基于分形理论的低渗透油藏油水相对渗透率模型  

Oil-water relative permeability model of low permeability reservoir based on fractal theory

作　　者：苏海波 张世明[2] 孙业恒 于金彪[2] 杨明林[2] 孟薇 汪勇 俞明理[3] SU Haibo;ZHANG Shiming;SUN Yeheng;YU Jinbiao;YANG Minglin;MENG Wei;WANG Yong;YU Mingli(Department of Thermal Science and Energy Engineering,University of Science and Technology of China,Hefei City,Anhui Province,230027,China;Exploration and Development Research Institute,Shengli Oilfield Company,SINOPEC,Dongying City,Shandong Province,257015,China;College of Chemical Engineering,China University of Petroleum(East China),Qingdao City,Shandong Province,266580,China)

机构地区：[1]中国科学技术大学热科学和能源工程系,安徽合肥230027 [2]中国石化胜利油田分公司勘探开发研究院,山东东营257015 [3]中国石油大学(华东)化学工程学院,山东青岛266580

出　　处：《油气地质与采收率》2020年第4期67-78,共12页Petroleum Geology and Recovery Efficiency

基　　金：国家科技重大专项“渤海湾盆地济阳坳陷致密油开发示范工程”(2017ZX05072);中国石化科技攻关项目“济阳坳陷页岩油可动性主控因素与甜点评价”(P19017-6)。

摘　　要：油水相对渗透率是研究低渗透油藏注水开发特征的重要参数之一,明确油水相对渗透率的影响因素对认识低渗透油藏的渗流规律有重要意义.在多孔介质分形理论的基础上,建立低渗透油藏油水相对渗透率模型和归一化的油水相对渗透率模型.新建立的油水相对渗透率模型是含水饱和度、驱替压力、毛细管力的函数,可以综合反映储层孔隙结构、非线性渗流和渗流干扰对油水相对渗透率的影响.理论分析结果表明:岩心孔隙结构越复杂,油水相对渗透率越低;驱替压力对油相相对渗透率有影响,表明在注水开发过程中相对渗透率存在动态变化特征;非线性渗流对油相相对渗透率的影响较大,而对水相的影响可忽略不计,随着油相非线性系数的增大油相相对渗透率减小;渗流干扰对油水相对渗透率均存在影响,油水相对渗透率随着干扰系数的增大而降低.为了验证模型的可靠性,将模型预测的油水相对渗透率与实验测试结果进行了对比,其结果表明吻合程度高.与经典相对渗透率理论模型预测结果的对比表明,新建模型对水相相对渗透率的预测结果优于经典理论模型的预测结果.Oil-water relative permeability is an important parameter for studying the characteristics of water flooding devel⁃opment in low permeability reservoirs.It is of great practical significance to understand the percolation law in the low per⁃meability reservoir by determining the influencing factors of oil-water relative permeability.Based on the fractal theory of porous media,a mathematical model of oil-water relative permeability in the low permeability reservoirs and a normalized oil-water relative permeability model are established respectively.The established oil-water relative permeability model is a function of water saturation,displacement pressure,and capillary pressure,which can comprehensively reflect the influ⁃ence of reservoir pore structure,nonlinear percolation and percolation interference on oil-water relative permeability.The theoretical analysis result shows that the more complex core pore structure is,the lower oil-water relative permeability is;the displacement pressure influences relative permeability of oil phase,which shows that there is a dynamic change of rela⁃tive permeability in the process of water flooding.Nonlinear percolation has a great influence on the relative permeability of oil phase,but the influence on the relative permeability of water phase may be ignored.The relative permeability of oil phase decreases with the increase of the nonlinear coefficient of oil phase.The percolation interference influences the rela⁃tive permeability of the oil and water phase which decreases with the increase of the interference coefficient.To verify the reliability of the model,the oil-water relative permeability predicted by the model is compared with the experimental re⁃sults.The predicted oil-water relative permeability of the model is highly consistent with the experimental results.In addi⁃tion,the comparison with the prediction results of the classical relative permeability theoretical model shows that the predic⁃tion results of the new model for the relative permeability of

关 键 词：低渗透油藏 油水相对渗透率 分形理论 孔隙结构 非线性渗流 渗流干扰 

分 类 号：TE348[石油与天然气工程—油气田开发工程]