Analysis Of The Cambrian Reservoir Conditions In LT1 Well And Its Adjacent Area In Weibei Area

Ordos basin is located in the west of north China platform.As the important oil and gas exploration area in our country,in recent years,a series of large-giant oil and gas field was found here,and carbonate rocks of lower Paleozoic has the extremely huge potential of exploration and research.Exploration degree of Cambrian is low in the southern ordos basin,so the study of hydrocarbon source rock characteristics,reservoir characteristics research,organic matter abundance,types and maturity of organic matter,reservoir petrology characteristics,reservoir space type and physical characteristics of Cambrian reservoir in the studied area is of important significance to guide the next exploration of oil and gas.The study is based on the basic geology,combining with the actual situation of the Cambrian strata in the study area,by some means(core,casting thin sections,physical properties,geochemical,sedimentary facies,diagenesis,pore types and structure characteristics of reservoir),to study the hydrocarbon source rock and reservoir characteristics.(1)The Cambrian strata in the study area is mainly in the tidal flat,restricted platform,open platform,and platform edge facies sedimentary environment.Dolomite is the main component of Sanshanzi group and Zhangxia group,and it is conducive to the formation of reservoir.Xuzhuang group and Maozhuang group have large set of mudstone and marl,which have the possibility of development of hydrocarbon source rocks.(2)The Cambrian strata of organic matter in the study area is high-to-over mature and the main organic matter types are ?,type is given priority to,three dashanzi and zhangxia group overall in the film,the dark carbonate medium abundance of hydrocarbon source rocks,Xu Zhuang,Mao Zhuang group mainly oxidation color of mudstone,high abundance ratios of hydrocarbon source rock is less,also a primary color mudstone and limestone in the organic matter abundance is better,overall for secondary hydrocarbon source rocks.(3)The main pore of upper-middle Cambrian strata are intergranular pore,intergranular dissolved pore,and a small amount of intragranular dissolution pore,intergranular dissolved pore and dissolution of fracture and tectonic broken.All kinds of secondary porosity reservoir space of the reservoir,all kinds of cracks is the main percolation passage.The main reservoir in the study area distribution in three dashanzi and zhangxia group,mainly divided into ? class medium reservoir,three groups against the shell near the dashanzi development ? class good reservoir.(4)The development of the reservoirs are mainly affected by sedimentary facies,dolomization,dissolution and tectonic fracture effect of several factors such as control.One of the main control factor is the dissolution,the ancient karstification is the main controlling factors of the reservoir in the area,especially in the table generated rock phase formation of the fresh water dissolution and burial dissolution of late diagenetic stage play a great influence on the formation of reservoir.