Distribution Of Favorable Reservoirs In The Second Member Of Jurassic Sangonghe Formation In Moxizhuang-Yongjin Area,Junggar Basin

Moxizhuang-Yongjin area is located in the abdomen of Junggar basin,with huge potential of oil and gas resources,but the overall exploration level is not high.The research area shows that the oil-water relationship is inverted,oil and water are suddenly changed,and the oil and gas concentration is unknown in the research area.In the early stage,it is recognized that the reservoir plays a key role in the process of oil and gas enrichment,Therefore,it is necessary to carry out targeted research on reservoir,implement favorable reservoir development mode and distribution law,so as to guide exploration and deployment.Based on previous research,this paper uses the trend analysis technology of logging spectrum attribute and maximum entropy analysis technology to divide the highprecision sequence stratigraphy of single well.Further,the seismic interpretation of the fourth order sequence interface is realized through the fine calibration of single well synthetic seismic record and the combination of well and earthquake,The high precision sequence stratigraphic framework of the second member of the Sangonghe formation of Jurassic system in Moxizhuang Yongjin area is established.Four sedimentary microfacies combination styles are identified in the study area,namely,cut-off underwater distributary channel,superimposed underwater distributary channel,lower residual river mouth dam and superimposed estuary dam.Further,based on the study of sedimentary facies subdivision and combination style,the hydrodynamic index analysis,conventional particle size parameter analysis,particle size parameter cluster and particle size end element analysis are carried out by using the particle size parameters such as average particle size,median particle size,separation coefficient,standard deviation,deviation,peak degree,etc.based on the study of sedimentary facies subdivision and combination style,The hydrodynamic characteristics and their variation rules of different sedimentary microfacies combination styles are defined.At the same time,the causes of low permeability reservoir in Jurassic system are studied by means of conventional thin sheet,cast thin sheet and SEM.The important factors affecting the properties of low permeability reservoir are analyzed.The influence of compaction,cementation and dissolution on the oil bearing property of low permeability reservoir is determined.It is clear that the relatively high quality reservoir is mainly distributed in the sand bodies with low plastic cuttings and coarse grain grades.The size of sandstone and the content of plastic rock cuttings control the oil bearing property of the reservoir by influencing the porosity reduction rate brought by compaction and then affecting the strength of dissolution and cementation.Finally,according to the sedimentary microfacies combination style proposed by Shengli Oilfield,the favorable reservoir development viewpoint is controlled.Under the constraints of high-precision sequence stratigraphic framework,the control effect of the middle reference level cycle change,the relationship between the accommodation space and sediment supply(a/s)and paleogeomorphology on the favorable reservoir is clarified,Based on the hydrodynamic conditions and reservoir micro characteristics of different sedimentary microfacies combination styles controlled by the reference level cycle,the heterogeneity caused by different sedimentary microfacies combination styles directly affects the effectiveness of the reservoir,explores the formation mechanism of favorable reservoirs in the target reservoirs in the study area,and establishes favorable reservoir development mode,The prediction scale is favorable for the reservoir to develop in the middle base level rising stage,superimposed river channel at the front of slope break zone and superimposed estuary dam development area.