【作者】 乔能林；

【导师】 王晓冬；

【作者基本信息】 中国地质大学（北京） ， 油气田开发工程， 2008， 硕士

【摘要】 本文以多孔介质作为研究对象,通过将多孔介质视为相互连通的通道和节点组成的三维网络结构,研究如何建立储层岩石孔隙空间的准静态网络模型,用逾渗理论描述微观渗流机制,模拟驱替过程;结合网络模型的研究,编制相应的软件,应用于流体渗流过程,求取宏观参数(相渗曲线和毛管压力曲线)。实验方法求取这些参数是非常昂贵,且耗费时间。应用网络模型模拟节省了大量的钱物及时间成本。描述孔隙网络空间的参数主要有:网络的维数、孔喉半径、孔喉长度、配位数、孔喉比、形状因子、孔喉分布规律以及其它性质参数。主要的分布函数有:正态分布、对数分布、伽玛分布、截断正态分布和截断威布尔分布。结合前人的研究成果,分析各个参数的分布规律(分布函数适应性)。研究了两大类网络模型(准静态网络模型和动态网络模型)的特征及其适用范围。本论文研究了准静态模型中的油水两相的渗流机理。研究不同驱替方式下的流体驱替模式(活塞式、卡断式、孔隙填充式),根据驱替过程中的油水接触情况得到的入口毛管压力公式表达式,计算相渗曲线和毛管压力曲线。应用网络模型分析微观参数对水驱开发效果的影响,主要思路是建立油水两相孔隙网络模型,分析不同微观参数对相渗曲线和采收率曲线的影响。研究结果表明,随着孔喉比的降低、配位数和形状因子的增大,两相共流区变大,残余油饱和度减小,在相同注入倍数下驱油效率增加;孔喉半径较大的模型,水驱最终采收率较好,孔道半径越长,水驱油效果越好。更多还原

【Abstract】 This research focuses on porous medium. A porous medium is modeled with a similar structure in three dimensions, the porous medium may be represented as a network of narrow chambers ( called throats ) that intersect at larger void spaces (called pores ). Using percolation theory to describe micro-flow mechanism, we have developed quasi-static models to simulate single-phase flow ,two-phase primary drainage and secondary imbibition in disordered networks. In particular. These models calculate capillary pressures, relative permeabilities, saturation paths, flow regimes, and spatial clusters of the different fluids in the network.Microscope parameters of pore networks, i.e., volumes, areas, lengths, inscribed circle radii and shape factors is very important for constructing the quasi-static models. We analysis the distribution of these parameters, goodness of fit to a theoretical probability distribution, the probability distribution functions: normal, lognormal, gamma, and weibull.There are two basic models of multiphase flow in pore networks: dynamic and quasi-static. In dynamic models, capillary, gravity, and viscous forces in the fluids are accounted for simultaneously,. In quasi-static models, capillary forces dominate, gravity modifies the magnitude of capillary pressure, and the microscopic fluid distributions are frozen at each level of the capillary pressure. In this study we adopt the quasi-static approach and ignore the effects of viscous forces. The pore-level displacement mechanisms: piston-type, snap-off, cooperative pore-body filling are considered with arbitrary receding and advancing contact angles. We describe the physics of two-phase flow in a single pore, i.e., the capillary entry pressure in piston-type displacement, snap-off and cooperative pore-body filling.Using pore network modeling, we analysis the effects of microscope parameters on water drive reservoir. Results show coordinate number and shape factor increasing, residual oil saturation decreasing. Water displacement recovery of model with large inscribed circle radii is improved.更多还原