Abstract

The MB Field is located on the coast of Northwest Java approximately 35 miles (56 kilometers) northeast of Jakarta. The oil field is one of several with reserves trapped in the Middle Miocene Mid-Main Carbonate reservoir. The productive interval overlies a basement horst block, the Rengasdengklok High. The faults which define the north-south trending horst may have acted as pathways for hydrocarbons migrating from nearby deeper basinal areas such as the Ardjuna/Pasir Putih subbasin or the Ciputat subbasin.

The discovery well, MB-1, was drilled in 1982 in the Atlantic Richfield Indonesia Inc. Offshore Northwest Java Contract Area. Subsequent seismic interpretations indicated that the MB structure extended onshore, to the south, into the Pertamina Unit III area. ARII approached Pertamina and proposed a delineation well, MB-2, in the onshore area for possible unitization in the MB area. Pertamina agreed to the proposal and at the same time proposed another onshore delineation well, MB-3, which originally was to be Pertamina's RDH-1 exploratory well.

The onshore delineation wells(MB-2 and MB-3/MB-3ST) were drilled in 1985 to confirm the extent of the oil reservoir in the southern part of the closure. The wells tested oil and were temporarily suspended for future production. An offshore tripod was placed about 600 feet southwest of MB-1 and four development wells were drilled. The tripod wells and the MB-1 well now produce at a combined rate of approximately 10,000 BOPD.

There is currently a letter of understanding signed by Pertamina and ARII to further the MB-unitization. An additional delineation well may be drilled onshore this year or early next year in order to better evaluate the distribution of reserves in the MB field.