Abstract
With the advancement of technology and the improvement of the level of understanding, deep hydrocarbon exploration in the Songliao basin has become one of the key objects. Wangfu fault depression is a typical oil-gas fault depression with a high degree of deep hydrocarbon exploration in the southeast of the Songliao basin. Finding out the oil-gas accumulation period of the deep hydrocarbon exploration is of great practical significance. The aim of the study is to find out the period and time of deep hydrocarbon accumulation in Wangfu fault depression, so as to provide an important theoretical basis for deep hydrocarbon exploration. The objective is to reveal the process and track of deep hydrocarbon accumulation of Huoshiling-Yingcheng Formations based on the lithofacies characteristics and the homogenization temperature distribution characteristics of fluid inclusions, combined with the burial history and thermal history simulation of strata in Wangfu fault depression. The results show that the reservoir of Huoshiling-Yingcheng Formations in Wangfu fault depression have experienced at least two periods of oil and gas filling events and two periods of oil filling events. The first hydrocarbon filling event was formed in the middle of Quantou period (about 95.4-97.5 Ma). Being influenced by the hydrocarbon expulsion from the source rocks of Huoshiling Formation, a large-scale oil and gas migration was formed. The second filling event occurred in the early Qingshankou period (about 93.6-92.0 Ma). During this period, the lake of the Songliao Basin expanded extensively, and the oil migrated and recharged through the opening fault on a large scale. The third filling event occurred in the late Qingshankou period (about 88.9-90.8 Ma), during which the source rocks of Shahezi Formation were in the peak of hydrocarbon generation and a large number of hydrocarbon migration occurred. The last large-scale filling event occurred in the early Nenjiang period (about 85.8-84.0 Ma). Affected by the rapid expansion of the lake basin in this period, the fault fractures reopened, resulting in the secondary migration and filling of oil.
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