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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 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 are present. Lithological characteristics of the formation such as the presence 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. 48 figs.« less

Inventors:
Publication Date:
OSTI Identifier:
7024492
Patent Number(s):
US 4882542; A
Application Number:
PPN: US 7-089697
Assignee:
ParaMagnetic Logging, Inc., Bothell, WA (United States) PTO; EDB-94-113938
DOE Contract Number:  
FG06-84ER13294
Resource Type:
Patent
Resource Relation:
Patent File Date: 26 Aug 1987
Country of Publication:
United States
Language:
English
Subject:
02 PETROLEUM; 03 NATURAL GAS; 47 OTHER INSTRUMENTATION; NATURAL GAS WELLS; WELL LOGGING; OIL WELLS; RESERVOIR ROCK; ELECTRICAL PROPERTIES; WELL LOGGING EQUIPMENT; DESIGN; LITHOLOGY; MWD SYSTEMS; OPERATION; EQUIPMENT; GEOLOGY; PETROLOGY; PHYSICAL PROPERTIES; WELLS; 020200* - Petroleum- Reserves, Geology, & Exploration; 030200 - Natural Gas- Reserves, Geology, & Exploration; 440400 - Well Logging Instrumentation

Citation Formats

Vail, W.B. III. Methods and apparatus for measurement of electronic properties of geological formations through borehole casing. United States: N. p., 1989. Web.
Vail, W.B. III. Methods and apparatus for measurement of electronic properties of geological formations through borehole casing. United States.
Vail, W.B. III. Tue . "Methods and apparatus for measurement of electronic properties of geological formations through borehole casing". United States.
@article{osti_7024492,
title = {Methods and apparatus for measurement of electronic properties of geological formations through borehole casing},
author = {Vail, W.B. III.},
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 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 are present. Lithological characteristics of the formation such as the presence 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. 48 figs.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1989},
month = {11}
}