Study On The Effect Of Dosage Combination Of Polymer Solution On Displacement Performance

At present, most of oil field in China is using water-flooding method.Polymer flooding is an inevitable trend when comes to later development phase.the molecular structure of the EOR polymer which the oil field used frequently can be divided into two kinds. The one is a kind of polymer that made up of linear molecular structure and the other is its molecular structure is dendritic polymer, there can be problems to use any kind of polymer separately. Therefore, this paper focus on two different molecular structures’flow characteristic discrepancy among porous media. Then, improving displacement performance under the premise of ensure the injunction and using different combinations of the two polymer solutions and find a best option to provide technical and theoretical basis for the follow-up polymer reseach.Two kinds of polymers are chosen for research. The one is linear polymer named SNF and the other is dendritic polymer. The research found that different molecular structure led to significant difference performance of polymer solution. Analysis suggests that dendritic polymer has better tackify performance than SNF because intermolecular forces and molecular action are different in the solution. As linear polymer SNF is not sensitive to salt so the mineralization has little effect on it.the shear action has small effect on dendritic polymer.As the molecular’s combination mode of polymer is different, SNF is mainly depend on string congestion.. dendritic polymer can form strong three-dimensional network structure,therefore, the intermolecular force of dendritic polymer is greater than SNF.Studying different molecular structure polymer solution in the porous media’s flow characteristic discrepancy through doing alternate experiments to polymer solution. SNF has better injectivity and conductivity than dendritic polymer. Polymer solution may lead to frond-end accumulation phenomenon and made the pressure of the entry end improve while the pressure of the middle section can not be replaced in time when dendritic polymer in the porousmedia which has low permeability. as dendritic polymer forms three-dimensionalnetworkstructure and can absorb, retention in the porous media, therefore, it can build higher resistancecoefficient and residualresistancefactor than SNF. The interaction between SNF and porous media is weaker than dendritic polymer. Thus, the flow diagram between them has obvious discrepancy. The mix polymer is made up of the above two polymer using the ratio of 1:1. The mix polymer not only improve the condition that dendritic polymer can not be easily injected under low permeability but also improve the status that linear polymer SNF is hard to retention in porous media and hard to build higer residualresistancefactor.Different combination of polymer solutions have been used to do the displacement experiment among nonhomogeneity porous media. The result is the closet for oil recovery when using xxx and mix polymer which the ratio is 1:1 for those two lower the moisture content and improve the oil reservoir heterogeneity. Among three groups of experiments, which is 0.1 PV DP/0.2PV SNF,0.15PV DP/0.15PV SNF,0.2PV DP/0.1PV SNF, the more the resin, the better the recovery efficiency. Thus, xxx can build higher resistance coefficient and the residual resistance factor can improve the recovery efficiency. In a word, the mix polymer not only improve the dendritic polymer injectivity issue, but also improve the recovery efficiency a lot so it can combine the advantages of the above two.