Deepwater Sandakan Basin, Philippines: The Improving Seismic Image
Mitra Energy Limited
The Sandakan Basin is a highly prospective, though still lightly explored deepwater basin located in Philippines waters in the western Sulu Sea. Mitra Energy has been exploring this basin in block SC 56 since 2006, confirming the presence of a working petroleum system and making two significant discoveries of gas in multiple stacked turbidite reservoirs with the Dabakan-1 and Palendag-1 wells.
Exploration challenges in this area include complex subsurface geology, limited well control, deep water, remoteness of location and oceanographic conditions. A key consideration in a high drilling cost environment such as this it is to extract maximum value from seismic data, through phases of acquisition, processing and reprocessing.
The timeline of exploration activity in SC 56 commenced with evaluation of existing 2D seismic data and offset wells, leading to acquisition of additional 2D data to confirm prospective trends and subsequently 3D data acquisition to mature prospects for drilling. A four well exploration drilling campaign resulted in three discoveries, with the fourth well having hydrocarbon shows.
Subsequently an important phase of post-drilling calibration of the seismic and integration of well results has been carried out, including 2D and 3D reprocessing, seismic inversion and additional 3D seismic acquisition to fully cover the prospective areas of the block. The resulting improvements in seismic imaging will be important in determining the next phase of exploration in this exciting basin.