Fauzil Radilas, Mohd Akmal Adnan, Kamal Ghaffar, Barry James Boyce, Robert Wong,
PETRONAS, Kuala Lumpur, Malaysia
Blocks 2A and 2B, located offshore Sarawak in east Malaysia, covers 9000 square kilometers in water depth 150 – 1500 m. Two dry wells were drilled both of which lack post-Middle Miocene Unconformity (MMU) reservoir. Mulu-1 was drilled in 1995 on Block-2B to Cycle 1 at a total depth 5,029 m, and Jelawat-1 drilled 60km SW of Mulu-1 on Block-F encountered significant C1 to C5 gas from MMU sequences. Gas was interpreted from mature post-MMU deep marine sources.
Thousands kilometers of fair to good 2D seismic data over the area indicate the presence of strong, continuous events near top MMU sequence boundary. Post-MMU seismic data is characterized by weak, bluer discontinuous reflectors interpreted as massive deep marine shales.
Several strong seismic anomalies in Post-MMU sequences have been delineated and are interpreted to be sourced from reworked Pre-MMU sequences. Strong amplitude seismic attribute analysis are wide spread and interpreted to be clastic basin fan floor sediments originating from several feeder channel systems. Amplitudes weaken at the fan edges.
Basin floor fans exist in lows and on the flanks of lows. These stratigraphically discontinuous units are enveloped within thick post MMU shales. Sourcing is not considered a problem due to local charging. Risked resources calculated indicate significant hydrocarbon potential are believed to be located in the area.
AAPG Search and Discovery Article #90072 © 2007 AAPG and AAPG European Region Conference, Athens, Greece