Description:A CUTTING ELEMENT
FIELD OF INVENTION
The invention relates to devices used in drilling and boring through subterranean formations. More particularly, the invention relates to a cutting element intended to be installed on a drill bit or other tools used for earth or rock boring, such as may occur in the drilling or enlarging of an oil, gas, geothermal or other subterranean borehole, and to bits and tools so equipped.
BACKGROUND
Earth boring or down hole drilling is acheived through drill bits including but not limited to roller cone bits (e.g., tricone bits), fixed cutter bits (e.g., polycrystalline diamond compact bits and natural diamond bits), drag bits, hybrid bits, and impregnated diamond bits. Roller cone bits, also known as tricone bits, are rotary drill bits featuring three rotating cones, each equipped with cutting teeth made of steel or tungsten carbide. As the bit rotates, the cones roll over the formation, crushing and chipping the rock. They're widely used in oil and gas, geothermal, and mining drilling operations. Fixed cutter bits are a type of drill bit used in oil and gas drilling. Unlike roller cone bits, they have no moving parts. Instead, they use fixed cutting elements, usually made of polycrystalline diamond compact (PDC) or natural diamond, that are permanently attached to the bit body. They are designed to excavate formations by shearing rather than crushing or chipping. Drag bits consist of fixed cutting blades that rotate with the drill string and cut by dragging the blades across the formation. They are effective in soft formation but not suitable for hard rock formations.
Cutting elements used in various drill bits are designed with different material grades, sizes, and shapes to effectively drill through rock formations of varying strength. These cutting elements typically consist of a supporting substrate and a cutting table, the latter often made from a superabrasive material such as polycrystalline diamond. In most conventional designs, the cutting elements are formed from circular bodies.
One such cutting element is disclosed in US Patent bearing No US8783387 and assigned to Smith International Inc. The patent discloses a polycrystalline diamond compact cutter, the cutter includes a substrate, and a cutting face perpendicular to an axis of the substrate, wherein the cross-section of the cutting face comprises multiple lobes, and the cross-section of the substrate is substantially circular.
Another such cutting element is disclosed in US9316058 assigned to Baker Hughes Inc. The Patent discloses a cutting elements comprising, a substrate base comprising a substantially cylindrical outer side surface and a longitudinal axis substantially parallel to the substantially cylindrical outer side surface.
Yet another cutting element is disclosed in US9650837 assigned to Baker Hughes Inc. The patent discloses a cutting element, the cutting element includes a substrate; a generally cylindrical side surface and a longitudinal axis parallel to the generally cylindrical side surface; and a volume of superabrasive material positioned on the substrate.
Still another cutting element disclosed in US10563464 assigned to CNPC USA Corp, describes a cutting tooth comprising; a cylindrical body, wherein the surface of an end portion of the cylindrical body is provided with three cutting ridges, wherein an inner end of each of the cutting ridges extends to a triangle at the vertex of a Reuleaux triangle at the end portion of the cylindrical body.
The limitations of cylindrical substrates include but are not limited to minimal geometric locking into the cutter pocket leading to reduced retention strength, poor load distribution, accelerated thermal degradation and low rate of penetration. Hence, there is a need for a cutting element which addresses the disadvantages of the available cutting elements and results in faster rock removal.
BRIEF DESCRIPTION OF DRAWINGS
So that the manner in which the recited features of the invention can be understood in detail, some of the embodiments are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
FIG.1 shows a schematic representation of a cutting element, according to an embodiment of the invention.
FIG. 2 shows a schematic representation of a top portion of a cutting element, according to another embodiment of the invention.
FIG. 3 (a) shows an isometric view of a cutting element showing a non-planar cutting surface, according to an embodiment of the invention.
FIG. 4 (b) shows a side view of a cutting element showing a non-planar cutting surface, according to an embodiment of the invention.
FIG. 4 shows a schematic representation of a top portion of a cutting element, showing width of a first ridge according to an embodiment of the invention.
FIG. 5 shows a schematic representation of different ridge geometries of the cutting element, according to an embodiment of the invention.
SUMMARY OF THE INVENTION
One aspect of the invention provides a cutting element for drill bits. The cutting element includes a top portion having an angular surface, the angular surface having atleast one first ridge extending from the angular surface, and a bottom portion formed in congruence with the top portion. The bottom portion having a lateral surface and a bottom circular surface, the lateral surface having atleast one second ridge with a tapering height. The width of the ridge ranges from 0.08 - 0.96 times the diameter of the top portion of the cutting element.

