Research On Rheological Properties Of Polymer Solution In Porous Media

In polymer flooding,the underground viscosity of polymer solution is the most basic input parameter for the design of development program,dynamic prediction and numerical simulation.The rheological study of polymer solution in porous media is the premise and foundation of correct calculation and analysis of polymer flooding reservoir engineering and guidance of mine experiment.Therefore,this paper selects two kinds of polymers:HP AM and P5,to study the macroscopic rheology and the rheological properties in porous media of HP AM and P5 solution in simulated Shengli Oilfield.At the same time,the plate model was used to study the relationship between the rheological properties and the oil displacement effect of HP AM solution in porous media.Through this article's research,we can provide theoretical and experimental basis for the design of polymer flooding scheme and field application.The paper has achieved the following achievement.?the macroscopic rheology of HP AM and P5 solutions were researched by simulating the high temperature and high salinity reservoir condition in Shengli Oilfield.The results showed that the thickening capacity of P5 solution is stronger than that of HP AM solution at 85? and room temperature.With the increase of concentration,the viscosity of P5 solution gradually increases,when the concentration reaches 2000mg/L,the viscosity increases rapidly,while the viscosity of HP AM solution showes a linear improve with the increase of concentration.At the same time,the power law model was used to fit the shearing rheological experimental data of HP AM solution,and obtained the power factor and the consistency coefficient.The power factor of the two polymer solutions is less than 1,which demonstrated polymer solution were non-Newtonian fluid.The consistency coefficient increases with the improve of polymer solution concentration,and the thickening capacity ehhances.?The results of dynamic viscoelasticity show that the storage modulus and loss modulus of HP AM and P5 solution increase with the enhance of frequency and concentration,and the loss modulus is always larger than the storage modulus in the experimental concentration and frequency range,showing that the solution consumes more energy under the influence of external stress.When the concentration of P5 solution reaches 2500mg/L,the storage modulus of P5 solution exceeds the loss modulus,and the solution is mainly elastic.?On the basis of researching the rheology and dynamic viscoelasticity of polymer solution,experiments were also carried to study the rheological properties of HP AM and P5 solution in porous media of 1.5D and 3D.The results show that the seepage resistance of P5 solution is higher than that of HP AM solution,and seepage resistance is very high in low permeability porous media.The results show that the seepage resistance of P5 solution is higher than that of HP AM solution,and seepage resistance is very high in low permeability porous media.The resistance coefficient of P5 solution decreases with the increase of flow velocity,while the resistance coefficient decreases firstly,then increases,and decreases at last at partial concentration.The resistance coefficient of HPAM solution decreases with the increase of flow rate fundamentally,and the resistance coefficient of HP AM solution increases with the improve of flow rate at low injection rate when HPAM solution with concentration of 1000mg/L and 2500mg/L seepaged in porous media with permeability of 1.5D.The residual resistance coefficient of P5 and HPAM solution increases firstly and then decreases with the increase of injection rate.The residual resistance coefficient of P5 solution is higher than that of HPAM solution in the whole injection speed range.?When the flow rate of injected fluid was increased from 1 mL/min to 2mL/min in the three-dimensional physical simulation model,the point of decreasing water cut in the polymer flooding stage advances,while the lowest water cut increases to 85.48%,and the oil recovery decreases to 3.32%in polymer flooding stage.At high injection rate,the resistance coefficient of HPAM solution decreases,which causes the mobility control ability declines and the swept volume of the polymer solution decreases.This indicates that the rheology of polymer solution in porous medium was closely related to the oil displacement effect.