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. 19, 1977
Filed:
Oct. 17, 1975
Wilbur Lee Daniel, Houston, TX (US);
Dresser Industries, Inc., Dallas, TX (US);
Abstract
A well logging instrument comprises a focus section having a focus upper guard, a center electrode and lower focus guard. The bottom section of the instrument includes a pad device having electrodes on its borehole wall-engaging surface and adapted to be urged against the borehole wall and also having one or more pressure relief devices, for example, spring-loaded check valves, located therein to reduce differential pressure which might otherwise build up between the surface of the pad and the borehole wall. The remote electrode of the focus portion of the instrument is the armor surrounding the logging cable. The lower focus guard serves a dual function in that it is also the mini-focus remote electrode. Means are provided for measuring the potential between the focus guard and the cable armor and also between the microguard and the lower focus guard, both measurements then being sent up the logging cable to the surface electronics.