Publications

The Sumpal Gas Field is a large onshore fractured basement field of approximately 1.6 TCF in place, located in the Corridor Block, South Sumatra, Indonesia. The top Pre-Tertiary (PRT) structural attribute is considered of major importance for basement characterization, as identified fault planes at this level, is a mean of imaging fractures density and eventually targets for well planning. Building on recent successful fault network characterization work based on beam migration reprocessing performed in Vietnam and the nearby Suban field in South Sumatra, a similar land 3D seismic reprocessing project for the Sumpal field was completed in 2013. However, the processing sequence was further enhanced by incorporating anisotropic pre-stack beam depth migration and azimuthal sector processing. Following successful reprocessing, the data was analyzed using various structural attributes including coherency, volume curvature, and ant tracking. This presented challenges in developing workflows to manage interpretation of a large number of seismic amplitude and attribute volumes. The adopted approach used attribute volumes based on a data set of combined independently migrated sectors azimuths as the base data set. The independently migrated azimuth volumes were then used for cross checking and incremental enhancements of the interpretation. The workflow resulted in the enhancement of: (1) fault plane definition, and, (2) the top Pre-Tertiary (PRT) basement horizon reflector continuity. The analysis shows a complex fracture network of varying fracture azimuths sufficient to provide an interconnected system to support the observed pressure communication across the Sumpal field.