Publications

The giant Arun gas field is located on the northern tip of Sumatra Island, within the prolific North Sumatra Basin hydrocarbon province. The field was discovered in 1971 and came on stream in 1977 with most of the gas delivered to the nearby Arun LNG plant. Sustained gas production from the Arun reservoir and adjacent satellite fields has helped maintain LNG cargo delivery to markets in Asia for approximately 30 years.The gas is reservoired in an Early to Middle Miocene carbonate build-up on NNE - SSW trending basement horst blocks associated with Paleocene-Oligocene rifting. Several significant sea-level fluctuations in the last stages of carbonate development resulted in secondary permeability within the upper reservoir unit and helped create the prolific production potential of this field. The reservoir is sealed by Miocene sag related shale.The shape of the Arun carbonate build-up is controlled by antecedent topography and the structure is defined by twenty 2D seismic lines and 118 wells. Hydrocarbon recovery is high and approximately 13 TCF of dry gas has been produced to date. Late stage field life has presented some significant development challenges. A long term appraisal well drilling program coupled with an extensive formation evaluation program helped to build detailed geologic and reservoir models which were used to optimize development drilling. Integration of reservoir description and depletion planning in managing this giant resource has contributed to high gas and condensate recoveries.