摘要
针对三重介质底水气藏压裂水平井渗流规律和底水侵入气藏导致气井产能下降的特点,基于溶洞系统和基岩系统中的天然气向裂缝系统窜流,经裂缝系统产出的物理模型,将底水边界视为半滤失边界,建立了该类储层介质的非稳态渗流数学模型,并利用源函数、有限Fourier余弦变换和贝塞尔函数的积分方法得到了模型的点源解。在此基础上,采用解析法与数值离散法相结合的半解析方法获得了三重介质底水气藏多级压裂水平井的压力响应和非稳态产能计算模型。利用Stehfest数值反演得到了气井非稳态产能随时间的变化关系曲线,分析了气井产能的变化规律,研究了压裂裂缝条数、裂缝半长、裂缝间距、孔—缝和缝—洞的窜流系数及缝洞储容比等参数对气井非稳态产能动态特征的影响。研究方法和结果对合理分析三重介质底水气藏压裂水平井生产动态特征和优化压裂参数设计具有一定的指导意义。
In order to investigate the seepage flow of the fractured horizontal well in the triple medium gas reservoir with bottom water and the reduction of the gas-well production due to the intrusion of bottomwater,based on a physical model where the gas in the cave and matrix systems channels to fracture system,and is produced through the fracture system,and the bottom-water boundary is considered as semi-filtration borders.The transient seepage mathematical model for triple medium gas reservoirs is established,and the mathematical model can be solved by the method of source function and the integral methods such as finite Fourier cosine transform and Bessel functions,and the point source solution is gotten.On this basis,the pressure response and the transient production model of multi-stage fractured horizontal wells are obtained by means of semi-analytical method which combines analytical method and numerical method.The transient production characteristic curve is obtained by means of the numerical inversion of Stehfest method.According to the analysis of the variation of gas production with time,the effect of fracture number,fracture half-length,fracture interval,the inter-porosity flow parameter and the storage-ratio on transient productivity is studied.The methods and results of this research contribute to the reasonable analysis of the production performance of fractured horizontal well in the triple medium gas reservoir with bottom-water and optimization of the fracturing design parameters.
出处
《天然气地球科学》
EI
CAS
CSCD
北大核心
2014年第11期1861-1867,共7页
Natural Gas Geoscience
基金
国家科技重大专项"复杂碳酸盐岩气藏开发技术"(编号:2011ZX05015-03)
西南油气田分公司2012年博士后科研项目"三重介质底水气藏治水开发机理研究"(编号:20120305-12)联合资助
关键词
三重介质气藏
底水边界
压裂水平井
点源
非稳态产能
Triple porosity gas reservoir
Bottom-water boundary
Fractured horizontal well
Source function
Transient productivity
