|Publication number||US20080156536 A1|
|Application number||US 11/619,418|
|Publication date||Jul 3, 2008|
|Filing date||Jan 3, 2007|
|Priority date||Jan 3, 2007|
|Also published as||US7392857, WO2008085622A1|
|Publication number||11619418, 619418, US 2008/0156536 A1, US 2008/156536 A1, US 20080156536 A1, US 20080156536A1, US 2008156536 A1, US 2008156536A1, US-A1-20080156536, US-A1-2008156536, US2008/0156536A1, US2008/156536A1, US20080156536 A1, US20080156536A1, US2008156536 A1, US2008156536A1|
|Inventors||David R. Hall, Scott Dahlgren|
|Original Assignee||Hall David R, Scott Dahlgren|
|Export Citation||BiBTeX, EndNote, RefMan|
|Referenced by (3), Classifications (12), Legal Events (4)|
|External Links: USPTO, USPTO Assignment, Espacenet|
This invention relates to the field of percussive tools used in drilling. More particularly, the invention relates to the field of downhole hammers which are actuated by the pressure of the drilling fluid. Some of these tools are generally known in the petroleum drilling industry simply as “downhole mud hammers”.
Typically, downhole hammers are used to affect periodic mechanical impacts upon a drill bit. Through this percussion, the drill string is able to more effectively apply drilling power to the formation, thus aiding penetration into the formation.
The prior art has addressed the operation of a downhole hammer actuated by drilling mud. Such issues have been addressed in the U.S. Pat. No. 5,396,965 to Hall, which is herein incorporated by reference for all that it contains. The '965 patent discloses improvements in downhole mud actuated hammers. According to its broadest aspect the invention is a downhole mud actuated hammer for use in a drill string, which includes a housing with an upper end having means for connecting to the drill string. A throat is located within the housing which throat includes a main flow passage to allow high pressure drilling mud to pass therethrough. A piston is provided which is adapted to move axially within the housing means to thereby reciprocate between an up position and a down position. The piston is moved between the up and down position by a minor portion of the high pressure mud which portion passes from the main flow passage into at least one piston actuating chamber. This minor portion of mud is exhausted from the piston actuating chamber to a low pressure region out of the housing without being returned to the main flow passage.
U.S. Pat. No. 6,367,565 to Hall, which is also herein incorporated by reference for all that it contains, discloses a method of creating an electric signal that describes the motion of a downhole, fluid-driven percussive tool. The signal is obtained by attaching an electromagnetic transducer to the percussive tool, the member impacted by it, or the drill string. The rebound characteristics of the tool yield a measurement of the physical characteristics of the subterranean formation being penetrated. The tool's position over time is useful for diagnosing and regulating the operation of the tool. The transducer can also be configured to generate a signal large enough to be used as a power source.
In one aspect of the present invention a drill bit comprises an axis of rotation and a drill bit body intermediate a threaded end and a working face. The drill bit body comprises a fluid passageway that has a first seat and houses a jack element substantially coaxial with the axis of rotation. A stop element is disposed within the passageway and has a first near-sealing surface. The jack element has a shaft intermediate an indenting end and a valve portion. The indenting end extends through the working face. The valve portion has a second near-sealing surface disposed adjacent the first near-sealing surface and a second seat disposed adjacent the first seat. As the formation being drilled strongly resists the jack element, the distance between the respective sealing surfaces narrows. This causes an increase in fluid pressure within the passageway and forces the indenting end down into the formation. This movement of the jack relieves the pressure build such that the formation pushes the jack element back, thereby oscillating the jack element.
In some embodiments, a nozzle may be disposed within an opening in the working face to control and direct the drilling fluid as well as control the flow of debris from the subterranean formation. The second near-sealing surface of the jack element may have a rounded geometry. It may also have a hard surface of at least 58 HRc. Materials suitable for the near-sealing surfaces may be selected from the group consisting of chromium, tungsten, tantalum, niobium, titanium, molybdenum, carbide, natural diamond, polycrystalline diamond, vapor deposited diamond, cubic boron nitride, TiN, AlNi, AlTiNi, TiAlN, CrN/CrC/(Mo, W)S2, TiN/TiCN, AlTiN/MoS2, TiAlN, ZrN, diamond impregnated carbide, diamond impregnated matrix, silicon bounded diamond, and combinations thereof. The indenting end of the jack element may be comprised of a superhard material. It may also have an asymmetric geometry used to guide the drill bit during a drilling operation
In some embodiments, a drill bit is attached to a downhole tool string component for use in oil, gas, and/or geothermal drilling; however, the present invention may be used in drilling applications involved with mining coal, diamonds, copper, iron, zinc, gold, lead, rock salt, and other natural resources, as well as for drilling through metals, woods, plastics and related materials. The downhole tool string may have a sensor that is adapted to receive acoustic reflections produced by the movement of the jack element. The sensor is used to determine the location of reflectors in subterranean formations. Examples of reflectors include boundaries between different sedimentary formations; faults, cracks, or cavities; zones permeated with different fluids or gases; and zones exhibiting a gradient in pore pressure.
