基于随机分形网络模型研究近井地带凝析油气非达西微观渗流机理

项目名称： 基于随机分形网络模型研究近井地带凝析油气非达西微观渗流机理

项目编号： No.51504039

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 矿业工程

项目作者： 李菊花

作者单位： 长江大学

项目金额： 20万元

中文摘要： 近井地带凝析油流动区受高毛管数和非达西效应影响的渗流机理复杂，难以用常规实验方法准确描述和表征。我们前期运用随机分形网络模型表征了静（拟静）态凝析油临界流动饱和度，对研究微观渗流机理起重要作用。针对近井地带多相渗流影响机制尚不明确的现状，本课题拟提出对重要参数分形定量化表征的设想。为了验证这个设想，课题首先基于微观储层特征建立随机分形孔隙网络模型，结合凝析油气相态实验结果，用Forchheimer方程取代常规的达西方程进行微观数值模拟，从微观储层静态参数（孔隙尺寸的分形表征）、凝析油气属性（凝析油含量、界面张力）、动态参数（压差）等层面研究多孔介质凝析油气两相微观渗流机理，建立近井地带临界流动饱和度、油气相对渗透率分形表征的数学模型。本研究成果可定量化地诠释高速非达西效应影响程度，深层次揭示近井地带凝析油气渗流能力的变化规律，为凝析气藏的经济高效开发提供理论指导和技术支持。

中文关键词： 多相流体渗流；非达西渗流；微观渗流；分形；渗流机理

英文摘要： The immediate vicinity of the wellbore where condensate flows involves a complex seepage mechanism due to the impacts of the high capillary number and non-Darcy effect. It is hard to accurately characterize by using a conventional experimental method. By means of random fractal network modeling, we quantitatively characterized the critical saturation of the static or quasi-static condensate to flow. This has great significance for characterizing and studying the microscopic gas condensate seepage mechanism of near-wellbore. Seeing that the near-wellbore multi-phase condensate seepage mechanism is not yet identified, we intended to quantitatively characterize the involved important parameters on the basis of the fractal network modeling. So, in the study, a random fractal pore network model was firstly created for the microscopic numerical simulation according to the microscopic reservoir features by using Forchheimer's equation rather than the conventional Darcy equation, then microscopic seepage characteristics of the two-phase condensate in the porous medium were studied in terms of static parameters (pore size fractal ), condensate properties (condensate oil content and interfacial tension), and dynamic parameters (differential pressure and velocity), and finally, a mathematical model featuring the fractal characterization of high-velocity non-Darcy flow coefficient and oil and gas relative permeabilities was created. The findings of the study can quantitatively interpret the impact of the high-velocity non-Darcy flow effect and thoroughly reveal the seepage capability variation law of the near-wellbore condensate flow region, thus providing a theoretical basis for gas condensate well production prediction and determination.

英文关键词： multi-phase flow;non-darcy flow;microscopic flow;fractal;flow mechanism