Determination of Hydrocarbon Production Zones using Well Logging Data in the "North_Rawa" Well of the South Sumatra Basin

Petrophysical analysis with well logging is carried out to determine the value of petrophysical parameters of rocks in the formation. Then to find out information about the subsurface structure as well as the depth zone of layers containing hydrocarbons and the types of hydrocarbons from the production field. In this research, an evaluation of reservoir formation was carried out in the North_Rawa field of the South Sumatra Basin, based on petrophysical log analysis from data from three wells in the North_Rawa field. Reservoir identification results from physical rock parameters such as porosity, shale content, water saturation and permeability obtained from formation evaluation calculations. Porosity is calculated to determine the pores, shale content is calculated to determine the volume of shale in the reservoir, water saturation is calculated to determine the water content in the formation, and permeability is calculated to determine the rock's ability to pass fluid. The results of petrophysical calculations were obtained in the hydrocarbon prospect zone in the North- rawa 1 well at a depth of 3387.5 – 3938 feet, the North- rawa 3 well at a depth of 2667.5 – 3735.5 feet, the North- rawa 4 well at a depth of 2759.5 – 3775 feet. The average porosity values for each well are 8%, 15.4%, 16%. The average shale content value for each well is 61%, 48%, 53%. Average water saturation values are 61%, 54%, 68%. Average permeability values 46.7 mD , 98.9 mD , 3.38 MD. The hydrocarbon prospect in the research well contains natural gas and oil hydrocarbons with sandstone and shale formation lithology.