In another aspect of the invention a method has steps for drilling a well bore with a drill bit having an axis of rotation and drill bit body intermediate a threaded end and a working face. The drill bit body may have a fluid passageway comprising a first seat and housing a jack element. The drill bit may also have a stop element disposed within the passageway comprising a first near-sealing surface. The jack element has a valve portion and an indenting end that extends through the working face. The valve portion may have a second near-sealing surface adjacent to the first near-sealing surface.
When a first axial force is applied by pressurizing the fluid passageway and an opposing force is also applied to the jack element, the near-sealing surfaces may form a restriction in the fluid passage from the fluid passageway to at least one opening disposed in the working face. Drilling mud may pressurize the fluid passageway, causing the first axial force. The opposing force may be generated by contacting the indenting end of the jack element against a subterranean formation. The restriction causes the pressure in the fluid passageway to build up until it overcomes the opposing force and displaces the jack element in the direction of the first axial force, opening the restriction and thereby relieving the pressure in the fluid passageway. The jack element may be displaced 0.010 to 0.100 inches. After relieving the pressure in the passageway, the opposing force overcomes the first axial force and substantially returns the jack element to its original position. This reestablishes the restriction in which the first axial force is reformed by pressurizing the fluid passageway. The building up and relieving of the pressure causes the jack element to oscillate. As a result, the drill bit is able to percussively fail a formation in a fluid environment.
In one embodiment of a method, the restriction may restrict all flow within the fluid passage. In other embodiments, the restriction may restrict a portion of the flow within the fluid passage. The jack element may be rotated by a motor or turbine. The jack element may also be rotationally isolated from the fluid passageway of the drill bit. A non-contact seal, such as a labyrinth seal, may be disposed in the fluid passageway to inhibit fluid passage. The jack element may also be laterally supported by a bearing that comprises a material with a hardness of at least 58 HRc. A spring coaxial with the jack element and proximal the drill bit may be positioned within the fluid passageway so as to engage the jack element.
A portion of the jack element 203 forms an adjustable restriction 213 in a fluid passage intermediate the fluid passageway 204 and an opening 214 disposed in the working face 201. The adjustable restriction 213 is adapted to move to relieve pressure build up in the passageway when a fluid is passed through the fluid passageway 204. When a fluid is passed through the fluid passageway 204, the jack element 203 is pushed against the formation which resists the jack element axially loading it in a direction depicted by arrow 215. The first and second near-sealing surfaces may contact each other, restricting fluid passage and therefore causing a pressure to build up in the fluid passageway 204. The pressure build up produces a first axial force. An opposing force may also be applied in the opposite direction. This force may be generated by contacting the indenting end 209 against a subterranean formation 105. If the first axial force overcomes the opposing force, the jack element 203 may displace in the direction of the first axial force in which the first seat 205 may contact the second seat 212. The opposing force may then overcome the first axial force causing the jack element 203 to substantially return to its original position, reforming the restriction. The continual displacing of the jack element 203 and reforming of the restriction 213 may produce an oscillation. The oscillation may provide the drill bit with some of the advantages found in a typically percussion bit, which may increase the bit's rate of penetration.
When drilling in soft formations, the first axial force may be greater than the opposing force wherein the jack element 203 may not necessarily oscillate, but rather the valve portion 210 will approximate the respective seats. However, when drilling in hard formations, the jack element 203 may oscillate since the formation will be able to substantially return the jack element to its original position In some embodiments, the restriction 213 may inhibit all fluid passage, and in other embodiments, the restriction 213 may always allow fluid passage. If the restriction 213 inhibits all fluid passage, the pressure will build up in the fluid passageway 204 at a rate greater than if the restriction 213 allows some fluid passage.
