Indenting Member for a Drill Bit
A drill bit has a bit body intermediate a working face and a shank end adapted for connection to a downhole drill string. The working face has at least three fixed blades converging towards a center of the working face and diverging towards a gauge of the bit, at least one blade having a cone region adjacent the center of the working face. The cone region increases in height away from the center of the working face and towards a nose portion of the at least one blade. An opening is formed in the working face at the center of the bit along an axis of the drill bit's rotation, the opening leading into a chamber with at least one wall. An indenting member is disposed within and extends from the opening, is substantially coaxial with the axis of rotation, and is fixed to the wall of the chamber.
1 . A drill bit, comprising:
a bit body intermediate a working face and a shank end adapted for connection to a downhole drill string;
the working face comprising at least three fixed blades converging towards a center of the working face and diverging towards a gauge of the bit;
at least one of the plurality of blades comprising a cone region adjacent the center of the working face;
the cone region increasing in height away from the center of the working face and towards a nose portion of the at least one blade;
an opening being formed in the working face at the center of the bit along an axis of the drill bit's rotation;
the opening leading into a chamber with at least one wall;
an indenting member being disposed within and extending from the opening and being substantially coaxial with the axis of rotation; and
the indenting member being rotationally and axially fixed to the wall of the chamber and being made of a material harder than the bit body;
wherein the indenting member does not extend beyond the nose portion of the at least one blade.
2 . The drill bit of claim 1 , wherein the indenting member is substantially cylindrical along its length.
3 . The drill bit of claim 1 , wherein the indenting member is a conical shape with a rounded distal end.
4 . The drill bit of claim 1 , wherein the indenting member is brazed to the wall of the chamber.
5 . The drill bit of claim 1 , wherein the indenting member is solid.
6 . The drill bit of claim 1 , wherein the indenting member fails a formation immediately in front of it in compression.
7 . The drill bit of claim 1 , wherein the indenting member comprises a larger diameter than a cutting element secured to at least one of the blades.
8 . The drill bit of claim 1 , wherein the indenting member comprises a larger volume than a cutting elements secured to at least one of the blades.
9 . The drill bit of claim 1 , wherein the indenting member comprises a substantially symmetric distal end.
10 . The drill bit of claim 1 , wherein the at least one blade also comprise a nose portion and a flank region.
11 . The drill bit of claim 1 , wherein the bit body is made of steel.
12 . The drill bit of claim 1 , wherein the bit body is made of matrix.
13 . The drill bit of claim 1 , wherein the indenting member is held within the chamber through an interference fit.
14 . The drill bit of claim 1 , wherein the chamber comprises a closed end.
15 . The drill bit of claim 1 , wherein the indenting member comprises a braze joint.
16 . The drill bit of claim 1 , wherein the chamber comprises a port in fluid communication with a bore formed in the bit body which is adapted to facilitate flow of drilling mud during a drilling operation.
17 . The drill bit of claim 1 , wherein a closest cutting attached to the at least one blade is pointed.
18 . The drill bit of claim 1 , wherein a junk slot comprising a base is formed by the blades; at least one high pressure nozzle disposed between at least two blades in a nozzle bore formed in an elevated surface from the base of the junk slots; the elevated surface being disposed adjacent the diamond working end of the least one cutting surface.
19 . The drill bit of claim 1 , wherein at least one cutting element attached the at least one blade has a conical shape with a rounded distal end.