基于震幅叠加的微地震事件定位在地面监测中的应用  

Application of Microseismic Event Location Using Amplitude Summation in Surface Monitoring

作　　者：吴建光[1] 张平[1] 吕昊[2] 曾晓献[2] WU Jianguang Zhang Ping Lu Hao Zeng Xiaoxian(China United Coalbed Methane Corporation, Beijing 100011, China College of Instrument Science and Electrical Engineering, Jilin University, Changchun 130026, China)

机构地区：[1]中联煤层气有限责任公司,北京100011 [2]吉林大学仪器科学与电气工程学院,长春130026

出　　处：《吉林大学学报（地球科学版）》2017年第1期255-264,共10页Journal of Jilin University：Earth Science Edition

基　　金：国家科技重大专项项目(2011ZX05060)~~

摘　　要：在微地震地面监测中,由于微地震信号能量微弱,因此很难对微地震事件进行精确拾取。本文提出了一种基于STA/LTA(short term averaging/long term averaging)的判别频率估计模式识别方法,可以避免由于设定阈值出现漏判小能量微地震事件的情况,并在精度上比传统的STA/LTA方法提升10%以上。采用基于震幅叠加的能量聚焦方法对微地震事件进行定位计算,同时通过对能量聚焦结果的分析,进一步剔除"假"的微地震事件,从而能够更加精确地描述地下裂缝的发育情况。最后,通过对河北北部一水平井的压裂监测对该方法进行验证,结果表明,本方法计算效率高、监测结果获得施工单位的认可,能够对下一步压裂施工方案提供理论指导。Because the microseismic signals are very weak,it is difficult to accurately pick up the microseismic events in the microseismic surface monitoring.To automatically identify microseismic signals,a discriminant frequency estimation algorithm of pattern recognition method based on STA/LTA was proposed in the article.This method can pick up low-energy microseismic events that could be missed by setting a threshold,and it is faster than traditional STA/LTA.In this paper,we also utilize amplitude stacking to locate the source of microseismic events.By analyzing the focus of energy of the stacked amplitude,false events can be further eliminated.Therefore,the method can describe the development of the underground cracks more accurately.Finally,the method is verified by a fracture monitoring experiment around a horizontal well in northern Hebei Province.The results show that the method is highly efficient in computation and the monitoring results are accepted by the fracturingoperators.It can provide theoretical guidance to the subsequent fracturing operations.

关 键 词：压裂监测 短长时窗 微地震事件 能量聚焦 频率估计 油田开发 

分 类 号：P631.4[天文地球—地质矿产勘探]