缝洞型油藏开发流体势数学模型及调控效果影响因素

缝洞型油藏具有储集空间类型多,孔、缝、溶洞尺寸差异大,宏观上表现为多种流动模式耦合等特征,其储渗条件和开发模式迥异于砂岩油藏。考虑缝洞型油藏储渗介质和流动模式,基于经典流体势理论,建立缝洞型油藏不同储层类型、不同开发阶段的开发流体势理论模型,并阐释流体势数学模型中位能、压能、动能、界面能和黏滞力能的计算方法。在此基础上,应用改进流线法开发缝洞型油藏开发流体势数值模拟程序。塔河油田缝洞型油藏调控效果研究表明,基于流体势计算的调控方法适用于断控岩溶、风化壳岩溶和复合岩溶3类岩溶背景,当水体倍数小于10倍、采液比为4~6时,排液量越大,缝洞型油藏流体势调控效果越好。

Study on mathematic model of development fluid potential of fracture-cavity reservoir and influencing factors of adjustment effect

The fracture-cavity reservoirs have many types of reservoir spaces,large differences in pore,fracture,and karst cave sizes,and are macroscopically characterized by coupling of multiple flow patterns.The reservoir and permeability con?ditions and development models are very different from those of clastic sandstone reservoirs.Considering the special geolog?ical conditions and flow patterns of fracture-cavity reservoirs,and based on the classic fluid potential theory,the theoretical model of development fluid potential for different reservoir types and different development stages of fracture-cavity reser?voirs is established.It also explains the calculation methods of potential energy,pressure energy,kinetic energy,interface energy and viscous energy in the mathematical model of fluid potential.Based on this,the improved streamline method is used to develop the numerical simulation program for the development fluid potential of fracture-cavity reservoirs.Re?search on the control effect of fracture-cavity reservoirs in Tahe Oilfield shows that the control method based on calculation of fluid potential is suitable for the three types of karst backgrounds:fault-controlled karst,weathered shell karst and com?posite karst.The production strength is greater,and the effect of fluid potential control in fracture-cavity reservoirs is better when the water body multiple is less than 10 times and the liquid production ratio is 4-6.