Polycrystalline diamond cutting element with improved cutting efficiency

Abstract

A cutting element may include a body, a concave cutting face formed at a first end of the body, the cutting face including one or more cutting ridges proximate a cutting tip, the cutting ridges protruding above the concave surface of the cutting face, and having a length of at least about 10% of the diameter of the cutting face. An edge is formed around a periphery of the cutting face, and the edge has an edge angle defined between a tangent line of the cutting face and a cylindrical side surface of the body, the edge angle being acute at the cutting tip and varying around the periphery of the cutting face.

Description

[0001] This application claims priority to and the benefit of U.S. Provisional Patent Application No. 62 / 893,831, filed on August 30, 2019, the entire contents of which are incorporated herein by reference. Background Art

[0002] Fixed cutter drill bits are widely used in the oil and mining industries for drilling boreholes through earth formations. The drill bit typically includes a drill bit body having a threaded connection at a first end for attachment to a drill string and a cutting structure formed at an opposite end for drilling through the earth formation. The cutting structure typically includes a plurality of blades extending radially outward from the longitudinal axis of the drill bit body. The superhard compact cutters are typically mounted in sockets formed in the blades and secured thereto by a press fit or brazing. Fluid ports may be located in the drill bit body to distribute fluid around the cutting structure of the drill bit and to flush formation cuttings away from the cutters and the bottom of the borehole during drilling.

[0003] The cutter used to fix the cutter bit generally includes a superhard composite piece, which includes a superhard material layer bonded to a lower hardness material substrate by a high pressure / high temperature (HP / HT) sintering process, a brazing process, a mechanical locking or other means known in the art. For example, a cutter can be formed having a substrate or support post made of a carbide (e.g., tungsten carbide) and a superhard cutting surface layer or table made of polycrystalline diamond or polycrystalline boron nitride material, which is deposited at the interface surface or otherwise bonded to the substrate. The cutter is generally cylindrical with a circular cross-section. Summary of the invention

[0004] This Summary is provided to introduce some concepts that are further described below in the Detailed Description. This Summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used to help limit the scope of the claimed subject matter.

[0005] Embodiments disclosed herein relate to a cutting element comprising a body, a concave cutting face formed at a first end of the body, the cutting face comprising one or more cutting ridges adjacent a cutting tip, the cutting ridges protruding above the concave surface of the cutting face, the length of the cutting ridges being at least about 10% of the diameter of the cutting face, and a blade formed around a periphery of the cutting face, the blade having a blade angle defined between a tangent line of the cutting face and a cylindrical side surface of the body, the blade angle being acute at the cutting tip and varying around the periphery of the cutting face.

[0006] Embodiments disclosed herein relate to a cutting element comprising a body, a concave cutting face formed at a first end of the body, the cutting face comprising one or more cutting ridges protruding above the concave surface of the cutting face. A blade surrounds the periphery of the cutting face, the blade having a blade angle defined between a tangent line of the cutting face and a cylindrical side surface of the body, the blade angle being acute at a cutting tip and varying around the periphery of the cutting face. The cutting face comprises a central dome protruding above the concave surface and at a distance from the cutting tip.

[0007] Embodiments disclosed herein relate to a cutting tool comprising a tool body and at least one cutting element attached to the tool body. The cutting element comprises a body, a concave cutting face formed at a first end of the body, the cutting face comprising one or more cutting ridges protruding above the concave surface of the cutting face and having a length of at least about 10% of the diameter of the cutting face. A blade surrounds the periphery of the cutting face, the blade having a blade angle defined between a tangent line of the cutting face and a cylindrical side surface of the body, the blade angle being acute at a cutting tip and varying around the periphery of the cutting face.

[0008] Embodiments disclosed herein relate to a cutting tool comprising a tool body and at least one cutting element attached to the tool body. The cutting element comprises a body, a concave cutting face formed at a first end of the body, the cutting face comprising one or more cutting ridges protruding above the concave surface of the cutting face. A blade surrounds the periphery of the cutting face, the blade having a blade angle defined between a tangent line of the cutting face and a cylindrical side surface of the body, the blade angle being acute at the cutting tip and varying around the periphery of the cutting face. The cutting face comprises a central dome protruding above the concave surface at a distance from the cutting tip.

[0009] Other aspects and advantages of the claimed subject matter will become apparent from the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figures 1A-1C 1 and 2 are perspective, top and cross-sectional views, respectively, of a cutting element according to one or more embodiments of the present disclosure.

[0011] Figure 2A -D is a perspective view of a cutting element according to one or more embodiments of the present disclosure.

[0012] Figure 3 is a cross-sectional view of a cutting element according to one or more embodiments of the present disclosure.

[0013] Figure 4 is a cross-sectional view of a cutting element according to one or more embodiments of the present disclosure.

[0014] Figure 5 is a cross-sectional view of a cutting element according to one or more embodiments of the present disclosure.

[0015] Fig. 6A -B is a cross-sectional view of a cutting element according to one or more embodiments of the present disclosure.

[0016] Fig. 7A and 7B is a schematic diagram of a cutting mechanism of a cutting element according to one or more embodiments of the present disclosure.

[0017] Fig. 8A -C is a perspective view and various cross-sectional views of a cutting element according to one or more embodiments of the present disclosure.

[0018] Fig. 9A -F is a view of a cutting element according to one or more embodiments of the present disclosure.

[0019] Fig.10 A drill bit according to one or more embodiments of the present disclosure is shown.

[0020] Fig.11A and 11B sectional views of different orientations of a cutting element within a cutter pocket according to one or more embodiments of the present disclosure.

[0021] Fig.12 A hole opener according to one or more embodiments of the present disclosure is shown.

[0022] Fig.13A -B is a side view of a cutting element according to one or more embodiments of the present disclosure.

[0023] Fig.14 is a view of a cutting element according to one or more embodiments of the present disclosure. DETAILED DESCRIPTION

[0024] Embodiments disclosed herein generally relate to cutting elements having a concave cutting surface that allows for a larger positive rake angle than conventional cutters, thereby providing higher cutting efficiency. Specifically, a cutting element according to one or more embodiments of the present disclosure may include a concave cutting surface that includes one or more cutting ridges raised above the concave surface of the cutting surface. The one or more cutting ridges may be disposed near the cutting tip. As described herein, the cutting surface may have a blade formed around its periphery, the blade having a blade angle defined by a tangent to the cutting surface and a cylindrical side surface of the body. The blade angle may be an acute angle at the cutting tip and vary around the periphery of the cutting surface.

