Similarity Research Of Multilayer Reservoir In Water Flooding Physical Simulation

At present,most of the domestic and overseas developed fields have serious vertical heterogeneity,which brings a series of adverse effects in the process of water flooding,such as bad performance in reservoir producing and oil production,serious interlayer interference.Since the oil demand increases greatly,studying the dynamic-physical modeling experiments of multi-layer water driving has a great significance on studying fluid-flow mechanism,the effect of level difference on the exploitation and analyzing the feasibility of variable density perforation in vertical well.Based on the five point method injection-production well pattern from Dongxin oilfield of Shengli and similarity criterion of water flooding the laboratory physical experiment of the formation with vertical heterogeneity was conducted.1.According to the percolation theory and similarity theory,the similarity criterion of water flooding for multi-layer reservoir has been deduced by test analysis.Then the dimensional analysis method was used to examine the correctness of the results derived.Finally taking Dongxin Oilfield as an example,the simulation model parameters and operating parameters were conversed on the basis of formation prototype parameters and indoor conditions.2.A multi-layer physical device has been built up based on those modeling parameters.With using operating parameters,physical simulation experiment in vertical well drilling was carried out.Here are the results.(1)In the process of commingled production,water drive has little effect and liquid production is and liquid production is very low in the layers with low permeability.And the producing degree is unequal in the vertical heterogeneous reservoir,due to the most of the injected water entered the high permeability layers.The production of slicing is higher than that of the multilayer commingled.(2)The variable density perforation technology can reduce the adverse impact of the vertical heterogeneity on the commingled production and effectively improve the liquid production of commingled production layer.3.Numerical models were established with uniform density perforation and variable density perforation separately by using COMSOL Multi-physics.Then the feasibility of variable density perforation technology for vertical wells is further demonstrated through analyzing the pressure distribution of the formation model.The oil production of numerical model and that of physical model fits well,which demonstrated the correctness of the results from physical simulation.