Publications

The Merapi district is located in the South Palembang Sub-Basin of the South Sumatra Basin. A compressional phase during Middle Miocene – Pliocene created a fold and fault in the surrounding area. The Air Benakat and Muara Enim Formation are the main subject of this research. Field observation, studio and laboratory analysis were used to discover the facies analysis of the Neogene deposit. Optical properties and organism track were used to understand the environment of rocks once they were deposited. The Air Benakat Formation was initially a regression deposition in the basin, overlain by the Muara Enim Formation. The rocks stacking pattern of the Air Benakat Formation show a tidal influence in a deltaic system environment. An authigenic minerals of glauconite indicates there was a sudden lateral shifting of facies from delta to shallow marine due to the fluctuation of sea level. Sandstone of Muara Enim Formation was deposited in fluvio-deltaic environment which characterized as a coarsening upward sequence. The plant organism represented by thick carbon-rich coal is characterized as a delta plain environment with high sulphur content. It shows a landward lateral shifting facies from transitional to fluvio-deltaic environment but still influenced by a tidal system. Both formations were controlled by an anticlinorium system which was generated by a third compressional phase known as a Muara Enim Anticlinorium. This anticlinorium has a role as a trap system for hydrocarbons and the Upper Air Benakat Formation which is highly thick with an impermeable layer that therefore could act as a seal for hydrocarbons. The relation of deposition setting and structural configuration result in the Merapi district having high potential for hydrocarbon exploration. Further research in this Late Neogene deposit is required to fullfill the advanced exploration that is required. Keywords : Delta, Neogene Deposit, Petroleum System, South Sumatra Basin