[0025] Figure 1A-C is a perspective view and a cross-sectional view of a cutting element according to one or more embodiments of the present disclosure. The cutting element 100 includes a body 110 and a cutting face 120 formed at a first end of the body 110. In some embodiments, the body may include a cutting layer on a substrate 102, wherein the cutting face 120 is formed on a face of the cutting layer opposite to an interface with the substrate 102. The cutting face 120 may be concave (e.g., substantially concave), which is intended to reflect the overall curvature of the face, particularly across the diameter of the cutting face. For example, as shown, the cutting face is not axisymmetric, but has two external raised areas 122 (forming the peak height of the cutting tip of the cutting face and the cutting element), which are spaced apart from the cutting face 120 and are located on opposite sides of the cutting face 120, so that the cutting face has a reduced height that moves radially inward toward the center. For clarity, as used herein, a concave cutting face includes a substantially concave cutting face, such as the cutting face described herein, wherein the cutting face also includes discrete convex areas. Specifically, as shown, the concave (e.g., substantially concave) cutting face 120 has one or more cutting ridges 124 proximate to the raised region 122 (and cutting tip) that protrude above the concave surface of the cutting face 120. The surface geometry of the cutting face 120 may be about Figure 1C The plane symmetry of the cross-section in the figure can also be symmetric about the plane perpendicular to the cross-section plane. For clarity, Figure 1C The cutting ridges 124 are not shown.

[0026] The cutting element according to the present disclosure generally includes at least one cutting ridge 124 on the cutting face 120. The cutting ridge is raised from the cutting face so that, for example, when the cutting face is concave, the ridge is raised above the concave surface of the cutting face (e.g., above the generally concave surface). The cutting ridge 124 of one or more embodiments of the present disclosure includes two side portions 127 joined together at a top line 129. The top line of the cutting ridge extends along the length of the ridge and is disposed at the interface of the two side portions. Relative to the cutting face (i.e., along the z-axis), the top line of the cutting ridge can be concave, convex, serrated, or planar along its length. In a view perpendicular to the length, the top line of some embodiments can be curved and, in a particular embodiment, have a radius from a lower limit of any one of 0.030, 0.040, or 0.050 inches to an upper limit of any one of 0.100, 0.125, or 0.150 inches, wherein any lower limit can be used in combination with any upper limit. In some embodiments, the thickness of the cutting ridges can vary along their length and can transition from thin to thick or from thick to thin in a radial direction from the center of the cutting face. The cutting ridges of one or more embodiments can have an inclusive angle ranging from a lower limit of any one of about 60, 70, 80, 90, 100, or 125 degrees to an upper limit of any one of about 155, 160, 165, or 170 degrees, wherein any lower limit can be used in combination with any upper limit.

[0027] The cutting ridges may have any length suitable for the intended function of the cutting element. In some embodiments, the length of the cutting ridges may be measured as a percentage of the diameter of the cutting face. For example, in one or more embodiments, the length of the cutting ridges may be at least 5%, at least 10%, at least 20%, or at least 30% of the diameter of the cutting face. In embodiments where there is more than one cutting ridge, the ridges may all be the same length, or they may each have a different length. In some embodiments, a cutting ridge according to the present disclosure may have a textured surface, which may include, for example, ridges or corrugations.

[0028] exist Figure 1A and 1BIn one or more embodiments shown, the cutting face 120 has a twofold rotational symmetry (a second-order discrete rotational symmetry) around the longitudinal axis, wherein the geometric configuration of the cutting element is the same when the cutting face is rotated 180° around the longitudinal axis. In some embodiments, the cutting face can be asymmetric, having a first-order rotational symmetry (wherein the geometric configuration of the cutting element remains unchanged after rotating a full 360° around the longitudinal axis), for example, when the cutting face surface geometry includes a single external raised area formed along less than the entire periphery of the cutting face. In some embodiments, the cutting face can have a threefold rotational symmetry (wherein the geometric configuration of the cutting element is the same when the cutting face is rotated 120° around the longitudinal axis), for example, when the surface geometry of the cutting face includes three external raised areas formed along the periphery of the cutting face. In some embodiments, the cutting face can have a fourfold (or more) rotational symmetry. In one or more embodiments, the cutting face can include two or more cutting ridges that are substantially parallel to each other. In some embodiments, the two or more cutting ridges can be related by a mirror plane that intersects the center of the cutting face and is perpendicular to the plane of the cutting face. In some embodiments, the mirror plane can be perpendicular to the longest dimension of the two or more ridges. In other embodiments, the mirror surface may be parallel to the longest dimension of two or more ridges.

[0029] At the junction between the cutting face 120 and the side 112 of the cutting element 100, an edge 130 is formed around the periphery of the cutting face 120. In some embodiments, for example Figure 1C As shown, the blade 130 can include a chamfer or bevel 132 formed at the junction between the cutting face 120 and the side surface 112, while in other embodiments, at least a portion of the blade can be formed at the junction of the cutting face and the side surface without a chamfer or bevel. In addition, it should also be understood that the blade 130 can include multiple bevels, radii, or combinations thereof. Any bevel can be continuous, multifaceted, or discontinuous around the periphery of the cutter.

[0030] The shape of the blade 130 can be described in terms of its cross-sectional profile along a plane that intersects the blade and is perpendicular to the side surface at the blade. For example, the profile of the blade can include a curved transition between the cutting face and the side surface portion at the blade, a chamfer formed at the junction between the cutting face and the side surface portion at the blade, or an inclined transition between the cutting face and the side surface portion at the blade. In addition, the blade can have a blade angle defined between the cutting face and the side surface of the cutting element. For example, as Figure 1C As shown, a line tangent to the cutting face 120 at the edge 130 and a line tangent to the side surface 112 at the edge 130 intersect to define an edge angle 134. The edge angle 134 may vary around the perimeter of the cutting face 120. For example, Figure 1CThe portion of the edge 130 shown in the cross-sectional profile of FIG. 1 has an acute edge angle 134. Other portions of the edge 130 may have a right angle or an obtuse edge angle, such as along portions of the edge 130 that are not adjacent to the outer raised area 122.

