Characterization of Hydrocarbon Reservoirs Through Acoustic Impedance and Sweetness Attributes in the Northern Kangean Waters

The North Kangean Waters is one of the top priorities for hydrocarbon exploration and development in the North East Java Basin, East Java. The Kudjung Formation in the North Kangean Waters, East Java, is a potential hydrocarbon reservoir composed of carbonate limestone at 1780- 2120 ft in the JS5-1 well. The JS5-1 well was drilled on a northeast-trending anticline in the East Java Basin, indicating localized structural uplift. The same structure has proven to be a hydrocarbon trap at the Kangean Block adjacent to the JS5-1 well. This study applies model-based acoustic impedance inversion and sweetness attribute analysis to enhance reservoir characterization in the northern waters of the Kangean Islands, East Java. The inversion results indicate hydrocarbonbearing layers with low impedance values from 27,729 to 33,575 (ft/s)(g/cc), validated by preinversion analysis with a correlation coefficient of 0.967 and a total error of 0.282. Sweetness attributes effectively identify hydrocarbon sweet spots at 180–320 ms. These findings improve seismic interpretation and can assess hydrocarbon exploration in complex carbonate formations