可控震源高效采集技术王井富.ppt

,可控震源高效采集技术,王井富2008-10-24,引 言,升板时间(4秒)+降板时间(6秒)+震源移动时间12.5米(11秒)=16秒 震源移动300米的时间90秒,每排6炮 假定一组震源施工,10秒,16秒,10秒,16秒,10秒,16秒,10秒,16秒,10秒,16秒,10秒,16秒,10秒,16秒,10秒,16秒,下一排,每炮需104秒每排炮需104*6=624(秒)最终折算每炮平均104+15=119(秒)每天有效放炮时间是按8小时算3600*8/19=242(VPs)3.62平方假设:10000平方的施工面积施工天数:10000/5.6=2756天=7.55年,Flip Flop-交替扫描Slip Sweep-滑动扫描DSSS(Distance Separated Slip Sweep)-滑动+距离分开ISS(Independent Simultaneous Sources)-独立震源工作模式HFVS(High Fidelity Vibratory Seismic)-基于高保真技术的高效采集,提 纲,Flip Flop-交替扫描采集方法,交替扫描采集技术（Flip-Flop Sweep）是使用两组震源交替作业，一组震源在另一组震源振动的同时移动搬点，从而节省震源搬点的时间，提高施工效率。,Flip Flop-交替扫描采集方法,两套震源位于相邻的两条炮线，第一套震源震动时，第二套震源关机或移动，两套震源位于不同炮线，相距180米，摆放位置如图所示：,利比亚RAMSA三维项目：总炮数约143316炮，单套震源作业：日效650炮，工期10个月（22天/月）交替扫描作业：日效1000炮，工期6.5个月（22天/月）增加收入（每天）：350炮X60USD/炮21000USD增加一套震源及其它设备折旧：每天约1000USD增加人员及材料、油料消耗：每天约1500USD整个项目创造效益：18500X 3.6月X22天146.52万USD缩短施工期约3.6个月，节约直接成本3.6X30X25000270万。甲方缩短勘探期3.6个月，节约相关费用20万美元以上。,Flip Flop-交替扫描采集方法,墨西哥北方Potenciales 2三维项目：总工作量为4199可km2，总炮数261193炮，价值工作量为8500万美元，BGP用两支可控震源队进行作业 单套震源作业：日效440炮交替扫描作业：日效775炮，增加收入（每天）：335炮X325USD/炮108875 USD增加10台震源及其它设备折旧：每天约2000USD增加人员及材料、材料消耗：每天约4000USD每天创造效益：102875 USD整个项目创造效益：102875X 10月X30天约3000万USD缩短施工期约4个月，节约成本9X4X301080万USD甲方缩短勘探期4个月，节约相关费用50万美元以上。,Flip Flop-交替扫描采集方法,交替扫描作业,Flip Flop-交替扫描采集方法,小结优点:提高施工效率缺点:1)噪音问题 2)投入更多的设备和人力应用交替扫描方式应综合考虑以下几方面问题:1)扫描参数是否适合 2)地质条件:技术(震次间相互影响）、地表条件 3)观测系统设计是否适合 4)噪音水平是否可以接受：选择合理的可控震源组之间的距离 5)综合采集方式决定使用哪种交替方式(Fleet by Fleet 或 Sweep by Sweep）6)投入和产出是否匹配等,Flip Flop-交替扫描采集方法,Flip Flop-交替扫描Slip Sweep-滑动扫描DSSS(Distance Separated Slip Sweep)-滑动+距离分开ISS(Independent Simultaneous Sources)-独立震源工作模式HFVS(High Fidelity Vibratory Seismic)-基于高保真技术的高效采集,提 纲,滑动扫描技术是一种连续放炮的高效采集方法，同时采用多组震源施工，下一组震源可以不必等待上一组震源完成震动即可开始施工，大大缩短了相邻两次扫描的间隔时间，从而大幅度地提高了生产效率。滑动时采用的扫描频率相同，通过相关处理过程可以分开成各自的记录。,常规扫描,滑动扫描,Slip Sweep-滑动扫描,Slip Sweep-滑动扫描,滑动扫描过程中，在放完每组炮之前，仪器连续记录，所有数据信息及包括TB和相关信号的辅助道信息都只是暂存入内存中，形成一个炮与炮间相互重叠的连续的记录（母记录），在放完最后一炮后，系统将依据TB和相关信号对（母记录内）每炮进行相关，分离出单个记录，并输出到磁带上。,Slip Sweep-滑动扫描,在震源Fleet1扫描的过程中，如果其他震源Fleet的已经“Ready”，将发送“Ready”信号和坐标中心给仪器。仪器检查组合中心是否在允许范围内，并判断滑动时间是否过期，如果都满足，则自动启动第二组震源的扫描，依次类推。,Slip Sweep-滑动扫描,滑动时间Salvo炮数变相位扫描震源组数,Slip Sweep-滑动扫描参数选择,Slip Sweep-滑动扫描,小结优点:采用滑动扫描可以大幅度提高施工效率，节约生产成本缺点:1)噪音问题 2)投入更多的设备和人力应用滑动扫描方式应综合考虑以下几方面问题:1)扫描参数的选择:滑动时间、相位、距离 2)观测系统设计是否适合 3)噪音水平是否可以接受 4)资源配置 5)其他,Flip Flop-交替扫描Slip Sweep-滑动扫描DSSS(Distance Separated Slip Sweep)-滑动+距离分开ISS(Independent Simultaneous Sources)-独立震源工作模式HFVS(High Fidelity Vibratory Seismic)-基于高保真技术的高效采集,提 纲,-,75 