[0031] A non-planar cutting face according to an embodiment of the present disclosure may include a wavy surface geometry in which relatively raised portions form both sides of the cutting element blade. In some embodiments, at least one raised portion may be formed between the outer raised portions at the blade and separated by relatively recessed portions. For example, a single central raised portion in the shape of a ridge may be spaced between the outer raised portions at the cutting element blade, or more than one ridge may be spaced between the outer raised portions of the cutting element blade, wherein each raised portion may be spaced from each other by relatively recessed portions. In some embodiments, a single central raised portion may be dome-shaped, i.e., the central raised portion does not extend through the entire diameter of the cutting element, but may be spaced a distance from the entire periphery. It is conceivable that a single central raised portion may be axisymmetric or not. In some embodiments, a single central raised portion may extend through the entire width or diameter of the cutter, although in other embodiments, a single central raised portion may extend along a portion of the width or diameter of the cutter. In embodiments where the raised portion extends across a portion of the width or diameter of the cutter, the raised portion may extend from the outer edge toward the center or axis of the cutting face, or may extend radially outward from the center of the cutting face toward the outer edge in a single direction or in each opposing direction.

[0032] Figure 1C One or more embodiments are depicted that feature a central dome 126. The central dome is raised from the cutting face, such that, for example, when the cutting face is concave, the central dome is raised above the concave surface of the face (e.g., above the overall concave surface). In some embodiments, the central dome can be disposed at a distance from one or more outer raised regions 122. The central dome can be disposed at a distance from the cutting tip.

[0033] In one or more embodiments, one or more cutting ridges may be long enough to intersect the central dome. When the dome intersects the cutting ridges, the cutting ridges may be set to be at most equal to the height of the dome. In some embodiments, this may more effectively lift and strip the formation.

[0034] Depending on the orientation of the cutting element in the cutting tool and the relative orientation between the tool and the formation engaged by the tool, some parts of the blade can be used as a cutting blade, which contacts and engages the formation. As used herein, the cutting tip is the first point of the cutting blade, which contacts the formation when the cutting depth increases from 0. In some embodiments, the cutting element can be located in a cutter recess formed on the cutting tool so that a portion of the blade with an acute angle forms a cutting blade. In some embodiments, the cutting element can be oriented in a cutter recess formed on the cutting tool so that the right angle or obtuse angle portion of the blade forms the cutting blade of the cutting element. In addition, in some embodiments, a cutting element with a non-planar surface geometry, such as disclosed herein, can be rotated in the cutter recess to change the blade angle portion as a cutting blade, thereby changing the effective back rake angle (or engagement angle). In some embodiments, a cutting element with a first surface geometry (e.g., a plane or non-planar surface geometry) can be replaced with a cutting element with a non-planar surface geometry as described herein to change the blade angle as a cutting blade, thereby changing the engagement angle of the cutting element.

[0035] As used herein, engagement angle refers to the angle measured between a tangent line to the portion of the cutting face that engages the formation and a line perpendicular to the engaged formation (or working surface). The portion of the cutting face that engages the formation can depend, for example, on the distance that the cutting element protrudes from the outermost surface of the cutting tool on which the cutting element is disposed (extended height) and the depth of cut of the cutting element. For cutting elements having a non-planar cutting face geometry at the cutting edge, such as disclosed herein, the engagement angle measured along the engagement region of the non-planar cutting face can vary along the depth of cut.

[0036] In one or more embodiments, a cutting ridge according to the present disclosure may be positioned proximate to a cutting edge. In some embodiments, one or more cutting ridges may be arranged substantially or substantially perpendicular to a tangent to the edge at the cutting tip. In some embodiments, one or more cutting ridges may be arranged radially on the cutting face. Figure 2A -D shows examples of different cutting elements according to one or more embodiments of the present disclosure. For example, Figure 2A -B shows a cutting element 200 having a concave (eg, substantially concave) cutting face with a single cutting ridge 224 extending across the entire diameter of the cutting face (as opposed to Figure 1A -C, which shows a cutting ridge extending less than the diameter). The side 227 of the cutting ridge 224 is as shown. Figure 2A -B shows the changes, Figure 2A The convex transition 240 between the side 229 and the concave surface 220 is shown. Figure 2B A concave transition portion 242 is shown. Figure 2A The top line 227 of the middle cutting ridge 224 is convex, and Figure 2B It is concave in the middle. Figure 2C -D shows another embodiment with multiple cutting ridges, as shown in the figure, each outer raised area has multiple cutting ridges 224 (with Figure 1A -C, which shows only one cutting ridge in each outer raised area). Similar to Figure 1A -C, Figure 2C The cutting ridge 224 in the embodiment does not extend the entire diameter (or chord) of the cutting face 220, but Figure 2D The cutting ridge 224 in the cutter extends the entire diameter and / or chord of the cutter face. Figure 2C In the case where the cutting ridge 224 does not extend the entire diameter of the cutting face, the central dome 226 may be more pronounced. Figure 2D The cutting ridges 224 in the cutting face 220 may be elevated above the concavity of the cutting face 220 (e.g., above the overall concavity), but may have a similar or substantially similar profile to the underlying cutting face 220. The outer ridges may be such that these are oriented radially, perpendicular to the cutting surface as shown, or any other orientation. These may also be curved rather than straight. The ridges may also be serrated.

[0037] Figure 3-5 Examples of three different cutting profiles for cutting elements at a given orientation are shown. As shown, although each cutting element is oriented at the same position, the different surface geometries of the engagement regions along the cutting face provide different engagement angles relative to the formation being engaged.

