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Title: Methods of operation of apparatus measuring formation resistivity from within a cased well having one measurement and two compensation steps

Patent ·
OSTI ID:868834

Methods of operation of an apparatus having at least two pairs of voltage measurement electrodes vertically disposed in a cased well to measure the resistivity of adjacent geological formations from inside the cased well. During stationary measurements with the apparatus at a fixed vertical depth within the cased well, the invention herein discloses methods of operation which include a measurement step and subsequent first and second compensation steps respectively resulting in improved accuracy of measurement. First and second order errors of measurement are identified, and the measurement step and two compensation steps provide methods to substantially eliminate their influence on the results. A multiple frequency apparatus adapted to movement within the well is described which simultaneously provide the measurement and two compensation steps.

Research Organization:
ParaMagnetic Logging, Inc. (Bothell, WA)
DOE Contract Number:
FG06-84ER13294
Assignee:
Para Magnetic Logging, Inc. (Woodinville, WA)
Patent Number(s):
US 5223794
OSTI ID:
868834
Country of Publication:
United States
Language:
English