Drill bit stabilizer

Abstract

A stabilizer for a drill string and drill bit is mounted behind the drill bit in the drilling assembly. The stabilizer comprises a tubular body having one or more stabilizer blades mounted thereon. The stabilizer blades extend radially outwardly from the stabilizer body. In a first position, the stabilizer blades are in vertical axial alignment behind the drill bit. Drill string pressure is utilized to release a locking mechanism permitting relative rotation between the stabilizer blades and the stabilizer body thereby rotating the stabilizer blades to a second position providing stabilization for the drill string and drill bit.

Description

BACKGROUND OF THE DISCLOSURE[0001] The present invention relates generally to drill bit stabilizers for drilling subterranean formations, particularly, to a stabilizer for providing full gauge stabilization for a drill bit.[0002] When drilling a well bore, for example drilling an oil and gas well, many problems are encountered. A substantial portion of such drilling problems relate to drill bit and drill string instability which places high stress on drilling equipment, not only on drill bits but also on downhole tools and the drill string. Drill bit instability problems are particularly inherent with bi-center bit designs because of an inability to provide full gauge stabilization near the bit. Bi-center bits drill a larger hole than the pass through diameter of the casing, therefore conventional stabilizers cannot pass through the casing with the bi-center bit. For this reason, bi-center bits are typically run with no stabilization within approximately the bottom 50 feet of the bo...

AI Technical Summary

Benefits of technology

[0006] It is yet another object of the present invention to provide a drill bit stabilizer which may rotationally deploy a stabilizer blade from a first position to a second position opposite the first position.

Problems solved by technology

When drilling a well bore, for example drilling an oil and gas well, many problems are encountered.

A substantial portion of such drilling problems relate to drill bit and drill string instability which places high stress on drilling equipment, not only on drill bits but also on downhole tools and the drill string.

Drill bit instability problems are particularly inherent with bi-center bit designs because of an inability to provide full gauge stabilization near the bit.

Bi-center drill bits, designed to simultaneously drill and under-ream a wellbore, are particularly prone to poor directional control, and often produce smaller than expected hole diameter because of the lack of stabilization.

While bi-center bits have been available for more than twenty years, they have seen limited use because of the inherent problems associated with bi-center drill bits.

While advances have been made to overcome the inherent instability of the bi-center bit, it has yet to realize its full potential as a reliable alternative to conventional undereaming.

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