[0038] Figure 3 310 is a cross-sectional view of a cutting element 300 having a non-planar cutting face 320 formed at a first end of a body 310. The cutting element 300 may be in a cutter recess (not shown) and have a partial edge 330 having an acute edge angle forming a cutting edge 331. When the cutting element engages with and moves through a formation 350, an engagement region 321 of the cutting face 320 extends into the depth of cut of the formation 350. An engagement angle 360 ​​is defined between a line 355 perpendicular to the formation 350 being cut and a line 325 tangential to the engagement region 321 of the cutting face 320. In the illustrated embodiment, the engagement region 321 of the cutting face 320 has a concave cross-sectional profile, and therefore, the engagement angle 360 ​​varies along the depth of cut. In some embodiments, the cross-sectional profile of the engagement region of the non-planar cutting face may have a planar region, wherein the engagement angle is constant along the depth of cut of the planar region. However, in some embodiments, the engagement region has planar and non-planar regions, or may be entirely non-planar, wherein the engagement angle may vary along the depth of cut that engages the varying regions of the engagement region.

[0039] According to embodiments of the present disclosure, the engagement angle 360 ​​formed at the acute edge of the cutting element may be positive, for example, within a range having a lower limit, an upper limit, or both a lower limit and an upper limit, including 0°, 2°, 5°, 10°, 15°, 20°, 25°, 30°, 40°, 50°, or any value therebetween, wherein any relatively low value may be selected in combination with any relatively high value. If the engagement angles disclosed herein are considered as back rake angles of conventional cutting angles, a positive back rake angle may not be achievable at the values ​​described herein.

[0040] Additionally, in some embodiments of the present disclosure, the engagement angle 360 ​​that varies along the depth of cut may have a difference greater than 2°, for example, up to 5°, up to 10°, or greater. For example, the engagement angle formed along a joint region having a concave cross-sectional profile may have a difference in engagement angle along the depth of cut ranging from about 5° to about 15° or greater, depending on the radius of curvature of the concave cross-sectional profile.

[0041] Figure 4 is with Figure 3 430 and 431. A cross-sectional view of a cutting element 400 in a cutter recess with the cutting elements 300 in the same orientation (i.e., the angle between the longitudinal axis of the cutting element and a line perpendicular to the formation is the same), wherein the cutting element 400 is positioned in the cutter recess such that the right angled portion of the blade 430 forms a cutting edge 431 of the cutting element. When the cutting element engages with and moves through the formation 450, the engagement region 421 of the cutting face 420 extends into the depth of cut of the formation 450. The engagement angle 460 is defined between a line 455 perpendicular to the formation 450 being cut and a line 425 tangential to the engagement region 421 of the cutting face 420. In the illustrated embodiment, the cutting element 400 can have a non-planar cutting face 420 formed at a first end of the body 410, wherein the non-planar cutting face includes a linear ridge extending between opposite sides of the blade 430, and wherein the cross section is taken along the linear ridge. The linear ridge can have a planar cross-sectional profile forming a right angled edge angle. In some embodiments, other cutting face geometries may form a square edge angle, such as a planar cutting face.

[0042] According to an embodiment of the present disclosure, the engagement angle formed at the right edge angle portion of the cutting element can be a negative value, for example, having the following lower limit, upper limit, or both lower and upper limits, including any one of 0°, -2°, -5°, -10°, -15°, -20°, -25°, -30°, or any value therebetween, wherein any relatively low value can be selected in combination with any relatively high value. The engagement angle can be constant along the planar cross-sectional profile of the engagement region 421.

[0043] Figure 5 For Figure 3 and Figure 4500 in a cutter recess with the cutting elements 300, 400 in the same orientation, wherein the cutting element 500 is positioned in the cutter recess so that the blunt angled edge portion of the blade 530 forms the cutting edge 531 of the cutting element. The blunt angled edge portion of the blade 530 can be formed by a ridge extending between opposite sides of the blade 530, wherein the ridge has a convex profile extending outwardly from the bottom surface of the cutting element 500. In some embodiments, other cutting face geometries can form blunt angled edges, for example, planar surfaces extending upwardly and radially inwardly from the blade. When the cutting element engages with the formation 550 and moves through the formation 550, the engagement region 521 of the cutting face 520 extends into the cutting depth of the formation 550. The engagement angle 560 is defined between a line 555 perpendicular to the formation 550 being cut and a line 525 tangential to the engagement region 521 of the cutting face 520.

[0044] According to an embodiment of the present disclosure, the engagement angle formed at the obtuse edge angle portion of the cutting element may be a negative value, for example, within a range having the following lower limit, upper limit, or both upper and lower limits, including any one of -5°, -10°, -15°, -25°, -30°, -40°, -50°, or a value therebetween, wherein any relatively low value may be selected in combination with any relatively high value. The engagement angle may vary along the convex cross-sectional profile of the engagement region 521. In some embodiments, the engagement angle varying along the depth of cut may have a difference greater than 2°, for example, up to 5°, up to 10°, or greater. For example, depending on the radius of curvature of the convex cross-sectional profile, the engagement angle formed along the engagement region having a convex cross-sectional profile may have a range of engagement angle differences from about 5° to about 15° or greater along the depth of cut. In an embodiment with an obtuse edge angle, a planar surface forms a cross-sectional profile of the engagement region, and the engagement angle may be constant or vary along the depth of cut.

[0045] Figure 3-5 It is shown how a cutting element having a non-planar cutting face according to an embodiment of the present disclosure can be rotated and positioned within a cutter recess at a given orientation to change the engagement angle of the cutting element. Similarly, a cutting element having a first type of cutting face surface geometry (e.g., a planar cutting face or a non-planar cutting face) can be replaced by a cutting element having a non-planar cutting face according to an embodiment of the present disclosure to change the engagement angle.

[0046] Furthermore, according to embodiments of the present disclosure, the engagement angle formed by the non-planar cutting surface may vary according to the cutting depth. Fig. 6A and 6B Shows Figure 3 The cutting elements are shown cutting at different cutting depths. Due to the curved profile of the cutting face area that contacts the formation 350 being cut, Fig. 6AThe engagement angle 360 ​​at the formation surface in the relatively deep cutting depth shown is relatively smaller than that in Figure 6B The engagement angle 360 ​​at the formation surface in a relatively shallow depth of cut is shown.

