应力作用下岩石介质两相流束缚流体饱和度分形预测模型研究  

A fractal model for predicting irreducible fluid saturation of two-phase flows in rock media under stress

作　　者：赵明凯 孔德森 滕森[1,2] 邓美旭 ZHAO Mingkai;KONG Desen;TENG Sen;DENG Meixu(College of Civil Engineering and Architecture,Shandong University of Science and Technology,Qingdao 266590,China;Shandong Key Laboratory of Civil Engineering Disaster Prevention and Mitigation,Shandong University of Science and Technology,Qingdao 266590,China)

机构地区：[1]山东科技大学土木工程与建筑学院,山东青岛266590 [2]山东科技大学山东省土木工程防灾减灾重点实验室,山东青岛266590

出　　处：《岩土工程学报》2024年第4期871-879,共9页Chinese Journal of Geotechnical Engineering

基　　金：山东省自然科学基金项目(ZR2019MEE027)。

摘　　要：束缚流体饱和度是预测两相流中相对渗透率的重要参数,在油气藏开发等工程领域有着重要作用。为此,基于分形理论和毛细管模型,首先将岩石等效为固体团簇的集合体,引入不同分形维数分别表征固体团簇的尺度分布特征和流动路径的迂曲性,然后提出了一种预测束缚流体在应力作用下的饱和度模型,并使用试验数据进行了验证,最后分析了束缚流体饱和度的应力敏感性和模型中各参数的影响机制。结果表明:束缚流体饱和度与流体黏度、孔隙结构参数、压降梯度以及弹性模量密切相关,有效应力会增大束缚流体饱和度,分形维数可以反映束缚流体形成的流体膜厚度和实际流动长度,量化了孔隙结构特征对束缚流体饱和度的影响。The irreducible fluid saturation is a significant parameter for predicting the relative permeability in two-phase flows and plays an important role in engineering fields such as oil and gas reservoir development.To this end,the rock is equated as an aggregate of solid clusters based on the fractal theory and capillary model,and different fractal dimensions are introduced to characterize the scale distribution of solid clusters and the tortuosity of flow paths,respectively.Then,a model for predicting the irreducible fluid saturation under stress is proposed and validated using the experimental data.Finally,the stress sensitivity of irreducible fluid saturation and the influence mechanism of each parameter in the model are analyzed.The results show that the irreducible fluid saturation is closely related to the fluid viscosity,pore structure parameters,pressure drop gradient and elastic modulus.The effective stress increases the irreducible fluid saturation.The fractal dimensions can represent the thickness of the fluid film formed by the irreducible fluid and the actual flow length,which quantifies the influences of the pore structure characteristics on the irreducible fluid saturation.

关 键 词：岩石 分形 两相流 有效应力 束缚流体饱和度 

分 类 号：TU45[建筑科学—岩土工程]