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. 14, 1987
Filed:
Feb. 24, 1986
Applicant:
Inventors:
Harold J Vinegar, Houston, TX (US);
Monroe H Waxman, Houston, TX (US);
Assignee:
Shell Oil Company, Houston, TX (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01V / ; G01V / ;
U.S. Cl.
CPC ...
324366 ; 324373 ; 364422 ;
Abstract
An induced polarization tool using focused electrodes that uses direct coupling in the focusing loop to prevent spurious phase shifts. The invention uses a differential-in differential-out amplifier and voltage-controlled resistances to provide zero potential difference between pairs of monitoring electrodes. The measured current and voltage are digitized downhole and transmitted to the surface. At the surface means are provided for determining in-phase and quadrature response.