilling direction when the drill bit is used to drill a wellbore.
U.S. Patent Publication No. 2010/0139980 to Neves et al., which is herein incorporated by reference for all that it contains, discloses a ball piston steering device and methods for use of ball piston devices. One aspect of the invention includes: a sleeve in fluid communication with a fluid source and a ball received within the sleeve. The ball is movable within the sleeve from a recessed position and an extended position.
U.S. Patent Publication No. 2006/0157283 to Hart, which is herein incorporated by reference for all that it contains, discloses a bias unit comprising at least one bias pad moveable by a piston between retracted and extended positions wherein the piston is of non-circular effective cross-sectional shape.
U.S. Patent Publication No. 2004/0206549 to Dewey et al., which is herein incorporated by reference for all that it contains, discloses a downhole tool that functions as an underreamer or as a stabilizer in an underrreamed borehole. The tool includes one or more moveable arms disposed within a body having a flowbore therethrough in fluid communication with the wellbore annulus. The tool alternates between collapsed and expanded positions in response to differential fluid pressure between the flowbore and the wellbore annulus. In one embodiment, the tool moves automatically in response to differential pressure. In a second embodiment, the tool must be selectively actuated before it is moveable. The tool may include borehole engaging pads that comprise cutting structure or wear structures or both, depending upon the function of the tool.
Despite the advancements as shown in the prior art, it is believed that there is still a need to develop improved piston assemblies used in downhole drill strings.
BRIEF SUMMARY OF THE INVENTIONIn one aspect of the present invention, a piston assembly may comprise a housing with a wall, and at least one chamber formed in the wall. A piston may be disposed within the chamber and at least one passageway may pass through the piston. At least one pin may be disposed within the passageway and be attached to the chamber, and the piston may be free to translate relative to the pin.
The housing may be selected from a group consisting of drill bits, calipers, reamers, shock absorbers, jars, clamps, tractors, stabilizers, fishing tools, and combinations thereof. When the housing consists of a drill bit, the wall and the chamber may be disposed on a gauge surface of the drill bit. The housing may comprise a tube and the wall may be disposed within or on a surface of the tube. The chamber may be in fluid communication with a fluid source.
The chamber may comprise a cross section selected from the group consisting of a circle, oval, polygon, star, rectangle with circular ends, and annulus. The chamber may be lined with a sleeve and the chamber and the sleeve may comprise openings to allow passage of the at least one pin. The chamber openings may also allow fluid communication with the chamber. A seal may be disposed between the chamber and the piston, the piston and the sleeve, or the chamber and the sleeve.
The piston may comprise a cross sectional shape similar to the chamber. The piston may comprise a working surface adjacent the wall, a base surface opposite the working surface, and an intermediate surface joining the working surface and the base surface. The working surface may comprise wear resistant elements disposed thereon. The base surface may be nonplanar and comprise a topography selected from the group consisting of grooves, dimples, flutes, fins, troughs, and protrusions. The base surface may also comprise an opening to the passageway. The passageway may intersect at least one of the intermediate surface and the base surface.
The pin may comprise a cross section selected from the group consisting of a circle, oval, polygon, star, rectangle with circular ends, and annulus. The pin may also comprise a sleeve surrounding at least a portion of the pin, and an aperture there through. The passageway may comprise a cross-sectional area greater than a cross-sectional area of the pin.
Referring now to the figures,
The present embodiment discloses the drill bit 104 configured to be a housing for a piston assembly 204. At least one chamber (hidden from view) may be formed in a wall 205 of the housing on the gauge surface 202. A piston 206 may be disposed within each chamber and may be configured to translate relative to a pin (hidden front view). The pin may be inserted into the piston 206 to retain the piston 206 in the piston assembly 204. The pin may be inserted through at least one entry passageway 207 and attached to the chamber.