[0047] A non-planar cutting face according to an embodiment of the present disclosure may include a wavy surface geometry in which relatively raised portions form two opposing sides of a cutting element blade. In some embodiments, at least one raised portion may be formed between outer raised portions at the blade and separated by relatively recessed portions. For example, a ridged single central raised portion (326) may be spaced between outer raised portions at the cutting element blade, or more than one ridge may be spaced between outer raised portions of the cutting element blade, wherein each raised portion may be spaced apart from each other by relatively recessed portions. In some embodiments, the single central raised portion may be dome-shaped, i.e., the central raised portion does not extend across the entire diameter of the cutting element, but may be spaced apart from the entire periphery by a distance. It is conceivable that the single central raised portion may or may not be axisymmetric. In some embodiments, the single central raised portion may extend across the entire width or diameter of the cutter, although in other embodiments, the single central raised portion may extend along a portion of the width or diameter of the cutter. In embodiments where the raised portion extends across a portion of the width or diameter of the cutter, the raised portion may extend from the outer edge toward the center or axis of the cutting face, or may extend radially outward from the center of the cutting face toward the outer edge in a single direction or in each opposing direction.

[0048] Fig. 7A and 7B Cutting with two different shear cutters is depicted. Fig. 7A A standard cutter 750 is shown that utilizes a known cutting element without a concave cutting surface or cutting ridges. Figure 7B Depicted is the improved cutting efficiency associated with the cutting element 700 of the present disclosure. One or more embodiments of the present disclosure provide greater positive rake angles and more efficient cutting, while the presence of the cutting ridges provides better shock load tolerance. In further embodiments, the cutting element provides better chip deflection and management than is known in the prior art.

[0049] The blade of the cutting element according to an embodiment of the present disclosure may have a bevel formed around the entire blade (e.g. Figures 8A-8CThe bevel shown in the middle blade 830), or the bevel / chamfer may be formed around less than the entire blade, such as along the high portion of the blade. In some embodiments, a curved transition surface can be formed at the junction of the cutting face and the side surface of the cutting element. The transition surface, such as a bevel, chamfer, or curved transition surface, can have a relatively small size compared to the size of the cutting element, and therefore can be ignored or nearly ignored when measuring the diameter of the cutting face and the height of the side surface of the cutting element. For example, the height of the bevel or curved transition surface can be less than 2%, or in some embodiments, less than 7%, of the total height of the cutting element, and can have a radial distance of less than 2%, or in some embodiments, less than 7%.

[0050] According to an embodiment of the present disclosure, the cutting element may include an inclined, slanted side surface extending radially outward from the base surface of the cutting element toward the cutting face of the cutting element. The entire side surface of the cutting element or less than the entire side surface may be inclined outward in a direction from the base surface toward the cutting face of the cutting element. Fig.13A The cutting layer side surface 214 is shown to be inclined or angled relative to the side surface of the substrate 212 . Fig. 13B The cutting layer side surface 214 is shown, which transitions from the side surface radius to the cutting surface 220. For example, as shown in FIG. Figures 8A-8C 816. As shown, a portion of the side surface 812 surrounding the cutting layer 814 can be inclined, while the entire side surface 812 surrounding the substrate 816 can be parallel to the longitudinal axis of the cutting element 800. The inclined portion of the side surface 812 surrounding the cutting layer 814 extends radially outward in a direction from the interface 815 to the high portion 832 of the blade 830. In other embodiments, the inclined portion can be inclined radially inward. The remaining portion of the side surface 812 extends parallel to the longitudinal axis of the cutting element, extending from the interface 815 to the base surface of the cutting element, and extending from the lower portion 834 of the blade 830 to the base surface of the cutting element.

[0051] exist Figures 8A-8C In the illustrated embodiment, the interface 815 is planar, wherein the thickness of the cutting layer 814 is greatest at the high portion 832 of the blade 830 and smallest along the recessed area 826 and the low portion 834 of the blade 830. In some embodiments, the interface between the substrate and the cutting layer can be non-planar. For example, the interface can have a non-planar geometry that corresponds in shape and orientation to the non-planar cutting face of the cutting element. In such an embodiment, the thickness of the cutting layer can be uniform along the entire cutting layer. In some embodiments, the interface can have a non-planar geometry that does not correspond in shape and / or orientation to the non-planar cutting face.

[0052] Still reference Figures 8A to 8B, two low portions 834 are located at the outer ends of the linear recessed area 826, wherein the linear recessed area 826 separates the two outer raised portions of the high portion 832 forming the blade 830. The linear recessed area 826 extends through the minor diameter 802 of the cutting face 820 and has a planar cross-sectional profile along a cross section taken through the minor diameter 802, wherein the planar portion of the cutting face 820 forms the right blade corner portion (see Figure 8C The cross-sectional profile of the cutting surface 820 taken through the major diameter 804 (see Figure 8B ) has a concave profile where the cutting face 820 extends downward from a high portion 832 toward a central region of the cutting face (linear recessed region 826) to a depth 840. The concave profile can have a radius of curvature that can range, for example, from two times the major diameter 804, up to four times the major diameter 804, up to six times the major diameter 804, or up to eight times the major diameter 804. In other embodiments, the concave profile can include linear segments that form a piecewise continuous profile.

[0053] In some embodiments, the side surface of the base material of the cutting element can extend substantially parallel to the longitudinal axis of the cutting element, and the side surface around the entire periphery of the cutting layer of the cutting element can be in a radially outward direction from the interface to the edge. In some embodiments, the entire side surface of the cutting element can extend radially outward from the base surface of the cutting element to the cutting face of the cutting element. In some embodiments, one or more portions of the side surface around the periphery of the cutting element can have an outwardly inclined profile from the base surface to the cutting face, while one or more other portions of the side surface can extend substantially parallel to the longitudinal axis from the base surface to the cutting face.

[0054] In some embodiments, the high portion at the end of the cutting element may include a planar, flat or right surface adjacent to the sharp edge portion. Figures 9A-9D Various views of a cutting element 900 are shown, according to some embodiments of the present disclosure. Fig. 9A is a perspective view of a cutting element 900, Fig. 9B and 9D is a side view of the cutting element 900, Fig. 9C yes Fig. 9B An enlarged view of the raised portion of the blade of cutting element 900. Fig.9E is a top view of cutting element 900 .

