三维四相多组分数学和数值模型

注气的目的是通过降低注入气与地层原油的界面张力,与原油达到混相(或部分混相)而开采地层剩余油。然而,由于向地层注入工作剂,使整个油气体系的热力学条件发生变化、体系的组分和组成的改变、以及体系的温度和压力的变化,从而有可能导致有机固相物质的沉积。从常规多组分模型的假设条件出发,补充完善考虑有机固相沉积的假设条件;应用达西定律并根据摩尔数守衡定理,建立三维四相(油相、气相、水相和有机固相)多组分数学模型;运用计算机求解时,利用有限差分方法,按顺序求解法建立相应的隐式压力,显示组成及饱和度的数值模型。

3D and 4 Phase Multi Compositional Mathematic and Numerical Models

Gas injection aims at reducing interfacial tension between oil and injected gas, forming miseible or partial miseible, and producing in-situ remained crude oil. However, such a gas injection process tends to changing tbermodynamic conditions in the petroleum system, including the system's composition, temperature and pressure, possibly giving rise to precipitation of organic solid materials. This paper begins with assumptions of conventional multi-composition model, supplements hypotheses required in precipitation of organic solid materials, finally, develops a multi-composition mathematic model with 3D and 4-Pbase (oil, gas, water and organic solids) by using Darcy's law and moles conservation theorem and a numerical model with explicit composition and saturation as well as implicit pressure by using finite difference method.