The piston assembly 204 may be part of a steering mechanism configured to steer the drill string 100. The piston assembly 204 may steer the drill string 100 by extending and retracting the pistons 206 which may push against the formation 105 forcing the drill string 100 to move in a desired direction. At least one chamber may be disposed relative to a desired turning radius of the drill bit 104. It is believed that the closer the pistons 206 are disposed to the cutting face 201, the greater a build rate can be for the steering mechanism. A 2.5 inch difference in placing the pistons 206 relative to the cutting face 201 may affect the steering capability by approximately 3 degrees per 100 feet. The steering mechanism of the present invention may dispose the pistons closer to the cutting face than the steering mechanisms in the prior art due to the present invention comprising substantially less working parts. Geometry constraints associated with the amount of working parts is a major limitation in placement of the steering mechanisms. The present invention also comprises smaller components that allow for larger junk slot volume leading to less restricted mud flow.
It is believed that a plurality of chambers and pistons disposed in a drill bit may be advantageous in that it provides redundancy. If one piston becomes jammed or dysfunctional, then another piston may not be affected and the piston assembly may still perform effectively. A plurality of pistons may also be configured to actuate independently and/or in combination with each other. By acting independently and/or in combination with each other, the pistons may extend and retract at specified time periods that may maximize the effectiveness of the piston assemblies. In some embodiments, each piston in the plurality may be configured to actuate individually but at determined time intervals which may allow the pistons to work off of each other. In some embodiments, the pistons may act in uniform which may increase the push force on the formation.
The piston 206 may also comprise a base surface 303 disposed opposite the working surface 302 and an intermediate surface 308 joining the working surface 302 and the base surface 303. In some embodiments a retaining passageway 311 may intersect at least one of the intermediate surface and base surface 303. The base surface 303 may be nonplanar and comprise a topography selected from a group consisting of grooves, dimples, flutes, fins, troughs, and protrusions which may be in fluid communication with a fluid source such as a bore 305 via fluid channels 304. The fluid may be drilling mud that is sent through the bore 305 of the drill string during normal operation. A valve (not shown) may redirect a portion of the drilling mud to the fluid channels 304 thus causing the piston 206 to actuate. In some embodiments, the fluid may be air, gas, foam, oil, water, or a combination thereof.
A pin 306 may retain the piston 206 within the chamber 301. The pin 306 may be inserted into the retaining passageway 311 within the piston 206. The pin 306 may allow the piston 206 to translate in a direction normal to a rotational axis 310 of the drill bit 104 but may prevent the piston 206 from rotating within the chamber 301. By preventing the piston 206 from rotating, the degrees of freedom for the piston 206 are decreased to only linear movement. The pin 306 may be comprised of tungsten carbide or other hard material that can withstand the rotational loads that may act upon the piston 206 during normal operations.
Fluid may push the piston 206 into an extended position and the pin 306 may be configured to keep the piston 206 within the chamber 301 by allowing the piston 206 to translate a specified distance. The retaining passageway 311 may comprise an edge or other stopping device that comes into contact with the pin 306 and inhibits further translational movement of the piston 206. The pin 306 may be adjusted to allow the piston 206 to translate within a range of 0.010 inch to 0.500 inch. The present embodiment discloses a magnified view of the piston 206 extending a distance 307 away from the wall 205.
The chamber 401 may be lined with a sleeve 403 which may also comprise openings to allow passage of the pin 416. The sleeve 403 may comprise a finish that allows the piston 406 to translate without having to overcome a substantial amount of friction. The sleeve 403 may also increase the life of the piston assembly. During normal operation, the piston 406 may translate back and forth causing the sleeve 403 to wear down over time. After the sleeve has worn down a specified amount, the sleeve 403 can be replaced. In other embodiments, the walls of the chamber 401 may be in direct contact with the piston 406. However, when the walls of the chamber 401 are worn down, the whole piston assembly may not be functional.
The piston 406 and sleeve 403 may collectively comprise a tight tolerance, around 0.001 inch diametrical difference between the two, that small particles may be prevented from jamming the system. The piston 406 and the sleeve 403 may be composed of the same material allowing them to maintain the tight tolerance under large temperature changes.
During normal operations when the piston 406 is extending and retracting, fluid may become trapped within the piston 406. The pin 416 may comprise at least one aperture 420 that is configured to allow passage for the trapped fluid. Trapped fluid may be exhausted by an opening, to the passageway 407 disposed in a base surface 413 of the piston 406. It is believed to be important to exhaust fluid from inside the piston 406 as trapped fluid may not allow the piston assembly to function properly.
