Maturation of a New Play Concept in Northern Provinces of Offshore Sarawak Basin, Malaysia

Northern provinces of Offshore Sarawak Basin represent a frontier area with low well density and relatively fair understanding of the petroleum system. Hydrocarbon prospectivity evaluationintegrating seismic, gravity, and well data of northern provinces of offshore Sarawak facilitatedmodeling of tectono-stratigraphic framework and geological evolution of the area, culminating in thedevelopment of a new play concept, hitherto untested in this part of Sarawak Basin. Stratigraphy ofthe study area is characterized by a lower synrift sequence, consisting of transitional to shallow marine sediments, unconformably overlain by passive margin sag phase deep water sediments.Exploration to date has focused on hydrocarbon plays in upper part of synrift section. Present paperdeals with maturation of Sequence-A play as a new concept, primarily based on seismic evidence.This sequence, consisting of postulated lacustrine sediments, filled the early formed half grabensduring the first phase of extension. Uplifted sections of this sequence on footwall closures arepotential hydrocarbon plays with charge from adjoining grabens. Regional review of equivalentsections suggests clastic sequence similar to Sampaguita-1 as the most likely analogue. Proving this play will open up substantial exploration potential in the northern provinces of Offshore Sarawak Basin, with significant economic value.