The company had earlier forecast that the Malampaya oil rim, which lies beneath the offshore gas field, holds around 25 mmbbl of recoverable oil reserves and could cost $300 million to $400 million to develop.
The company has previously drilled 11 wells on the field since 1989 but only one well produced oil and was spudded and plugged at 8,000bopd in December 2001.
The three trillion cubic feet field is owned by Shell (45%), ChevronTexaco (45%) and the Philippine National Oil Co-Exploration Corp (10%).
