复合驱油藏非线性渗流试井模型的影响因素

 在基于变截面孔喉模型建立的黏弹性本构方程的基础上，考虑黏弹性与流变参数的变化，建立了碱-表面活性剂-聚合物（ASP）溶液不稳定渗流的试井模型，并用有限差分方法求解，得到了相应的有量纲与无量纲试井曲线。通过有量纲试井曲线，分析了幂律指数、注入速度、稠度系数、渗透率、特征时间、孔隙因子等参数对复合驱油藏注入压力的影响；通过无量纲试井曲线，分析了这些参数对复合驱油藏试井曲线形态的影响。研究表明，在进行复合驱驱油藏试井分析应用的过程中应适当考虑流变参数变化与黏弹性的影响；而在流变参数变化不太剧烈、黏弹性不太大的情形下，幂律试井模型具有很好的适用性。该试井模型的分析研究对复合驱渗流规律的探讨具有一定的借鉴意义。

Influencing Factors of Nonlinear Flow Well Test Model in ASP Compounded Flooding Reservoir

The oil industry shows a great deal of interest in Alkali-Surfactant-Polymer(ASP) flooding in recovery operations. For its application, it is necessary to study the mechanisms of non-Newtonian flow through porous media. The present investigation shows that ASP solutions exhibit power-law and elastic properties within certain shear rates. The effect of viscoelasticity on the well test curve is studied from macroscopic perspective. Based on a varying cross-section throat model, the established viscous-elastic constitutive equation, with the consideration of the viscoelasticity and the variation of rheological parameters of ASP solutions, the seepage well test model of alkaline-surfactant-polymer solutions is established and solved by finite difference method, to obtain dimensional and dimensionless well test curves. From the dimensional typical curve, the effect of the parameters on the dimensional well test curve can be seen, such as the power-law exponent, injective rate, consistency coefficient, permeability, relaxation time, and tortuosity factor. The influence of these parameters can also be seen on the configuration of the well test curve in ASP reservoir. It is shown that it is necessary to consider the variation of rheological parameters and viscous-elasticity to some extent, in the application of the well test analysis method for ASP flooding reservoir. However, the power-law well test model is appropriate for ASP reservoir under the condition that rheological parameters change gently and with relatively small viscoelasticity. The research results of the well test model provide some food of thought for further investigation into ASP seepages.