陆地水体气枪震源重复性的影响因素及控制方法

(1.中国地震局地球物理研究所,北京 100081;2.中国科学技术大学地球和空间科学学院,合肥 230026)

气枪震源;重复性;影响因素;控制方法;反褶积

Influence Factors and Control Methods for the Repeatability of Air Gun Source in Land Reservoirs
YANG Wei1,WANG Baoshan2,WANG Weitao1,HU Jiupeng1

(1. Institute of Geophysics,China Earthquake Administration,Beijing 100081,China;2. School of Earth and Space Sciences,University of Science and Technology of China,Hefei 230026,China)

Air gun;Repeatability;Influence factors;Control methods;Deconvolution

DOI: 10.13512/j.hndz.2020.04.01

备注

近十几年的实验研究表明,气枪震源是一种较为理想的重复性人工震源,可监测地下介质波速的微弱变化,服务于地震物理过程的分析研究。气枪震源信号重复性的进一步提高,有利于提升波速变化的监测精度。结合陆地水体气枪震源的技术系统和激发环境,分析了陆地水体气枪震源重复性的影响因素和改善方法。在硬件系统方面,通过气枪激发间隔选择,激发延迟监控和反馈补偿,装置定期维护等方面确保气枪震源的激发同步性,保持激发系统每次激发的状态一致。在数据分析方面,采用反褶积方法降低震源环境变化对信号的影响,一定程度上消除源场信号的差异。通过软硬件的联合改善,可进一步提升气枪震源的重复性,为利用陆地水体气枪震源进行地下介质动态变化研究提供技术支撑。

The experiments in recent ten years showed that air gun source is an ideal repetitive artificial source which can monitor the weak change of seismic wave velocity in underground medium, and be used for research on the physical process of an earthquake. The higher the repeatability of air gun source signal is, the higher the monitoring accuracy of seismic wave velocity change is. Combined with the technical system and excitation environment of air gun source in land reservoirs, this paper analyzed the influencing factors of the repeatability and improvement methods. On the hardware system, the synchronization and repeatability of air gun source can be ensured through the selection of air gun shooting interval,excitation delay monitoring and feedback compensation,and regular maintenance of the device. On the data analysis,deconvolution method is used to reduce the impact of the signal change caused by source environment,and eliminate the difference of source signals to some extent. The repeatability of air gun source can be further improved by the joint improvement of software and hardware,which provides technical support for the study on dynamic change of seismic wave velocity in underground medium by using air gun source in land reservoirs.