The present disclosure relates generally to superhard cutting elements having a rotating cutting layer and downhole tools, such as bits, containing these elements.
Various types of tools are used to form wellbores in subterranean formations for recovering hydrocarbons such as oil and gas lying beneath the surface. Examples of such tools include rotary drill bits, hole openers, reamers, and coring bits. Rotary drill bits include fixed cutter drill bits, such as polycrystalline diamond (PCD) bits. A drill bit may be used to drill through various levels or types of geological formations. However, as the formation changes, for example, from lower compressive strength to higher compressive strength, a different configuration of cutting layer may be more efficient and/or effective.
A more complete understanding of the present disclosure and its features and advantages thereof may be acquired by referring to the following description, taken in conjunction with the accompanying drawings, in which like reference numbers indicate like features, and wherein:
The present disclosure relates to cutting elements having a cutting layer bordered by a cutting face. The cutting layer is formed from a superhard material, such as a polycrystalline diamond (PCD) or cubic boron nitride. The cutting layer is attached to a rotating substrate portion, which is able to move with respect to a stable substrate portion. The stable substrate portion may be fixed to a downhole tool, such as a fixed cutter drill bit. For example, the cutting layers may be configured to rotate during drilling operations. Rotation of the cutting layers with respect to the stable substrate portion may occur based on a characteristic of the formation being cut, the wear of the cutting layer, or any other suitable criteria for modifying the cutting edge of the cutting layer. For example, when rotation is based on the wear of the cutting edge, the cutting layer rotates such that an unworn cutting edge begins cutting the formation.
In some embodiments, rotating the cutting layer may allow the cutting layer and associated cutting element to have an increased useful life and less cutting element replacement may be necessary. The cutting layer may be configured to rotate and cease rotation or otherwise restrain the cutting layer from rotating by various mechanisms and may be secured within a cutting element by various methods.
Further, based on a characteristic of the formation, a cutting edge with a particular set of characteristics may be a more effective and/or efficient cutting edge. For example, the cutting layer may have multiple backrake angles, bevels, chamfers, slopes, materials, or other properties may be based on the characteristics of the formation to be cut. Embodiments of the present disclosure and its advantages may be further understood by referring to
Cutting elements of the present disclosure may also be used in a drilling system, such as drilling system 100 in
Drilling system 100 may include drill string 103 associated with drill bit 101 that may be used to form a wide variety of wellbores or bore holes and that may include cutting elements of the present disclosure. Bottom hole assembly (BHA) 120 may be formed from a wide variety of components configured to form a wellbore 114. For example, components 122a, 122b and 122c of BHA 120 may include, but are not limited to, drill bits (e.g., drill bit 101) drill collars, rotary steering tools, directional drilling tools, downhole drilling motors, drilling parameter sensors for weight, torque, bend and bend direction measurements of the drill string and other vibration and rotational related sensors, hole enlargers such as reamers, under reamers or hole openers, stabilizers, measurement while drilling (MWD) components containing wellbore survey equipment, logging while drilling (LWD) sensors for measuring formation parameters, short-hop and long haul telemetry systems used for communication, and/or any other suitable downhole equipment. The number of components such as drill collars and different types of components 122 included in BHA 120 may depend upon anticipated downhole drilling conditions and the type of wellbore that will be formed by drill string 103 and rotary drill bit 101. BHA 120 may also include various types of well logging tools (not expressly shown) and other downhole tools associated with directional drilling of a wellbore. Examples of such logging tools and/or directional drilling tools may include, but are not limited to, acoustic, neutron, gamma ray, density, photoelectric, nuclear magnetic resonance, rotary steering tools and/or any other commercially available well tool. Drill bit 101 may be designed and formed in accordance with teachings of the present disclosure and may have many different designs, configurations, and/or dimensions according to the particular application of drill bit 101.
Cutting elements of the present disclosure may be used in a downhole tool, such as a fixed cutter drill bit.
Drill bit 101 may include one or more blades 202 (e.g., blades 202a-202g) that may be disposed outwardly from exterior portions of rotary bit body 204 of drill bit 101. Rotary bit body 204 may be generally cylindrical and blades 202 may be any suitable type of projections extending outwardly from rotary bit body 204. For example, a portion of blade 202 may be directly or indirectly coupled to an exterior portion of bit body 204, while another portion of blade 202 may be projected away from the exterior portion of bit body 204. Blades 202 formed in accordance with teachings of the present disclosure may have a wide variety of configurations including, but not limited to, substantially arched, helical, spiraling, tapered, converging, diverging, symmetrical, and/or asymmetrical.
