Research On Reservoir Heterogeneity In Yangerzhuang Oilfield

The reservoir of Guantao Formation and lower Minghua Member in Yangerzhuang Oilfield are main development layers in this block,and they are at extra-high water cut development period nowdays.The relationship between oil and water and the distribution of remaining oil is complex.As the key factor affecting the distribution of remaining oil,the characterization method of reservoir heterogeneity is mainly based on the research of sedimentary facies and reservoir physical parameters at present,but it is lack of the dissection of internal structure of sand body,and it is difficult to meet the needs of meticulously tapping of the remaining oil in late period of oilfield development.Therefore,this arcticle comprehensively uses data from cores,well logging,logging,analysis testing and production dynamics,conducts research of reservoir heterogeneity based on the research of internal structure of sand bodies in different kinds of rivers,and analyzes the influence of reservoir heterogeneity on the distribution of remaining oil and oilfield development,and the following major achievements and understanding have been achieved:(1)The interlayer between oil formations,small layers and single sand layers are contolled by level 5 to lever 7 configuration interface in fluvial sand bodies.There is a big difference in interlaye between single sand layers,the interlayer between lower Minghua Member in meandering river deposit is more stable compared with the interlayer between Guantao Formation in braided river deposit.In the entire destination layers,the interlayer between Nm?4-2 and Nm?4-3 single sand layers is the most stable with a development rate of 94.4%,and interlayer between Ng?1-2 and Ng?1-3 single sand layers is the most unstable with a development rate of 56.5%.(2)Mud intercalary strata which is corresponding to level 9 configuration interface is the main influence factor of reservoir heterogeneity within the reservoir.The main causes are silt layer in braided river reservoir and lateral alluvium in meandering river deposit.The dip angle of the former is 0.5-2.5°,and the dip of the latter is 2-4°.(3)The distribution of channel bar,point bar and river channel which are corresponding to level 8 configuration unit affect reservoir heterogeneity,Guantao Formation mainly develops flake sand body,lower Minghua Member mainly develop flake,interlaced banding,banding sand body.(4)The reservoir heterogeneity has great effects on the distribution of remaining oil,water absorption status and oil production characteristics.The remaining oil in braided river is in the lower part of interlayers in channel bar,interbed remaining oil mainly distributes on the bottom of unstable interlaye between single sand layers,plane remaining oil mainly distributes on the edge of river channel with poor physical properties.The remaining oil in meandering river is mainly concentrate in lateral accretion sandbodies which is blocked by lateral alluvium and uncontrolled by injection-production well pattern,interbed remaining oil mainly distributes on main layers with abundant original geological reserves.Plane remaining oil mainly distributes on the edge of river channel with poor physical properties and point bar,river channel sand bodies with abundant original geological reserves.