x 50m 网格,6 vibs,slip sweep,12秒扫长+6滑动秒最高效率 600 VPs/hour平均每台震源 36秒完成一炮,6组震源交替滑动扫描方式,DSSS(Distance Separated Slip Sweep)-滑动+距离分开,-,run,Distance separated,DSSS(Distance Separated Slip Sweep)-滑动+距离分开,75 x 50m 网格,6 vibs,slip sweep,12秒扫长+6滑动秒最高效率 1200 VPs/hour平均每台震源 36秒完成一炮,Distance Separated Slip Sweep(DS3),DSSS(Distance Separated Slip Sweep)-滑动+距离分开,DSSS(Distance Separated Slip Sweep)-滑动+距离分开,DSSS(Distance Separated Slip Sweep)-滑动+距离分开,DSSS(Distance Separated Slip Sweep)-滑动+距离分开,DSSS(Distance Separated Slip Sweep)-滑动+距离分开,滑动比交替：提高效率=(67-37)/67=44.78%DSSS比滑动提高一倍,小结优点:大幅度提高施工效率，节约生产成本缺点:1)噪音问题 2)投入更多的设备和人力,DSSS(Distance Separated Slip Sweep)-滑动+距离分开,操作难点:1)大道数:固定排列8000-8500道接收 2)能管理5-6组震源进行滑动扫描(VE464)3)同一组两套相距12公里震源同步启动 4)电台通讯(仪器与震源,震源与震源间)5)对现场处理要求高,Flip Flop-交替扫描Slip Sweep-滑动扫描DSSS(Distance Separated Slip Sweep)-滑动+距离分开ISS(Independent Simultaneous Sources)-独立震源工作模式HFVS(High Fidelity Vibratory Seismic)-基于高保真技术的高效采集,提 纲,25 kms,7 km,8000 道实时接收 16 L*500道 RL=450 RI=50,ISS(Independent Simultaneous Sources)-独立震源工作模式,Conventional Seismic-One or two fleets of vibrators move along the shot line.Active spread is rolled as they progress.Sweep time+Listen time+Spread roll+move-up delays.-Typically 1200 VPs/day,Independent Simultaneous Sweeping-Individual vibrators work separate parts of the spread.All stations record continuously.Needs large recording spread,and high fold data is essential.Typically 750 VPs/day per vibrator.9000VP/s day with 12 vibs.,ISS(Independent Simultaneous Sources)-独立震源工作模式,ISS(Independent Simultaneous Sources)-独立震源工作模式,V V V V V V V V VV V V V V V V V VV V V V V V V V VV V V V V V V V VV V V V V V V V VV V V V V V V V VV V V V V V V V V V V V V V V V V V V V V V V V V V V,Orthogonal shooting constant separation,Note:Vibrators wont beperfectly synchronised for ISS,ISS(Independent Simultaneous Sources)-独立震源工作模式,continuous recorded data(8000 channels),Vib 1 T0,Vib 2 T0,Vib 1 record,Vib 2 record,ISS(Independent Simultaneous Sources)-独立震源工作模式,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,ISS changing the way we work.,Days work for one vibratorInsonify a 1.8 sq.km area720 VPs in difficult terrain.,Omit inaccessible VPs635 VPs to acquire,Start with VPs on the plateau,Complete all VPs at one level,Continue at next level,Plan next days shooting,ISS(Independent Simultaneous Sources)-独立震源工作模式,ISS keeps rolling,Using the ISS method,if one vibrator fails to meet its daily quota of VPsthe deficit can be made up the