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. 16, 1980
Filed:
Mar. 05, 1979
Donald W Oliver, Houston, TX (US);
Richard B Culver, Houston, TX (US);
Dresser Industries, Inc., Dallas, TX (US);
Abstract
In a neutron induced gamma ray well logging instrument, a neutron generator is pulsed at a clock frequency of 20 KHz. Each neutron burst produces inelastic scattering gamma rays which are detected during a first time interval coinciding with the neutron source being on. Capture gamma rays are detected during a second interval subsequent to the end of each neutron burst. Upon detection of the scattered gamma rays, a detection pulse is transmitted during each of the two detection intervals. Sync pulses are generated at a scaled down frequency rate of 200 Hz within the well logging instrument for transmission to the earth's surface. The scaled-down sync pulses are applied to a phase-locked loop system for regenerating the sync pulses to the same frequency as that of the clock frequency used to pulse the neutron source and to open the detection gates in the borehole instrument. The regenerated sync pulses are then used in surface instrumentation to route the pulse occurring during the inelastic scattering interval to one section of a multi-channel analyzer. Similarly, the pulse occurring in the capture interval is routed into another section of the multi-channel analyzer. The use of memory address decoders, subtractors and ratio circuits enables both a carbon/oxygen ratio and a hydrogen/iron ratio to be obtained, substantially independent of chlorine content of the borehole and formation.