The Calamian area is situated within the Northwest Palawan block, and is characterized by a variety of play types, including horst and graben features, locally distributed anticlines and compressional structures, carbonate platform and reefal buildups.

The reefal play is considered to be the most attractive, as the leads in the Calamian area are interpreted to lie along the same reef trend as the Malampaya, Camago and San Martin gas discoveries. Potential source rocks within the Tertiary half-grabens underlie the extensive carbonates. The Nido Limestone, which is the only proven reservoir for all the commercial discoveries in offshore Palawan finds its extension further northeast, well into the Calamian area.

SC-57 was awarded by the DOE to PNOC EC on September 15, 2005. The acreage covers an area of 7,200 square kilometers in the Calamian area in offshore Northwest Palawan. PNOC EC then signed a farm-in agreement (FIA) with Mitra Energy Ltd. (MEL) in March 2006, and with China National Offshore Oil Corporation (CNOOC) in April 2006. With the FIA, CNOOC acquires 51% participating interest and operatorship of the project, with MEL acquiring 21% stake, and PNOC EC retaining the remaining 28% participating interest of the project. In 2006, the consortium acquired 2,268 line-kilometers of 2D seismic data, and about 1,000 line-kilometers of old seismic data were also reprocessed to supplement the new data. The consortium plans to conduct further studies in the earlier mapped structures to mature them into drillable status.