Depositional Environment And Vertical Distribution Based on Core Analysis to Evaluate The Production Rate of The Reservoir (Case Study: Arun Carbonate Reservoir, North Sumatra, Indonesia)

Abstract

The Arun natural gas field is one of the world biggest gas fields by volume of reserves and this field was found in a coastal region within the North Sumatra Basin, Indonesia. This field has been producing gas and condensate since 1977. Based on Atmadibrata and Joenoes (1993) gas production in this field had increased at that time up to an average level of 3,300 million standard cubic feet per day (MMSCFD). The total daily volume of 2.230 MMSCFD was transported to the LNG plant for liquefaction and trade, 145 MMSCFD was provided to the household showcase and domestic market, 55 MMSCFD was utilized for fuel and 870 MMSCFD was reinjected into the reservoir in order to maximize condensate recovery. This study intends to understand the relationship between the depositional environment of the Arun field reservoir to the production rate of the reservoir. The data in this study is mainly secondary data and consists of geological properties (core description and petrographic analysis), geophysical properties (well logging) and petrophysical properties (porosity and permeability).