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:
Jul. 06, 1993
Filed:
Jan. 21, 1992
Applicant:
Inventors:
Joseph H Frantz, Pittsburgh, PA (US);
Alfred Brown, Houston, TX (US);
Richard A Deans, Stamford, CT (US);
Assignee:
Texaco Inc., White Plains, NY (US);
Primary Examiner:
Int. Cl.
CPC ...
G01V / ;
U.S. Cl.
CPC ...
250260 ; 250259 ;
Abstract
A potassium salt which is soluble either in water or in an oil-based drilling mud is forced via filtrate invasion into permeable subsurface formation zones adjacent a well borehole via an over-balanced drilling mud or completion system. Well logging is then performed in an interval of interest in the formations using natural gamma ray spectrometry. Gamma radiation at an energy of 1.46 MeV from the naturally occurring radioactive potassium isotope .sup.40 K is detected. Gamma radiation levels of the isotope .sup.40 K above normal background readings indicate the presence of permeable formations.