A diamond mining core drill bit tool including a cylindrical body with first and second ends and an inner axial opening therethrough, the cylindrical body having a ring groove extending about the second end; the tool further including cutting segments circumferentially spaced about the second end; the tool having a first weld bead between a first portion of the segments and the second end of the cylindrical body; the tool further including at least one weld ring wherein the ring groove is shaped to receive the at least one weld ring such that the at least one weld ring extends about the ring grove; the tool further including at least one second weld bead between a second portion of the segment and the ring groove and a method for the same.

A diamond mining core drill bit tool including a cylindrical body with first and second ends and an inner axial opening therethrough, the cylindrical body having a ring groove extending about the second end; the tool further including cutting segments circumferentially spaced about the second end; the tool having a first weld bead between a first portion of the segments and the second end of the cylindrical body; the tool further including at least one weld ring wherein the ring groove is shaped to receive the at least one weld ring such that the at least one weld ring extends about the ring grove; the tool further including at least one second weld bead between a second portion of the segment and the ring groove and a method for the same.

A drill bit for cutting a hole in a formation. The drill bit has a shank and a crown. The crown has a plurality of crown portions that are spaced about an operative circumference of the drill bit. The shank and crown cooperate to define an interior space that receives water or other drilling fluid. Each crown portion has two longitudinal edges, an outer surface, at least one inner surface and a cutting face. The crown has a base surface that is spaced from the cutting faces of the crown portions and cooperates with the inner surface of each of the two crown portions to define a slot.

A drill bit includes a shank having a threaded coupling formed at an upper end thereof; a bit body mounted to a lower end of the shank and having a plenum; a gage section forming an outer portion of the drill bit; a cutting face forming a lower end of the drill bit and including: a core receptacle formed at a center of the cutting face, operable to receive a core of earth, and including: a concave core cutter mounted to a bottom of the bit body; and a core port extending from the plenum through the bottom of the bit body and operable to discharge drilling fluid onto the core and core cutter; a plurality of blades protruding from a bottom of the bit body and extending from a periphery of the core receptacle to the gage section; and a plurality of leading cutters mounted along each blade.

A drill bit includes a shank having a threaded coupling formed at an upper end thereof; a bit body mounted to a lower end of the shank and having a plenum; a gage section forming an outer portion of the drill bit; a cutting face forming a lower end of the drill bit and including: a core receptacle formed at a center of the cutting face, operable to receive a core of earth, and including: a concave core cutter mounted to a bottom of the bit body; and a core port extending from the plenum through the bottom of the bit body and operable to discharge drilling fluid onto the core and core cutter; a plurality of blades protruding from a bottom of the bit body and extending from a periphery of the core receptacle to the gage section; and a plurality of leading cutters mounted along each blade.

A drill bit can be configured to form core segments during drilling. The drill bit can have having a central axis and a shank defining an inner bore. A crown can be coupled to the shank. The crown can define a cutting face and a core receiving slot that extends inwardly into the crown from the cutting face. The crown can define an inner operative circumference. A core break structure can be disposed within the shank. The core break structure can define a core break surface that extends inwardly toward the central axis and intersects an imaginary 3D projection of the inner circumference projected along the central axis.

A drill bit can be configured to form core segments during drilling. The drill bit can have having a central axis and a shank defining an inner bore. A crown can be coupled to the shank. The crown can define a cutting face and a core receiving slot that extends inwardly into the crown from the cutting face. The crown can define an inner operative circumference. A core break structure can be disposed within the shank. The core break structure can define a core break surface that extends inwardly toward the central axis and intersects an imaginary 3D projection of the inner circumference projected along the central axis.

A method for designing a core bit to control and reduce the cutting forces acting on a core of rock is disclosed. The method includes generating a model of a core bit including a plurality of cutting elements on a plurality of blades. The method may additionally include simulating a coring operation with the model of the core bit. The method may further include calculating at least one force vector generated by at least one of the plurality of cutting elements on the model of the core bit during the coring operation. The method may further include determining at least one force acting on a core in the model of the core bit based on the at least one force vector and generating a design of the core bit based on the at least one force acting on the core.

A method for designing a core bit to control and reduce the cutting forces acting on a core of rock is disclosed. The method includes generating a model of a core bit including a plurality of cutting elements on a plurality of blades. The method may additionally include simulating a coring operation with the model of the core bit. The method may further include calculating at least one force vector generated by at least one of the plurality of cutting elements on the model of the core bit during the coring operation. The method may further include determining at least one force acting on a core in the model of the core bit based on the at least one force vector and generating a design of the core bit based on the at least one force acting on the core.

A retrievable core sampling assembly for latching to or relative to a rotatable tubular housing of a core sampling apparatus to allow the capture and retrieval of a core from a subterranean formation, the assembly comprising or including: a core catcher barrel for a core, the barrel being rotationally isolated from the tubular housing and cooperable with a core taking bit coupled to the rotatable tubular housing to retain a core, and a hammer for providing impact to the core taking bit along a longitudinal impact path that is or is substantially decoupled from the core catcher barrel so that when latched, rotation and impact of the core taking bit captures and passes core material from the formation to the core catcher barrel in manner that isolates a core in the core catcher barrel from rotation and impact forces.