Spatial and temporal evolution of paleo-highs/lows of the permian strata and its petroleum significance in the Sichuan basin, SW China

Abstract

ABSTRACT The Sichuan basin has a great potential for hydrocarbon exploration. In recent years, Permian strata have been identified as one of the main target strata for natural gas exploration in the Sichuan basin. Not only the source rocks are abundant, but also there are good reservoirs due to the wide and complex continental oceanic interaction. However, there are still many shortcomings, especially the relationship between the tectonic evolution and the hydrocarbon accumulation model. Therefore, this research aims at understanding the characteristics of paleo-highs/lows of the Permian strata and their controlling effects on hydrocarbon migration/accumulation in the Sichuan basin. Firstly, the distribution patterns of paleo-highs/lows in the Permian strata at each critical tectonic period were constructed by integrating spatial erosion calculation. Then the temporal evolution of the Permian strata at each critical tectonic period will be revealed by restoring the upper strata sequentially. The results of this research improve the precision of paleo-highs/lows reconstruction and provide useful hints for the hydrocarbon exploration of the Sichuan basin: (i) Paleo-highs/lows directly determine the development location of the Permian key reservoirs; (ii) Tectonic evolution controls many factors and the process of hydrocarbon accumulation.