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:
Jun. 19, 1984
Filed:
Jun. 08, 1981
Paul L Sinclair, Houston, TX (US);
Schlumberger Technology Corporation, Houston, TX (US);
Abstract
A digital induction resistivity logging system is disclosed for digitally measuring in one phase sensitive detector both the in-phase (R) and quadrature (X) phase components in a receiver signal generated in response to eddy currents flowing in the earth's sub-surface formations. The induction logging system includes a central processing unit (CPU) located at the surface for receiving digital signals from a digital induction logging tool located downhole, and for processing the received data. The digital induction tool includes a digital sinewave generator for generating a highly phase stable, low distortion transmitter signal the frequency of which is selectable from among at least two transmitter frequencies. Automatic phase compensation is included to dynamically compensate for both static and temperature dependent phase shift errors introduced by circuits of the tool involved in the component measurements. A floating point analog-to-digital convertor capable of handling the wide dynamic range in the detected phase component signals is provided to convert the phase detector output into digital samples for use by the CPU.