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:
Mar. 17, 1987
Filed:
Jul. 25, 1986
Gary L Marsh, New Orleans, LA (US);
Shell Offshore Inc., Houston, TX (US);
Abstract
The present invention is directed to a pressurized fluid accumulator adapted to be connected to a subsea valve actuator on a drilling wellhead assembly, prior to lowering the combined assembly to the ocean floor. The apparatus of the present invention consists of a pressure compensated piston located in a first hydraulic cylinder. Movement of this piston causes pressurized hydraulic fluid to be delivered in sufficient volume to activate a subsea hydraulically-activated valve. The first piston is connected to and driven by a second piston contained in a second hydraulic cylinder. Charging and accumulation of pressurized hydraulic fluid in the first cylinder causes a nearly absolute vacuum to be developed under the second piston. The pressure differential between this vacuum and the prevailing sea pressure is used to move the first piston during delivery of the hydraulic fluid to the actuator of the hydraulically activated valve.