[0055] The cutting element 900 can have a body 910, a non-planar cutting face 920 (not shown for clarity) having two outer raised areas and one or more cutting ridges disposed thereon, and an edge 930 extending around the perimeter of the non-planar cutting face 920. The height of the edge 930 varies around the perimeter of the cutting element 1300, wherein a first raised portion 932 of the edge 930 can extend higher than a second recessed portion 934 of the edge 930. In one or more embodiments, the cutting element 900 can include a dome located at the center of the cutting element 926, a ridge passing through the cutting element, and / or another raised portion 922.

[0056] With respect to blade angle, cutting element 900 differs from the above-described cutting elements because it incorporates a flat portion adjacent to the blade at first raised portion 932. In particular, first raised portion 932 may have an outermost blade angle greater than 90° at the intersection with bevel 931 (or with the side surface if there is no bevel 931). First portion 932 may include a flat portion 935 (e.g., a substantially flat portion) and an optional inclined portion 939. Blade angle 941 of flat portion 935 (measured between flat portion 935 and the side of cutting element 930) may be approximately 90°, while blade angle 937 of inclined portion 939 may be an acute angle. At a cutting depth exceeding the length of flat portion 935, blade angle 937 is an effective blade angle that affects engagement with the formation and cutting efficiency. In one or more embodiments, the acute edge angle 937 measured between the tangent line of the inclined portion 939 and the side of the cutting element 930 is in the range of greater than 35°, greater than 45°, or greater than 60° and up to 89°. In a particular embodiment, the acute edge angle 937 can be between 65° and 75°.

[0057] At the first portion 932, the non-planar cutting surface 920 can be piecewise continuous. For example, near the edge 930, the first raised portion 932 can start from a flat top surface and transition into a valley of the second recessed portion 1334 (e.g., at an acute edge angle 1337 of 50° to 85°). It has been found that the flat portion 935 provides increased edge durability, and the size of the flat portion can be varied to achieve the cutting efficiency and durability required for a particular application. Fig.9FAs shown, in some embodiments, the flat portion 935 can be formed as a chord area or a chord plane. In some embodiments, the radial length 933 of the flat portion 935 in the radial direction (i.e., the distance between the innermost portion and the outer surface of the flat portion) can be in the range of from 0.25 mm to 4 mm, from 0.5 mm to 2.5 mm, or from 1 mm to 2 mm. In some embodiments, the length 933 of the flat portion can be expressed as a percentage of the diameter of the cutting element 900, or as a percentage of the major diameter or minor diameter of the elliptical cutting element. For example, the length 933 can be a range having the following lower limit, upper limit, or both lower and upper limits, including any one of 2%, 5%, 8%, 10%, 13%, 17%, 20% of the diameter or any value therebetween. In some embodiments, the length 933 can be 2.5% to 13.5%, 3.5% to 7.5%, or 5% to 10% of the diameter (or width) of the cutting element 900.

[0058] Although the flat portion 935 is described as a chord-shaped region, in other embodiments, the flat portion 935 may have other shapes. For example, the flat portion 935 may not extend across the entire chord width. In other embodiments, the flat portion 935 may be annular and extend around all or part of the circumference of the cutting edge 930. In such embodiments, the length of the flat portion 935 may be constant (e.g., substantially constant) over all or part of the circumference of the cutting edge 930, rather than being substantially constant as in the embodiment of FIG. Fig.9E As shown, it has a variable length 933 that is largest at the center and decreases toward each outer end. In other embodiments, the length 933 can vary around a flat area 935 of an annular or other shape.

[0059] Fig. 9A -F shows two flat areas 935; however, in embodiments according to the present disclosure, any number of flat areas 935 may be used. For example, in some embodiments, three or four flat areas 935 may be included and spaced at equal or unequal angular intervals along the circumference of the cutting edge 930. In other embodiments, a single flat area (e.g., an annular flat area) may be used. In other embodiments, the flat areas 935 may be described in terms of the amount of circumferential coverage provided to the cutting edge 930, rather than the number of flat areas. For example, as shown in FIG. Fig.9EAs shown, one of the flat areas 935 can extend to provide a circumferential coverage within a range of about 40 ° to 60 ° of the cutting edge 930. Therefore, its two flat areas 935 can provide a coverage range of about 80 ° to 120 ° of the cutting edge 930 (that is, between about 20% to about 35% of the periphery of the cutting edge 930). As described herein, the number, length and shape of the flat areas 935 can vary. Therefore, by increasing or decreasing the length of the flat areas 935, or by increasing or decreasing the number of the flat areas 935, the coverage can be within the range including the following lower limit, upper limit or both the lower limit and upper limit, including any one of 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% and 100% of the cutting edge circumference or periphery, or any value therebetween. For example, in some embodiments, the total circumferential coverage of the one or more planar regions may be greater than 20%, less than 75%, between 5% and 75%, between 10% and 50%, or between 25% and 30%.

[0060] A third raised portion 936 may be formed in the central region of the cutting face 920, spaced between two first raised portions 932 of the blade 920 having a flat portion 937 and an inclined portion 939, wherein the inclined portion of the blade is at an angle of less than 90°. The raised portion 936 may also be spaced between two second recessed portions 934 of the blade having an edge angle of about 90° or greater. The raised portion 936 may be raised and may extend less than, equal to, or greater than the height of the first portion 932 of the blade 930. In addition, the recessed portion 934 of the blade also extends to a height less than the raised portion 932. In some embodiments, the recessed portion 934 also extends to a height less than the central raised portion 936, but in other embodiments, it may be greater than the raised portion 936.

[0061] In some embodiments, the raised portion of the blade may include multiple portions, but not a flat portion. Fig.14 One or more embodiments of cutting elements including a continuous, piecewise acute angle portion are shown. Fig.14The cutting element shown has two parts 1435 and 1439, each part has a blade angle (1437 and 1441) less than 90°. In particular, the first inclined portion 1435 adjacent to the bevel 1431 can be inclined to a first acute blade angle 1441. The acute blade angle 1441 as measured between a line tangent to the first inclined portion 1435 and the side of the cutting element 1430 can be greater than 45°, greater than 60°, or greater than 70° and up to 89°. For example, the acute blade angle 1441 can be between 60° and 89°, or between 75° and 85°. The second inclined portion 1439 can be adjacent to the first inclined portion 1435 and can extend to a recessed portion (not shown). The blade angle 1441 of the second inclined portion 1439 can be greater than 35°, greater than 45°, or greater than 60° and up to 89°. For example, the acute edge angle 1441 may be between 50° and 80°, or between 65° and 75°. Fig.14 In the embodiment, the edge angle 1437 can be an acute angle, 90°, or an obtuse angle.

