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:
Aug. 01, 1989
Filed:
Jun. 26, 1987
Andre M Dorleans, Le Perray-En-Yvelines, FR;
TOTAL Compagnie Francaise des Petroles, Paris, FR;
Abstract
A drill string has a bulge equipped with a system of n injection ducts connecting the interior of the string surrounding annular space and opening upwardly into the space to divert a part of the drilling fluid supplied to the bit. This arrangement makes it possible to produce below the bulge a pressure decrease H markedly greater than 10 meters of water by setting the flow of drilling fluid in the system of injection ducts at a value, expressed in m.sup.3 /s, equal to approximately: .sqroot.10H.times.S.times.s33 n, S and s being the cross-sections, expressed in m.sup.2, respectively, of a part of the portion of the annular space included between the periphery of the bulge and the drill string and of the group of n injection ducts.