Abstract

The 1985 Production Sharing Contract, which is a revision of the first generation of the mid-70s PSC was introduced by PETRONAS in 1987. Since then, PETRONAS signed a total of 27 PSC’s and awarded about 300,000 km² of exploration acreage. The exploration effort which includes seismic data acquisition of 420,000 km (total 2D and 3D), and 208 exploration wells (170 wildcats and 38 appraisals) drilled surpassed the pledged minimum commitment by 280% and 180% respectively.

In total some USD 1.5 billion was spent on exploration and added about 1.3 billion barrels of oil and 20 Tcf of gas as new additional resources to Malaysia. Twenty oil and eight gas fields have been declared as commercial fields and currently four oil fields have been brought into production.

A simple mathematical calculation based on this exploration decade of statistics indicates that the commercial success ratio in Malaysia is 1: 6 yielding an average field size of about 160 million barrels of oil equivalent and that the exploration finding cost was USD 0.32 per barrel of oil equivalent.

The most significant exploration contributions are the new play fairways discovered. The new 200 km by 50 km oil/gas belt discovered in the northeastern flank of the Malay Basin (Hee, 1997) is marked by the producing oil fields of Bunga Kekwa in the north and Yong / Raya in the south. These are basement related fault structures and oil is reservoired in the Late Oligocene/Early Miocene sandstones of Groups J and K of the Malay Basin. The Rhu discovery which is a drape-over-basement ramp play, production tested about 6,000 BOPD from the syn-rift Oligocene sandstones, confirmed a valid petroleum system in the Penyu Basin.

In Sarawak: the Jintan gas field is a large, low relief Cycle IV carbonate buildup located on an extensive carbonate platform in the Central Luconia Province; whereas the Helang gas field is reservoired in Early Pliocene Cycle VI clastics trapped within two east-west trending growth faults in the Baram Delta Province.

The Kinabalu oilfield, with reserves of 200 million barels of oil and 2 Tcf of gas is a major downthrown growth fault feature located in offshore southwestern Sabah. The Kebabangan gas field in 600ft of water depth, is a complex turbidite play dominated by the presence of shale diapirs in offshore Sabah.

These significant discoveries and hydrocarbon fairways tested will breathe “new life in mature areas” for exploration in Malaysia.