Numerical Simulation Study On Crosslinked Polymer Profile Control

With the development of the oilfields in China,polymer flooding has become a major and widely applied enhanced oil recovery(EOR)method to improve the recovery ratio in its mature fields.As polymer flooding becomes more and more popular,a new technology of using crosslinked to further enhance oil recovery has been developed based on polymer flooding.However,it is lack of the numerical simulation models and associated software to study crosslinked polymer profile control.At present,researches on the mathematical model and software for the crosslinked polymer profile control are still insufficient.It is necessary to conduct numerical simulation studies in this area,particularly on the models and software development,to meet the field needs in Chinese matured oilfield.In this thesis,an extended black oil model is developed to study the crosslinked polymer profile control.New pseudo components of polymer,brine,crosslinking agent and gel were added to the three-component black oil model(oil,gas and water).As a result,a three-dimensional and three-phase numerical model of expanded seven components was established.This model has incorporated the principal physical and chemical phenomena of polymer gel system,such as viscosity increasing,adsorption retention,inaccessible porosity,permeability decline,crosslinking reaction kinetics and aging degradation,and the corresponding physical and chemical parameter equations were established.Full implicit scheme finite-difference discretization is used to solve the mathematical model.A crosslinked polymer profile control numerical simulator was developed with programmed chemical computational features on a traditional black oil simulator.Simple verification models,as well as a complex field model are used to run the developed numerical simulation modules.The test results show that the cross-linked polymer model of seven components generates correct results and is capable of describing all the major fluid flow mechanisms of polymer profile control.Comparing with commercial numerical simulator,the seven components simulator runs fast and reliable.The field test showed that the seven components simulator is capable to simulate typical black oil,polymer flooding,and crosslinked polymer profile control processes.Its mathematical discretization,linear algebraic solver and functionalities are able to meet the requirements of simulation studies of field scale works.