Publications

Tectonically, southwest offshore Matindok Block is located in the wedge top part of Banggai Sula foreland basin, which is the most active part. It consists of Miocene carbonate platform imbricate thrust sequences as a result of collision tectonics. Tiaka oil field is a proven example of imbricate thrust play in this area. The latest interpretation on a SW-NE 2D composite seismic line proposed that the new Miocene duplex carbonate play, is actually imbricate thrust sequences older than the proven Tiaka thrust, that was squeezed and sub-thrusted beneath the ophiolite zone. Due to the poor quality in the 2D seismic data, the biggest challenge for this kind of play is to identify the closure area and trapping system. The poor seismic data quality is caused by the presence of broad and thick overlying ophiolite belt. In fact, due to the poor seismic data quality, two geological models, with and without the duplex carbonate play, have been interpreted and proposed. In order to investigate the proper seismic response of this new play, we performed seismic synthetic forward modeling on the two interpreted geological models previously mentioned. The forward modeling workflow consists of building the geological model with appropriate physical properties, generating shot gathers based on each model using proper marine seismic survey parameters, and processing the data through Kirchhoff’s PSTM and PSDM workflows. The results show that the imbricate thrust model was clearly imaged in both the PSTM and PSDM sections. However, there are several strong reflections associated with duplex carbonate structure beneath the ophiolite appearing only in the PSDM section. It suggests that PSDM can handle complex structural imaging far better than PSTM. Hopefully, this result could trigger increased exploration beneath the ophiolite thrust zone, especially in the northeast onshore area of Matindok Block.