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, 1999
Filed:
Mar. 03, 1997
Applicant:
Inventors:
Assignee:
Baker Hughes Incorporated, Houston, TX (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F21B / ;
U.S. Cl.
CPC ...
175 71 ; 175205 ;
Abstract
A casing or tubing segment or segments are disclosed which can be used to create a parasite annulus during drilling. The cased wellbore receives a string containing valves and the drillstring operates through it. As the mud circulates, the segments of the tubing or casing provide communication at various depths from the parasite annulus (i.e., the outermost annulus) into the circulating mud, which is the innermost annulus. Each valve is adjustable to alter the amount of differential pressure required in order to open it. The valves are also in hydraulic pressure balance so that only the pressure added by the injected gas acts to open them. The valves close by a spring bias.