Patent Application
20240328259
Embodiments of the present disclosure generally relate to earth-boring operations. In particular, embodiments of the present disclosure relate to earth-boring tool geometry and associated apparatus and methods.
Wellbore drilling operations may involve the use of an earth-boring tool at the end of a long string of pipe commonly referred to as a drill string. An earth-boring tool may be used for drilling through formations, such as rock, dirt, sand, tar, etc. In some cases, the earth-boring tool may be configured to drill through additional elements that may be present in a wellbore, such as cement, casings (e.g., a wellbore casing), discarded or lost equipment (e.g., fish, junk, etc.), packers, etc. In some cases, earth-boring tools may be configured to drill through plugs (e.g., fracturing plugs, bridge plugs, cement plugs, etc.). In some cases, the plugs may include slips or other types of anchors and the earth-boring tool may be configured to drill through the plug and any slip, anchor, and other component thereof.
Earth-boring tools may include cutting structures formed from abrasive materials having high hardness characteristics. The cutting structures may be configured to engage the formations and additional elements removing material therefrom. As the cutting structures engage the formations and additional elements, debris (e.g., chips, cuttings, loose material, etc.) and significant amounts of heat may be generated. If the debris and heat are not dissipated they may contribute to premature failure of the cutting structures requiring the earth-boring tool to be removed for repair and or replacement. This may result in significant losses of time reducing the efficiency and increasing the costs of a drilling operation.
Fixed blade drill bits include polycrystalline diamond compact (PDC) drill bits and other drag-type drill bits. These drill bits typically include a bit body having an externally threaded connection at one end for connection to a drill string, and a plurality of cutting blades extending from the opposite end of the bit body. The cutting blades form the cutting surface of the drill bit. A plurality of cutting elements, such as PDC cutters or other materials that are hard enough to deform and/or cut through earth formations, are attached to or inserted into the blades of the bit. These cutters extend from the bit and form the cutting profile of the bit. The cutting elements include polycrystalline diamond or cubic boron nitride, for example, which is formed on or bonded to a substrate, which is usually comprised of cemented tungsten carbide. The cutting elements are arranged in selected locations on the blades or other structures on the bit body with the diamond cutting elements facing generally in the direction of bit rotation. This plurality of cutting elements is used to cut through the subterranean formation during drilling operations when the drill bit is rotated by a downhole motor or a drilling rig at the surface. Fixed blade drill bits have the advantage of being much more aggressive during drilling and therefore usually drill much faster at equivalent weight-on-bit (WOB) levels than, for instance, a roller cone bit. In addition, they have no moving parts, which makes their design less complex and more robust. They also require more torque to rotate during drilling. During a drilling operation, fixed blade drill bits are rotated against a formation being drilled under applied weight-on-bit to remove formation material. The cutting elements on the fixed blade drill bits are continuously engaged as they scrape material from the formation, while in a roller cone drill bit, the cutting elements on each roller cone indent and crush the formation intermittently with little or no relative scraping motion between the cutting element and the formation.
Roller cone bits are earth boring drill bits that are known as a durable tool for drilling hard and abrasive formations. The roller cone type of drill bit typically includes a bit body with an externally threaded connection at one end, and a plurality of circumferentially spaced roller cones (typically three) attached at an offset angle to the longitudinal axis of the drill bit at the other end of the drill bit. These roller cones are rotatable about bearings, and rotate individually with respect to the bit body. The bit is secured to the lower end of a drill string that is rotated from the surface or by downhole motors or turbines. The roller cones mounted on the bit roll and slide upon the bottom and sides of the borehole as the drill string is rotated, engaging and disintegrating the formation material to be removed. The roller cones are provided with inserts mounted in pockets of the cone or teeth integral with the cone that are forced to penetrate and gouge the bottom of the borehole by rotation of the drill string in combination with weight from the drill string, commonly termed weight on bit (WOB). The cuttings from the bottom and sides of the borehole are washed away and disposed of by a drilling fluid. The drilling fluid is pumped down from the surface through the hollow, rotating drill string, and then through the nozzles (orifices) on the drill bit. Eventually, the cuttings are carried away in the drilling fluid to the surface up the exterior of the drill string in an annulus between the drill string and a wall of the borehole.