The drill bit 104 may comprise a spring 216 coaxial with the jack element 203 and proximal the drill bit 104. The spring 216 may be positioned within the fluid passageway 204 adapted to engage the jack element 203. The spring 216 may be a coil spring, a Belleville spring, a compression spring, a tension spring, or a gas spring. In some embodiments the spring may be the stop element.
The second near-sealing surface 211 may have a rounded or flat geometry and may have a hardness of at least 58 HRc. The surface 211 may comprise a material selected from the group consisting of chromium, tungsten, tantalum, niobium, titanium, molybdenum, carbide, natural diamond, polycrystalline diamond, vapor deposited diamond, cubic boron nitride, TiN, AlNi, AlTiNi, TiAlN, CrN/CrC/(Mo, W)S2, TiN/TiCN, AlTiN/MoS2, TiAlN, ZrN, diamond impregnated carbide, diamond impregnated matrix, silicon bounded diamond, and combinations thereof. The restriction 213 also comprises a surface with a hardness of at least 58 HRc.
The drill bit 104 may also comprise an axle 217 generally coaxial with the axis of rotation 200. The axle 217 may be rotated by a motor or turbine. The an end of the axle 217 which may interlock with the jack element 203 may be generally cylindrically shaped, generally rectangular, or generally polygonal. In some embodiments, the jack element 203 is rotationally isolated from the fluid passageway 204 of the drill bit 104 and the axle 217 may rotate the jack element 203.
Preferably, the indenting end 209 comprises a superhard material and an asymmetric geometry. During a drilling operation, the rotational velocity of the jack element 203 may be adjusted so that the indenting end 209 may steer the drill bit 104 in a desired direction. Thus in drilling applications where a changed direction is preferred, the jack element 203 may not rotate and thereby the indenting end 209 may guide the drill bit 104 in the preferred direction. Further, when the current direction is preferred, the jack element 203 will rotate at a given velocity so that the indenting end 203 may guide the drill bit 104 in the current direction.
A non-contact seal 218 may be disposed in the fluid passageway 204 of the drill bit 104 to inhibit fluid passage. The non-contact seal 218 may allow some fluid passage or may restrict all fluid passage. The non-contact seal 218 may generally be a labyrinth seal. A portion of the jack element 203 may be laterally supported by a bearing 219. The bearing 219 comprises a material with a hardness of at least 58 HRc. The bearing 219 may support the jack element 203 when it is subjected to lateral loads.
Sensors 1002 may be located in the drill bit itself, at some location along the tool string or at the surface. In some embodiments, the sensors may be located in a tool string component attached to the drill bit 104. Other sensors (not shown) may be used to record the frequency of the jack element's oscillations and as well as time stamp at least some of jack element's impacts into the formation. This information may be correlated with the time and frequency of acoustic reflections received, which may help identify the distance from the bit and type of acoustic boundary that is encountered. Also the used inclination and direction package may help determine the location of the acoustic impedance boundary.
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.
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US7900720 *||Dec 14, 2007||Mar 8, 2011||Schlumberger Technology Corporation||Downhole drive shaft connection|
|US8869885 *||Aug 10, 2010||Oct 28, 2014||Baker Hughes Incorporated||Fluid metering tool with feedback arrangement and method|
|US20120037362 *||Aug 10, 2010||Feb 16, 2012||Baker Hughes Incorporated||Fluid metering tool with feedback arrangement and method|
|U.S. Classification||175/57, 175/389, 175/425|
|International Classification||E21B1/00, E21B7/24, E21B10/62, E21B10/40|
|Cooperative Classification||E21B10/38, Y10T408/9095, E21B4/14|
|European Classification||E21B4/14, E21B10/38|
|Jan 3, 2007||AS||Assignment|
Owner name: HALL, DAVID R., MR., UTAH
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:DAHLGREN, SCOTT, MR.;REEL/FRAME:018703/0760
Effective date: 20070103
|Oct 20, 2008||AS||Assignment|
Owner name: NOVADRILL, INC.,UTAH
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:HALL, DAVID R.;REEL/FRAME:021701/0758
Effective date: 20080806
|Mar 10, 2010||AS||Assignment|
Owner name: SCHLUMBERGER TECHNOLOGY CORPORATION,TEXAS
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:NOVADRILL, INC.;REEL/FRAME:024055/0378
Effective date: 20100121
Owner name: SCHLUMBERGER TECHNOLOGY CORPORATION, TEXAS
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:NOVADRILL, INC.;REEL/FRAME:024055/0378
Effective date: 20100121
|Nov 30, 2011||FPAY||Fee payment|
Year of fee payment: 4