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, 1991
Filed:
Sep. 14, 1989
Applicant:
Inventors:
Mario Ruscev, Issy Les Moulineaux, FR;
Patrick Vandenabeele, Clamart, FR;
Assignee:
Schlumberger Technology Corporation, New York, NY (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01B / ;
U.S. Cl.
CPC ...
73784 ;
Abstract
The present invention relates to a method and apparatus for measuring subsidence by evaluating the distance between radioactive markers which have previously been implanted in the formation traversed by a borehole. The apparatus comprises an elongate body containing at least two nuclear detection assemblies which are spaced apart along the longitudinal axis of the body. Each detection assembly inludes at least one position sensitive detector for detecting position along the longitudinal axis of the body. Measurements are performed while the apparatus is held stationary opposite the markers.