Abstract: Improving Field Economics Using Seismically Integrated Geologic Modeling

Helwick, S. J.; Craig S. Calvert, R. Scott Hubbard, Kamal Bhuyan - Exxon Production Research Co.

The availability of accurate three-dimensional geologic models for fields with limited well control is important for planning development wells and for developing depletion plans. In the study of the Mobile Bay field (Gulf of Mexico), seismic data were used to supplement well data and proved to be a valuable source of information for building a geologic model for an area in the field that was penetrated by only three wells.

The 3-D seismic survey was used to interpret the upper limit of producible reservoir, which defined the top of the geologic model. The interpreted base of the Norphlet Formation defined the base of the geologic model. This reservoir interval consisted of amalgamated aeolian dunes.

Seismic-attribute analysis provided a dense grid of predictions for the major reservoir facies: crestal, flank, and interdune. It also provided quantitative estimates of porosity and lateral porosity continuity. Analyses were performed in three dimensions so that vertical changes in facies and porosity could be obtained over the reservoir interval.

Geologic modeling used cokriging-based geostatistical simulation to build the porosity model. Modeling integrated the well data with seismic information on reservoir facies, porosity, and porosity continuity. The resulting porosity model was transformed to permeability using a cloud transform method that preserved reservoir heterogeneity. The resulting model was used in flow simulation studies to evaluate several scenarios for developing the field.

AAPG Search and Discovery Article #90933©1998 ABGP/AAPG International Conference and Exhibition, Rio de Janeiro, Brazil