Abstract

A sequence stratigraphic study was conducted to develop a stratigraphic framework for Miocene to Pliocene age outer shelf, slope, and basin floor sediments in the Makassar PSC, offshore Kutei Basin. A series of seismic sequences has been identified and tied into existing stratigraphic schemes for deltaic and inner shelf sediments using wireline log and biostratigraphic data.

The study has confirmed the potential for transportation and deposition of sand in both slope basin and basin floor settings. Lowstand features, including incised valleys and intra-slope to basin floor sedimentary thicks, have been identified and linked to earlier sand prone deposits on the upper shelf. Identification of these features substantially reduces the reservoir risk associated with this deep water depositional environment. Integration of this study with regional geological and geochemical studies suggests that substantial hydrocarbon potential is present in the outer shelf and slope environments of the Kutei Basin.

Seismic amplitude versus offset (AVO) analysis was applied to seismic lines over areas showing depositional pathways and prospective structures. Sequences which contained reservoir sands in nearby wells gave a strong AVO response over map areas that correlated closely with structural highs and fault boundaries. The intial stratigraphic framework coupled with rigorous internal seismic amplitude analysis has yielded a number of encouraging exploration leads and prospects in the Makassar PSC.