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:
Apr. 09, 2002
Filed:
Nov. 18, 1999
Pierre Eisenmann, Paris, FR;
Jan W. Smits, Paris, FR;
Ollivier Faivre, Paris, FR;
Jean Claude Trouiller, Saint Remy les Chevreuse, FR;
Schlumberger Technology Corporation, Ridgefield, CT (US);
Abstract
A method of measuring the resistivity of drilling mud in a borehole passing through a terrestrial formation includes the steps of a) inserting a sonde into the borehole, the sonde having an elongate body provided with at least one annular current electrode (A , A′ ) and at least two annular guard electrodes (A, A′, A , A′ , A , A′ ) situated on either side of the annular current electrode; b) performing computed focusing to simulate an operating mode in which at least one current I is emitted into the surrounding formation from the annular current electrode, the current I being focused in the formation by emitting two currents I and I′ from the two annular guard electrodes situated on either side of the annular current electrode; and c) producing a signal representative of the resistivity R of the drilling mud from the simulated operating mode. Apparatus for measuring the resistivity of drilling mud in a borehole includes the sonde, and electronic circuitry for performing computed focusing and computing a signal representative of the resistivity R of the drilling mud on the basis of the computed focusing.