The current embodiment also discloses a seal 408 disposed around the chamber 401. The seal 408 may be disposed between the chamber 401 and the sleeve 403. In other embodiments a seal may be disposed between the chamber and the piston, or the piston and the sleeve. When operating in high pressure environments, fluid may enter or exit the piston assembly between the sleeve 403 and chamber 401. The seal 408 may be configured to prevent fluid from passing through the piston assembly. In some embodiments a seal may not be necessary if the parts of the piston assembly have a tight tolerance; in other embodiments more than one seal may be needed.
In the present embodiment, a housing comprises a tube and at least one chamber 1004 may be formed in an inside wall 1006 within the tube. The chamber 1004 may open to the inside wall 1006 thus allowing a piston 1007 disposed within the chamber 1004 to come into contact with a body 1008 of the inner bit 1003. As the piston 1007 extends and retracts, the piston 1007 may push the body 1008 of the inner bit 1003 thus rotationally moving the inner bit 1003 and steering the drill string.
The present embodiments disclose the pistons forming at least one extendable arm that is configured to extend away from the drill string and come into contact with a formation. The pistons may be configured to translate in a direction normal to a rotational axis of the housing and may be configured to actuate independently or in combinations with each other.
Valleys 1105 may be formed between walls. The valleys 1105 may allow drilling mud and debris to travel between the drill string 1101 and the formation during normal drilling operations. The wall 1102 may be configured to partially curve or spiral around the drill string 1101. The valleys 1105 may thus also curve or spiral around the drill string 1101 which may force the drilling mud and debris to spiral around the drill string 1101 as it travels up the annulus of the wellbore. By spiraling, the drilling mud may exert forces on the drill string 1101 which may help the drill string 1101 rotate.
The piston 1203 may also be configured to clamp onto the formation with maximum efficiency due to the ability of the piston 1203 to actuate independently of other pistons. The formation may not comprise an even surface for the piston 1203 to clamp on to so actuating independently may allow the piston 1203 to clamp onto as much of the formation as possible.
Incorporated into the piston 1203 may be a formation hardness testing mechanism. It is believed that the type of formation may be determined by measuring its hardness. The piston 1203 may extend and the cutting elements 1204 may contact the formation. The forces applied to the piston 1203 and the amount the cutting elements 1204 penetrate into the formation may be used to determine the hardness of the formation.
The piston 1203 may be configured to work in combination with each other such that the piston 1203 may push on one side of the formation forcing the drill string 1201 against the opposite side. Forcing the drill string 1201 against one side of the formation may be desirable when measurements, such as resistivity or seismic, are taken. With the drill string 1201 in contact with the formation, the measurements may be able to better identify signals as they propagate through the formation.
In some embodiments, sensors, such as resistivity or seismic sensors may also be disposed within the telescoping portion of the drill string. The pistons at each location may extend and clamp onto the formation. The sensors disposed between the top location and the bottom location may identify signals traveling through the formation because of the contact of the top and bottom locations with the formation. The signals may propagate through the formation and pistons to the sensors.
In some embodiments, the piston 1403 may comprise calipers that may be configured to measure the distance that the piston 1403 extended before contacting the formation. Because the piston 1403 may act independently of other pistons, the diameter of the wellbore at the locations of the piston 1403 may be accurately measured.
Whereas the present invention has been described in particular relation to the drawings attached hereto, it should be understood that other and further modifications apart from those shown or suggested herein, may be made within the scope and spirit of the present invention.
Claims
1. A piston assembly, comprising:
- a housing comprising a wall;
- at least one chamber formed in the wall;
- a piston disposed within the chamber;
- wherein the piston comprises a working surface adjacent the wall, a base surface opposite the working surface, and an intermediate surface joining the working surface and the base surface;
- at least one passageway through the piston;
- wherein the base surface comprises an opening to the passageway;
- at least one pin disposed within the passageway and attached to the chamber; and
- wherein the piston is free to translate relative to the pin.
2. The assembly of claim 1, wherein the chamber is in fluid communication with a fluid source.
3. The assembly of claim 1, wherein the housing is selected from a group consisting of drill bits, calipers, reamers, shock absorbers, jars, clamps, tractors, stabilizers, fishing tools, and combinations thereof.
