Iagifu/Hedinia Field: First Oil from the Papuan Fold and Thrust Belt
The Iagifu/Hedinia accumulation will support the first large-scale petroleum development in the Papuan fold and thrust belt. The discovery well, Iagifu-2X, was drilled in 1986 and flowed 45° API oil and gas from a thrust-cored anticlinal structure with closure enhanced by sealing across the sole fault. The primary reservoir is the Early Cretaceous (Berriasian) Toro sandstone. Well locations are selected on the basis of surface geology and existing well results only, because it has proved impossible to acquire seismic data of reasonable quality in a cost-effective manner. Delineation drilling continued until early 1990, with wells ultimately outlining a broad subsurface structure that extends beneath and is detached from the surface anticlines at Iagifu and Hedinia. A development plan was submitted to the Papua New Guinea government in May 1990, citing estimated reserves of 146.6 million bbl of oil in the Toro sandstone and proposing first production in 1992. The region has excellent petroleum potential. Oil and gas accumulations have now been discovered on nearby structures along a 70-km trend with total estimated potential in excess of 300 million bbl of oil and 4 tcf of gas.