DETAILED DESCRIPTION OF THE INVENTION
The following discussion is directed to various exemplary embodiments. However, one skilled in the art will understand that the examples disclosed herein have broad application, and that the discussion of any embodiment is meant only to be exemplary of that embodiment, and not intended to suggest that the scope of the disclosure, including the claims, is limited to that embodiment. Unless otherwise defined, all terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. Throughout the drawings and the detailed description, unless otherwise described, the same drawing reference numerals are understood to refer to the same elements, features, and structures. The relative size and depiction of these elements may be exaggerated for clarity, illustration, and convenience.
Various embodiments of the invention provide a cutting element for drill bits. Particularly, embodiments disclosed herein relate to a cutting element having a non-circular cross section. The cutting element as disclosed in the present invention includes a top portion having an angular surface with atleast one first ridge extending from the angular surface and a bottom portion formed in congruence with the top portion. The bottom portion includes a lateral surface having atleast one second ridge with a tapering height and a bottom circular surface. The incorporation of a ridge on the cutting element significantly improves the rock-removal efficiency of the drill bit by enhancing the surface area of cutting surface available for rock removal. The ridge concentrates the applied force onto a smaller contact area, generating higher stress levels at the point of contact with the rock. As a result, the cutting element is able to fracture/shear and remove rock more effectively, which leads to a higher rate of penetration (ROP) during drilling operations. This effect is observed equally among cutting elements placed on rotary drill bits and fixed cutter bits. The cutting element is configured to detachably attach to the drill bit. The cutting element described briefly herein above shall be explained in detail through FIG. 1 to FIG. 5.
FIG.1 shows a schematic representation of a cutting element, according to an embodiment of the invention. The cutting element includes a top portion 1 and a bottom portion 3 formed in congruence with the top portion 1. The top portion 1 forms a cutting surface which is formed from a ultra-hard material including but not limited to poly crystalline diamond(PCD), thermally stable PCD, impregnated diamond, nano-structured diamond, and CVD diamond, boron nitrite and other ultra-hard materials known in the art and combinations thereof. The top portion 1 is formed on the bottom portion 3 by methods known in the art. In one embodiment of the invention, the top portion 1 is layered on the bottom portion 3 by using sintering process. The cutting surface of the top portion 1 is either planar or non-planar. In some embodiments of the invention, the cutting surface of the top portion 1 is planar. In some embodiments of the invention, the cutting surface of the top portion 3 is non-planar and may exhibit a conical shape, a dome shape, a pyramidal shape, or may have a plurality of ribs that are arranged concentrically, parallely or criss-cross. The bottom portion 3 is formed from tungsten carbide or other suitable 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 bottom portion, such as cobalt, nickel, iron, metal alloys, or mixtures thereof. In some embodiments of the invention, top portion 1 is formed from the same materials as the bottom portion 3. In some embodiments of the invention, top portion is formed from different materials than the bottom portion. In some embodiments top portion is formed from poly crystalline diamond and bottom portion is formed from tungsten carbide. The top portion 1 have an angular surface 5 with atleast one first ridge 7 extending from the angular surface 5. In one example of the invention, the two opposingly placed first ridges 7 extend from the angular surface 5. In another example of the invention, one first ridge 7 extends from the angular surface 5 (FIG. 2). A bottom portion 3 is formed in congruence with the top portion 1. The bottom portion 3 have a lateral surface 9 and a bottom circular surface 11. The lateral surface 9 of the bottom portion 3 has atleast one second ridge 13 extending from the lateral surface 9. The second ridge 13 is formed in congruence with the first ridge 7. The second ridge 13 tapers in height as it reaches towards the bottom to form the circular bottom surface 11. The first ridge 7 and the second ridge 13 can be identical or different. In some embodiments of the invention, the second ridge 13 is identical to the first ridge 7. The top portion 1 of the cutting element has a planar cutting surface. In some embodiments of the invention, the cutting surface is non-planar. FIG 3(a) and 3(b) shows a schematic representation of a cutting element showing non-planar cutting surface. The cutting element has a top portion 1 with a non-planar cutting surface. The top portion 1 forms a pyramidal cutting surface having two sloping surfaces 15 that forms a linear rib 17 at the centre of the cutting surface. The two sloping surfaces 15 substantiate an angle A1 ranging from 5o to 135o between them.
