Research On Characteristics And Controlling Factors Of Sandstone Reservoir Of The Second Member Of Dongying Formation In The South Depression Of LiaoZhong Sag

The area of Liaodong Bay,as one of the most important oil-gas region,has great petentical in oil exploration.For the past few years,the out come of exloratory development has indicated that Dongying and Shahejie Formation of southern Liaozhong sag have good oil and gas reservoir forming condition,which lay a solid foundation for large petroleum fields.But,owing to relatively low exploration level and weakly basic research,the main control factor and mechanism of prospective reservoir have not been fully recognized,lagging further petroleum exploration.It based on previuos studies about reservoir,the date of drilling and logging,observation of core in paper,In the following aspects has obtained the certain understanding:(1)it determine about reservoir formation that its sedimentary environment is braided river delta in the south depression of Liaozhong sag of Dongying formation of secondary member.The sand developed in mainly sedimentary microfacies: submerged distributary channel,mouth bar,etc..(2)analyzing the of characteristics petrology,determining the type of rock,the type of diagenesis and divided the reservoir diagenetic stages.The main rock type contact arkose and lithic arkose sandstone;the reservoir diagenesis type are mainly consisted of compaction,cementation,dissolution and metasomatism etc.;there are two diagenetic stages: the later of early diagenetic stage(B stage)and the earlr period of middle diagenetic stage(A stage).(3)The primary pore type are secondary dissolution pores and primary intergranular pores,the dissolution pores contact mainly feldspar dissolution and a mixed cement and dissolution expanded hole of the base.According to the characteristics of capillary pressure curve,the porosity in the study area is divided into four types: ?type,?type,?type and ? type.?type of pore are the best,the ?and the ? are the secondary,? type of pores are less.(4)The major control factors of favorable sedimentary were the development of reservoir,diagenesis and structural factors,comprehensive study area Dongying formation of secondary member sedimentary microfacies plan,buried depth chart,and hydrocarbon generation intensity plan for predicting favorable reservoir distribution.The paper through the study of sedimentary facies of reservoir characteristics,reservoir petrology features,reservoir diagenesis,reservoir property characteristics etc.,the south depression in LiaoZhong sag of dongying formation second memember reservoir are comprehensive analyed,that finding out the favorable reservoir control factors,and then to provide powerful basis for delineating favorable oil and gas blocks in the study area,and the favorable reservoir zone in dongying formation in the study area are comprehensive evaluation and prognosis,and provide powerful basis for exploration and development in the area.