微观物理模拟水驱油实验及残余油分布分形特征研究

收稿日期:2005-08-27

基金项目:国家“973”重点基础研究发展规划项目(G 1999022509)

作者简介:李中锋(1976-),男(汉族),河南遂平人,博士研究生,从事油气田开发及油气藏工程研究。

文章编号:167325005(2006)0320067205

微观物理模拟水驱油实验及残余油分布分形特征研究

李中锋1,何顺利1,杨文新2,门成全1

(1.中国石油大学石油天然气工程学院,北京102249;2.中国石化江汉油田分公司,湖北潜江433000)

摘要:研究制作了能真实反映岩石孔隙结构的微观仿真孔隙模型,应用微观渗流物理实验模拟技术和图像分析技术,开展了微观模型水驱油物理模拟实验,对水驱油过程及微观物理模型中残余油的形成和分布进行了观察,模拟了不同驱替速度、孔隙结构、粘度比等条件下的水驱过程。应用分形几何学的基本理论,给出了数盒子法和R/S 分析法定量研究微观残余油分形特征的关系式,结合水驱油残余油分布图像,建立了用分形维数定量表征残余油及空间分布的测定方法。研究结果表明,随驱替速度增大,形成的残余油量减少;随原油粘度增大,形成的残余油量增多。容量维数表征了残余油的多少,它与残余油饱和度、孔隙结构有关;分形维数则表征了残余油空间分布的非均质性,分形维数越大,残余油空间分布的非均质性越强。

关键词:微观孔隙模型;水驱油;残余油;驱替速度;分形特征;容量维数;分形维数中图分类号:TE 319;TE 112 文献标识码:A

Physical simulation experiment of w ater driving by micro 2model and

fractal features of residual oil distribution

L I Zhong 2feng 1,HE Shun 2li 1,YAN G Wen 2xin 2,M EN Cheng 2quan 1

(1.Faculty of Pet roleum Engineering in China U niversity of Pet roleum ,Beijing 102249,China ;

2.Jianghan Oilf ield ,China Pet rochemical Corporation ,Qianjiang 433000,Hubei Province ,China )

Abstract :By manufacturing an emulation porous micro 2model and applying the simulation technology of micro 2flow physical experiment and image analysis technology ,the physical simulation experiment of water driving micro 2flow was developed.The process of water driving as well as the form and distribution of residual oil in thephysical micro 2model was investigated ,and water driving processes under different dis placement rate ,porous structure and viscosity ratio were simulated.With the help of the basic theory of fractal geometry ,the box algorithm and R/S analysis relationship formula were deduced ,which are used to quantitatively study residual oil microscopic fractal bined with the figures of water driving residual oil distribution ,the quantitatively measuring method of figuring the size and spatial distribution of the residual oil saturation was established.The results show that the residual oil decreases with the enhancement of dis p lacement rate ,and the residual oil increases with the increase of viscosity of crude oil.The volume dimension figures the quantity of residual oil and is related to the residual oil saturation and pore structure ,while fractal dimension shows the homogeneity degree of the residual oil spatial distribution which becomes strong when the fractal dimension ex pands.

K ey w ords :porous micro 2model ;water driving ;residual oil ;dis placement rate ;fractal features ;volume dimension ;fractal

dimension

储层微观非均质性是指砂体的孔隙、喉道大小及均匀程度,孔隙喉道的配置关系和连通程度直接影响着注入水的微观驱替效率,从而控制着孔隙中残余油的微观分布。微观孔隙模型是近几十年发展

起来的用于研究流体在多孔介质中流动特性的实验

方法,它能直观地揭示不同润湿性和驱替剂的微观渗流特征。早期制作的微观模型有粒状填充模型、规则网络模型和刻蚀的人工随机模型等,但它们与

2006年　第30卷 中国石油大学学报(自然科学版) Vol.30　No.3　第3期 Journal of China University of Petroleum J un.2006