Mark D Hinton

US Patent:

57462798, May 5, 1998

Filed:

Feb 20, 1996

Appl. No.:

8/602485

Inventors:

Kenneth Havlinek - Missouri City TX
Thomas D. MacDougall - Sugar Land TX
Alan Sallwasser - Houston TX
Miles Jaroska - Richmond TX
Duane LaDue - Sugar Land TX
Wayne A. Tyler - Pearland TX
Mario Flores - Houston TX
Mark L. Hinton - Sugar Land TX
Thomas D. Svoboda - Pasadena TX
Michele Tesciuba - Houston TX

Assignee:

Gas Research Institute - Chicago IL

International Classification:

E21B 2906
E21B 43112

US Classification:

175 52

Abstract:

An apparatus and method are disclosed for the removal and replacement of the used drill bit after each perforation through casing, cement, and into rock while using a flexible drive shaft. This apparatus involves both a bayonet-style "quick connector" between the flexible shaft and the drill bit and a cartridge that holds the drill bits while they await their turn to be used. The apparatus also has a means for indexing the cartridge so that the flexible shaft can have access to each of the drill bits in the cartridge. The method disclosed involves the process of connecting the flexible shaft to the drill bit at the start of the perforating process, the disconnecting of the used bit at the end of the perforation, and the indexing of the cartridge so that the next drill bit is in line with the flexible shaft for the next perforation.