SIMMS, STEVEN CASEY, Saudi Aramco, Dhahran, Saudi Arabia

ABSTRACT: Integration of 3-D Seismic Data With Reservoir Modeling of a Stratigraphically Complex Reservoir, Central Saudi Arabia

A 425-sq km, three-dimensional (3-D) seismic survey was shot in 1992 over one of the recently discovered oil fields in central Saudi Arabia. The primary objective of this survey was to provide stratigraphic control within a complex fluvial reservoir. The Permian age reservoir is a multistory, multilateral sequence of sandstones interbedded with nonproductive mudstones and siltstones. The seismic data were integrated with well control from over 50 wells to produce a 3-D geologic model of the reservoir. Numerous examples of the seismic and well data are presented in this case history. Stratigraphic cross sections through the wells illustrate that the complex nature of the reservoir and seismic sections through these wells show good correlation between seismic character and stratigraphy. Meandering channels and massive siltstone/mudstone bodies are clearly visible on seismic horizon slices and time slices. Faulting is evident on both seismic sections at time slices. Acoustic impedance sections produced from both forward and inverse modeling of the seismic data are compared with geologic models of porosity and lithology based on well control alone. Good correlation between acoustic impedance and porosity/lithology allow the use of the seismic data to guide the model between well locations. A geostatistical approach was used to interpolate between well control using the inverted seismic as "soft data." 3-D visualization of the geological model illustrates increasing complexity from well control only to an integrated model.

AAPG Search and Discovery Article #90990©1993 AAPG International Conference and Exhibition, The Hague, Netherlands, October 17-20, 1993.