Study On Matching Relationships Of Polymer Flooding Parameters With Oil Viscosity And Pore Throat Structure

At present,there are few studies on the matching relationships of polymer flooding parameters with oil viscosity and pore throat structure.There are many empirical technical boundaries of polymer flooding in the field,all of which take the viscosity of crude oil as a single condition.However,with the increasing application of polymer flooding and the deepening of research,the existing limits will change.In addition,different fields have different properties of pore-throat structure.Most of the studies adopt numerical simulation and coreflooding experiments,which are limited to the macroscale and core scale,and lack of researches on remaining oil distribution and polymer flooding mechanism under microscopic scale.So.it is very necessary to research on matching relationships of polymer flooding parameters with oil viscosity and pore throat structure.In order to accurately analyze the effect of subsequent core flooding experiments and numerical simulations,the properties of five different molecular weight polymers were tested to determine their tackify characters,temperature resistance,anti-shear adsorption and aging viscosity reduction.Secondly,in order to study the matching relationship between polymer flooding parameters and pore-throat structure,five different molecular weight polymers were mixed,and the performance parameters of compounding polymers were tested.The test results show that the performance parameters of the compound polymer are very similar to those of 10 million molecular weight polymers.Core flooding experiment and on-line nuclear magnetic resonance imaging technique were used to study the matching relationship between polymer flooding parameters and pore throat structure.Based on the quantitative characterization of pore throat recovery of different sizes,the ratio of recovery ratio of polymer flooding in different sizes is calculated and analyzed.Research suggests that the smaller molecular weight polymer in the compound polymer has a smaller unobtainable pore volume,which can effectively drive the fluorine oil in the small size pore throat,while the higher molecular weight polymer can effectively repel the fluorine oil in medium and large pores.Therefore,the multi molecular weight compound polymer has a better oil displacement effect than the single molecular weight polymer.In order to solve the matching relationship between polymer flooding parameters and oil viscosity,numerical simulation and economic evaluation methods were adopted to analyze and test the factors influencing factors of polymer flooding parameters.Based on the screening boundaries of polymer flooding,Plackett-Burman test and Box-Behnken design were used to determine the maximum incremental oil production per ton of polymer under under different oil price.Finally,the screening boundary map of oil viscosity in polymer flooding was established.