A cutting element has a cutting face at an opposite axial end from a base, a side surface extending from the base to the cutting face, an edge formed at the intersection between the cutting face and the side surface, and an elongated protrusion formed at the cutting face and extending between opposite sides of the edge, wherein the elongated protrusion has a geometry including a border extending around a concave surface and sloped surfaces extending between the border and the edge, and wherein the concave surface has a major axis dimension measured between opposite sides of the border and a minor axis dimension measured perpendicularly to the major axis dimension and ranging from 50 percent to 99 percent of the major axis dimension.

In a drill bit insert of the present invention, an insert body of the drill bit insert includes: a rear end portion forming a columnar shape or a disk-like shape; an intermediate portion having an outer diameter smaller than that of the rear end portion; and an end portion having an outer diameter from the center line of the insert gradually decreasing toward the tip side, the hard surface layer is coated on the insert body from a surface of the end portion of the insert body to an outer periphery of the intermediate portion, and an outer diameter of the hard surface layer on the intermediate portion is equal to that of the rear end portion.

Systems and methods are disclosed for a rotating superhard cutting element. The rotating cutting element includes a substrate comprising a rotating portion and a stable portion. The stable portion has a cavity and is configured to be fixed to a blade of a drill bit. The rotating cutting element further includes a retainer that rotatably secures the rotating portion of the substrate in the cavity of the stable portion of the substrate, and a cutting layer on the rotating portion of the substrate. The cutting layer has a plurality of cutting surfaces. One of the plurality of cutting surfaces has a property different from another one of the plurality of cutting surfaces. The cutting layer is configured to rotate with respect to the stable portion of the substrate and use one of the plurality of cutting surfaces based on a characteristic of a formation to be cut.

In one example, a method of designing a drill bit comprises obtaining a baseline orientation of a shaped cutter with respect to a bit body. The shaped cutter includes a shaped cutting element secured to a substrate. The baseline orientation is defined, at least in part, with respect to an rotational position of the shaped cutting element about a longitudinal axis of the shaped cutter. A wear imbalance is determined between opposing portions of the shaped cutting element at the baseline orientation. An adjusted orientation of the shaped cutter is generated having a different rotational position of the shaped cutting element about the cutter axis expected to reduce the wear imbalance.

Cutters for a downhole drill bit can be formed by providing a catalyst-free synthesized polycrystalline diamond (PCD) having a cross-sectional dimension of at least 8 millimeters; providing a substrate comprising tungsten carbide; and attaching the synthesized PCD to the substrate comprising tungsten carbide to form a PDC cutter.

A cutter element for a drill bit includes a base portion having a central axis, a first end, and a second end. In addition, the cutter element includes a cutting layer fixably mounted to the first end of the base portion. The cutting layer includes a cutting face distal the base portion. The cutting face includes a first planar surface and a second planar surface that is circumferentially-spaced from the first planar surface. Each planar surface is positioned at an outer periphery of the cutting face adjacent the radially outer surface of the cutting layer. The cutting face also includes a saddle surface including a crown and a pair of lateral side surfaces that slope down and away from the crown toward the radially outer cylindrical surface of the cutting layer. The crown extends from the first planar surface to the second planar surface.

Cutting elements for earth-boring tools may include a rotationally leading end positioned and configured to engage with, and remove, a material of an earth formation. A transition region may extend from proximate to a periphery of the cutting element radially inward and axially toward the rotationally leading end. The transition region may include first faceted surfaces, each first faceted surface extending at a first angle relative to a central geometric axis of the cutting element. The transition region may also include second faceted surfaces, each second faceted surface extending at a second, different angle relative to the central geometric axis of the cutting element. The first faceted surfaces and the second faceted surfaces may intersect one another at edges around a periphery of the transition region.

A cutting element for use on a drill bit is disclosed. The cutting element includes a polycrystalline diamond table having a multi-tiered surface. The polycrystalline diamond table has at least a first cutting surface and a second cutting surface. The polycrystalline diamond table has a step between the first and second cutting surfaces. The step is transitional surface feature between the first and second cutting surfaces, which are positioned at different elevations in the polycrystalline diamond table.

A drill bit includes a bit body providing one or more blades and defining a cone section extending from a centerline of the bit body a first distance, a nose section extending from the cone section a second distance, a shoulder section extending from the nose section a third distance, and a gauge section extending from the shoulder section a fourth distance. The drill but further includes one or more cutting elements mounted to the one or more blades outside of the cone section such that the cone section is void of cutting elements, and a plurality of milling elements secured to the bit body within the cone section.

A cutting element has a cutting face with a geometry including at least one protrusion spaced a radial distance apart from an edge of the cutting element, the edge extending around an entire periphery of the cutting face, and a lower portion extending within the distance between the at least one protrusion and the edge, wherein a lower portion axial height measured between the edge and a base of the at least one protrusion is less than 30 percent of a greatest axial height of the at least one protrusion measured between the base of the at least one protrusion and an axially highest point of the at least one protrusion.