Reservoir Characteristics Of The Middle JurassicQiketai Formation-1 Memberin Shengbei-honglian Area,Tuha Basin

With the development of oil and gas,the hydrocarbon reservoir exploration potential is attracting more and more attention in the Shengbei-Honglian area,Tuha basin of Middle Jurassic,this thesis is based on the Qiketai Formation-1 member in Shengbei-Honglian area of Middle Jurassic as the research object,systematically carry out the graphic classification and correlation,sedimentary facies,reservoir distribution,combing diagenesis and diagenetic facies,starting reservoir classification and prediction of favorable areas,providing favorable geological theory and data support for the exploration and development of underground oil and gas in Tuha basin.Under the comprehensive analysis of typical drilling and logging data,Shengbei-Honglian area can be divided into 2 members;combining with the well analysis,considering the study area Qiketai Formation-1 member sandstone reservoir developed well,and the study area from west to east depth decreases,Shengbei area overall deeply buried,but the strata was preserved well,and Honglian area is shallow,some formation is gone.In the Qiketai Formation-1 member,the braided river delta and lake are mainly developed,the distributary channel and the mouth bar sand body are more developed in the two member group.Based on the core observation,cast slice,scanning electron microscope,the reservoir rocks are mainly feldspar lithic sandstone and lithic sandstone,cementing with iron calcite,kaolinite,miscellaneous base are mainly mud,the sandstone reservoir of Qiketai Formation-1 member is low compositional maturity,the primary and secondary pores and fractures are distributed in the research area,and the reservoir space is dominated by residual primary intergranular pores.The diagenesis of the study area can be divided into two categories: constructive and destructive.Among them,improving the pore and reservoir diagenesis are mainly chlorite cementation,dissolution and fracturing,and compaction,pressolution,cementation is blocking the throat,hinder the development of reservoir.The diagenetic stage of Qiketai Formation-1 member is generally in the middle diagenetic stage B,developing 6 types of diagenetic facies,and rim agglutination of chlorite-siliceous cementation,kaolinite-residual primary intergranular pore(crack / dissolution pores)is the favorable diagenetic facies.Reference to previous sandstone reservoir division scheme,according to the actual situation of Shengbei-Honglian area in the Middle Jurassic Qiketai Formation-1 member,making the reservoir classification scheme as specific Division I-V reservoir,contrasting the surrounding oil and gas exploitation,starting the evaluation and prediction of reservoir,the results of evaluation show that the price of the reservoirs in the Qiketai Formation-1 member mainly developed II and III reservoir,reservoir mainly developed in the distributary channel(under water).On this basis,combining with the actual production data of oil field,we can predict and circle the favorable exploration blocks,which can be used as the favorable direction for key exploration in the next step.