4. The assembly of claim 3, wherein the housing consists of a drill bit and the wall and the chamber are disposed on a gauge surface of the drill bit.
5. The assembly of claim 1, wherein the housing comprises a tube and the wall is disposed within the tube.
6. The assembly of claim 1, wherein the housing comprises a tube and the wall is disposed on a surface of the tube.
7. The assembly of claim 1, wherein the chamber comprises a cross section selected from the group consisting of a circle, oval, polygon, star, rectangle with circular ends, and annulus.
8. The assembly of claim 1, wherein the piston comprises a cross sectional shape similar to the chamber.
9. The assembly of claim 1, wherein the chamber comprises openings to allow passage of the pin and fluid communication with the chamber.
10. The assembly of claim 1, wherein the chamber is lined with a sleeve and the sleeve comprises openings to allow passage of the at least one pin.
11. The assembly of claim 1, wherein the passageway intersects at least one of the intermediate surface and base surface.
12. The assembly of claim wherein the working surface comprises wear resistant elements disposed thereon.
13. The assembly of claim 1, wherein the base surface is nonplaner and comprises a topography selected from the group consisting of grooves, dimples, flutes, fins, troughs, and protrusions.
14. The assembly of claim 1, wherein the pin comprises a cross section selected from the group consisting of a circle, oval, polygon, star, rectangle with circular ends, and annulus.
15. The assembly of claim 1, wherein the pin comprises an aperture there through.
16. The assembly of claim 1, wherein the pin comprises a sleeve surrounding at least a portion of the pin.
17. The assembly of claim 1, wherein the passageway comprises a cross-sectional area greater than a cross-sectional area of the pin.
18. The assembly of claim 1, further comprising a seal disposed between the chamber and the piston, the piston and the sleeve, or the chamber and the sleeve.
19. A piston assembly, comprising:
- a housing comprising a wall, the housing having a longitudinal axis;
- a first piston disposed within the wall and configured to translate relative to the housing; and
- a second piston disposed within the wall and configured to translate relative to the housing, the second piston being offset from the first piston in a direction along the longitudinal axis, and at least a part of the second piston overlapping at least a part of the first piston about the longitudinal axis, wherein the first piston and the second piston are configured to actuate independently.
20. The piston assembly of claim 19, wherein the first piston is retained within the wall of the housing by contact with a shoulder.
21. The piston assembly of claim 19, further comprising a first chamber and a fluid channel in communication with at least the first chamber, the first piston positioned at least partially within the first chamber.
22. The piston assembly of claim 19, wherein the second piston is angularly aligned with the first piston relative to the longitudinal axis.
23. The piston assembly of claim 19, wherein the first piston and second piston are configured to translate relative to the housing at a specific time period.
24. The piston assembly of claim 19, further comprising a pin extending through the first piston and part of the housing, the pin configured to limit rotational and translational movement of the first piston relative to the housing.
25. The piston assembly of claim 19, wherein at least part of the first piston or second piston includes diamond.
26. The piston assembly of claim 25, further comprising at least one cutting element positioned on a working surface of the first piston or the second piston.
27. The piston assembly of claim 19, further comprising a seal positioned between the first piston and the wall of the housing.
28. The piston assembly of claim 19, wherein the housing is selected from a group consisting of drill bits, calipers, reamers, shock absorbers, jars, clamps, tractors, stabilizers, fishing tools, and combinations thereof.
29. The piston assembly of claim 19, wherein the first piston and the second piston are configured to actuate independently and in combination with each other.
30. A method of steering a drilling system, the method comprising:
- positioning a piston assembly adjacent a formation, the piston assembly including a first piston and a second piston, the second piston being offset from the first piston along a longitudinal axis of the piston assembly;
- opening a valve to redirect a portion of drilling fluid;
- extending the first piston radially using the portion of the drilling fluid applied to a base surface of the first piston;
- contacting the formation with the first piston;
- extending the second piston radially using the portion of the drilling fluid applied to a base surface of the second piston; and
- contacting the formation with the second piston, wherein contacting the formation with the first piston and the second piston pushes the drilling system to move in a desired direction.
31. The method of claim 30, wherein extending the first piston and extending the second piston occur at different times.
32. The method of claim 30, wherein extending the first piston includes applying a fluid pressure to the base surface of the first piston.
