Releasable drill string stabilizer

A stabilizer adapted to be releasably positioned on a drill collar for use in a drill string positioned in a well bore and above a drill bit which comprises:

• an elongate tubular body having a set of helical threads on the exterior;
• a multiturn coil spring positioned inside said tubular body having upper and lower ends thereof;
• first means for anchoring one end of the coil spring;
• second means for anchoring the remaining end of said spring after said spring has been wound around the drill collar on which the stabilizer is to be positioned sufficiently right to frictionally grip the drill collar and including a first tubular bolt nut which threads into said tubular body, and a second tubular bolt concentrically received in said first bolt, said first and second bolts having abutting end located shoulders and said spring is connected to the second bolt, and said shoulders include an irregular surface defined by angular surfaces interrupted by transverse shoulders which define a ratchet mechanism enabling said spring to tighten about the drill collar without slippage between said bolts;
• and
• said first and second means fixedly connecting said tubular body to said coil spring.

A stabilizer for releasable mounting with a drill string, comprising:

• a tubular body positionable around the drill string;
• a coil spring mounted within said tubular body and positionable around the drill string, said spring having a first and second end;
• anchoring means mounted with said body for preventing the circumferential movement of the first end of said spring around the drill string;
• and
• rotating means mounted with said body for moving the second end of said spring circumferentially around the drill string and anchoring the second end after said spring has gripped the drill string sufficiently tight to secure the body to the drill string while permitting the second end to be released when desired.