Insights into the Petroleum Potential of the Western Philippines from New Regional Seismic Data

Ballesteros, Mark¹; Robinson, Paul²
¹Searcher Seismic Ltd, West Perth, WA, Australia;
²Spectrum Petroleum Sources, Perth, WA, Australia

A new long offset regional 2D survey was recently acquired covering the Palawan, Mindoro-Cuyo, Sulu Sea and Sandakan basins in the Western Philippines. The 7086 km survey provides the first consistent link between these basins, and provides a unique opportunity to understand the regional tectonic and stratigraphic framework of the area.

The western part of the Philippines underlain by continental crust rifted from mainland China during the opening of the South China Sea in the Oligocene, and is distinct from the mobile arc that characterises the eastern part of the country. The basins in the area include the most important petroleum-producing basins in the country as well as areas that are relatively unexplored.

The demonstrated petroleum systems that characterise the area are similar to other Tertiary basins in Southeast Asia, but the ability to fully evaluate the extent and potential of these petroleum systems has been restricted by limited data availablity over the distal and deeper water areas. Preliminary results from the new survey suggest that the development of Paleogene grabens and half-grabens may be significantly more extensive than previously suspected. Similar rift structures elsewhere in Southeast Asia are commonly associated with prolific source rocks, and thus identifying and understanding the tectonic and stratigraphic evolution of these rift structures has significant implications to defining the petroleum potential of the area.

Comparison the line locations of the new survey with a regional Tertiary sediment thickness map provides indications of potential Eocene grabens with over 2 seconds of sediments in areas where no Tertiary sediments are indicated in the western part of the Northern Palawan Basin. Although only brute stacks are available at the present time, the data already provide encouraging indications that syn-rift structural development is extensive in some areas previously considered to have limited sedimentary section, and suggests significant unexplored petroleum potential may exist in the area.

AAPG Search and Discovery Article #90155©2012 AAPG International Conference & Exhibition, Singapore, 16-19 September 2012