Abstract

The KH Field is located in the southwest corner of the Kakap Production Sharing Contract Area, some 1250 kms north of Jakarta, Indonesia. Exploration within the original 5165 sq km Kakap Block commenced in 1977 with the drilling of two dry holes. During 1978, a significant discovery was made on the KG structure, followed two years later by the discovery of the larger KH Field nearby.

The KH oil and gas trap is a faulted anticline with four-way dip. The structure appears to be associated with an east-west trending, deep-seated, right-lateral, strike-slip fault. Some argillokinetic movement may have contributed to the KH structure.

Within the KH Field, oil and gas are reservoired in fluvial channel sands of the Late Oligocene Gabus Formation. Overlying sands of the Early Miocene Arang Formation provide a reservoir for nonassociated gas.

Porosities within the sands average 19-21 percent, with permeabilities of hundreds of millidarcies. Reservoir properties are the result of a complex diagnetic history, involving alternate episodes of porosity reduction and enhancement due to mineral precipitation and dissolution.

Integrated, detailed geochemical and biostratigraphical data suggest that the probable timing of effective hydrocarbon generation and migration from adjacent areas of mature source rock is very late (5 m.y.b.p.), postdating the regional unconformity at the base of the Late Miocene to Pleistocene Muda Formation. The oils produced are light, waxy crudes having gravities in the range of 42-47.5° API at 65°F.

The petroleum geology of the field is discussed in relation to development plans for the KH oil occumulation.