Integrated Modeling of Salt Features in a GIS Environment: Examples from the Gulf of Mexico and Kazakhstan

By

Weber, R.W. and Odegard, M.E.

Geophysical Exploration Technology, Inc. (GETECH), Stafford, TX

Features such as salt dome, wings and turtle structures are important primarily for hydrocarbon exploration, but also for mining and storage. We integrate seismic, well, geological, gravity and magnetic data to model salt features. GETECH (with Precision Mapping) has modeled over four hundred of these features worldwide. We present examples of these models along with examples of how the results were used in exploration, production and storage.

Our method begins with the assembly of seismic, well and geological data, which are used to constrain the inversion and modeling of the salt. Magnetic data are used to constrain basement features and the extent of salt. Densities are derived from well log data and from lithologies.

Modeling begins with Cordell-Henderson inversion for the initial salt body shapes. The shape is then constrained further with available local seismic and well penetrations. The gravity field is calculated from initial and subsequent models using the Talwani-Ewing method. The measured gravity field, calculated field and their difference are displayed as GeoTiffs in a highly integrated ArcView GIS environment along with the salt contours as shape files. The contour shape files are edited in ArcView to better match the measured field. This process continues in an iterative manner until the calculated and measured fields match closely. The final result can then be viewed with our 3-D model viewing software.