可控震源高效采集技术介绍.ppt

Distance Separated Slip Sweep ( DS3 ) Orthogonal shooting – constant separation ISS – changing the way we work. ISS keeps rolling Source effort options Data Volumes Continuous recording for ISS Assume – 60 second record, 8000 channels, 4msec sample interval, SEGD format File size = 458 Mbytes Assume – continuous recording for 10 hours 600 files of 458Mbytes = 275 Gbytes. = 1 IBM 3592 tape cartridge = 7 IBM 3590E tape cartridges Typical NAS disk pack holds 1Terabyte or more Combed + correlated shot records Assume – Offset limit to 5 kms in-line, 3200 channels, 5 second records. File size = 15.5 Mbytes per shot record. Assume – 9000 VP/day 140 Gbytes of shot records per day (or slightly less due to roll-on/roll-off) HFVS 数据采集的关键点 震次至少与震源的台数一样多 记录震源力信号并应用于数据分离 为了提高数据分离效果，每次扫描每台震源要进行相位编排（it helps reduce harmonic noise） 为了降低震源间相互干扰，震源间应分开一段距离(min distance should be in 200 – 300 m) 欢迎各位提出您的意见和看法! * ISS method. N = Number of vibrators (12) 9 hours operation = 32,400 secs SL = sweep length (secs) (16) PU = pad up time (secs) (4) PD = pad down time (secs) (6) MU = move time (50m) (secs) (17) Daily VPs = N * 32,400 / (SL+PU+MU+PD) = 12 * 32400/(43) = 9,041 16 s 43 s ISS(Independent Simultaneous Sources)-----独立震源工作模式 Day’s work for one vibrator Insonify a 1.8 sq.km area 720 VPs in difficult terrain. Omit inaccessible VPs 635 VPs to acquire Start with VPs on the plateau Complete all VP’s at one level Continue at next level Plan next day’s shooting ISS(Independent Simultaneous Sources)-----独立震源工作模式 Using the ISS method, if one vibrator fails to meet it’s daily quota of VPs the deficit can be made up the next day, either By reducing the shot density By using the spare vibrator By the vibrators either side doing extra work. ISS(Independent Simultaneous Sources)-----独立震源工作模式 All options have 25m x 25m bin size, with simila