摘要
在围压(外压)或孔压(内压)发生变化的条件下,致密砂岩及泥页岩泊松比的变化特征及机制仍有待厘清。本研究从Terzaghi有效应力理论和国内学者提出的新有效应力概念出发,基于松辽盆地高台子组致密砂岩、青山口组泥页岩三向动、静态泊松比测定结果,剖析了两类岩石泊松比的变化特征及机制。岩石样品三向泊松比变化曲线的分布呈现显著的各向异性,这将对压裂缝的延展规律产生一定的影响;就“有效应力”概念厘定的科学性而言,“Terzaghi有效应力”适用于裂缝较为发育的储层,而“新有效应力”适用于孔隙度较大且分布较为均匀的泥页岩。结论将为致密油气的有效开发提供较为重要的理论依据。
When the confining pressure(external pressure)or pore pressure(internal pressure)changes,the variation characteristics and mechanism of Poisson's ratio for tight sandstone and shale still need to be clarified.On the basis of the effective stress theory of Terzaghi and the new concept of effective stress proposed by domestic scholars,this study analyzes the characteristics and mechanism of Poisson's ratio change based on the dynamic and static Poisson's ratio measurement results.The rock types consist of tight sandstone of the Gaotaizi Formation and shale of the Qingshankou Formation in the Songliao Basin,respectively.The anisotropic distribution of Poisson's ratio curves is obvious,which would have some impacts on the propagation law of compression fractures;as far as the scientific definition of“effective stress”is concerned,“Terzaghi effective stress”is suitable for fractured reservoirs while“new effective stress”is suitable for shale with large porosity and uniform pore distribution.The conclusion will provide some important theoretical basis for the effective development of tight oil and gas.
作者
杜书恒
梁耀欢
师永民
关平
DU Shuheng;LIANG Yaohuan;SHI Yongmin;GUAN Ping(School of Earth and Space Sciences,Peking University,Beijing 100871,China;State Key Laboratory of Nonlinear Mechanics,Institute of Mechanics,Chinese Academy of Sciences,Beijing 100190,China)
出处
《地学前缘》
EI
CAS
CSCD
北大核心
2021年第1期411-419,共9页
Earth Science Frontiers
基金
中国石油科技创新基金项目(2019D-5007-0214)
国家科技重大专项“大型油气田及煤层气开发(2017ZX05013005-009)”。
