The Oil And Gas Resources Potential Assessment In Mesozoic And Upper Paleozoic In Beidagang Uplift,Huanghua Depression

The Beidagang structural belt is a complex oil and gas accumulation area with many oil-bearing strata,including Ordovician,Carboniferous,Permian and Mesozoic.The oil and gas accumulation resources and resource potential of buried hill in the Mesozoic and Upper Paleozoic are still controversial.Based on the major tectonic units in Beidagang structural belt,other data collection and test sampling analysis,basin simulation technology is used to simulate the burial history,thermal history,hydrocarbon generation,expulsion history and migration history in Beidagang Uplift.Combined with the basin simulation method and analogy method,the quantitative analysis and evaluation of the potential of oil and gas resources in the Mesozoic-Upper Paleozoic are analyzed and evaluated.The main controlling factors and distribution patterns of Mesozoic and Upper Paleozoic of buried hill oil and gas reservoirs in the study area are determined.Combined with the structural evolution,the characteristics of source reservoir cap assemblage and the characteristics of migration and accumulation in the study area,the probability distribution of Mesozoic and upper Palaeozoic reservoirs in the North Dagang uplift is quantitatively analyzed.The prediction of the favorable area was carried out and the favorable exploration direction in the next step was pointed out.Through burial history simulation,the burial process of the North Dagang uplift has experienced multi-stage tectonic uplift.After the deposition of the upper Paleozoic,it mainly goes through three stages:Differential settlement in late Indo-early Yanshan;Subsidence in late Yanshan;stablely deposited after in lifting Himalayan period.The thermal history analysis shows that the Hercynian period is in the low temperature field.The Yanshan period is in the high temperature field,and the Himalayan period is in the low temperature field..The history of hydrocarbon generation and expulsion indicates that the source rocks of the upper Paleozoic and E_s formation experienced two hydrocarbon generation and Hydrocarbon expulsion.The hydrocarbon generation and expulsion stage of the upper Paleozoic source rock is in the Triassic and Nm period.The hydrocarbon generation and expulsion of E_s source rocks occurred in late Ed and Nm.The most important period of hydrocarbon generation is the period of Nm.The simulation of migration and accumulation history shows that the evolution of oil and gas migration has three stages:the oil and gas accumulation in the late Hercynian to Indosinian period,oil and gas and oil gas accumulation in Yanshan and adjustment of Himalaya source migration and adjust the setting,the main oil and gas migration and accumulation period is in Nm.In view of the particularity and complexity of the research area,based on the theory of oil and gas accumulation system and on the basis of systematic analysis and reunderstanding of oil and gas accumulation in oil and gas reservoir system,basin simulation method and analogy method have been applied to calculate the total Mesozoic and Upper Paleozoic buried hill oil and gas resources in the Beidagang structural belt.It shows that the total oil and gas resources in the area is about 0.4×10~8t and the potential of oil and gas is good.Based on the previous basin simulation and the calculation of oil and gas resources,combined with structural evolution,source reservoir cap characteristics and transportation conditions,the main controlling factors of oil and gas in Mesozoic-Upper Paleozoic for Beidagang structural belt were analyzed:rich oil source;Ancient and modern structure inversion is favorable for docking of hydrocarbon source rock and reservoir;good transport system;dominant reservoir and cover combination.The distribution of oil and gas for buried hill reservoirs in Mesozoic-Upper Paleozoic is summarized:Multi-layer and multi type reservoir oil;The upper Paleozoic is more abundant than the Mesozoic,and the reservoir is mainly oil;The Mesozoic reservoirs are mainly sandstone and volcanic reservoirs,and the upper Paleozoic reservoirs are mainly sandstone and carbonate reservoirs;oil and gas differential and accumulation distribution along bedrock fracture.The distribution map of the accumulation probability of oil and gas accumulation system has been obtained according to the quantitative favorable area prediction method of oil and gas accumulation system.Favorable areas for oil and gas exploration in the Mesozoic and Upper Paleozoic has pointed out:uplifted zone of Gangxi fault area,banshen31 southern area and the southwest of tai 9.