next day,eitherBy reducing the shot densityBy using the spare vibratorBy the vibrators either side doing extra work.,ISS(Independent Simultaneous Sources)-独立震源工作模式,Source effort options,All options have 25m x 25m bin size,with similar offset/azimuth distribution fold calculated with offsets limited to 3150m x-line,3200m in-line,3600m max,ISS(Independent Simultaneous Sources)-独立震源工作模式,High Fold ISS,Standard orthogonal,ISS In-line section comparison,ISS data with 90m crossline spacing,orthogonal with 360m crossline spacing,ISS(Independent Simultaneous Sources)-独立震源工作模式,High Fold ISS,Standard orthogonal,ISS Timeslice comparison,ISS(Independent Simultaneous Sources)-独立震源工作模式,Data Volumes,Continuous recording for ISSAssume 60 second record,8000 channels,4msec sample interval,SEGD format File size=458 MbytesAssume continuous recording for 10 hours600 files of 458Mbytes=275 Gbytes.=1 IBM 3592 tape cartridge=7 IBM 3590E tape cartridges Typical NAS disk pack holds 1Terabyte or moreCombed+correlated shot recordsAssume 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),ISS(Independent Simultaneous Sources)-独立震源工作模式,小结优点:大幅度提高施工效率缺点:1)噪音问题、能量问题 2)投入更多的设备和人力,操作难点:1)大道数:固定排列8000-8500道接收 2)要求能记录下每台震源启动的T0时间 3)震源本身能监控震源的状态 4）能记录震源的震动性能信号(参考、力、重锤、平板）5)电台通讯(仪器与震源,震源与震源间)6)对现场处理要求高,ISS(Independent Simultaneous Sources)-独立震源工作模式,i 运算速度快ii 大的存储空间iii 处理系统有数据分离和三维FKK滤波等模块、并且模块算法适合处理大的数据量,Flip Flop-交替扫描Slip Sweep-滑动扫描DSSS(Distance Separated Slip Sweep)-滑动+距离分开ISS(Independent Simultaneous Sources)-独立震源工作模式HFVS(High Fidelity Vibratory Seismic)-基于高保真技术的高效采集,提 纲,HFVS 是 Exxon Mobil 的一项专利技术，这项技术要求记录未相关的的原始数据每台震源的每次扫描的震动信号。之所以称之高保真因为在数据分离过程中用到了震源的力信号。,High Fidelity Vibratory Seismic,HFVS(High Fidelity Vibratory Seismic)-基于高保真技术的高效采集,Increase Productivity（高效率）：Reduce acquisition time by recording more than one Vibrator at a timeRequirement for increased productivity particularly on high density wideazimuth surveys Resolution提高分辨率：点激发、点接收There is no arrays,point source receiver techniques Processing records as unique source points allows for correction of intra-array statics and differential velocity move-out which wouldnt be possible with conventional recording where vibrator arrays are summed in the field.Correlate the ground force with vibrator data用地面力信号替代参考信号 Denser geometries lead to finer spatial sampling高密度空间采样,240米,4 台震源/组,6个检波器堆放,地下界面,HFVS(High Fidelity Vibratory Seismic)-基于高保真技术的高效采集,线性升频扫描：6-96Hz,HFVS 扫描过程中每台震源的相位编排,240m,HFVS(High