Study On Measurement Method For Parameters Of Microemulsion Flooding Numerical Simulation In Low Permeability Reservoir

At present,the application of microemulsion flooding is still in the experimental stage.Industrial application has not been carried out in the whole oil field.The numerical simulation method is usually used to study the effect of microemulsion flooding and predict its development effect.The key to the numerical simulation of microemulsion flooding is to determine the parameters of numerical simulation.However,the physical and chemical parameters of microemulsion cannot be measured directly under reservoir condition.Scholars have done a lot of research work for determining the true physical and chemical parameters.The main method is that the parameters can be adjusted by checking static database repeatedly combined with dynamic monitoring data and refer to the results of empirical formula.Using the parameters obtained by the above methods can indeed get a better fitting result through history matching.However,the numerical simulation of microemulsion flooding involves a lot of physical and chemical phenomena.The fitting results are affected by many uncertain factors.The above methods directly adjust or recalculate a parameter and its randomness is bigger.The accuracy requirements and research needs of practical oilfield development cannot be satisfied.Aiming at this problem,in this paper microemulsion is taken as an example which is prepared by twelve sodium dodecyl sulfate(SDS),n-butanol,sodium chloride and crude oil.Firstly,the phase behavior of the microemulsion system is studied.The main research contents are the effects of surfactant concentration,cosurfactant concentration,salinity and temperature on the phase behavior of microemulsion.In addition,physicochemical parameters(adsorption parameters,interfacial tension,phase density,phase viscosity)and seepage characteristic parameters(starting pressure gradient,relative permeability curve)of the microemulsion flooding numerical simulation were measured under the simulated conditions of low permeability reservoir.At the same time,the influencing factors of each parameter are studied,and its change rule is analyzed.On this basis,laboratory experiments are carried out to simulate the microemulsion flooding process.Sensitivity analysis of the above parameters is conducted through small scale of core numerical simulation.The results show that the starting pressure gradient measured in the experiment is quite different from the actual situation.Through an amendment to the starting pressure gradient of microemulsion flooding,the numerical simulation results fit well with the experimental data.This shows that the parameter can be used in the numerical simulation of oil field.The research of this paper makes the numerical simulation of microemulsion flooding can be successfully applied in oil field.