Abstract: A PDC cutter utilizes the combination of an elliptical shape with higher thermal resistance obtained through leaching to provide a cutter which is more effective than a cutter using either concept alone. The PDC cutter includes a tungsten carbide portion with protrusions extending from a surface thereof in a pattern. The diamond volume is mounted to the surface wherein the protrusions allow for the diamond volume to be larger about a perimeter edge of the cutter and smaller/shallower in a center region of the cutter. The protrusions providing surfaces for the diamond layer (table) to bond to the underlying tungsten carbide portion. With this configuration, diamond volume is maximized around the edge of the cutter.

Abstract: A rotary drill bit includes a bit body that includes a plurality of upright legs that terminate in an exterior bearing surface. At least one roller cutter is affixed to a corresponding exterior bearing surface of one of the plurality of legs. The roller cutter has an exterior cutting surface and a base edge and defines an interior bearing surface that is complementary to a corresponding exterior bearing surface. At least one duct is defined by the lower surface of the lateral wall and is adjacent to at least one exterior bearing surface. A plug is disposed in the duct at a distance from the base edge one of the roller cutters so that if either the interior bearing surface or the exterior bearing surface wears beyond a threshold, the plug will cause a remotely-sensible indication of excessive bearing wear to be asserted.

Abstract: A system and method for detecting the wear of a roller bit bearing on a roller drill bit body where the roller element has a plurality of cutting elements and is rotatably attached to the roller drill bit body at the bearing. In the invention, a rotation impeder is in between the roller element and roller drill bit body and upon uneven rotation of the roller element which indicates that the roller element bearing may fail, the rotation impeder impedes the rotation of the roller element. The drill rig operator at the surface can cease drilling operations upon detection of the cessation of rotation of the roller element. The rotation impeder can also be seated in a drilling fluid outlet and cause a detectable loss in drilling fluid pressure when dislodged to otherwise cease rotation of the roller drill bit.

Abstract: A system and method for detecting the wear of a roller bit bearing between a roller drill bit body and a roller bit rotatably attached to the roller drill bit body. A valve-plug is placed between the roller drill bit body and roller bit such that the valve-plug is removably fitted in a drilling fluid outlet in the roller drill bit body, and the valve-plug extends into a channel in the roller bit whereby uneven rotation or vibration of the roller bit causes the valve-plug to impact the sides of the channel which removes the valve-plug from the drilling fluid outlet to cause drilling fluid to flow through the drilling fluid outlet. The drop in pressure from the drilling fluid flowing through the drilling fluid outlet indicates that the roller bit is worn and may fail.

Abstract: A rotary drill bit includes a bit body that includes a plurality of upright legs that terminate in an exterior bearing surface. At least one roller cutter is affixed to a corresponding exterior bearing surface of one of the plurality of legs. The roller cutter has an exterior cutting surface and a base edge and defines an interior bearing surface that is complementary to a corresponding exterior bearing surface. At least one duct is defined by the lower surface of the lateral wall and is adjacent to at least one exterior bearing surface. A plug is disposed in the duct at a distance from the base edge one of the roller cutters so that if either the interior bearing surface or the exterior bearing surface wears beyond a threshold, the plug will cause a remotely-sensible indication of excessive bearing wear to be asserted.

Abstract: A system and method for detecting the wear of a roller bit bearing between a roller drill bit body and a roller bit rotatably attached to the roller drill bit body. A valve-plug is placed between the roller drill bit body and roller bit such that the valve-plug is removably fitted in a drilling fluid outlet in the roller drill bit body, and the valve-plug extends into a channel in the roller bit whereby uneven rotation or vibration of the roller bit causes the valve-plug to impact the sides of the channel which removes the valve-plug from the drilling fluid outlet to cause drilling fluid to flow through the drilling fluid outlet. The drop in pressure from the drilling fluid flowing through the drilling fluid outlet indicates that the roller bit is worn and may fail.

Abstract: A system and method for detecting the wear of a roller bit bearing on a roller drill bit body where the roller bit has a plurality of cutting elements and is rotatably attached to the roller drill bit body at the bearing. In the invention, a rotation impeder is in between the roller bit and roller drill bit body and upon uneven rotation of the roller bit which indicates that the roller bit bearing may fail, the rotation impeder impedes the rotation of the roller bit. The drill rig operator at the surface can cease drilling operations upon detection of the cessation of rotation of the roller bit. The rotation impeder can also be seated in a drilling fluid outlet and cause a detectable loss in drilling fluid pressure when dislodged to otherwise cease rotation of the roller drill bit.