Petroleum Geology Condition Analysis And Exploration Targets In Fujian, Zhejiang And Jiangxi Area

The Mesozoic-Cenozoic fault basin in the Fujian,Zhejiang and Jiangxi provinces is one of the regions with the lowest degree of oil and gas exploration on land in China.This paper focuses on the re-determination and comparison of the Lower Cretaceous strata in the Fujian,Zhejiang and Jiangxi regions,and establishes the chronostratigraphic framework of the region.Through the study of regional tectonic evolution,it has been clarified that the Mesozoic-Cenozoic faulted basins in the Fujian,Zhejiang and Jiangxi provinces are mainly volcanic fault depressions and sedimentary fault depressions.On this basis,in-depth studies were carried out from the conditions of hydrocarbon source rock,reservoir characteristics,supporting conditions of source rock,and preservation conditions.Further analysis and clarification of basic oil and gas geological conditions in the Fujian,Zhejiang,and Jiangxi Provinces.Comprehensive prospective analysis and selection queuing were conducted for exploration prospects in each basin,and favorable exploration blocks were proposed.The lower cretaceous strata in Fujian,Zhejiang and Jiangxi area can be further divided into the lower cretaceous strata and the upper cretaceous strata according to the unconformity surface formed by the min-zhejiang movement,each contains two sets of black shale from different eras.The dark clay shale of the Lengshui group in Jiangxi province and the Guantou group in Zhejiang province can be compared in the times.The dark clay shale of the Bantou group in the west of Fujian and Xiaoxi group in the east of Fujian can be compared in the times.The basins in the Fujian,Zhejiang and Jiangxi provinces are mainly volcanic faulted basins and sedimentary faulted basins.Three sets of hydrocarbon source rocks were developed in Yiyang basin,including the Permian Wulinshan Formation,the Triassic Anyuan Formation and the Cretaceous Lenshuiwu Formation,among them,the organic carbon content of hydrocarbon source rocks in the Permian Wulinshan Formation and the Triassic Anyuan Formation is high,but the chloroform"A"content is low,the organic matter type is Type II₂,and the degree of thermal evolution reaches the stage of high-maturity;the organic matter abundance of hydrocarbon source rocks in the Cretaceous Lenshuiwu group is high,and the organic matter types are mainly Type II and Type I,the heat evolution degree of organic matter has reached a mature stage,and it is the most favorable hydrocarbon source rock formation system in the area.The organic matter content of the hydrocarbon source rock in the Lishan Formation and the Cretaceous Bantou Formation under the development of the Juan Basin was still possible,and the asphalt value was low.The comprehensive evaluation concluded that the hydrocarbon source rock lacked oil production conditions;The organic carbon abundance of the hydrocarbon source rock in the Cretaceous Bantou group is high,and the organic matter type is mainly II₁^II₂ type,which contains type III,the thermal evolution of the machinery is generally mature-high maturity evolution stage,which is the most favorable hydrocarbon source rock formation in the area.The comprehensive evaluation of hydrocarbon source rock,reservoir and tectonic background indicates that Jiangxi Yiyang basin has good petroleum geological conditions and great exploration potential.The exploration prospects in the basins of Huzhou areas,Julan,Yongtai and shengxian are general.The exploration prospects of Fuding,Ningbo and changhe basin are poor.Guixi sag in Yiyang basin of Jiangxi province has good petroleum geological conditions,and the Huangjinbei traps in a series of traps have the best preservation conditions and the best reservoir forming conditions.