Faulted structural surfaces present difficult problems for the computer mapper, though several solutions are possible. In this paper, I present a method whereby the fault plane is treated as if it were a structural surface. The method uses fault picks, oil/water contact data, directional survey data, and reservoir data. The data are manipulated and mapped with a commercially available mapping package using standard gridding, editing, and data-to-grid manipulations. The resulting fault grids can be integrated with grids of structural surfaces, used as boundary surfaces, or used to develop fault gaps on structure maps.
Fault-surface modeling is most applicable to large oil fields with many wells. Several advantages have been realized, including accurate fault locations at all horizons and accurate predicted fault penetrations for new well locations. When new penetrations are encountered, they can be used to update the fault plane and then the revision can be employed to correct the structure maps. Multiple interpretations for the fault surface can be tested for validity. The techniques and products described were developed for the Wilmington oil field in Long Beach, California.
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Computer Modeling of Geologic Surfaces and Volumes
A collection of papers on computer-mapping case studies, this publication is a useful “go-by” for both beginners and advanced users of computer-mapping software. Fore the most part, the papers concentrate on the geologic features of significance to mapping, the methods used and their justification, and results obtained. The publication is separated into two parts. Part 1 consists of 12 papers dealing with data and surface modeling. Part 2 consists of 7 papers dealing with three-dimensional geologic block modeling.