Blades 202 and drill bit 101 may rotate about bit axis 208 in a direction defined by directional arrow 214. Blades 202 may include one or more cutting elements 206 disposed outwardly from exterior portions of each blade 202. For example, a base portion of cutting element 206 may be directly or indirectly coupled to an exterior portion of blade 202 while the cutting layer of cutting element 206 may be projected away from the exterior portion of blade 202. Cutting elements 206 may be any suitable device configured to cut into a formation, including but not limited to, primary cutting elements, backup cutting elements, secondary cutting elements or any combination thereof. By way of example and not limitation, cutting elements 206 may be various types of cutters, compacts, buttons, inserts, and gage cutters satisfactory for use with a wide variety of drill bits 101.
Cutting elements 206 may be retained in recesses or cutter pockets 240 located on blades 202 of drill bit 101. A brazing material, welding material, soldering material, adhesive, or other attachment material may be placed between substrates 230, particularly stable substrate portion 230b, and cutter pockets 240. Cutting element 206 may also be removed from cutter pocket 240 by re-heating the brazing material, then physically dislocating cutting element 206. A new cutting element 206 may then be inserted into cutter pockets 240 and attached via a braze joint. Cutting elements 206 may also be coupled to a blade, such as blade 202 of drill bit 101, by use of another securing mechanism. However, in some embodiments, cutting elements 206 may be coupled to any other component of drill bit 101, such as the top of blade 202 or as a back-up cutting element.
At least one cutting element 206 is a cutting element according to the present disclosure. In some embodiments, all cutting elements may be a cutting element according to the present disclosure. In some embodiments, at least one or all non-gage cutting elements may be a cutting element according to the present disclosure. According to another embodiment, at least one or all gage cutting elements may be a cutting element according to the present disclosure.
Uphole end 220 of drill bit 101 may include shank 222 with drill pipe threads 224 formed thereon. Threads 224 may be used to releasably engage drill bit 101 with a bottom hole assembly whereby drill bit 101 may be rotated relative to bit axis 208.
Cutting elements 206 may include cutting layer 232 disposed on one end of substrate 230. Cutting layer 232 includes a cutting face that engages adjacent portions of a downhole formation to form a wellbore when used on a drill bit, or performs a similar function on other downhole tools. Cutting layer 232 may include cutting face 234 and cutting edge 236. Contact of cutting face 234 and optionally also cutting edge 236 with the formation may form a cutting zone associated with each cutting element 206. Cutting layer 232 may have a flat or planar cutting face 234, but may also have a curved cutting face 234. In some embodiments, cutting face 234 may have multiple cutting surfaces and/or cutting edges with a variety of different properties, such as, hardnesses, configurations, and/or impact resistance or other properties based on material used, such as diamond grain size, and treatment, such as leaching.
Substrate 230 contains a rotating substrate portion on which cutting layer 232 is disposed, and stable substrate portion, which may be attached to a downhole tool. Substrate 230 may have various configurations and may be formed from tungsten carbide or other suitable materials associated with forming cutting elements for rotary drill bits. Tungsten carbides may include, but are not limited to, monotungsten carbide (WC), ditungsten carbide (W2C), macrocrystalline tungsten carbide and cemented or sintered tungsten carbide. Substrate 230 may also be formed using other hard materials, which may include various metal alloys and cements such as metal borides, metal carbides, metal oxides and metal nitrides. Additionally, various binding metals may be included in the substrate 230, such as cobalt, nickel, iron, metal alloys, or mixtures thereof. For some applications, cutting layer 232 may be formed from substantially the same materials as the substrate. In other applications, cutting layer 232 may be formed from different materials than the substrate.
