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Title: Dual excitation acoustic paramagnetic logging tool

Abstract

New methods and apparatus are disclosed which allow measurement of the presence of oil and water in geological formations using a new physical effect called the Acoustic Paramagnetic Logging Effect (APLE). The presence of petroleum in formation causes a slight increase in the earth's magnetic field in the vicinity of the reservoir. This is the phenomena of paramagnetism. Application of an acoustic source to a geological formation at the Larmor frequency of the nucleons present causes the paramagnetism of the formation to disappear. This results in a decrease in the earth's magnetic field in the vicinity of the oil bearing formation. Repetitively frequency sweeping the acoustic source through the Larmor frequency of the nucleons present (approx. 2 kHz) causes an amplitude modulation of the earth's magnetic field which is a consequence of the APLE. The amplitude modulation of the earth's magnetic field is measured with an induction coil gradiometer and provides a direct measure of the amount of oil and water in the excitation zone of the formation. The phase of the signal is used to infer the longitudinal relaxation times of the fluids present, which results in the ability in general to separate oil and water and to measuremore » the viscosity of the oil present. Such measurements may be performed in open boreholes and in cased well bores. The Dual Excitation Acoustic Paramagnetic Logging Tool employing two acoustic sources is also described. 6 figs.« less

Inventors:
Issue Date:
OSTI Identifier:
7271362
Patent Number(s):
4804918 A
Application Number:
PPN: US 7-153061
Assignee:
ParaMagnetic Logging, Inc., Woodinville, WA (United States) PTO; EDB-94-113939
DOE Contract Number:  
FG06-84ER13294
Resource Type:
Patent
Resource Relation:
Patent File Date: 8 Feb 1988
Country of Publication:
United States
Language:
English
Subject:
02 PETROLEUM; 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; OIL WELLS; SONIC LOGGING; RESERVOIR ROCK; PARAMAGNETISM; WELL LOGGING EQUIPMENT; DESIGN; OPERATION; AQUIFERS; CONCENTRATION RATIO; RESERVOIR FLUIDS; VISCOSITY; EQUIPMENT; FLUIDS; MAGNETISM; WELL LOGGING; WELLS; 020200* - Petroleum- Reserves, Geology, & Exploration; 400400 - Electrochemistry

Citation Formats

Vail, W.B. III. Dual excitation acoustic paramagnetic logging tool. United States: N. p., 1989. Web.
Vail, W.B. III. Dual excitation acoustic paramagnetic logging tool. United States.
Vail, W.B. III. Tue . "Dual excitation acoustic paramagnetic logging tool". United States.
@article{osti_7271362,
title = {Dual excitation acoustic paramagnetic logging tool},
author = {Vail, W.B. III.},
abstractNote = {New methods and apparatus are disclosed which allow measurement of the presence of oil and water in geological formations using a new physical effect called the Acoustic Paramagnetic Logging Effect (APLE). The presence of petroleum in formation causes a slight increase in the earth's magnetic field in the vicinity of the reservoir. This is the phenomena of paramagnetism. Application of an acoustic source to a geological formation at the Larmor frequency of the nucleons present causes the paramagnetism of the formation to disappear. This results in a decrease in the earth's magnetic field in the vicinity of the oil bearing formation. Repetitively frequency sweeping the acoustic source through the Larmor frequency of the nucleons present (approx. 2 kHz) causes an amplitude modulation of the earth's magnetic field which is a consequence of the APLE. The amplitude modulation of the earth's magnetic field is measured with an induction coil gradiometer and provides a direct measure of the amount of oil and water in the excitation zone of the formation. The phase of the signal is used to infer the longitudinal relaxation times of the fluids present, which results in the ability in general to separate oil and water and to measure the viscosity of the oil present. Such measurements may be performed in open boreholes and in cased well bores. The Dual Excitation Acoustic Paramagnetic Logging Tool employing two acoustic sources is also described. 6 figs.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1989},
month = {2}
}