Influence Of Plane Heterogeneity And Well Pattern Type On The Distribution Characteristics Of Remaining Oil

In the actual production and development process,there are many problems in vertical well water injection,such as high starting pressure and high water injection pressure,which seriously restricts the harvesting efficiency of water injection development,resulting in a large amount of remaining oil not being produced or even suffered.Later,with the development of science and technology,horizontal well technology continued to improve,mining costs gradually decreased,and the use of horizontal well mining can avoid some problems caused by vertical well mining,so the oilfield began to use a large number of horizontal wells for mining.Based on petroleum geology,sedimentary petrology,reservoir physics simulation,oil ore geology and reservoir physics theory,this paper deeply understands the reservoir characteristics of the study area,summarizes the typical horizontal well patterns of the study area,and analyzes the areal heterogeneity characteristics of the study area,then use the similar principle to design a two-dimensional physical model device and carry out related water flooding experiments.According to the experimental data and picture,analyzing the law of displacement of different reservoirs heterogeneity configuration relationship and different well pattern modes,also,analyzing the distribution characteristics of remaining oil under different conditions,and compare the development effects.The research indicates that the Nm?-1(1167 sand body)in the study area belongs to the high-porosity and high-permeability reservoir,and the plane is moderately heterogeneous;In homogeneous reservoirs,parallel horizontal wells can be used to obtain higher production levels,and the remaining oil is mainly distributed in the toe area of the production wells;this is due to the pressure of the heel between parallel horizontal well is the largest,the water injection tends to flow to the heel of the horizontal production well,and the displacement effect near the toe is relatively poor;and because the injection-production pressure distribution between the horizontal injection-production wells is relatively uniform,the well-net control reserves are large.Moreover,the water injection line is uniformly propelled to the production well,so the displacement effect is relatively good.With the joint well pattern development,the pressure difference between the vertical injection well and production wells is large,and the water injection tends to flow straight to the production well,The spread range is small;and the water production rate rises rapidly after water breakthrough in the vertical well,which seriously affects the mining effect of the reservoir on one side of the horizontal well,thus resulting in poor final displacement effect.The remaining oil is mainly distributed in the toe area of the horizontal production well.in the heterogeneous reservoir,the displacement effect is better with the joint well network development,in the reservoir with a permeability difference of 4,the remaining oil is mainly distributed in the heel and toe of the horizontal production well,and the right side of the vertical well;in the reservoir with a permeability difference of 6,the remaining oil is mainly distributed in the relatively low-permeability reservoir near the heel of the horizontal production well;this is due to when using vertical well to inject water,the water injection pressure is relatively high,The water injection velocity in the relatively low permeability reservoir is faster than that by using horizontal well to inject water,and because there is a horizontal production well in the joint well network and a vertical well production well in the low permeability reservoir,There is a certain amount of oil production in the relatively low permeability and relatively high permeability reservoirs.so its comprehensive mining effect is better than the mining effect developed by parallel horizontal well pattern.The research results can provide a basis for the potential oil tapping measures and well network deployment of oilfield on-site development.