Study On Reservoir And Sedimentary Characteristics Of Permian Wutonggou Formation In Xiquan Area Of Junggar Basin

In this paper,the Permian Wutonggou formation in the Xiquan 029-Fu 001 well area of the North Santai uplift,Junggar basin is taken as the research object.Based on the sedimentary characteristics of the Permian Wutonggou formation reservoir in the study area,aiming at the present situation of Permian reservoir exploration potential in the study area,the sedimentary characteristics of the study area and the main controlling factors of the reservoir are solved.In this paper,based on the previous research conclusions,field profile survey and core observation description,combined with X-ray diffraction of casting thin section,scanning electron microscopy,physical properties,mercury injection at constant pressure and other reservoir micro experimental analysis,in-depth study of the reservoir micro rock and mineral fabric and micro pore structure characteristics,study the diagenesis mode and diagenetic sequence,clear the main control factors of high-quality reservoir,comprehensive research results are as follows: The following conclusion:(1)the Permian Wutonggou formation in the study area is generally lacustrine sedimentary,and only a few wells develop a small amount of fluvial facies deposits.Lake facies can be further divided into shore shallow lake subfacies,shore subfacies and semi deep lake subfacies.(2)the lithology of the Permian Wutonggou formation in the study area is mainly medium sandstone,followed by glutenite,fine sandstone and siltstone.The reservoir of the Permian Wutonggou formation in the study area is a medium porosity and low permeability reservoir,and the reservoir space is mainly intergranular pore.(3)the key diagenesis of the Indo Gou formation in the study area is three: the first is compaction;the second is dissolution;and the third is cementation.The initial stage of diagenesis is early diagenesis a,and the final stage is middle diagenesis B.(4)there are three controlling factors in the study area: the first is rock type,the second is diagenesis,and the third is sedimentary facies.The rock type shows that with the increase of rock particle diameter,the physical properties of the reservoir also increase;The sedimentary facies reflect that the different sedimentary facies,it will lead to the different sorting,roundness and maturity of sedimentary particles,which determines the quality of reservoir physical properties.In diagenesis,compaction is the most important destructive diagenesis of reservoir physical properties,resulting in the decrease of reservoir physical properties.At the same time,the cement mainly composed of laumontite and calcite blocks the pore throat,which is also the main cause of low permeability in the target layer.The above research results will provide an important basis for enriching the geological understanding of the Wutonggou formation and the next step oil and gas exploration in the Xiquan 029 well area of the Junggar basin.