Perpustakaan Digital ITB

Oil production and resources of Southeast Asian countries are declining. To fulfill the energy need, importing oil has become more common. However, importing oil is not a long-term solution. Thus, Enhanced Oil Recovery (EOR) is needed to boost production. East Natuna gas field is the largest gas field in Indonesia but cannot economically produce due to the high content of CO2. The Natuna gas field has Initial Gas in Place (IGIP) of 222 TSCF with 71% CO2, 28% CH4, and 1% of H2S and N2. This high resource is also accommodated with the field’s high gas rate and potent wellhead pressure. This paper technically and economically assesses the idea of utilizing this gas resource as a source of CO2 gas injection for enhancing oil recovery of nearby oil fields. The idea is implemented by choosing the location where Natuna gas will be transported. Kalimantan (Bontang), Brunei Darussalam (Belait), and Malaysia (Kuantan) are chosen for the preferred distance. The distance is taken from the map by using Google Earth Pro from the East Natuna gas field to the respective areas. The gas Transportation model by subsea and land pipeline is made using PIPESIMTM by inputting the data needed. The output of the PIPESIMTM model is then inputted to the ExcelTM model to determine the best pipeline scenario for each area. The PIPESIMTM model result includes varying sizes of pipeline diameter along with the gas rate and pressure output, and the ExcelTM model result includes the minimum mix gas price of each scenario and area, to reach the breakeven point and Minimum Acceptable Rate of Return (MARR) of 10% (assumed) in 10 years. It is determined that the best pipeline outer diameter size is 72, 66, and 62 inches from Natuna to Kalimantan, Brunei, and Malaysia respectively. The author has also calculated the effect of gas erosional velocity, credit interest rate, and inflation rate in the models to further detail the feasibility of this operation in solving the declining production problem in Southeast Asian countries.