Study On The Reservoir Characteristics Of Chang-6 Extra Low Permeability Oil Reservoir In The Southeast Of Ordos Basin

Due to the deepening of the exploration and development degree of the chang-6 reservoir in Ganguyi Oilfield,Ordos Basin,the relationship between oil and water distribution in the oil formation becomes more complicated,the corresponding development law and oil displacement characteristics have changed,and the existing production and development data is difficult to meet the needs of the next stage of exploration and development,therefore,it is urgent to study the distribution and reservoir characteristics of sand bodies in Ganguyi oilfield in order to find relatively high quality reservoirs,and to provide theoretical basis and scientific and effective solutions for the problems encountered in the development of later oilfields.In view of the above problems,under the theoretical guidance of hydrocarbon reservoir geology,sedimentary rock petrology and oil mine geology,comprehensive utilization of core,logging and various kinds of analytical laboratory data,combined with the more advanced constant speed mercury and NMR testing technology in recent years,this paper probes into the characteristics of the chang-6 reservoir of the extension team leader of Ganguyi oilfield,which focuses on the relationship between the microscopic pore structure and the seepage capacity of the reservoir,and puts forward a targeted standard for the evaluation of the later reservoir.The research shows that the chang-6 reservoir mainly develops the underwater shunt channel deposition in the delta front,the sand body is stable,the thickness is large,the distribution is wide,the sand body is the banded distribution,the lithology mainly is the fine granular feldspar sandstone,the reservoir diagenesis is relatively strong,mainly includes the compaction compaction,the cementation,the metasomatic alteration,the dissolution dissolution and it has a certain influence on reservoir capacity,and the pore structure of reservoir is complex,with III?middle row displacement pressure-fine hole laryngeal type?,IV?high discharge displacement pressure-microporous laryngeal type?,the average porosity of reservoir is 8.21%,the average permeability is 0.52×10^-3?m²,the overall physical property is poor,it is a typical special low permeability reservoir.The physical property of chang-6reservoir in Ganguyi oilfield is mainly controlled by laryngeal tract,and the relationship between pore and throat is closely related to the effect of oilfield exploration and development.According to the sedimentary facies distribution and reservoir characteristics of the chang-6 reservoir in Ganguyi Oilfield,combined with its oil testing means of production,a comprehensive evaluation standard is established,which conforms to the actual situation of chang-6 reservoir,and divides the chang-6 reservoir into 4 types,among which,I and II Reservoir is the best reservoir in Ganguyi,which is mainly concentrated in the giant thick sand body in the center of underwater shunt channel with strong hydrodynamic conditions,the sand body is well sorting,its primary pores and secondary pores are very developed,mainly represents the residual intergranular hole and the dissolution hole,and is the high quality reservoir of the chang-6 reservoir.