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:
Feb. 02, 2016
Filed:
Oct. 15, 2013
National Oilwell Varco, L.p., Houston, TX (US);
Frank B. Springett, Spring, TX (US);
Svein Ove Aanesland, Høllen I Søgne, NO;
Geoffrey Alexander Pickett, Sugar Land, TX (US);
National Oilwell Varco, L.P., Houston, TX (US);
Abstract
A dual gradient drilling system comprises a primary riser that is coupled to a drilling rig and a subsea wellhead and an auxiliary riser that is coupled to the drilling rig and to the primary riser by a fluid conduit that is disposed at a point between the drilling rig and the wellhead. The fluid conduit provides fluid communication between the primary riser and the auxiliary riser. A pump system is disposed within the auxiliary riser and is in fluid communication with the fluid conduit. A drive string is disposed within the auxiliary riser and is coupled to the pump system so as to operably couple the pump system to the drilling rig.