Three-dimensional electromagnetic cross-well inversion

Journal Article · Fri Jan 01 00:00:00 EST 1993 · IEEE Transactions on Geoscience and Remote Sensing (Institute of Electrical and Electronics Engineers); (United States)

DOI:https://doi.org/10.1109/36.210452· OSTI ID:6764430

Tripp, A C; Hohmann, G W ^[1]

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1. Univ. of Utah, Salt Lake City (United States)

Effective use of electromagnetics in delineating and monitoring hydrocarbon reservoirs will require the rapid computerized inversion of large cross-well data sets subject to constraint by other data such as seismic data and well-logs. Ideally, an inversion algorithm would be capable of inverting data to a three-dimensional model without theoretical limitations on the geometry or resistivity distribution of the model. The authors research has concentrated on developing such an algorithm for a vertical magnetic dipole source and a vertical magnetic field component receiver. An inversion algorithm requires an effective numerical solution for calculating the electromagnetic response of a particular trial reservoir model. The authors use a three-dimensional integral equations algorithm which has been extensively tested, is well understood, and does not require an exorbitant amount of computer time or storage for moderately complicated models. The inversion formalism used is the Marquardt technique of nonlinear least-squares optimization. The system derivatives are calculated using an exact expression derived from reciprocity. The derivative calculation involves introducing sources at the receiver locations with subsequent back-substitution into the impedance matrix equation. They have tested the inversion algorithm on data gathered with a laboratory scale model. Convergence to the neighborhood of the correct model from distant initial trial models is good. However, accurate estimation of resistivity requires that constraints be placed on the model space.

• DOE Contract Number: AC03-76SF00098
• OSTI ID: 6764430
• Journal Information: IEEE Transactions on Geoscience and Remote Sensing (Institute of Electrical and Electronics Engineers); (United States), Vol. 31:1; ISSN 0196-2892
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
03 NATURAL GAS
47 OTHER INSTRUMENTATION
ELECTROMAGNETIC SURVEYS
DATA ANALYSIS
DATA PROCESSING
NATURAL GAS DEPOSITS
PETROLEUM DEPOSITS
ALGORITHMS
DATA COMPILATION
DIPOLES
EXPLORATION
NATURAL GAS WELLS
OIL WELLS
RESERVOIR ROCK
THREE-DIMENSIONAL CALCULATIONS
WELL LOGGING
WELL LOGGING EQUIPMENT
DATA
ELECTRICAL SURVEYS
EQUIPMENT
GEOLOGIC DEPOSITS
GEOPHYSICAL SURVEYS
INFORMATION
MATHEMATICAL LOGIC
MINERAL RESOURCES
MULTIPOLES
PROCESSING
RESOURCES
SURVEYS
WELLS
020200* - Petroleum- Reserves
Geology
& Exploration
030200 - Natural Gas- Reserves
Geology
& Exploration
440400 - Well Logging Instrumentation