33. The method of claim 30, wherein the first piston and the second piston are both extended by a fluid pressure of a single fluid source.
34. The method of claim 30, further comprising:
- measuring a first distance traveled by the first piston while extending the first piston, wherein measuring the first distance includes measuring with a first set of calipers connected to the first piston; and
- measuring a second distance traveled by the second piston while extending the second piston, wherein measuring the second distance includes measuring with a second set of calipers connected to the second piston.
35. The method of claim 30, wherein extending the first piston and extending the second piston occur at different times.
36. The method of claim 30, wherein the portion of the drilling fluid is applied to the base surface of the first piston and the portion of the drilling fluid is applied to the base surface of the second piston by activating the valve.
37. The method of claim 30, further comprising connecting a bit to the piston assembly.
38. A downhole tool comprising:
- a body comprising a wall, the body having a longitudinal axis and an outer surface;
- a first chamber in the wall and having an opening in the outer surface of the body;
- a first piston positioned in the first chamber and configured to translate within the first chamber and relative to the body;
- a second chamber in the wall and having an opening in the outer surface of the body;
- a second piston positioned in the second chamber and configured to translate relative to the body, the second piston being axially displaced from the first piston along the longitudinal axis, and at least a part of the second piston angularly overlapping at least a part of the first piston about the longitudinal axis; and
- a valve configured to redirect a portion of a drilling fluid to contact the first piston and the second piston to cause the first piston and the second piston to actuate.
39. The tool of claim 38, wherein the first piston includes at least one sensor.
40. The tool of claim 39, wherein the at least one sensor includes at least one of a pressure transducer, linear displacement variable transformer, resistivity sensor, or seismic sensor.
41. The piston assembly of claim 38, further comprising a cutting structure.
42. The piston assembly of claim 41, wherein the cutting structure includes a bit.
43. The piston assembly of claim 42, wherein the wall is on a gauge surface of the bit.
44. The piston assembly of claim 41, wherein the cutting structure includes at least one of a bit, a caliper, a reamer, a shock absorber, a jar, a clamp, a tractor, a stabilizer, or a fishing tool.
3593810 | July 1971 | Fields |
4117897 | October 3, 1978 | Lloyd |
4693328 | September 15, 1987 | Furse |
4848490 | July 18, 1989 | Anderson |
4947944 | August 14, 1990 | Coltman et al. |
5511627 | April 30, 1996 | Anderson |
5553678 | September 10, 1996 | Barr et al. |
6290002 | September 18, 2001 | Comeau |
6550548 | April 22, 2003 | Taylor |
7849936 | December 14, 2010 | Hutton |
8087479 | January 3, 2012 | Kulkarni et al. |
8141657 | March 27, 2012 | Hutton |
8205686 | June 26, 2012 | Beuershausen |
20040206549 | October 21, 2004 | Dewey et al. |
20040222022 | November 11, 2004 | Nevlud et al. |
20060157283 | July 20, 2006 | Hart |
20070145131 | June 28, 2007 | Perkin et al. |
20080000693 | January 3, 2008 | Hutton |
20090044979 | February 19, 2009 | Johnson et al. |
20090133931 | May 28, 2009 | Rolovic |
20090223716 | September 10, 2009 | Eppink |
20090223717 | September 10, 2009 | Eppink |
20090277689 | November 12, 2009 | Lee |
20100071962 | March 25, 2010 | Beuershausen |
20100139980 | June 10, 2010 | Neves et al. |
20110162890 | July 7, 2011 | Radovan |
20120168229 | July 5, 2012 | Lee |
20130206390 | August 15, 2013 | Hall et al. |
Type: Grant
Filed: Oct 3, 2018
Date of Patent: Mar 22, 2022
Assignee: SCHLUMBERGER TECHNOLOGY CORPORATION (Sugar Land, TX)
Inventors: David R. Hall (Provo, UT), Jonathan Marshall (Provo, UT)
Primary Examiner: Catherine S Williams
Application Number: 16/150,875
International Classification: E21B 17/10 (20060101); E21B 27/00 (20060101); E21B 7/06 (20060101); E21B 10/62 (20060101);