The region discussed includes Burma, the peninsulas of Indo-China and Malaysia, the island of Taiwan, the archipelagos of Indonesia and the Philippines, and all contiguous marine areas. In area, this region is roughly as large as all of Canada, including the Arctic Islands. Excluding a narrow strip of mainland China and the city/state of Singapore, the area comprises nine sovereign states and five of these have established oil and/or gas production.

All production to date has been from beds of Oligocene, Miocene or Pliocene age in both clastic and carbonate rocks. Although 46 Tertiary basins have been identified, oil and gas occurrence has been proven in only a few.