06039131 is referenced by 137 patents and cites 10 patents.

A PDC bit for cutting a hole below a point in a formation, the diameter of the hole being greater than the diameter of the hole above the point, comprising: a bit body having an axis of rotation, a first cutting portion having a first radial extent from the axis of rotation, a second cutting portion that is not axially spaced apart from the first cutting portion and that has a second radial extent that is greater than said first radial extent, wherein the total imbalance forces resulting from engagement of said first and said second cutting portions with the formation are balanced such that the resulting torque on the bit is minimized and in particular, the component of the torque on the bit about an axis normal to the axis of rotation is minimized. In some embodiments, the bit has a central recessed portion on its face, which receives a short "core" portion that enhances stabilization of the bit.

Title
Directional drift and drill PDC drill bit
Application Number
8/918763
Publication Number
6039131
Application Date
August 25, 1997
Publication Date
March 21, 2000
Inventor
Timothy P Beaton
Houston
TX, US
Agent
Rosenthal & Osha
Assignee
Smith International
TX, US
IPC
E21B 10/00
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