A relatively new type of drill bit has emerged in the drilling arena, and it is known as the “hybrid” drill bit. This drill bit combines both fixed cutting blades and rolling cones on its working face. The hybrid drill bit is designed to overcome some of the limiting characteristics of the roller cone and fixed cutter drill bits, such as balling, reducing drilling efficiency, tracking, and wearing. PDC fixed cutter bits have replaced roller cone bits in many applications. However, roller cone bits are uniquely situated for applications involving hard, abrasive, and interbedded formations, as well as for complex directional drilling applications and applications involving high torque requirements. In these applications, hybrid drill bits can substantially enhance the performance of a roller cone bit with fewer limitations compared to a conventional PDC bit.
Embodiments of the present disclosure may include an earth-boring tool. The earth-boring tool may include a tool body, at least one blade, and a roller cone pocket defined in the tool body adjacent the at least one blade, a surface of the roller cone pocket defining at least one protruding ridge. The earth-boring tool may also include a roller cone assembly disposed in the pocket, the roller cone assembly including a plurality of cutting elements extending from a surface of the roller cone assembly.
Another embodiment of the present disclosure may include a method of forming an earth-boring tool. The method may include forming a tool body comprising at least one blade and a pocket defined in the tool body adjacent to the at least one blade, a surface of the pocket defining at least one ridge, and disposing a roller cone assembly into the pocket, wherein the at least one ridge is positioned between at least two cutting elements from the roller cone assembly.
Another embodiment of the disclosure may include an earth-boring tool. The earth-boring tool may include a roller cone assembly configured to rotate relative to a tool body of the earth-boring tool about a longitudinal axis of the roller cone assembly. The earth-boring tool may also include one or more ridges extending from the tool body toward a surface of the roller cone assembly, the one or more ridges configured to break up debris or prevent debris from forming in a region between the roller cone assembly and the tool body.
While the specification concludes with claims particularly pointing out and distinctly claiming embodiments of the present disclosure, the advantages of embodiments of the disclosure may be more readily ascertained from the following description of embodiments of the disclosure when read in conjunction with the accompanying drawings in which:
The
“Hybrid” drill bits are designed to combine both fixed cutting blades and rolling cones on the working face to overcome some of the limiting characteristics of roller cone and fixed cutter drill bits, such as balling, reducing drilling efficiency, tracking, and wearing. However, in conventional hybrid drill bits, the roller cones may have a minimal amount of clearance (e.g., less than 0.100″) from the bit body due to spacing constraints or blade integrity concerns. Because of this, cuttings may accumulate at the tops of the roller cones or between rows of inserts or teeth carried on a surface of the roller cones. This problem is exacerbated by some conventional bit frames that make using water-based drilling fluids to clean the hybrid drill bits more difficult. For example, roller cones in particular may be susceptible to balling in certain types of shale/clay formations, resulting in reduced cutting effectiveness and a lower rate of penetration (ROP). Moreover, as cuttings ball on the roller cones, the cuttings may begin to be packed in areas of the bit body (e.g., areas of a roller cone pocket in which a roller cone assembly is carried) that may cause reduction in effective compact projection or may cause abrasion and damage to the bit body. Furthermore, higher density placement of inserts or teeth on the surface of the roller cones accentuates these tendencies.
Accordingly, to prevent balling and the problems caused thereby, some embodiments of the present disclosure include an earth-boring tool having both blades and rotatable structures (e.g., roller cones) and a surface of the earth-boring tool configured to reduce the accumulation of cuttings on the rotatable structures. In particular, the earth-boring tool may include a roller cone pocket configured to receive a roller cone where a surface of the roller cone pocket defines one or more protruding ridges that intermesh with one or more inserts or teeth carried on the roller cone. For example, the roller cone may include rings of inserts or teeth extending circumferentially around a surface of the roller cone and substantially perpendicular to an axis of rotation (e.g., a center longitudinal axis) of the roller cone where the one or more protruding ridges may extend such that a ridge of the one or more protruding ridges extends toward a surface of the roller cone between two adjacent rings of inserts or teeth of the roller cone. The one or more ridges may remove cuttings and other debris or prevent cuttings and debris from packing between two or more inserts or teeth of the roller cones as the cones rotate, preventing reduced bit performance by clearing of the debris as well as bit damage. By preventing bit damage, the working life of the bit body of the earth-boring tool may be increased and the bit body may require fewer expensive repairs throughout its lifespan. Additionally, the increased lifespan reduces the frequency of needing to replace the drill bit, saving additional cost over time.
