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Title: Methods and apparatus for measurement of electronic properties of geological formations through borehole casing

Abstract

Methods and apparatus are provided for measuring electronic properties of geological formations and cement layers adjacent to cased boreholes including resistivities, polarization phenomena and dielectric constants. Current is passed from an electrode in electrical contact with the interior of the borehole casing to an electrode on the surface of the earth. At least three voltage measuring electrodes in electrical contact with the interior of the casing measure the voltage at various points thereon. The voltage differences between discrete pairs of the voltage measuring electrodes provide a measurement of the differential current conducted into formation in the vicinity of those electrodes. These measurements facilitate calculation of the resistivities of the adjacent geological formations as well as an indication of whether cement is present. Measurements of the differential voltage response to transient currents provide a measurement of the polarization phenomena in formation as well as the capacitance of the casing in contact with the formation which is useful for determining whether oil and gas present. Lithological characteristics of the formation such as the pressence or absence of clay can also be determined. A calibration procedure is provided for minimizing errors induced by variations in the casing. The device also may be placedmore » within the pipe attached to a drill bit while drilling open holes.« less

Inventors:
 [1]
  1. (Bothell, WA)
Publication Date:
Research Org.:
ParaMagnetic Logging, Inc. (Bothell, WA)
OSTI Identifier:
867955
Patent Number(s):
US 5043668
Assignee:
ParaMagnetic Logging Inc. (Woodinville, WA)
DOE Contract Number:  
FG06-84ER13294
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
methods; apparatus; measurement; electronic; properties; geological; formations; borehole; casing; provided; measuring; cement; layers; adjacent; cased; boreholes; including; resistivities; polarization; phenomena; dielectric; constants; current; passed; electrode; electrical; contact; interior; surface; earth; voltage; electrodes; measure; various; thereon; differences; discrete; pairs; provide; differential; conducted; formation; vicinity; measurements; facilitate; calculation; indication; response; transient; currents; capacitance; useful; determining; oil; gas; lithological; characteristics; pressence; absence; clay; determined; calibration; procedure; minimizing; errors; induced; variations; device; placed; pipe; attached; drill; bit; drilling; holes; measuring electrodes; dielectric constants; geological formations; dielectric constant; electrical contact; drill bit; voltage measuring; cased boreholes; electronic properties; borehole casing; adjacent geological; geological formation; voltage difference; transient current; calibration procedure; pipe attached; cased borehole; casing measure; cement layers; differential current; voltage differences; electrodes provide; current conducted; polarization phenomena; measuring electronic; measuring electrode; errors induced; layers adjacent; discrete pairs; cased bore; /324/

Citation Formats

Vail, III, William B. Methods and apparatus for measurement of electronic properties of geological formations through borehole casing. United States: N. p., 1991. Web.
Vail, III, William B. Methods and apparatus for measurement of electronic properties of geological formations through borehole casing. United States.
Vail, III, William B. Tue . "Methods and apparatus for measurement of electronic properties of geological formations through borehole casing". United States. https://www.osti.gov/servlets/purl/867955.
@article{osti_867955,
title = {Methods and apparatus for measurement of electronic properties of geological formations through borehole casing},
author = {Vail, III, William B.},
abstractNote = {Methods and apparatus are provided for measuring electronic properties of geological formations and cement layers adjacent to cased boreholes including resistivities, polarization phenomena and dielectric constants. Current is passed from an electrode in electrical contact with the interior of the borehole casing to an electrode on the surface of the earth. At least three voltage measuring electrodes in electrical contact with the interior of the casing measure the voltage at various points thereon. The voltage differences between discrete pairs of the voltage measuring electrodes provide a measurement of the differential current conducted into formation in the vicinity of those electrodes. These measurements facilitate calculation of the resistivities of the adjacent geological formations as well as an indication of whether cement is present. Measurements of the differential voltage response to transient currents provide a measurement of the polarization phenomena in formation as well as the capacitance of the casing in contact with the formation which is useful for determining whether oil and gas present. Lithological characteristics of the formation such as the pressence or absence of clay can also be determined. A calibration procedure is provided for minimizing errors induced by variations in the casing. The device also may be placed within the pipe attached to a drill bit while drilling open holes.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1991},
month = {1}
}

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