Experimental Study Of The Determination Of Polymer Gel Physicochemical Parameters Used In Numerical Simulation

In the development process of high-permeability oilfields,it is necessary to use numerical simulation software for reservoir historical fitting and prediction.However,there is a problem that the entered data is inconsistent with the actual parameters when using commercial numerical simulation software.To solve this problem,it is necessary to clarify the key physicochemical parameters involved in numerical simulation of profile control and plugging.Experiments were conducted to study the changing rules and influencing factors of each parameter and provide more accurate physicochemical parameters for numerical simulation.In this paper,by studying the established three-dimensional oil-water two-phase crosslinked polymer flooding mathematical model and combining the mechanism of cross-linked polymer flooding,the significance of each parameter in the mathematical model is further analyzed,and the key physicochemical parameters in cross-linked polymer flooding numerical simulation are clarified.The rheological experiments,spectrophotometry,displacement experiment,and other methods were used to study the variation of cross-linked polymer viscosity,gelation time,adsorption,inaccessible pore volume,resistance factor,residual resistance coefficient,and diffusion coefficient of the polymer component.The main influencing factors of each parameter were clarified,and a set of parameter testing procedures that could be applied in numerical simulation was determined.The main points of this article are as follows: The cross-linking reaction between polymer and cross-linking agent mainly goes through three stages: slow reaction stage,rapid reaction stage,and stabilization stage.Increasing the concentration of polymer and cross-linking agent can both improve viscosity of the gel.The static adsorption amount of the polymer is far greater than the dynamic adsorption amount.The dynamic adsorption amount data should be applied to the numerical simulation.The dynamic adsorption amount is negatively correlated with the water permeability of the core.Besides,the higher polymer concentration,the larger dynamic adsorption amount.The presence of inaccessible pore volume will affect the sweep volume during the plugging process.The size of this parameter is inversely related to the concentration of polymer solution and core permeability.The resistance coefficient and the residual resistance coefficient of the cross-linked polymer injection process are mainly affected by the polymer concentration and the core permeability.The higher the concentration of injection and the lower core permeability,the higher the resistance coefficient and the residual resistance coefficient in polymer flooding.Besides,resistance coefficient of cross-linked polymer follows the polymer flooding law,but the residual resistance coefficient of cross-linked polymer increases with permeability.During the polymer injection process,the higher the concentration of the polymer in the cross-linked polymer solution,the greater the diffusion coefficient of the polymer.At the same time,the increase of core permeability can reduce the diffusion coefficient of the polymer.