Publications

“Barokah” Field, South Sumatera Basin is an exploration field containing four wells. Based on logging and drill stem test data, three wells in the southwest study area contain oil and gas from a limestone reservoir of the Baturaja Formation. Acoustic impedance inversion, porosity, and permeability estimation are needed to map the reservoir distribution and determine the hydrocarbon-bearing zone. Linear relationship between acoustic impedance and porosity has been used for porosity estimation. Permeability estimation has been made by an instantaneous Q method based on seismic data. The value of acoustic impedance in hydrocarbon-bearing zones in the limestone reservoir range between 11960 - 14040 (m/s)*(g/cc). Porosity values range between 5.4 – 11.6 %. The permeability value is about 20 - 40 mD. The range of value of porosity is poor, but the range of value for permeability is good based on classification in Table 1 (Koesoemadinata, 1980)' The value range of the porosity is enough to hold gas while good permeability values allow the gas to flow easily into the reservoir. Based on the estimation results derived from seismic inversion and instantaneous Q method, there are three prospective zones of hydrocarbon. The first is zone A located to the north of the PBG-1 well, the second is zone B to the northeast of the PBG-1 well, and finally is zone C to the northeast of the PBG-2 well. Keywords: limestone, baturaja formation, seismic inversion, acoustic impedance, porosity, instantaneous Q method, permeability