碳酸盐岩多段酸压水平井线性复合渗流新模型

摘要

碳酸盐岩储层具有独特的孔隙结构,水平井多段酸压后的渗流过程极其复杂,弄清酸压缝的特性参数及与天然缝的沟通情况是单井高效开发的前提.根据碳酸盐岩储层实际地质特征,且充分考虑酸压裂缝呈非等间距、非等半长、非等缝高、非等任意倾角的实际情况,建立线性复合碳酸盐岩多段酸压水平井的渗流模型;利用点源函数理论、Laplace变换、正交变换等数学方法对模型进行求解,编程绘制压力动态特征曲线,揭示线性复合碳酸盐岩多段酸压水平井的渗流规律;同时开展相关参数的敏感性分析研究成果将为碳酸盐岩储层研究提供新的渗流模型,为水平井酸压后的高效开发奠定理论基础.%The flow process of multiple-acidized-fractured horizontal well in carbonate formation is very complex because carbonate formation possesses special pore structures,and knowing about the property parameters of acidized fractures and the connection conditions of natural fractures is the premise of efficient development of a single horizontal well,therefore it is in urgent need of deep study on the porous flow theory of multiple-acidized-fractured horizontal well in carbonate formation.According to the practical geological traits of carbonate formation,the linear composite porous flow model of multiple-acidized-fractured horizontal well is established,and this model considers more practical circumstance of acidized-fractures,such as non-equidistance between the neighbor fractures,unequal half-length for each fracture,unequal half-height for each fracture,and unequal arbitrary angle;the mathematical model is solved using the theory of point source function,Laplace transformation and the method of orthogonal transformation,and then the pressure dynamics curves are plotted using some computer programs;accordingly the porous flow laws and hydrodynamic behavior characteristics of multiple-acidized-fractured horizontal well are revealed;at the same time,the sensitivity characteristics of changing relevant parameters which affect the type curves are analyzed thoroughly.The research result provides a new porous flow model for carbonate formation,and lays the theory foundation for efficient development of acidized-fractured horizontal wells.