Abstract: Reservoir Modeling in the Bunyu Tapa Gas Field--An Integrated Case Study
Susanto Nugroho, Steve Hansen, Mandhiri Susanto
Bunyu Tapa gas field is located on the western edge of Bunyu Island, approximately 12 km northwest of Bunyu Nibung oil field; it is the main gas producer for the Bunyu methanol plant. Initially, the Bunyu Tapa sands were believed to be deposited as a blanket-type sheet sand, but after drilling 21 wells in this field, it is obvious that these sands lack lateral continuity. The Bunyu Tapa reservoir sands were deposited in a deltaic environment. Several wells, which were producing gas close to the structurally high western edge of this field, are exhibiting a high-water cut. This water production is not expected in a deltaic lens environment, especially since these wells are updip to other gas-producing wells.
This Bunyu Tapa reservoir modeling study is an integrated investigation of 2-D seismic data, electric logs, dipmeter, petrophysical analysis, and production history data. The results of this integrated study show that the sands were deposited as distributary channel sands across the field and extend offshore. Structurally, the wells on the western edge are in fact on the eastern flank of a north-south-trending anticline, close to the gas/water contact and are separated from the eastern wells by north-south-trending normal faults. In the near future, as a result of this study, a deviated well is planned to evaluate the offshore area to the west.
AAPG Search and Discovery Article #90982©1994 AAPG International Conference and Exhibition, Kuala Lumpur, Malaysia, August 21-24, 1994