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:
May. 14, 1996
Filed:
Oct. 12, 1994
Bruce J Watkins, Houston, TX (US);
Gerald W Crotwell, Sugar Land, TX (US);
Dril-Quip, Inc., Houston, TX (US);
Abstract
There is disclosed well apparatus wherein a so-called 'backout sub' connected by right-hand threads at its lower end to a lower well pipe has both left-hand threads thereabout for connection with left-hand threads on the lower end of one upper tubular member to permit it to be released and raised from the lower tubular member, in response to right hand rotation of the upper tubular member, and right-hand threads for connection with right-hand threads on the lower end of another upper tubular member for use in tying the lower tubular member and thus the lower well pipe back to the head of the well in response to right-hand rotation.