The
The blades 102 may each include a face 110 and a shoulder region 112. The face 110 may be oriented to face the area ahead of the blade 102 in a direction of bit rotation and the shoulder region 112 may transition from the outer extent of the face 110 to the radially outer region of the blade 102. The blade 102 may include multiple cutter pockets 114 formed along an edge of the face 110 of the blade 102. The cutter pockets 114 may be configured to receive shear-type cutting elements, such as polycrystalline diamond compact (PDC) cutting elements. The cutting elements may be arranged such that cutting faces of the cutting elements face in the direction of bit rotation as the face 110 of the blade 102 and back raked from the plane of the face 110. The fluid flowing from the nozzles 108 may be configured to clear debris and formation materials away from the cutting elements and face 110 of the blade 102 into junk slots 106 as well as cooling the cutting elements.
The earth-boring tool 100 may also include one or more roller cone pockets 116 defined in the tool body of the earth-boring tool 100 between at least two of the blades 102. The roller cone pockets 116 may each be configured to receive one of the roller cone assemblies 104. Each of the roller cone assemblies 104 may be rotatably secured to an arm 118 extending from the earth-boring tool 100. Each of the arms 118 may be substantially aligned with an associated roller cone pocket 116. The arms 118 may position the roller cone assemblies 104, such that the roller cone assemblies 104 may rotate freely about a longitudinal axis 128 of the respective roller cone assemblies 104. The roller cone pocket 116 may have an inside diameter greater than an outer diameter of the associated roller cone assembly 104, such that the associated roller cone assembly 104 may rotate within the roller cone pocket 116 without contacting walls of the roller cone pocket 116.
The roller cone assemblies 104 may include elements in the form of inserts or teeth 120 extending from a surface 122 of the roller cone assemblies 104. The inserts or teeth 120 may be arranged in rings 126 about the respective roller cone assemblies 104, such that each insert or tooth 120 in a ring 126 is substantially a same distance from a face 124 of the associated roller cone assembly 104. Each of the rings 126 may be positioned a different distance from the face 124 of the associated roller cone assembly 104 along longitudinal axis 128 of arm 118 carrying the roller cone assembly 104. The inserts or teeth 120 may be configured to engage a formation when the earth-boring tool 100 is deployed. The inserts or teeth 120 may break material from the formation as the roller cone assemblies 104 rotate within the earth-boring tool 100. The cutting elements secured to the blades 102 may be configured to then remove the material broken away from the formation by the inserts or teeth 120 of the roller cone assemblies 104 as well as shear formation material not engaged by inserts or teeth 120 of the roller cone assembly rotationally preceding a respective blade 102. The formation materials may be cleared from the blades 102 by the fluid flowing from the nozzles 108 as described above. However, in some cases, portions of the formation material may be captured by the inserts or teeth 120 of the roller cone assemblies 104. The formation material may be trapped between the roller cone assemblies 104 and surfaces of the earth-boring tool 100 in the roller cone pocket 116, which may create excess friction between walls of the roller cone pocket 116 and the roller cone assembly 104. The excess friction may increase wear on the inserts or teeth 120 of the roller cone assembly 104 and/or may substantially prevent the roller cone assembly 104 from rotating relative to the earth-boring tool 100, which may reduce the benefits of the roller cone assembly 104 over the stationary cutting elements coupled to the blades 102. The increased wear and friction caused by the formation material trapped between the roller cone assemblies 104 and surfaces of the earth-boring tool 100 may also wear away the surfaces 122 of the roller cone assemblies 104. As the surfaces 122 of the roller cone assemblies 104 are worn away inserts or teeth 120 carried in pockets of a roller cone may loosen and/or fall out of the roller cone assembly 104. In some instances formation material trapped between roller cone assemblies 104 and surfaces of the earth-boring tool 100 in the roller cone pockets 116 may also reduce the effective exposure of the inserts or teeth 120. Reducing the effective exposure of the inserts or teeth 120 may reduce a potential rate of penetration of the earth-boring tool 100.
The roller cone pocket surface 208 may define ridges 202 that extend generally radially inward from the roller cone pocket surface 208. The ridges 202 may also extend at least partially across the roller cone pocket surface 208. For example, the ridges 202 may form one or more continuous ridges that extend across the roller cone pocket surface 208 at least substantially perpendicular to the longitudinal axis 128 of the roller cone assembly 104 when the roller cone assembly 104 is disposed within the roller cone pocket 116. The one or more ridges may be positioned or spaced on the side surface 206 in positions substantially offset from the rings 126 of the inserts or teeth 120 of the roller cone assembly 104, as described in further detail below in regard to
In some embodiments, the ridges 202 may include one or more interface cutting elements. For example, one or more cutting elements may be disposed along a crest of at least one of the ridges 202 and extend toward the surface 122 of the roller cone assembly 104 between or adjacent to the rings 126 of inserts or teeth 120 without contacting the surface 122 or the inserts or teeth 120 of the roller cone assembly 104.
