Abstract: Source Facies and Oil Families of the Malay Basin, Malaysia
Steve Creaney, Abdul Hanif Hussein, David J. Curry, Kevin M. Bohacs, Redzuan Hassan
The Malay Basin consists of a number of separate petroleum systems, driven exclusively by nonmarine source rocks. These systems range from lower Oligocene to middle Miocene and show a progression from lacustrine-dominated source facies in the lower Oligocene to lower Miocene section to coastal plain/delta plain coal-related sources in the lower to middle Miocene section. Two lacustrine sources are recognized in the older section, and multiple source/reservoir pairs are recognized in the younger coaly section. The lacustrine sources can be recognized using well-log analysis combined with detailed core and sidewall core sampling. Chemically, they are characterized by low pristane/phytane ratios, low oleanane contents, and a general absence of resin-derived terpanes. These sources have T Cs in the 1.0-4.0% range and hydrogen indices of up to 750. In contrast, the coal-related sources are chemically distinct with pristane/phytane ratios of up to 8, very high oleanane contents, and often abundant resinous compounds. All these sources are generally overmature in the basin center and immature toward the basin margin.
The oils sourced from all sources in the Malay Basin are generally low in sulfur and of very high economic value. Detailed biomarker analysis of the oils in the Malay Basin has allowed the recognition of families associated with the above sources and demonstrated that oil migration has been largely strata parallel with little cross-stratal mixing of families.
AAPG Search and Discovery Article #90982©1994 AAPG International Conference and Exhibition, Kuala Lumpur, Malaysia, August 21-24, 1994