Examples of materials used to form cutting layer 232 may include PCD, including synthetic polycrystalline diamonds, thermally stable polycrystalline diamond (TSP), and other suitable materials. In some embodiments, to form cutting layer 232, a rotating substrate portion may be placed proximate to a layer of ultra-hard material particles, e.g., diamond particles, and subjected to high temperature and pressure to result in recrystallization and formation of a polycrystalline material layer, e.g. PCD layer. Cutting layer 232 and rotating substrate portion may be formed as two distinct components of the cutting element 206, or cutting layer 232 and a rotating substrate portion may alternatively be integrally formed. In some embodiments, cutting layer 232 may include different configurations of cutting edges and/or cutting surfaces. The properties of cutting edges and cutting surfaces of cutting layer 232 may be based on a characteristic of the formation to be cut by the drill bit. Further, cutting layer 232 may have sections (e.g., cutting edges and/or cutting surfaces) with a variety of different properties, such as, hardnesses, configurations, and/or impact resistance or other properties based on material used, such as diamond grain size, and treatment, such as leaching. Although shown in
In some embodiments, cutting layer 232 may be able to cut different formations due to different properties of different sections of cutting layer 232. As cutting layer 232 contacts a formation, shearing of the formation may cause the cutting layer to rotate with respect to a stable substrate portion. Rotation of cutting layer 232 may allow different sections (e.g., cutting edges or cutting surfaces) of cutting layer 232 to contact the formation. As such, once one section of cutting layer 232 becomes worn, the cutting layer may rotate with respect to a stable substrate portion so that a different section of cutting layer contacts the formation. Cutting layer 232 and cutting element 206 may thus have a longer effective life and increase the efficiency of drilling operations.
Cutting layer 302 may be disposed on one end of rotating substrate portion 304a. Cutting layer 302 may be similar to cutting layer 232 discussed with reference to
Returning to
In some embodiments, retainer 316 may include one or more pins or a mechanical interlocking device that rotatably secures rotating substrate portion 304a within recess 310. Moreover, multiple retention mechanisms or retainers 316 may be used. Retainer 316 may be made of any material capable of withstanding compressive forces acting while the cutting assembly 306 engages the formation. In some embodiments, for example, retainer 316 may be made of steel, a steel alloy, carbide (e.g., tungsten carbide, silicon carbide, etc.), or any other suitable material. Once inserted, retainer 316 may prevent disengagement of rotating substrate portion 304a from stable substrate portion 304b.
Restraining mechanism 340 may include one or more shear pins 312 located within recess 310 of stable substrate portion 304b. In some embodiments, shear pin 312 may be made of metal or metal alloy, such as steel or brass. Shear pin 312 may extend into groove or cavity 324 within recess 310. Shear pin 312 may also extend into groove or cavity 326 within rotating substrate portion 304a that is sized to accommodate shear pin 312. When seated in groove 324, shear pin 316 may substantially prevent rotating substrate portion 304a and cutting assembly 306 from rotating around axis 318 until a predefined force is exerted on shear pin 316. During operation, a force may be applied to cutting assembly 306 based on contact of cutting layer 302 with the formation. The force, once it increases to a predefined force, may cause shear pin 312 to shear, thereby permitting cutting assembly 306 to rotate with respect to stable substrate portion 304b. Cutting assembly 306 may rotate with respect to stable substrate portion 304b until groove 326 reaches an additional shear pin (not expressly shown), stop in the mating surface, or locking mechanism, such as locking pin 314, at which point the additional shear pin or locking mechanism may extend into groove 326 and substantially prevent cutting assembly 306 from further rotation with respect to stable substrate portion 304b at least temporarily.
As example, locking pin 314 may include a spring-loaded plunger that, when engaged, extends through and couples rotating substrate portion 304a and stable substrate portion 304b. Locking pin 314 may be coupled to or formed as part of cavity 310. For example, locking pin 314 may be configured in recess or groove 328 of stable substrate portion 304b. When locking pin 314 is engaged with rotating substrate portion 304a, rotating substrate portion 304a may be prevented from rotational movement with respect to stable substrate portion 304b.
In some embodiments, locking pin 314 may be configured and located relative to one or more shear pins 312 to allow rotating substrate portion 304a to rotate a defined number of degrees with respect to stable substrate portion 304b. For example, locking pin 314 may be located such that when shear pin 312 shears, rotating substrate portion 304a rotates approximately ninety degrees around axis 318. Although discussed with reference to a rotation of approximately ninety degrees, the amount of rotation may range from approximately ten degrees to approximately 180 degrees depending on the characteristics of the formation to be cut or other parameters.
