Deepwater North West Borneo: hydrocarbon accumulation in an active fold and thrust belt

In the deepwater acreage of North West Borneo an active offshore fold and thrust belt hosts a number of proven hydrocarbon accumulations and promises to deliver considerable additional hydrocarbon volumes as a result of ongoing exploration campaigns. Typical trapping geometries observed in this Neogene large-scale linked fold and thrust belt are hanging-wall anticlines, foreland folds and ridges and sub-thrust footwall cut-offs. Commercial drilling targets lie within the deformed Miocene and Pliocene sediment pile and these have been charged with oil and gas from a petroleum system that is still active at the present day. A major challenge here is to avoid drilling traps that have expelled their hydrocarbons during periods of active deformation and uplift in recent geological time. Studies of tectonic deformation phases are beginning to illuminate some key controls on trap formation and hydrocarbon retention history. This paper focuses on providing an overview of the North West Borneo deepwater fold and thrust belt and introduces some key issues and challenges for future hydrocarbon exploration in the region.