Developing a Naturally Fractured Reservoir for Underground Gas Storage

In this paper we present a field development case study of a gas storage field within a fractured reservoir during which the integration of multiple data sets was required and which proved critical to the project’s success. During this study the interpretation of seismic attribute volumes, generate through spectral decomposition, was shown to be the key step in the data integration. The interpretation of 3-D iso-frequency seismic volumes, the results of the spectra decomposition, successfully identified subtle structural features, previously unresolved, which controlled the natural fracture system. The existence of these subtle structural features, small displacement shear faults, were subsequently confirmed when eight horizontal gas storage wells were drilled through these faults and borehole image logs were obtained. This study was performed to develop the Oriskany reservoir in the Steckman Ridge Underground Gas Storage (UGS) Field, which is located in Bedford County, Pennsylvania, USA.