Now referring to FIG. 4, the figure shows a schematic representation of a top portion of a cutting element, showing width of a first ridge according to an embodiment of the invention. The top portion 1 of the cutting element has a diameter D. The top portion forms two opposingly placed first ridges 7 extending from the angular surface. The first ridge 7 has a width, ridge width (Rw), ranging from 0.08 to 0.96 times the diameter (D) of the cutting element. The diameter of the top portion of the cutting element varies from 0.16 inch to 1 inch. The geometry of the first ridge 7 includes but is not limited to a trapezoidal ridge, a rectangular ridge, a circular ridge and a triangular ridge. The geometry of the second ridge 13 includes but is not limited to a trapezoidal ridge, a rectangular ridge, a circular ridge and a triangular ridge.
FIG. 5 shows a schematic representation of different ridge geometries of the cutting element, according to an embodiment of the invention. In one embodiment of the invention, the geometry of the first ridge 7 and the second ridge 13 is trapezoidal (FIG. 5a). The ridge width (Rw) for the trapezoidal ridge varies from 0.08 to 0.96 times the diameter (D) of the top portion of the cutting element. In another embodiment of the invention, the geometry of the first ridge 7 and the second ridge 13 is rectangular (FIG. 5b). The ridge width (Rw) for the rectangular ridge varies from 0.08 to 0.96 times the diameter (D) of the top portion of the cutting element. In still another embodiment of the invention, the geometry of the first ridge 7 and the second ridge 13 is circular (FIG. 5c). The ridge width (Rw) for the circular ridge varies from 0.08 to 0.96 times the diameter (D) of the top portion of the cutting element. In yet another embodiment of the invention, the geometry of the first ridge 7 and the second ridge 13 is triangular (FIG. 5d). The ridge width (Rw) for the triangular ridge varies from 0.08 to 0.96 times the diameter (D) of the top portion of the cutting element.
Example 1: In one example of the invention, the cutting element includes a top portion 1 and a bottom portion 3 formed in congruence with the top portion 1. The top portion 1 is formed from poly crystalline diamond and the bottom portion 3 is formed from tungsten carbide. The top portion 1 has a planar cutting surface and is formed by layering on the bottom portion 3 by using sintering process. The thickness of the top portion 1 is about 0.8 inch and has a diameter (D) of 0.63 inch. The length of the cutting element is 0.52 inch. The top portion 1 have an angular surface 5 with two opposingly placed first ridges 7 extending from the angular surface 5. The bottom portion 3 have a lateral surface 9, and a bottom circular surface 11. The lateral surface 9 of the bottom portion has two opposingly placed second ridge 13. The second ridge 13 tapers in height as it reaches towards the bottom to form the circular bottom surface 11. The two opposingly placed second ridge 13 are formed in congruence with the two opposingly placed first ridges 7. The first ridge 7 has a width, ridge width (Rw), of 0.13 inch and the geometry of the ridge is rectangular. The cutting element is configured for detchably attaching to a fixed cutter bit.
The cutting element of the current invention achieves a high rate of penetration as incorporation of a ridge on the cutting element enhances the surface area of cutting surface available for rock removal. The ridge concentrates the applied force onto a smaller contact area, generating higher stress levels at the point of contact with the rock, resulting in larger volume of rock removal, thereby reducing the time and impvoving the effieciency of the rock removal procedure.
The foregoing description of the invention has been set merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to person skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.

, Claims:We claim:
1. A cutting element for a drill bit, the cutting element comprising of:
a top portion (1) having an angular surface (5) with atleast one first ridge (7) extending from the angular surface, the ridge having a width in the range of 0.08 * D - 0.96* D; and
a bottom portion (3) having a lateral surface (9) formed in congruence with the top portion (1) having atleast one second ridge (13) with a tapering height and a bottom circular surface (11).
2. The cutting element as claimed in claim 1, wherein D is the diameter of the top portion of the cutting element.
3. The cutting element as claimed in claim 1, wherein the geometry of the first ridge (7) is selected from a group comprising of a trapezoidal ridge, a rectangular ridge, a circular ridge and a triangular ridge.
4. The cutting element as claimed in claim 1, wherein the geometry of the second ridge (13) is selected from a group comprising of a trapezoidal ridge, a rectangular ridge, a circular ridge and a triangular ridge.
5. The cutting element as claimed in claim 1, wherein the first ridge (7) and the second ridge (13) can be identical or different.
6. The cutting element as claimed in claim 1, wherein the top portion (1) has either a planar or a non-planar cutting surface.
7. The cutting element as claimed in claim 1, wherein the cutting element is configured for detachably attaching to the drill bit.