Distinct Tectonic Evolutions and Its Effect on Hydrocarbon Accumulation of the Papuan Basin

Based on the comprehensive analysis of previous research, detailed interpretation of the 2D seismic data, and combined with the analysis of basin petroleum geological conditions, the structural and tectonic features of Papuan basin and its relationship with hydrocarbon accumulation have been studied in this paper. The results show that: (1) There are significant differences between the eastern and western parts of the Papuan basin in structural-tectonic styles. In the western part of the basin, the thin-skinned structure occupies the main deformation style, and the large-scale thrust-fold tectonics are formed, which can be divided into four deformation zones—thrust belt, fold-thrust belt, broad fold belt and stable platform from north to south. While in the eastern part of the Papuan basin, the foreland basin structure is formed. (2) Attributed to the differences in structural-tectonic styles, significant differences of hydrocarbon accumulation and potential also presents between the eastern and western parts of the Papuan basin. The western part of the basin is dominated by the Mesozoic petroleum system and thrust-controlled structural traps. And the Mesozoic source rock turns into mature stage because of the overlying thickening strata, caused by the overthrust sheet. Meanwhile in the eastern part of the Papuan basin, the Neogene petroleum system is the main petroleum system. The overlying huge thick strata sedimentation in foreland basin stage causes the Neogene source rock become mature. And the thrust-controlled structural traps only present in Aure thrust-fold belt. (3) The presence or absence of the Mesozoic incompetent beds is the key factor which causes the differences between the eastern and western parts of the Papuan basin in structural-tectonic styles.