UDEGBUNAM, EMMANUEL, and BRYAN HUFF, Illinois State Geological Survey, Champaign, IL

ABSTRACT: Integrated Geologic and Engineering Model for Improved Reservoir Development and Management at Energy Field, Williamson County, Illinois

This paper describes the techniques used, and results from, an integrated geological and engineering study of the reservoir geology, field development, 3-D geologic and pressure and production history matching, sensitivity analyses and reservoir performance predictions for two adjacent Aux Vases Sandstone (Mississippian) reservoirs in the southern part of Energy field, Williamson County, Illinois. The Illinois State Geological Survey is using state-of-the-art systems to take maximum advantage of limited data for reservoir characterization and management to identify unproduced mobile oil and deter abandonment of stripper wells. Reservoir description was achieved using porosity, permeability and fluid saturation values from correlation of core data to old electrical logs and new logsuit s. In wells for which no core data is available, the values were mathematically extrapolated using logs and the correlations previously developed. Sensitivity analyses of the recovery efficiencies of past development plans showed that neither reservoir has achieved optimal performance. Comparisons among several strategies for improving future recovery of mobile oil showed that waterflooding in combination with strategically located infill wells would yield the greatest oil recoveries. Use of this type of integrated geologic and engineering study leads to greater oil recovery and prudent field development strategies. Many of the results and techniques used in this study are transferable and can guide reservoir management plans in similar reservoirs.

AAPG Search and Discovery Article #90987©1993 AAPG Annual Convention, New Orleans, Louisiana, April 25-28, 1993.