In some embodiments, the face surface 204 may include one or more ridges that extend toward a face 124 of the roller cone assembly 104. For example, the face surface 204 may define one or more ridges that may be arranged at least partially circumferentially about the longitudinal axis 128 of the roller cone assembly 104 when the roller cone assembly 104 is disposed in the roller cone pocket 116. The face 124 of the roller cone assembly 104 may be substantially free of inserts or teeth 120 such that the face 124 of the roller cone assembly 104 may be substantially planar.
Furthermore, the profile of each of the ridges 202 may vary as the ridges 202 extend across the roller cone pocket surface 208. For example, the ridges 202 may vary in height (e.g., the distance from a plane defined by the roller cone pocket surface 208 at the base of the ridges 202), width, crest position (e.g., the crest of a profile of a ridge 202 relative to a longitudinal axis of the profile of the ridge 202), slope (e.g., across a surface of a ridge of the ridges 202), or cross-sectional profile shape as the ridges 202 extend across the roller cone pocket surface 208. The ridges 202 may extend from a leading edge 302 of the roller cone pocket 116, across the roller cone pocket surface 208, as shown in
The ridges 202 may be arranged such that there is a longitudinal space 306 between adjacent ridges 202, as illustrated in
The arrangement of the longitudinal spaces 306 and the gaps 304 may facilitate both the ridges 202 and the inserts or teeth 120 to pass into a plane of the opposing ridges 202 and inserts or teeth 120 without contacting the opposing ridges 202 and inserts or teeth 120. Debris caught in the inserts or teeth 120 may span the gap 304 between the inserts or teeth 120. Thus, as the roller cone assembly 104 rotates about the longitudinal axis 128, the debris spanning the gap 304 between the one or more inserts or teeth 120 may contact one or more of the ridges 202 positioned within the gaps 304 (e.g., at leading edge 302) such that the debris may be broken up through the interface between the ridges 202 and the inserts or teeth 120. For example, the ridges 202 and rotating inserts or teeth 120 may combine to form a scissor-like engagement (e.g., at leading edge 302) that may break up the debris caught in the inserts or teeth 120 of the roller cone assembly 104. Moreover, as the ridges 202 extend across the roller cone pocket surface 208 and extend into the gap 304, the ridges 202 may prevent debris from forming in the gap 304 as debris enters into the space between the roller cone assembly 104 and the roller cone pocket surface 208 during operation of the earth-boring tool 100.
In some embodiments, the roller cone pocket surface 208 may define more than one ridge extending toward surface 122 of the roller cone assembly 104 between two of the inserts or teeth 120. As a specific non-limiting example, the roller cone pocket surface 208 may define two ridges that extend toward surface 122 of the roller cone assembly 104 at a position that coincides with a gap (e.g., gap 304) between two rings (e.g., rings 126 of
In some embodiments, the ridges 202 may be formed with a body of the earth-boring tool 100. For example, the ridges 202 may be machined into a pre-formed bit body. For example, a roller cone pocket surface of a preformed bit body may be machined (e.g., have material taken away through various machining processes) into a bit body to define the ridges 202. Furthermore, after the body of the earth-boring tool 100 has been formed, a roller cone assembly 104 may be disposed into a roller cone pocket 116 defined by the body such that a first ring of the inserts or teeth 120 comprising a first formation engaging structure of at least two formation engaging structures is positioned on a first side of at least one ridge 202 and a second ring of inserts or teeth 120 comprising a second formation engaging structure of the at least two formation engaging structures is positioned on a second opposite side of the at least one ridge. When the roller cone assembly 104 is disposed within a roller cone pocket 116 of the body, the roller cone assembly may be rotatably coupled to an arm extending into the pocket.
The ridges 202 may define one or more gaps (e.g., gaps 402) along a length of the ridges 202, as illustrated in
The arrangement of the gaps 402 along the length of the ridges 202 may facilitate the flow of debris through the area between the roller cone assembly 104 and the roller cone pocket surface 208. For example, in operation as the roller cone assembly 104 rotates about longitudinal axis 128, debris (e.g., cuttings from rock formations) may enter into the area between the roller cone assembly 104 and the roller cone pocket surface 208. The gaps 402 may allow the debris to flow such that the debris is eventually expelled from the area between the roller cone assembly 104 and the roller cone pocket surface 208, which may aid in preventing balling of the debris onto the roller cone assembly 104. Furthermore, the sides of the ridges 202 defining the gaps 402 may provide additional edges along the roller cone pocket surface 208 to combine with the rotating inserts or teeth 120 to form additional scissor-like engagements between the ridges 202 and the inserts or teeth 120 that may break up debris caught in the inserts or teeth 120 of the roller cone assembly 104.
