ESTIMATION OF PROSFECTIVE HYDROCARBON ZONE BASED ON LOG INTERPRETATION IN “Z” AREA SOUTH SUMATERA BASIN

Log analysis is one way to estimate hydrocarbon zone and evaluate the reservoir formation, it applied to get the physical characteristics consist of porosity (), resistivity (R), water saturation (Sw), and permeability (K). The main object of this study is performing petrophysical analysis to estimate hydrocarbon zone of Well-K1, located in South Sumatera basin. The methods are log interpretation and core analysis. First, well logging interpretation using Interactive Petrophysics (IP) software. Secondly, determining productive zone using Petrophysical properties, include permeability by gamma ray (GR) log, porosity by Schlumberger method, water saturation by Archie’s equation which a factor and cementation exponent were derived from the core analysis in laboratory. Then, analyze fluid rock type using Electric logs, with resistivity values of oil is 60-100Ωm, and gas >100Ωm. As a result, there is one prosfective hydrocarbon zone in well-K1, located in 2295-2397ft below surface in Air Benakat Formation. Average petrophysical parameter values of these hydrocarbon zone are =31%, Sw=30%, R=96Ωm. Based on resistivity values, this productive zone is contained oil (LLD=60-100Ωm). The lithology of this zone is dominated by sandstone with Gamma Ray logs values around 21-46 API, indicating excellent reservoir quality. The petrophysical properties of the reservoirs in Well-K1 are enough to permit hydrocarbon production.