[0062] Cutting elements according to embodiments of the present disclosure may be fixed or otherwise positioned on a cutting tool in an orientation to have a selected effective back rake angle or engagement angle. Fig.10 An example of a drill bit 1000 having a cutting element 1050 according to an embodiment of the present disclosure is shown. Drill bit 1000 includes a drill bit body 1010 having a longitudinal axis 1005 extending therethrough and a plurality of blades 1020 extending outwardly from drill bit body 1010. Cutter recesses are formed in blades 1020 in selected orientations for receiving cutting elements. Cutting elements 1060 having planar cutting faces 1062 are optionally located in some of the cutter recesses, and cutting elements 1050 having non-planar cutting faces 1052 according to embodiments disclosed herein are disposed in some of the cutter recesses. The non-planar cutting face 1052 includes at least one acute angled edge corner portion 1054 of the cutting element edge that is oriented as a cutting edge to engage a formation during drilling. According to embodiments of the present disclosure, at least one cutting element having a non-planar cutting face as disclosed herein may be located on a cutting tool, such as a Fig.10 The drill bit 1000 is shown to form a cutting profile for a cutting tool.

[0063] When the cutting elements 1050, 1060 engage the formation, the engagement angle formed between the cutting elements 1050, 1060 may depend on the orientation of the cutter recess in which the cutting elements are located, and the surface geometry of the cutting faces 1052, 1062. For example, the engagement angle may be changed by changing the orientation of the cutter recess relative to the drill bit (changing the angle between the tangent of the sidewall of the cutter recess relative to the axis of the cutting tool), and / or, the engagement angle may be changed by changing the surface geometry of the non-planar cutting face (e.g., so that a selected edge angle is provided as a cutting edge). In some embodiments, the engagement angle formed between the formation and the non-planar cutting element (having different edge angles formed around the edge of the non-planar cutting face) may be changed by rotating the non-planar cutting element within the cutter recess to provide different edge angles of the non-planar cutting face as a cutting edge. Thus, non-planar cutting elements according to embodiments disclosed herein may be used to change one or more engagement angles on a cutting profile of an already formed cutting tool. Thus, in some embodiments, rather than (or in addition to) designing or changing the orientation of the cutter recess relative to the cutting tool in which the cutter recess is formed so as to provide a selected engagement angle between the cutting element in the cutter recess and the formation, the non-planar cutting element according to embodiments of the present disclosure may have an edge angle oriented at the cutting edge position in the cutter recess in the already formed cutter recess so as to provide a selected engagement angle. In some embodiments, the non-planar cutting elements 1050, 1052 may have a desired engagement angle while the cutter recess is at a back rake angle between 5° and 50° or between 10° and 45°. This may include non-planar cutting elements 1050, 1052 in the cone, nose, shoulder, or gauge region of the drill bit, or in any combination of the cone, nose, shoulder, and gauge region of the drill bit.

[0064] Fig.11A and 11B An example of how the engagement angle can be changed using a cutting element according to an embodiment of the present disclosure is shown. Fig.11A and 11B, two different orientations of the cutting element 1000 within the cutter recess 1100 are shown. The cutter recess 1100 has a bottom wall 1101 (shown as intersecting the base surface of the cutting element 1000) and a side wall 1102 (shown as intersecting the side surface of the cutting element 1000), and is formed along a cutting portion of a cutting tool 1200. The cutting element 1000 has a non-planar cutting face 1002 that includes different edge angles along the perimeter of the cutting face 1002. In a first rotational orientation in the cutter recess 1100, a first acute edge angle portion of the cutting face 1002 is positioned as a cutting edge 1003 of the cutting element, wherein the first acute edge angle at the cutting edge 1003 forms a positive engagement angle 1300. In a second rotational orientation in the cutter recess 1100, the second acute angled edge portion of the cutting face 1002 is positioned as the cutting edge 1003, wherein the second acute angled edge portion at the cutting edge 1003 forms a negative engagement angle 1302. As shown, the engagement angle formed by the cutting element according to embodiments of the present disclosure can be changed within a single cutter recess by rotating the cutting element within the cutter recess to provide different edge angle portions at the cutting edge. In some embodiments, the cutting element according to embodiments of the present disclosure can be rotated within a single cutter recess from a position where the cutting element has an acute angled edge portion at the cutting edge to a position where the cutting edge has a square angled edge portion and / or a position where the cutting edge has an obtuse angled edge portion.

[0065] In addition, if Fig.11A As shown, when the cutter recess 1100 in which the cutting element 1000 is located otherwise orients the conventional cutting element to have a negative back rake angle, the cutting element 1000 according to an embodiment of the present disclosure can form a positive engagement angle 1300. As shown, the cutter recess 1100 can be oriented to have a line 1103 tangent to the sidewall 1102, which extends at an acute angle 1400 to the longitudinal axis 1202 of the cutting tool 1200 on which the cutting element 1000 is disposed. If a cutting element having a planar surface (or having a right-angled portion positioned as a cutting edge) were to be located in the cutter recess 1100, the back rake angle at the cutting edge would be negative.

[0066] According to an embodiment of the present disclosure, the engagement angle can be changed by rotating a cutting element according to an embodiment of the present disclosure in a cutter recess formed on a cutting tool (such as a drill bit). For example, the drill bit may include a drill bit body having a longitudinal axis extending therethrough, at least one blade extending outwardly from the drill bit body, a cutter recess formed in an outermost surface of the at least one blade, the cutter recess having a side wall and a bottom wall, and a line tangent to the side wall extending downward from the longitudinal axis at an acute angle. A non-planar cutting element may be disposed in the cutter recess, wherein the non-planar cutting element may include a body, a non-planar cutting face, and a cutting edge extending around the periphery of the cutting face, and a plane tangent to a portion of the cutting face at the cutting edge forms a positive engagement angle (or an effective back rake angle) with the longitudinal axis of the drill bit.

