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. 14, 1984
Filed:
Sep. 28, 1981
Arnold M Walkow, Houston, TX (US);
Dresser Industries, Inc., Dallas, TX (US);
Abstract
An apparatus for determining the natural current flow in the casing of a well. The apparatus includes earth surface control and recording equipment connected by a cable to an instrument housing. A casing collar locator on the instrument is used to assist in positioning the instrument in the well casing. A plurality of electrodes on the instrument are contactable with the interior of the casing. The earth surface equipment and the electrodes are used to measure voltages and to pass an electrical current through the casing. Measurements of native voltages in the casing and the change in voltage between two locations in the casing during application of a known current are used to determine the casing's resistance at that location in the well and the native current flow between the well casing and the earth formation throughout the well.