Characteristics And Structure Coupling Analysis For The Minghuazhen Group In The Raised Middle Of Shijiutuo Ialand

Shi Jiu Tuo is one of the Island which contains the better quality oil and gas compared with others in the sea area of Bohai, this Island is located at the middle north of Bohai Sea, and next to the depressed areas of both Middle Bohai Sea and South of Qin Mountain. The high volume of gas and oil fields such as Q32-6 had been found in the raised paleogene system of Shi Jiu Tuo in 90 s, which could be consumed as the introduction of the convex shallow lithologic of oil and gas exploration. The storage level had been confirmed based on the exploration of the field in 2011, which means that the third level of geological storage of lithologic hydrocarbon reservoir such as Q33-2 and Q33-3 could be consumed as 4900 million units in this area. Moreover, most of the shallow minghuazhen groups had not been discovered in this field at the mornent, which means the storage of oil and gas is possible to increase to10000 million units after the exploration.This essay is based on the petroleum geology theory, high resolution sequence stratigraphy, the basic theory of structural geology, as well as the analysis of geology, logging, and geophysical research, in order to indicate the differences of depositional system with structure, sequence body layer theory, and the lithofacies paleogeography.First of all, according to the background and resources of the regional tectonic, the combination of materials including drilling, logging and earthquake, as well as the research results of sequence stratigraphy, the classification and characteristics of sedimentary system, and the compression of layer. It could be said that the oil and gas enrichment is at an advanced level in this field because of the large area of lithologic trap, which been formed by the sand of shallow area in the delta. At the same time, it had been found that most of the gas and oil is concentrated stored in the Huqinyu. Finally, this essay forecast the target zone of oil and gas exploration from Shi Jiu Tuo to the neogene system of Mingxia. The main results and findings based on the research are including:The detailed summary of division scheme on Mingxia had been formulated by referring to the analysis and comparison in terms of 25 of wells and five cross sections of sequence stratigraphy, which forms the structure of sequence of geological layer. Furthermore, the composite columnar sections had been structured based on the sequence stratigraphy of wells and depositional system, frame map of sequence stratigraphy and sequence stratigraphy of earthquake, as well as chart of comparative depositional system had been be formatted. In addition, the evidence of the lake sedimentary and types in Mingxia’s research area had been found out by combined with the background of sedimentary, and the sedimentary model of both upper plain and under plain had been discussed by following. Through analysing sequence of layer structure, as well as considering the influences of ancient landform and level cycle to the sand disperse system, the control reasons for sand disperse system in delta of Shi Jiu Tuo had been detailed summarised and concluded.