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

Abstract

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. 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.

Inventors:
 [1]
  1. (Bothell, WA)
Issue Date:
Research Org.:
ParaMagnetic Logging, Inc. (Woodinville, WA)
Sponsoring Org.:
USDOE
OSTI Identifier:
868103
Patent Number(s):
5075626
Application Number:
07/434,886
Assignee:
ParaMagnetic Logging, Inc. (Woodinville, WA)
Patent Classifications (CPCs):
G - PHYSICS G01 - MEASURING G01V - GEOPHYSICS
DOE Contract Number:  
FG22-88BC14243
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
electronic; measurement; apparatus; movable; cased; borehole; compensating; casing; resistance; differences; methods; operation; pairs; voltage; electrodes; vertically; disposed; measure; resistivity; adjacent; geological; formations; inside; stationary; measurements; fixed; vertical; depth; discloses; step; subsequent; compensation; steps; respectively; resulting; improved; accuracy; multiple; frequency; simultaneously; moved; disclose; current; conducted; formation; provide; acquire; accurate; results; moved vertically; compensation steps; measurement apparatus; vertically disposed; voltage measurement; measurement electrodes; geological formations; adjacent geological; geological formation; multiple frequency; simultaneously provide; cased borehole; casing resistance; improved accuracy; frequency methods; operation result; discloses methods; fixed vertical; electronic measurement; electrodes vertically; cased bore; /324/

Citation Formats

Vail, III, William B. Electronic measurement apparatus movable in a cased borehole and compensating for casing resistance differences. United States: N. p., 1991. Web.
Vail, III, William B. Electronic measurement apparatus movable in a cased borehole and compensating for casing resistance differences. United States.
Vail, III, William B. Tue . "Electronic measurement apparatus movable in a cased borehole and compensating for casing resistance differences". United States. https://www.osti.gov/servlets/purl/868103.
@article{osti_868103,
title = {Electronic measurement apparatus movable in a cased borehole and compensating for casing resistance differences},
author = {Vail, III, William B.},
abstractNote = {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. 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.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1991},
month = {1}
}