TECTONIC REGIME CHANGE AND HYDROCARBON SYMBIOTIC COMPOSITE ACCUMULATION IN THE SOUTHERN MARGIN AREA OF JUNGGAR BASIN

In the southern margin area of Junggar Basin, there are many stages of tectonic regime change, forming complex structural deformation characteristics, especially the development of faults and folds. Many scholars have studied the tectonic evolution process of the southern margin in detail, but there are still some controversial points in the understanding of the transformation process of the tectonic regime.In this paper, we analyze the structural development history of the southern margin area from the perspective of tectonic regime change, and study the geological effect and its influence on hydrocarbon accumulation by combining field outcrop and geochemical data. Tectonic regime change plays a key role in controlling the hydrocarbon accumulation process, which is mainly reflected in the influence on traps, transport systems, hydrocarbon generation and expulsion, and the temporal and spatial distribution among them. In addition, the exploration results in recent years show that under the effect of regional tectonic regime change, conventional and unconventional oil and gas resources coexist in the southern margin area, and the corresponding hydrocarbon accumulation process is combined and superimposed. The original hydrocarbon accumulation model is no longer suitable for studying this symbiotic and composite relationship. A new one should be established to systematically study the law of symbiotic composite accumulation of conventional and unconventional oil and gas resources in the southern margin area.