Spectral decomposition and reservoir engineering data in mapping thin bed reservoir, stratton field, South Texas

Spectral decomposition is an innovative seismic attribute that showed excellent results particularly in tertiary basins such as the Gulf of Mexico and West Africa on which the technique was first implemented. Therefore many interpreters worried that it would not work well in other environments. We conducted a spectral decomposition study at Stratton Field, in South Texas. We focus on Middle Frio fluvial F-39 reservoir, a gas producing reservoir in the Stratton field. The main purposes of this study are: First, to test spectral decomposition ability to infer information documented in previous work about this thin and deep reservoir. Second, to reveal more stratigraphic features that might not be revealed previously. Due to the complexity of the reservoir, well data calibration and correlation played a key role to locate the reservoir interval. Interestingly, spectral decomposition could successfully image reservoir and its compartments and provide information that correlate very well with production history and reservoir's pressures data. Moreover, it enabled us to map the reservoir compartments' boundaries and a meandering channel reservoir that was unseen in seismic broadband. Indeed, the study shows that spectral decomposition can work very well even in very complex and extremely thin reservoirs. Furthermore, it shows how geophysics, geology, and reservoir engineering technologies when best integrated can address very complex formations and reveal much reliable information.