Fractured Basement Reservoirs in South Pattani Basin: Seismic Recognition and Integrated Multi-attributes Analysis

Abstract

The South Pattani Basin Fractured Basement Reservoir (SPB FBR) potential covers an area of at least 166 km². It is composed of a horst-graben structure with a high vertical offset. The SPB FBR differs from other explored FBR due to the trigger mechanism which is poly-phase deformation of a rift and transform tectonic. Integration of 3D seismic attributes was used to identify potential basement high areas and fault features. There was a combination of structural and amplitude attributes used in this study such as variance, RMS amplitude, structural filtering, sweetness, energy amplitude and distance to faults attributes. The potential basement high area influenced by north-south striking normal faults and divided into three basement crest areas with one of them in a northeast-southwest direction. The three-basement high potential areas are north FBR zone, west FBR zone and east FBR zone. The faults have high angle dipping on Tertiary strata and transformed into low angle faults in Pre-Tertiary basement area. Intra-basement area showed low angle dipping seismic reflection and strong amplitudes. Multi attributes analysis identified the potential FBR area located at near major fault and its synthetic faults. Variance and ant-track attributes delineated the possible fault corridor alongside the major faults. The western basement high zone exhibited cross-cutting fracture pattern in the western side of the major fault and became the high porous and permeable zone. The FBR zone consisted of north-south trending fractures while eastern FBR zone had northeast-southwest trending fractures.