Thermal evolution history reconstruction of Carboniferous source rocks on the northeastern margin of Junggar Basin using TSM basin simulation technology

Abstract

Multiple sets of source rocks developed in the Carboniferous on the northeastern margin of Junggar Basin. Modelling the thermal evolution history of source rocks is of great importance to deepen the understanding of hydrocarbon accumulation. Based on the study of basin evolution and source rock development characteristics, this paper applies a TSM Basin Simulation and Resource Evaluation System to establish one-dimensional and three-dimensional basin simulation models so as to reconstruct the burial, thermal evolution and hydrocarbon generation histories of different structural units. There are obvious differences in the hydrocarbon generation and evolution process of Carboniferous source rocks in different sags on the northeastern margin of the Junggar Basin. The Carboniferous source rocks in the Wulungu Depression entered the low-maturity evolution stage at the end of the Carboniferous, stagnated due to uplifts in the Permian, reached the threshold of secondary hydrocarbon generation at the end of Triassic when burial resumed, and are now in the over-mature stage, mainly generating dry gas (Ro>2.0%). The Carboniferous source rocks in the Sannan Sag entered the low-maturity stage in the Permian and are now in the high-maturity gas-producing stage (Ro=1.5%-1.9%). The Carboniferous source rocks in the Dishuiquan Sag entered the low-maturity stage in the Triassic and are now in the mature oil-producing stage (Ro=0.8%-1.3%). Simulation calculations show that the cumulative hydrocarbon generation of the source rocks in the Carboniferous Jiangbasitao Formation in the Wulungu Depression amounts to 20.5×109 t, in which the cumulative hydrocarbon generation until the end of Carboniferous is 10.3×109 t, which is the main oil generation stage. The cumulative gas generation at the end of Cretaceous is 18.4×109 t, which is the main gas generation period.

Keywords

• source rock
• thermal evolution
• tsm basin modelling
• carboniferous
• wulungu depression
• junggar basin