The crosswell electromagnetic response of layered media

Thesis/Dissertation · Fri Apr 01 04:00:00 EST 1994

DOI:https://doi.org/10.2172/10165270· OSTI ID:10165270

Deszcz-Pan, Maria ^[1]

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1. Univ. of California, Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering

Crosswell electromagnetic measurements are a promising new geophysical technique for mapping subsurface electrical conductivity which can provide information about the subsurface distribution of water, oil or steam. In this work the fields from a low frequency vertical magnetic dipole have been examined from the specific point of view of their application to the determination of the conductivity of a layered medium. The source and the receiver were placed inside two separate boreholes. The range of penetration of such a crosswell system for typical earth resistivities and for currently available transmitter and receiver technologies was found to be up to 1,000 meters so problems in ground water and petroleum reservoir characteristics can be practically examined. An analysis of the behavior of the magnetic fields at the boundary between two half-spaces showed that the horizontal magnetic field component, H{rho}, and the vertical derivative of a vertical component, {delta}H{sub z}/{delta}z, are more sensitive to conductivity variations than H{sub z}. The analysis of derivatives led to the concept of measuring the conductivity directly using a second vertical derivative of H{sub z}. Conductivity profiles interpreted from field data using this technique reproduced accurately the electrical logs for a test site near Devine, Texas. It was found in this study that the inversion techniques are more stable when the first vertical derivative of H{sub z} is used rather than H{sub z} itself. Using data from a salt water injection experiment at the Richmond Field test site in Berkeley it was also found that these robust layer inversions were successful in identifying the preferential flow direction of the injected brine to four boreholes surrounding the injection well.

• Research Organization: Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 10165270
• Report Number(s): LBL--35487; ON: DE94014929
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200
15 GEOTHERMAL ENERGY
150303
58 GEOSCIENCES
580000
DATA ANALYSIS
ELECTRIC CONDUCTIVITY
ELECTROMAGNETIC SURVEYS
EXPERIMENTAL DATA
EXPLORATORY DRILLING AND WELL LOGGING
FLUID FLOW
GEOSCIENCES
GEOTHERMAL WELLS
Geothermal Legacy
OIL WELLS
PERFORMANCE TESTING
RESERVES, GEOLOGY, AND EXPLORATION
RESERVOIR FLUIDS
RESERVOIR ROCK
WATER WELLS
WELL LOGGING EQUIPMENT