[0067] Non-planar cutting elements according to embodiments of the present disclosure may be provided on a variety of downhole cutting tools, including, for example, drill bits, reamers, and other hole-opening tools. Fig.12 An example of a hole opener 830 including one or more cutting elements 840 of the present disclosure is shown. The hole opener 830 includes a tool body 832 and a plurality of blades 838 disposed at selected azimuthal positions around its circumference. The hole opener 830 may include connectors 834, 836 (e.g., threaded connectors) such that the hole opener 830 may be coupled to adjacent drilling tools, such as a drill string and / or a bottom hole assembly (BHA) (not shown). The tool body 832 may include a hole therethrough such that drilling fluid may flow through the hole opener 830 when drilling fluid is pumped from the surface (e.g., from a surface mud pump (not shown)) to the bottom of the wellbore (not shown).

[0068] Although the embodiments of the present disclosure are described for drill bits and other cutting tools for downhole applications, the present disclosure is not limited to such environments and can be used in other environments, including manufacturing and utility pipeline laying. The numbers, percentages, ratios or other values ​​described herein are intended to include the value, as well as other values ​​of "approximately" or "approximately" the value, as understood by those of ordinary skill in the art covered by the embodiments of the present disclosure. Therefore, the values ​​or terms such as "approximately", "approximately", "generally", etc. should be interpreted as being broad enough to include values, orientations or features that are at least close enough to the value, orientation or feature to perform the desired function or achieve the desired result. The values, features and orientations include at least the expected changes in suitable manufacturing or production processes, and may also include deviations within 5%, within 1%, within 0.1% or within 0.01% of the value, orientation or feature. In the case where the numerical range includes various lower or upper limits, any two values ​​can define the limits of the range, or any single value can define an upper limit (e.g., up to 50%) or a lower limit (at least 50%).

[0069] Although only a few embodiments are described in detail above, it will be readily understood by those skilled in the art that various modifications may be made to the embodiments without departing substantially from the present invention. It should be understood that reference to "one embodiment" or "an embodiment" of the present disclosure is not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the features. For example, any element or feature described with respect to the embodiments herein may be combined with any element or feature of any other embodiment described herein. Therefore, all such modifications are intended to be included within the scope of the present disclosure. Equivalent structures including functional "device plus function" clauses are intended to cover structures described herein that perform the functions, including structural equivalents that operate in the same manner and equivalent structures that provide the same functions. It is the clear intention of the applicant not to refer to "device plus function" or other functional technical solutions for any technical solution, except for technical solutions in which the term "device for..." appears together with the relevant functions.

Claims

1. A cutting element, comprising: main body; a concave cutting face at the first end of the body, the concave cutting face comprising one or more cutting ridges adjacent the cutting tip, the one or more cutting ridges protruding above the concave surface of the concave cutting face and having a length that is at least 10% of a diameter of the concave cutting face, the concave cutting face further comprising a central dome completely surrounded by a first portion of the concave cutting face, wherein the central dome extends above the first portion; and A blade surrounding the periphery of a concave cutting surface, the blade having a blade angle defined between a tangent line of the concave cutting surface and a cylindrical side surface of the body, the blade angle being acute at a cutting tip and varying around the periphery of the concave cutting surface, wherein the blade further comprises a first raised blade portion and a second raised blade portion, and wherein the concave cutting surface defines a valley between the first raised blade portion and the second raised blade portion, and wherein the central dome extends into the valley between the first raised blade portion and the second raised blade portion.

2. The cutting element according to claim 1, wherein The one or more cutting ridges include two sides and a top line extending along the length of the ridge where the two sides intersect.

3. The cutting element according to claim 1, wherein The body includes a cutting layer on a substrate, and the concave cutting surface is formed on the cutting layer opposite to an interface with the substrate.

4. The cutting element according to claim 1, wherein The one or more cutting ridges have an included angle ranging from 60 to 170 degrees.

5. The cutting element according to claim 1, wherein At least one cutting ridge is disposed perpendicular to a tangent line of the edge at the cutting tip.

6. The cutting element according to claim 1, wherein One or more cutting ridges intersect the central dome.

7. The cutting element of claim 1 further comprising a flat region between the bevel of the edge and the inclined portion of the concave cutting face near the cutting tip.

8. The cutting element according to claim 1, wherein The body includes a curved or inclined portion connecting the sloped surface to a cylindrical side surface of the body.

9. The cutting element according to claim 1, wherein: The concave cutting surface includes two or more ridges.

10. The cutting element according to claim 9, wherein At least the first ridge is perpendicular to a tangent line of the edge at the cutting tip.

11. A cutting element, comprising: main body; a concave cutting face at the first end of the body, the concave cutting face comprising one or more cutting ridges raised above a concave surface of the concave cutting face; a blade around a perimeter of the concave cutting face, the blade having a blade angle defined between a tangent line of the concave cutting face and a cylindrical side surface of the body, the blade angle being acute at a cutting tip and varying around a perimeter of the concave cutting face, wherein the blade further comprises a first raised blade portion and a second raised blade portion, and wherein the concave cutting face defines a valley between the first raised blade portion and the second raised blade portion; and A central dome is completely surrounded by the first portion of the concave cutting face, wherein the central dome extends above the first portion and a distance from the cutting tip, and wherein the central dome extends into the valley between the first raised edge portion and the second raised edge portion.

12. The cutting element according to claim 11, wherein The one or more cutting ridges include two sides and a top line extending along the length of the ridge where the two sides intersect.

13. The cutting element of claim 11, wherein: The one or more cutting ridges intersect the central dome.

14. The cutting element of claim 11, wherein: The body includes a cutting layer on a substrate, and the concave cutting surface is formed on the cutting layer opposite to an interface with the substrate.

15. The cutting element of claim 11, wherein: The one or more cutting ridges have an included angle ranging from 90 degrees to 160 degrees.

16. The cutting element of claim 11, wherein: At least one cutting ridge is disposed perpendicular to a tangent line of the edge at the cutting tip.

17. The cutting element of claim 11, further comprising a flat region disposed between the bevel of the edge adjacent the cutting tip and the inclined portion of the concave cutting face.

18. The cutting element of claim 11, wherein: The blade also includes a curved or inclined portion connecting the bevel to the cylindrical side surface of the body.

19. The cutting element of claim 11, wherein: The concave cutting surface includes two or more ridges.

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