Subvolcanic Rock Petroleum System Potential in the South Malang Region, East Java, Indonesia

The South Malang Region is located in the south-eastern part of Southern Mountain Volcanic Arc; it presents different opportunities for hydrocarbon exploration. stratigraphy study area from old to young consists Oligocene rocks (Mandalika, Watupatok, and Arjosari Formation), Early Miocene Carbonates (Campurdarat Jaten Middle (Wuni Late Miocene-Pliocene (Nampol, Oyo, Wonosari Holocene alluvial deposits (Kalipucang Formation). dominance volcanic makes this considered an without play prospects. Petroleum system potential revealed by evaluating analyzing source rock reservoir outcrop samples. shows that Nampol Formation can be as a gas-prone rock, with type III kerogen, total organic content ranging 3.48 - 26.18 wt%, possess produce good very hydrocarbons hydrogen index 43 86 mgHC/g TOC. Furthermore, core analysis petrographic studies were carried out on sandstone where samples showed properties. However, limestone was secondary target possesses low quality This there petroleum existence subvolcanic arc, which indicated presence one various elements processes present system.