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:
Dec. 08, 1987
Filed:
Apr. 01, 1985
Michael A Ondrik, Albuquerque, NM (US);
S.I.E., Inc., Fort Worth, TX (US);
Abstract
A method of measuring earth formation characteristics using a pulsed neutron source computes the characteristics by using a cumulative count curve. A pulsed neutron source and detector are pulled upwardly through a borehole. The pulsed neutron source repetitively irradiates the earth formations with pulses of fast neutrons from the neutron source, creating thermal neutrons due to collisions in the formations. Detectors in the downhole instrument detect gamma rays emanating from the irradiated formations as a result of the capture of thermal neutrons. The gamma rays are cumulatively counted in a plurality of separate time bins between each of neutron pulses. The cumulative counts define points on a cumulative count versus time curve which has a mathematical expression. Count data is transmitted to a surface panel, which uses iterative least squares fit techniques to calculate the formation lifetime decay constant. The processor changes the pulse firing rate every two inch depth increment based on the new formation lifetime constant calculated.