Unlocking Potential of Tight Gas Sand in South Sumatera: Measurement of Porosity, Capillary Pressure, and Mineralogy Characterization

Abstract Tight Gas Sand reservoirs are unique because their characteristics differ from those of conventional hydrocarbon reservoirs. There is a strong relationship between water or brine capillary pressure and the caprock of tight gas sand reservoirs. In the tight gas sand reservoirs, gas is trapped by brine capillary pressure, meaning the reservoir does not require closure or an anticline to trap the gas potential. The Lahat formation dates from the Eocene to the Oligocene, where the Upper Lahat Shale is rich in Quartz, potentially making it a giant hydrocarbon layer of Tight Gas Sand. Volcanic activity from 50-30 million years ago might have produced the richness of Quartz at the top of Lahat, especially in the Western part of South Sumatra. We measured the characteristics of brine capillary pressures, mineralogy, and porosity parameters of the Tight gas sand reservoir potential in the Lahat formation. The results, Quartz content including capping pressure of Top Lahat samples are promising for the giant potential of the Tight Gas Sand in the Lahat Formation of South Sumatra.