The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 13, 1991
Filed:
Jun. 11, 1990
Applicant:
Inventor:
Kirk R Shirley, Houston, TX (US);
Assignee:
Other;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
E21B / ; E21B / ;
U.S. Cl.
CPC ...
175 76 ; 175325 ;
Abstract
An improved drill steering apparatus which includes a lower stabilizer assembly mounted on the drill string in close relationship to the drill bit and an upper stabilizer assembly mounted on said drill string at a position spaced above said lower stabilizer assembly. In the preferred form of the invention, the pressure responsive element of the stabilizer assemblies are pressure responsive bladders and the lower or slave bladders have a larger effective pressure area than the upper bladders. In a modified form of the invention, the pressure responsive elements are pistons and the lower stabilizer assembly includes at least one more piston in each ground than the upper stabilizer assembly.