ABSTRACT

The Pachuta Creek Oil field, located in T-2-N, R-14-E Clarke County, Mississippi, was discovered in 1968. Since that time, the field has yielded over twenty-four million barrels of oil from the Smackover Formation. In addition to the 81 wells which have been drilled in the field, there exists a good coverage of seismic data. However, previous studies of the Pachuta Creek area have been unable to thoroughly integrate the geophysical and geological data into structural maps. This difficulty is due to the dynamic nature of the acoustic velocities associated with the changing lithologies in the area. The creation of average acoustic velocity maps has been accomplished by close correlation of the seismic data with the subsurface well information. These velocity maps represent the average acoustic velocity configuration from sea level to the top of each of three formations: the Haynesville, Smackover and Louanna Salt. These average velocity maps provide the key for transforming seismic data (in time) to subsea depths consistent with the subsurface well control. Subsurface structure maps have been constructed at the top of each of the three formations previously identified. These maps represent a thorough integration of both geological and geophysical data and provide a means for accurately ascertaining remaining hydrocarbon potential in this area. The algorithms which have been used for the combination of the geologic and seismic data in this study may be used to provide more complete subsurface interpretations in other areas.