Petroleum system modelling in a compressional tectonic setting: The eastern Kuqa Depression, Tarim Basin, Northwestern China

The eastern Kuqa Depression is part of a tectonically active foreland basin and hosts structure-related petroleum systems with Jurassic coals and Triassic lacustrine mudstones acting as source rocks. However, the relationship between the recent structural evolution and the development of petroleum systems is poorly understood. In this study, the paleo-geometries are restored by structural reconstruction based on a regional 2D seismic section. The geological evolution of the petroleum systems was modelled integrating structural restoration with basin and petroleum system model. Results show significant structural dependencies of the thermal history and hydro-carbon charge. Source rock thermal maturity in the Yangxia Sag and Dina Fold Belt in the south increased continuously since the onset of tectonic compression, whereas the maturity of the Yiqikelike Anticline in the north remained unchanged due to structural uplift. Hydrocarbon accumulations are modelled across different structural units, emphasising the control of tectonics on petroleum systems' development. Hydrocarbon accu-mulations occur mainly in structural traps located in the Dina Fold Belt and Dibei Slope. The present-day ac-cumulations are characterised by multiple stages of hydrocarbon filling, during which the proportion of gas components was increasing. Finally, the different sources of hydrocarbons in various reservoirs are recognised and prospects are predicted. The fold-and fault-related traps and tight sand reservoirs in the Dina Fold Belt and Dibei Slope should be treated as prospective targets in the area. This study highlights the importance of inte-grating structural restoration and petroleum system modelling, which is particularly important for tectonically active basins.

Automated summary

This study explores the relationship between structural evolution and petroleum system development in the eastern Kuqa Depression. Structural restoration and petroleum system modeling reveal the significant influence of tectonics on hydrocarbon accumulations, with traps in the Dina Fold Belt and Dibei Slope identified as prospective targets.