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:
Jun. 16, 2015
Filed:
Sep. 24, 2012
Applicant:
Reelwell, A.s., Royneberg, NO;
Inventors:
Tore Høgset, Stavanger, NO;
Harald Syse, Royneberg, NO;
Assignee:
Reelwell, A.S., Stavanger, NO;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
E21B 21/12 (2006.01); E21B 21/10 (2006.01);
U.S. Cl.
CPC ...
E21B 21/12 (2013.01); E21B 21/10 (2013.01);
Abstract
A method for operating a dual drill string disposed in a wellbore, the string having a shutoff valve for at least a fluid return drill string therein proximate a bottom end thereof includes pumping fluid into the fluid return string such that a pressure therein is substantially equal to a fluid pressure in the wellbore. Circulation of fluid in the wellbore is initiated by pumping fluid into a fluid supply string of the dual drill string such that the shutoff valve on the fluid return string opens to enable the fluid leaving the wellbore to enter the fluid return string.