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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 the 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 maymore » be placed within the pipe attached to a drill bit while drilling open holes. 48 figures.« less

Inventors:
Publication Date:
OSTI Identifier:
7178970
Patent Number(s):
US 5043668; A
Application Number:
PPN: US 7-435273
Assignee:
ParaMagnetic Logging Inc., Woodinville, WA (United States)
DOE Contract Number:  
FG06-84ER13294
Resource Type:
Patent
Resource Relation:
Patent File Date: 30 Oct 1989
Country of Publication:
United States
Language:
English
Subject:
02 PETROLEUM; 03 NATURAL GAS; 47 OTHER INSTRUMENTATION; NATURAL GAS WELLS; RESISTIVITY LOGGING; OIL WELLS; WELL LOGGING EQUIPMENT; DESIGN; OPERATION; DIELECTRIC PROPERTIES; ELECTRIC CONDUCTIVITY; LITHOLOGY; MWD SYSTEMS; POLARIZATION; RESERVOIR ROCK; WELL CASINGS; ELECTRIC LOGGING; ELECTRICAL PROPERTIES; EQUIPMENT; GEOLOGY; PETROLOGY; PHYSICAL PROPERTIES; WELL LOGGING; WELLS; 020200* - Petroleum- Reserves, Geology, & Exploration; 030200 - Natural Gas- Reserves, Geology, & Exploration; 440400 - Well Logging Instrumentation

Citation Formats

Vail, III, W B. Methods and apparatus for measurement of electronic properties of geological formations through borehole casing. United States: N. p., 1991. Web.
Vail, III, W B. Methods and apparatus for measurement of electronic properties of geological formations through borehole casing. United States.
Vail, III, W B. 1991. "Methods and apparatus for measurement of electronic properties of geological formations through borehole casing". United States.
@article{osti_7178970,
title = {Methods and apparatus for measurement of electronic properties of geological formations through borehole casing},
author = {Vail, III, W 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 the 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 figures.},
doi = {},
url = {https://www.osti.gov/biblio/7178970}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Aug 27 00:00:00 EDT 1991},
month = {Tue Aug 27 00:00:00 EDT 1991}
}