聚合物驱油过程中不同粘度比情况下波及系数计算方法

在分析聚合物驱油机理的基础之上，建立了考虑吸附因子和不可入孔隙体积的聚合物驱油的五点井网模型。应用流管法将二维平面模型简化为若干个一维驱替模型，从而建立了聚合物驱油的一维数学模型。利用前缘驱替理论，通过求解每根流管中的驱替动态，然后叠加至整个五点井网，从而模拟二维平面上完整的聚合物驱油过程。将该计算过程编制成VBA程序，绘制了不同含水率条件下，聚合物驱油波及系数与流度比的关系图版，为矿场实施聚合物驱提高采收率项目时，对聚合物溶液粘度的配制提供了理论依据。将计算得到的聚合物驱油动态参数和实验结果对比，发现两者具有较好的一致性。文章建立的流管模型的优点在于输入参数较少，计算快捷，适应性强，同时克服了传统矩形网格油藏数值模拟带来的数值弥散作用，为使用聚合物驱油的油田早期筛选及油藏动态管理提供了一种有效工具。

Calculation methods of sweep efficiency under different viscosity ratios for polymer flooding process

Considering the absorbing factor and inaccessible pore,a five-spot well pattern model of polymer flooding was built on the base of polymer flooding mechanism analysis.By applying the stream tube method,the areal two-dimensional model was simplified to several one-dimensional displacement models,and a one-dimensional mathematical model of polymer flooding was established.On the basis of frontal displacement theory,the whole process of two-dimensional polymer flooding was simulated by superimposing the displacement performance in each stream tube on the five-spot well pattern.This calculation process was compiled into the VBA software to map the relation between the sweep efficiency and mobility ratios under different water cut conditions are draw,thus providing a theoretical criteria for the polymer solution viscosity preparation when performing IOR through polymer flooding.Comparison between the dynamic parameters with the experimental results shows a good consistency.The advantages of the stream tube model set up in this paper are as follo-wing:less input parameters,quick calculation,well-adapting,and no dispersion effect of numerical simulation as in the traditional rectangular grid.Therefore,this method offers an effective tool for the early selection for polymer flooding and reservoir dynamic management.