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:
Jan. 19, 1988
Filed:
Dec. 22, 1986
Applicant:
Inventor:
Thomas B Dellinger, Duncanville, TX (US);
Assignee:
Mobil Oil Corporation, New York, NY (US);
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
E21B / ;
U.S. Cl.
CPC ...
175 61 ; 175 73 ;
Abstract
Directional drilling is carried out with a rotary drilling tool having a drill string, a drill bit, a drill motor for rotating the drill bit independently of the drill string, an extension sub having both axially contracted and axially extended positions for providing weight to the drill bit when moving from a contracted to an extended position so as to effect a drilling stroke by the drill bit into the wellbore bottom when drilling with the drill bit independently of rotation of the drill string and a relaxation device for removing any excess weight on the drill bit that would otherwise be detrimental to the direction drilling of a deviated wellbore.