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. 15, 2008
Filed:
Jan. 19, 2005
Applicants:
Bruno Best, Rijswijk, NL;
Egbert Jan Van Riet, Rijswijk, NL;
Inventors:
Bruno Best, Rijswijk, NL;
Egbert Jan Van Riet, Rijswijk, NL;
Assignee:
Shell Oil Company, Houston, TX (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
E21B 4/02 (2006.01);
U.S. Cl.
CPC ...
Abstract
A hydraulic motor for use in subterranean drilling operations in which a drive fluid within a first reservoir is forced through the motor by a high pressure working fluid, such as drilling mud, the drive fluid entering a second reservoir upon exiting the motor. Upon a change in valving, the drive fluid in the second reservoir is forced through the motor by the high pressure working and back into the first reservoir.