The gaps 402 may be formed at the same time as the ridges 202. For example, as the roller cone pocket 116 is machined into the body of the earth-boring tool 100, the ridges 202 may be formed on a roller cone pocket surface. The ridges 202 may then be machined (e.g., milled) to define one or more of the gaps 402.
Additionally, one or more cutting elements (e.g., cutting element 502) may be embedded or positioned along a length of the ridges 202, as illustrated in
The cutting element 502 may be positioned or spaced along a ridge 202 such that the cutting element 502 positioning is substantially offset from the rings 126 of the inserts or teeth 120 of the roller cone assembly 104. Furthermore, the cutting element 502 may be positioned such that a face of the cutting element 502 generally opposes a direction of rotation of the roller cone assembly 104. Though shown at a particular angle, the cutting element 502 may be positioned at any angle relative to the roller cone pocket surface 208 or a ridge 202 so long as the cutting element 502 is able to engage with cuttings or debris during operation of the earth-boring tool 100.
The cutting element 502 may be disposed within a cutting element pocket 504 defined along a length of a ridge 202 and within the roller cone pocket surface 208. In some embodiments, the cutting element pocket 504 may be formed at the same time as the ridges 202. Furthermore, the cutting element pocket 504 may be machined (e.g., milled) into a ridge 202 and into the roller cone pocket surface 208. In some embodiments the cutting element pocket 504 may extend into the roller cone pocket surface 208 such that the cutting element pocket 504 extends through a plane defined by the roller cone pocket surface 208. In other embodiments the cutting element pocket may be defined in a ridge 202 such that the cutting element pocket 504 does not extend into a plane defined by the roller cone pocket surface 208.
In some embodiments the roller cone assembly 104 may include one or more sensors configured to detect the torque experienced by the roller cone assembly 104. When the detected torque of the roller cone assembly 104 surpasses a predetermined threshold, the earth-boring tool may be configured to cause an alert to be generated and sent to an operator that may indicate that the earth-boring tool 100 should be pulled out of the hole to prevent damage or loss of equipment.
As used herein, the term “earth-boring tool” means and includes any type of bit or tool used for drilling during the formation or enlargement of a wellbore in a subterranean formation. For example, earth-boring tools include fixed-cutter bits, roller cone bits, percussion bits, core bits, eccentric bits, bi-center bits, reamers, mills, drag bits, hybrid bits (e.g., rolling components in combination with fixed cutting elements), and other drilling bits and tools known in the art.
As used herein, the term “roller cone” means and includes a rotatable formation engaging structure mounted to an earth-boring tool and carrying inserts or teeth for gouging and crushing subterranean formation material, without regard to the specific shape of the rotatable formation engaging structure.
As used herein, the term “substantially” in reference to a given parameter means and includes to a degree that one skilled in the art would understand that the given parameter, property, or condition is met with a small degree of variance, such as within acceptable manufacturing tolerances. For example, a parameter that is substantially met may be at least about 90% met, at least about 95% met, at least about 99% met, or even at least about 100% met.
As used herein, relational terms, such as “first,” “second,” “top,” “bottom,” etc., are generally used for clarity and convenience in understanding the disclosure and accompanying drawings and do not connote or depend on any specific preference, orientation, or order, except where the context clearly indicates otherwise.
As used herein, terms such as ahead and behind are used in reference to a direction of movement of the associated element. For example, as a drill string moves into a borehole the bottom of the borehole is ahead of the elements of the drill string and the surface is behind the elements of the drill string. In another example, in relation to a cutting element on a rotating earth-boring tool a portion of the formation that has not yet been contacted by the cutting element is ahead of the cutting element whereas a portion of the formation that has already been contacted by the cutting element is behind the cutting element.
As used herein, the term “and/or” means and includes any and all combinations of one or more of the associated listed items.
While the present disclosure has been described herein with respect to certain illustrated examples, those of ordinary skill in the art will recognize and appreciate that the present invention is not so limited. Rather, many additions, deletions, and modifications to the illustrated and described examples may be made without departing from the scope of the invention as hereinafter claimed along with their legal equivalents. In addition, features from one example may be combined with features of another example while still being encompassed within the scope of the invention as contemplated by the inventor.
