The Method And Application Of Well Testing With Polymer Flooding By Considering Different Injection Mode

A large number of well test data shows the phenomenon that the late pressure derivative of the data exhibits an obvious upturn in heterogeneous polymer flooding reservoir.However,there exists no appropriate model to interpret this test data recently.On the one hand,the consideration maintains simple either multilayer reservoir or composite model in single layer.On the other hand,the polymer solution is just taken as power law fluid even though considering the heterogeneous and composite property.So it takes great need to establish analysis method for heterogeneous reservoir by considering different injection mode.Firstly,this paper establishes viscosity model,permeability model and porosity model by considering basic flowing properties and physicochemical characteristic(adsorption)of non-Newton fluid.Seven transient pressure analysis models are built based on the parameter model and different injection mode.There are two-layered crossflow model with polymer flooding after water flooding,two-layered crossflow model with water flooding after polymer flooding,three-layered crossflow model with polymer flooding after water flooding,three-layered crossflow model with water flooding after polymer flooding,Newton-Non-Newton-Newton three zone composite model,Non-Newton-Newton-Newton three zone composite model and alternating polymer flooding model.Finite differences are used for solving the nonlinear model numerically because of polymer solution.Then type curves are achieved and sensitivity analyses are carried out.The transient pressure analysis software is compiled based on GUI platform and MATLAB language.Several test data are interpreted based on proposed model and established software.The results prove that the proposed model can accurately evaluate formation characteristic and flooding front,which emphasizes the potential application of this method in oil industry.