Microcosmic Displacement Mechanism Of Polymer Solution Viscoelasticity Driving Residual Oil

In this thesis, a great deal of work is reviewed including mechanism of polymer microcosmic displacement oil, it is shown that all thought it is true that viscoelastic polymer can enhance the mechanism displacement efficiencies at present, but still haven't the study that only thinking about the elasticity function of HPAM. For thus, this thesis set out from the study that flow characteristic of viscoelastic polymer in model with landscape orientation slot, and end with full systemic displacement experiment study drove by viscoelastic polymer solution and viscous glycerine solution in all kinds of model (blind end model ,mixed-wet model , simulation model). It is proved sufficiency that viscoelastic polymer can enhance the mechanism displacement efficiencies , and measured polymer solution elasticity effect during the course of microcosmic displacement. 1. Flow characteristic of viscoelastic polymer in model with landscape orientation slot(blind end) This thesis study the flow characteristic of viscoelastic polymer in model with landscape orientation slot under truly stratum condition, select upper-convected Maxwell model which is generally applied to numerical calculation of viscoelastic fluid flowing in complex channels. We calculate stream function field, velocity field in experiment condition, and gained the lines of constant velocity and lines of constant streamlines in experiment condition. Result of numerical calculation shows that viscoelasitc effect of polymer fluid in pore media can be showed in the model with landscape orientation slot. 2. Mechanism of viscoelastic polymer solution displacing pore throat and blind end residual oil It is proved that the residual oil in pore throat can't be driven by outside force in theory. Which is formed by the function of capillary force and heterogeneity. We show the displacement result of different concentration polymer solution flooding and different concentration glycerine solution flooding, result of experiment shown that the displacement efficiencies after polymer solution flooding is higher than after glycerine solution flooding in oil-wet blind end, the higher part is considered the function of polymer solution elasticity. In experiment, polymer solution can't drove the residual oil in water-wet blind end, i.e. polymer solution can't enhance the non-movability oil displacement efficiencies in water-wet core, but we can draw a conclude that residual oil of movability oil after polymer flooding is lower than water flooding, from polymer solution droving the residual oil in water-wet core. 3. Mechanism of viscoelastic polymer solution displacing mixed-wet residual oil after water flooding According to the microcosmic displacement experiment, we show the relation of viscidity and displacement efficiencies, which is gained from a series of polymer solution and glycerine solution droving the residual oil continuously. Both polymer solution and glycerine solution drove the residual oil can enhance the displacement efficiencies and decline residual oil saturation, but declining numerical value of residual and enhancing numerical value of displacement efficiencies after polymer flooding is higher than that after glycerine flooding, we regarded that the difference is the function of polymer solution viscidity. As different concentration polymer driving residual oil , study the relation of polymer solution concentration and residual oil film thickness, i.e. with polymer solution concentration increasing non-dimension oil film thickness minish. Also, displacement efficiencies after polymer solution flooding is higher than that after glycerine solution flooding, the difference is the result the difference is the function of polymer solution viscidity also. 4. Mechanism of viscoelastic polymer solution displacing simulation model residual oil From the experiment that simulation model core was drove by different concentration polymer solution, we draw a conclusion that viscoelastic polymer solution can enhance displacement efficiencies in simulation model core, and that with polymer concentration increasing, displacement efficiencies increase, but for the residual oil has cut down, the value of displacement efficiencies increasing is lesser, the descend range of residual oil is lesser. heterogeneity core was drove by polymer solution can enhance the displacement efficiencies substantially and decent residual oil saturation. i.e. the increasing value that of heterogeneity core displacement efficiencies is higher than that of homogeneous core. viscoelastic polymer solution and viscous glycerine solution drive the residual oil in simulation model core, the experiment result show that the residual oil quantity after polymer flooding is lesser than that after glycerine solution flooding, this prove that polymer solution elasticity affect displacement from the other side.