Abstract: A downhole tool assembly is configured for repeated and selective hydraulic actuation and deactuation. A piston assembly is configured to reciprocate axially in a downhole tool body. The piston assembly reciprocates between a first axial position and second and third axial positions that axially oppose the first position. The downhole tool is actuated when the piston assembly is in the third axial position and deactuated when the piston assembly is in either of the first or second axial positions. A spring member biases the piston assembly towards the first axial position while drilling fluid pressure in the tool body urges the piston assembly towards the second and third axial positions. Downhole tool actuation and deactuation may be controlled from the surface, for example, via cycling the drilling fluid flow rate.

Abstract: A drill bit for drilling a borehole in an earthen formation. In an embodiment, the bit comprises a first blade having a cutter-supporting surface. In addition, the bit comprises a plurality of primary cutter elements with cutting faces mounted to the cutter-supporting surface. The cutting profiles of the cutting faces define an outermost cutting profile P0 in rotated profile view. Further, the bit comprises a stabilizing member having an end distal the cutter-supporting surface. The end includes a tip. The tip is offset from the outermost cutting profile P0 in rotated profile view.

Abstract: A method of manufacturing an earth-boring bit having a fluid plenum and a plurality of fluid pathways includes modeling flow characteristics of the fluid plenum and the plurality of fluid pathways, optimizing the flow characteristics to minimize fluid separation through each fluid pathway, constructing a plenum blank from the optimized model, and sintering matrix power between the plenum blank and a bit head mold to create the fluid plenum and plurality of fluid pathways.

Abstract: A method for designing a drill bit comprising modeling a domain between a drill bit and a surrounding wellbore. A region is defined within each of a plurality of flow paths through which fluid travels through the domain. An allocation of flow among the plurality of flow paths through the domain is determined and the drill bit is modified such that the allocation of flow is substantially uniform among the plurality of flow paths. A drill bit comprises a bit body having a plurality of blades projecting there from, wherein at least one blade has a greater length than at least one other blade. A plurality of nozzles, or ports, are disposed on the body and a plurality of junk slots are formed between adjacent blades so that the flow of fluid through each of the plurality of junk slots is substantially uniform.

Abstract: An earth boring bit includes a bit body including plurality of PDC cutter elements and a fluid plenum connecting a fluid inlet to at least one fluid orifice. Furthermore, a ledge formed between a bottom of the fluid plenum and the at least one fluid orifice includes a relief region formed therein located across a flow change angle. Additionally, a method to improve a polycrystalline diamond compact drill bit body design includes determining flow change angles from a fluid plenum into a fluid orifice and modeling a relief region on a ledge to optimize fluid into the fluid orifice.

Abstract: A drill bit configures hydraulic streams from the bit nozzles for the particular cutting structure to be cleaned based on the cutting structure location and geometry. The projected impingement location for each hydraulic stream projected fluid path is customized for a corresponding roller cone, with each nozzle or nozzle receptacle being individually positioned according to improve cone cleaning. At least two nozzles or nozzle receptacles should differ on the drill bit.

Abstract: The present invention relates to a roller cone drill bit that has improved flow characteristics. The roller cone drill bit includes forming at least one relief region inside a bit body of the roller cone drill bit on a ledge formed between a fluid plenum and at least one of the fluid orifices. A method of locating the at least one relief region is also disclosed.

Abstract: A rotary cone rock bit includes one or more hole cleaning nozzles and one or more bit cleaning nozzles. The hole cleaning nozzles of one drill bit define a projected fluid path disposed at a lateral angle of less than six degrees in order to achieve a large impingement pressure on the hole bottom. The bit cleaning nozzles of the same drill bit define a projected fluid path disposed at a lateral angle of at least six degrees in order to pass within 0.5 inches of the teeth on leading edge of the lagging roller cone. This results in a drill bit that both cleans the bottom hole and cleans cone inserts.