实时微地震监测金坛盐穴储气库稳定性

地下腔体的稳定性是盐穴储气库安全平稳运行的重中之重。为了实时监测盐穴储气库注水排卤和注采气过程中腔体状态进而评价注采运行参数的合理性，利用微地震技术连续监测23 d，通过井中方式布置12级检波器，采用地面震源进行检波器空间定向，联合P波S波信息进行微地震事件空间定位。通过微地震事件数量和注采参数的交汇分析研究生产工艺对腔体稳定性的影响。研究成果表明，为期23 d的监测过程中共发生419个有效信号；在2口造腔井各监测到16个微地震信号，在注采井中并未监测到明显信号；在两口注采井之间监测到大量微地震信号，结合三维地震数据及b值分析认为是天然裂缝活动；分析监测到微地震震源属于剪应力和张应力共同作用，其中张应力占主要作用的震源较多。研究认为，当前的注采运行参数满足盐穴储气库的安全运行要求；建议后续的研究过程中延长监测时间以加强微地震数量和注采参数的统计规律，加强气腔之间的天然裂缝活动研究以保证储气库的安全运行。

Real-time Microseism Monitoring of Stability of Salt-cavern Gas Storage in Jintan

To undertake the real-time monitoring of the cavity state in the process of water injection and brine displacement, gas injection and production of a salt-cavern gas storage, microseism technology is applied during continuous monitoring for 23 d. The 12-level detector is arranged using the in-well method, and the surface energy source is used for the spatial orientation of the detector. Moreover, the information of the P wave and S wave is combined for spatial orientation of the microseism events. Through a cross analysis on the number of microseism events and injection-production parameters, the influences of production technology on cavity stability are studied. The results show that 419 effective signals occurred during the 23 d monitoring process; sixteen microseism signals are detected in two cavity construction wells, without any obvious signal detected in injection and production wells. Many microseism signals are detected between two injection and production wells, which is considered as natural fracture activity through three-dimensional seismic data obtained with a b-value analysis. The microseism sources are detected as the joint action of shear stress and tensile stress after analytic monitoring, and the sources where tensile stress plays a leading role are more. It is believed that the current injection-production operation parameters meet the safe operation requirements of a salt-cavern gas storage; it is suggested to extend the monitoring time to enhance the microseism quantity and establish statistical laws for injection-production parameters in the follow-up studies, to strengthen the study on natural fracture activity among cavities, thereby ensuring the safe operation of a gas storage.