In some embodiments, as noted, rotating cutting element 300 may include additional shear pins 312 that engage in place of locking pin 314, such that the additional shear pins 312 may shear at different predefined forces. For example,
In some embodiments, other restraining mechanisms 340 may be utilized to restrain rotating substrate portion 304a and cutting layer 302 from rotating around axis 318, at least temporarily. For example, a plug (not expressly shown) may be utilized as a temporary block to keep rotating substrate portion 304a from rotating with respect to stable substrate portion 304b. The plug may be formed from a degradable or dissolvable (collectively referred to as dissolvable) material such as polylactic acid (PLA); a pliable water, oil, or gas soluble resin; or any other suitable dissolvable material. Rotating cutting element 300 may be configured to have a fluid flow proximate to the plug and dissolve the plug. When the plug is dissolved, rotating substrate portion 304a may rotate a defined number of degrees with respect to stable substrate portion 304b until rotation is halted by use of a locking pin, an additional plug, or other suitable component. Additionally, any other types of stops in any of the mating surfaces may be employed to restrain rotating substrate portion 304a, at least temporarily.
Stable substrate section 410 of rotating cutting element 400 may have various configurations and may be formed of the same materials as rotating substrate section 404. Stable substrate section 410 may be secured, e.g., brazed, into a cutter pocket of a drill bit, such as cutter pocket 240 of drill bit 101 discussed with reference to
Rod 412 may couple stable substrate section 410 with rotating substrate section 404. In some embodiments, rod 412 may be made of metal or metal alloy, such as steel or brass. Rod 412 may extend into a groove or cavity within stable substrate section 410 and rotating substrate section 404. Further, actuator 408 may be configured in a cavity or recess of stable substrate section 410 or may be enclosed within stable substrate section 410.
Cutting layer 402 may be disposed on one end of rotating substrate section 404. Cutting layer 402 may be similar to cutting layer 232 discussed with reference to
A. A rotating cutting element that includes a substrate including a rotating portion and a stable portion. The stable portion has a cavity and is configured to be fixed to a blade of a drill bit. The rotating cutting element further includes a retainer that rotatably secures the rotating portion of the substrate in the cavity of the stable portion of the substrate. Additionally, the rotating cutting element includes a cutting layer on the rotating portion of the substrate. The cutting layer has a plurality of cutting surfaces, and one of the plurality of cutting surfaces has a property different from another one of the plurality of cutting surfaces. The cutting layer is configured to rotate with respect to the stable portion of the substrate and use one of the plurality of cutting surfaces based on a characteristic of a formation to be cut.
B. A drill bit includes a bit body and a blade on an exterior portion of the bit body. The drill bit further includes a rotating cutting element on the blade. The rotating cutting element includes a substrate including a rotating portion and a stable portion. The stable portion has a cavity and is configured to be fixed to the blade. The rotating cutting element further includes a retainer that rotatably secures the rotating portion of the substrate in the cavity of the stable portion of the substrate. Additionally, the rotating cutting element includes a cutting layer on the rotating portion of the substrate. The cutting layer has a plurality of cutting surfaces, and one of the plurality of cutting surfaces has a property different from another one of the plurality of cutting surfaces. The cutting layer is configured to rotate with respect to the stable portion of the substrate and use one of the plurality of cutting surfaces based on a characteristic of a formation to be cut.
Each of embodiments, A and B may have one or more of the following additional elements in any combination: Element 1: wherein the property is a chamfer. Element 2: wherein the property is a backrake angle. Element 3: wherein the property is a cutting material. Element 4: wherein the property is a radius. Element 5: wherein the cutting layer has a cutting face that is non-circular. Element 6: further comprising a restraining mechanism configured in the cavity and retains the rotating portion in a position until a rotation event occurs. Element 7: wherein the restraining mechanism comprises a shear pin. Element 8: wherein the rotation event comprises sufficient force applied to the cutting layer to shear the shear pin. Element 9: further comprising a locking mechanism configured in the cavity, the locking mechanism configured to prevent further rotation of the rotating portion after the rotating portion has rotated a defined number of degrees. Element 11: wherein the locking mechanism comprises a locking pin. Element 12: wherein the defined number of degrees ranges from approximately ten to approximately 180 degrees. Element 13: further comprising a second restraining mechanism configured in the cavity and retains the rotating portion in a second position until a second rotation event occurs. Element 14: wherein the restraining mechanism comprises a dissolvable plug.
Although the present disclosure and its advantages have been described in detail, it should be understood that various changes, substitutions and alternations can be made herein without departing from the spirit and scope of the disclosure as defined by the following claims. It is intended that the present disclosure encompasses such changes and modifications as fall within the scope of the appended claims.
Filing Document | Filing Date | Country | Kind |
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PCT/US2015/012855 | 1/26/2015 | WO | 00 |