基于时窗能量比和AIC的两步法微震初至自动拾取
|
摘要
传统的微地震数据震源定位算法依赖于波至时间的拾取。由于微地震数据量较大且信噪比较低,手动拾取纵波和横波的波至时间很耗时,且引入的人为误差不易控制。笔者在分析已有方法特点的基础上,给出一种较快捷、准确的两步法微地震初至自动拾取方法。该方法首先使用时窗能量比法识别微震事件并大致确定波至时间,然后使用局部AIC精确拾取波至时间。与常规时窗能量比法相比,该方法减弱了时窗大小对拾取精度的影响;与常规的AIC法相比,由于只在局部使用AIC,避免了在低信噪比情况下AIC会出现多个局部极小从而难以准确拾取的问题,同时也提高了拾取效率。最后通过野外实际微地震数据进行了测试,分析了该方法的性能,验证了该方法的有效性和实用性。
Determining an accurate first arrival time of P wave and S wave is very important in locating microseismic events,and manual picking is extremely time-consuming and subjective.An automatic two-step method based on after-term average over before-term average ratio(ATA/BTA) and the Akaike Information criterion(AIC) is developed.The ATA/BTA is used to detect the event and the AIC is utilized for picking.The method can attenuate the impact of window length and improve the precision of picking.The examination of the algorithm in different window lengths and various SNR environments by using the real data proves its effectiveness and practicability.
Determining an accurate first arrival time of P wave and S wave is very important in locating microseismic events,and manual picking is extremely time-consuming and subjective.An automatic two-step method based on after-term average over before-term average ratio(ATA/BTA) and the Akaike Information criterion(AIC) is developed.The ATA/BTA is used to detect the event and the AIC is utilized for picking.The method can attenuate the impact of window length and improve the precision of picking.The examination of the algorithm in different window lengths and various SNR environments by using the real data proves its effectiveness and practicability.
引文
[1]Earle P S,Shearer P M.Characterization of global seismograms u-sing an automatic picking algorithm[J].Bulletin of the Seismologi-cal Society of America,1994,84:366-376.
[2]吴治涛,李仕雄.STA/LTA算法拾取微地震事件犘波到时对比研究[J].地球物理学进展,2010,25(5):1577-1582.
[3]叶根喜,姜福兴,杨淑华.时窗能量特征法拾取微地震波初始到时的可行性研究[J].地球物理学报,2008,51(5):1574-1581.
[4]Song F,Kuleli H S,Toksoz M N,et al.An improved method forhydrofracture-induced microseismic event detection and phasepicking[J].Geophysics,2010,75(6):A47-A52.
[5]陈爱萍,邹文,何光明,等.基于分维和相关性的自动初至拾取技术及应用[J].物探化探计算技术,2009,31(2):100-107.
[6]姚姚.用人工神经网络自动拾取地震初至[J].石油地球物理勘探,1994,29(1):112-116.
[7]潘树林,高磊,周熙襄.一种实现初至波自动拾取的方法[J].石油物探,2005,44(2):163-166.
[8]潘树林,高磊,周熙襄.基于单道边界检测和样条插值的初至波自动拾取[J].石油物探,2006,45(3):245-249.
[9]St-Onge A.Akaike information criterion applied to detecting firstarrival times on microseismic data[G].SEG Technical ProgramExpanded Abstracts,2011:1658-1662.
[10]Takanami T,Kitagawa G.Estimation of the arrival times of seismicwaves by multivariate time series model[J].Annals of the Instituteof Statistical Mathematics,1991,43(3):407-433.
[11]宋维琪,吕世超.基于小波分解与Akaike信息准则的微地震初至拾取方法[J].石油物探,2011,50(1):14-21.
[12]张军华,赵勇,赵爱国,等.用小波变换与能量比方法联合拾取初至波[J].物探化探计算技术,2002,24(4):309-336.
[13]Akaike H.Infromation theory and an extension of the maximumlikelihood principle[C]//Second international symposium on in-formation theory,1973:267-281.
[14]Maeda N.A method for reading and checking phase times in auto-processing system of seismic wave data[J].Zisin,1985,38(3):365-379.
[2]吴治涛,李仕雄.STA/LTA算法拾取微地震事件犘波到时对比研究[J].地球物理学进展,2010,25(5):1577-1582.
[3]叶根喜,姜福兴,杨淑华.时窗能量特征法拾取微地震波初始到时的可行性研究[J].地球物理学报,2008,51(5):1574-1581.
[4]Song F,Kuleli H S,Toksoz M N,et al.An improved method forhydrofracture-induced microseismic event detection and phasepicking[J].Geophysics,2010,75(6):A47-A52.
[5]陈爱萍,邹文,何光明,等.基于分维和相关性的自动初至拾取技术及应用[J].物探化探计算技术,2009,31(2):100-107.
[6]姚姚.用人工神经网络自动拾取地震初至[J].石油地球物理勘探,1994,29(1):112-116.
[7]潘树林,高磊,周熙襄.一种实现初至波自动拾取的方法[J].石油物探,2005,44(2):163-166.
[8]潘树林,高磊,周熙襄.基于单道边界检测和样条插值的初至波自动拾取[J].石油物探,2006,45(3):245-249.
[9]St-Onge A.Akaike information criterion applied to detecting firstarrival times on microseismic data[G].SEG Technical ProgramExpanded Abstracts,2011:1658-1662.
[10]Takanami T,Kitagawa G.Estimation of the arrival times of seismicwaves by multivariate time series model[J].Annals of the Instituteof Statistical Mathematics,1991,43(3):407-433.
[11]宋维琪,吕世超.基于小波分解与Akaike信息准则的微地震初至拾取方法[J].石油物探,2011,50(1):14-21.
[12]张军华,赵勇,赵爱国,等.用小波变换与能量比方法联合拾取初至波[J].物探化探计算技术,2002,24(4):309-336.
[13]Akaike H.Infromation theory and an extension of the maximumlikelihood principle[C]//Second international symposium on in-formation theory,1973:267-281.
[14]Maeda N.A method for reading and checking phase times in auto-processing system of seismic wave data[J].Zisin,1985,38(3):365-379.
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心