【摘要】 概括了近年来国内外关于CO2地质封存的研究现状,对CO2封存监测技术进行了简要总结,关注了基于地震法的相关监测技术。利用数值计算的手段,对地脉动方法在CO2地质封存工程安全监测中应用的可行性进行了初步探讨。先从理论上分析了CO2注入引起岩石密度和波速变化范围,在此基础上研究了岩石密度、波速等因素改变对地表面波频散特性的影响。分析表明:①当CO2密度和体积模量与岩石孔隙中物质相差较大时,CO2驱替岩石中孔隙介质对波速的影响较大,反之则小;②CO2储层横波波速改变相对于纵波或密度改变对面波波速影响较大;③CO2储层的波速和密度等参数变化对面波的影响随频厚积变化而变化;④当CO2储层薄但埋深大时,面波频散特性对储层弹性参数改变不敏感。更多还原

【Abstract】 This paper provides a general state-of-the-art of carbon dioxide(CO2) geological storage and related monitoring techniques.Seismicity-based methods are of primarily interests.Feasibility study was performed to evaluate the monitoring approach based on collecting and analyzing microtremors.Theoretical analyses were first carried out to investigate the effects of CO2 injection on wave propagation velocities of a porous rock.Numerical simulations were then conducted on a layered reservoir model to study surface wave velocity variations due to elastic parameter changes of the CO2 storage layer.It is concluded that:(1) The greater the difference of densities and bulk moduli between the injected CO2 and the original media in rock pores,the more dramatic velocity change occurs for the seismic wave propagation through the porous rock.(2) The surface wave dispersion characteristic is more sensitive to the changes of shear wave velocities of the CO2 storage layer than those of the density and the compressive wave velocity.(3) Most significant changes of surface wave velocities due to elastic parameter variations of the CO2 storage layer.(4) For a deep underground storage of a thin CO2 layer reservoir,the surface wave dispersion characteristics are not sensitive to elastic parameter changes of the CO2 storage layer.更多还原