Development Sedimentary Concept – An Overlooked Opportunity In Bentayan Structure, North Palembang Sub-Basin, South Sumatra Basin

Abstract

Bentayan's structure is one of the major structures in PT. Pertamina EP, whose daily production at July 2019 reached 1,649.2 BOPD. This production is the largest one in the southern part of Pertamina EP Asset 1 (Jambi, Lirik, Ramba). Bentayan is also one of the structure with a large area that extends from South East (SE) to North West (NW) which until now has only been one-third produced. Building concept is carried out on this field, in order to get new opportunities, especially in the two-thirds of the
Bentayan Structure. Sediment concept of Bentayan, especially TAF, was formed at the Late Oligocene age, dominated by precipitated sandstone deposits with repeated shale and coal rocks, which are either delta or fluvial deposits. The formation of TAF itself can be divided into two characteristics, its lower TAF and upper TAF, which in lower TAF conditions can be seen once the pattern of the fluvial channel sediment pattern and above TAF is the deltaic sediment system with the influence of waves. The formation of the precipitate was allegedly from the North - North East provenance, which is a high named Sembilang high and Merang High. In determining a reservoir tank at a structure, the zonation division on TAF is divided into 4 (four) zones, namely A layer, B layer, C layer and E Layer. In the four zonations it has a special character from the High Stand System Tract condition, where the fluvial deposit dominate the Lower TAF and the Delta Front deposits are above it. Channels formed on lower TAF intersect with other channels and cause the channel pattern that is formed to be unpredictable due to amalgamation due to the intersection of each channel as reservoir tanks in these conditions. This is an advantage in developing structural properties through a development drilling mechanism, although having the same reservoir pressure value in the reservoir C Layer (TAF) is due to the individual permeability barrier by reason of the presence of shale in highstand system tract conditions This new sedimentation concept will generate a new opportunity to add new reserves, 1.33 MMSTB in the wild area. Even still able to open Giant Prospect with high opportunities in NW section of working area. It can be believed that the presence of hydrocarbons with this Potential is flanked by two large fields, first one is Grissik Field (the largest gas producer in Indonesia) and second one is Bentayan Existing Field (Cumulative Production of 29,676 MSTB). The optimization of the field will be carried out with the latest concept so that the optimal development process and method can be obtained.