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Title: Electronic measurement apparatus movable in a cased borehole and compensating for casing resistance differences

Abstract

Methods of operation are described for 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. The invention also discloses multiple frequency methods of operation resulting in improved accuracy of measurement while the apparatus is simultaneously moved vertically in the cased well. The multiple frequency methods of operation disclose a first A.C. current having a first frequency that is conducted from the casing into formation and a second A.C. current having a second frequency that is conducted along the casing. The multiple frequency methods of operation simultaneously provide the measurement step and two compensation steps necessary to acquire accurate results while the apparatus is moved vertically in the cased well. 6 figures.

Inventors:
Issue Date:
Research Org.:
Paramagnetic Logging Inc
Sponsoring Org.:
USDOE
OSTI Identifier:
7027207
Patent Number(s):
5075626 A
Application Number:
CNN: 5088-212-1664; PPN: US 7-434886
Assignee:
ParaMagnetic Logging, Inc., Woodinville, WA (United States) NETL; EDB-94-111631
DOE Contract Number:  
FG22-88BC14243
Resource Type:
Patent
Resource Relation:
Patent File Date: 13 Nov 1989
Country of Publication:
United States
Language:
English
Subject:
47 OTHER INSTRUMENTATION; RESISTIVITY LOGGING; WELL LOGGING EQUIPMENT; OPERATION; DATA ACQUISITION; ELECTRIC CONDUCTIVITY; FREQUENCY DEPENDENCE; RESERVOIR ROCK; ELECTRIC LOGGING; ELECTRICAL PROPERTIES; EQUIPMENT; PHYSICAL PROPERTIES; WELL LOGGING; 440400* - Well Logging Instrumentation

Citation Formats

Vail, W.B. III. Electronic measurement apparatus movable in a cased borehole and compensating for casing resistance differences. United States: N. p., 1991. Web.
Vail, W.B. III. Electronic measurement apparatus movable in a cased borehole and compensating for casing resistance differences. United States.
Vail, W.B. III. Tue . "Electronic measurement apparatus movable in a cased borehole and compensating for casing resistance differences". United States.
@article{osti_7027207,
title = {Electronic measurement apparatus movable in a cased borehole and compensating for casing resistance differences},
author = {Vail, W.B. III.},
abstractNote = {Methods of operation are described for 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. The invention also discloses multiple frequency methods of operation resulting in improved accuracy of measurement while the apparatus is simultaneously moved vertically in the cased well. The multiple frequency methods of operation disclose a first A.C. current having a first frequency that is conducted from the casing into formation and a second A.C. current having a second frequency that is conducted along the casing. The multiple frequency methods of operation simultaneously provide the measurement step and two compensation steps necessary to acquire accurate results while the apparatus is moved vertically in the cased well. 6 figures.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1991},
month = {12}
}