层理缝对页岩渗透率的影响及表征  

Effect of Bedding Seam on Shale Permeability and Its Characterization

作　　者：朱维耀[1] 马东旭[1] Zhu Weiyao;Ma Dongxu(University of Science ＆ Technology Beijing, Beijing 100083, China)

机构地区：[1]北京科技大学,北京100083

出　　处：《特种油气藏》2018年第2期130-133,共4页Special Oil & Gas Reservoirs

基　　金：国家重点基础研究发展计划("973")项目"中国南方海相页岩气的高效开发的基础研究"(2013CB228002)

摘　　要：层理页岩中发育层理缝,为研究层理缝对储层渗透率及产气量的影响,选取四川气田下志留统龙马溪组层理发育岩样,开展了层理页岩渗透率实验研究,并结合微观孔隙特征对岩样渗透率进行分析,在此基础上运用渗流力学理论,建立了考虑层理缝影响的渗透率模型。研究结果表明:层理缝是导致页岩渗透率各向异性的主要因素;层理缝长度及其与渗流方向的角度是影响岩样渗透率的关键因素,并与岩样渗透率呈非线性变化关系;鉴于层理缝对储层渗透率的影响及应力作用下易闭合的特性,建议在页岩气开发中合理控制生产压差,从而避免应力作用对产能的影响。该项目研究对页岩气产能预测以及合理制订开发方案具有指导意义。Due to the well-developed bedding seam in shale formation, the shale samples from the Lower Silurian Longmaxi Formation in Sichuan Gasfield are taken to carry the shale permeability test and the microscopic pore characterization is combined to determine the effect of bedding seam on shale reservoir permeability and gas produc- tion. A permeability model considering bedding seam effect is established based on the seepage mechanics theol. Research indicates that bedding seam is considered as a key factor results in shale permeability anisotropy. The shale permeability is greatly dependent on the bedding seam length and seepage angle, which shows a nonlinear re- lation with shale sample permeability. Due to the effect of bedding seam on shale permeability and the closure per- formance with stress, it is suggested that the producing pressure drawdown should be restricted to slow down the bedding seam stress-sensitivity on gas well productivity. This research could provide certain guidance for the shale gas productivity forecast and development program design.

关 键 词：页岩气 层理缝 各向异性孔隙度 渗透率 

分 类 号：TE371[石油与天然气工程—油气田开发工程]