Fidelity Vibratory Seismic)-基于高保真技术的高效采集,实时的相位变换,HFVS(High Fidelity Vibratory Seismic)-基于高保真技术的高效采集,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),HFVS(High Fidelity Vibratory Seismic)-基于高保真技术的高效采集,4 FDU,1 LAUR,1 LRU,DSD,RecorderSercel 428,AHV-IV Vibrator,HFVS(High Fidelity Vibratory Seismic)-基于高保真技术的高效采集,通过无线采集方式记录震源力信号,Record each auxiliary channel of 4 vibrators,total 20 auxiliary channels need to be QC-ed,HFVS(High Fidelity Vibratory Seismic)-基于高保真技术的高效采集,HFVS data inversion&seperation,In time domain data(D)is a convolution of the earth response(E)with Source Signature(S)In the frequency domain we can write this as a Matrix as given below,If the sweeps are repeated at least the same number of times as the number of vibrators then the earth response for each vibrator can be separated by inverting a matrix of vibrator signatures in the frequency domain and applying the resultant filter to the geophone data.,HFVS(High Fidelity Vibratory Seismic)-基于高保真技术的高效采集,HFVS raw data inversion,separation,29s,1 sweep of 4 vibs vibrating simultaneouslyuncorrelated raw record,Vib 1,sweep 1,Vib 2,sweep 1,Vib 3,sweep 1,Vib 4,sweep 1,+,Generate separated,inverted&stacked raw records for each vibrators,HFVS(High Fidelity Vibratory Seismic)-基于高保真技术的高效采集,2 fleets x 4 Vibrators(240m apart)4 sweeps per VP,Crews further apart possibly to avoid cross-contamination,Active patch,HFVS(High Fidelity Vibratory Seismic)-基于高保真技术的高效采集,23 Receiver lines,HFVS(High Fidelity Vibratory Seismic)-基于高保真技术的高效采集,Moving 8 receiver lines between two swaths,HFVS(High Fidelity Vibratory Seismic)-基于高保真技术的高效采集,vib interval:240m 23 RL receiving,V1,V2,V3,V4,4vib*4sweeps,Always select the V1s source number to push the shoot button,every one push,4 vib will shake 4 times at same time,HFVS(High Fidelity Vibratory Seismic)-基于高保真技术的高效采集,V1,V2,V3,V4,240 m,240 m,30 m,HFVS(High Fidelity Vibratory Seismic)-基于高保真技术的高效采集,HFVS 现场处理,Conventional 3D:20M/VP,HFVS 3D:3680 channels 28 s raw data 1500 VPs/daySize:200M/VPTotal:300G/day,Recorder:6 NAS disks(360G/each),QC:Disk Array(20 T),IBM disk array,The following data needed before data separation;,HFVS ID of each record Corresponding vibrator number of each auxiliary channel Location of each vibrator(line number,VP number)Coordinate of each vibratorCoordinate of each trace in the record Status of each vibrator including;Phase,Amplitude and Drive Level,HFVS数据从SEG-D转换到SEG-Y,Signal corrupted,need to be re-shoot,Signal lost,HFVS 辅助道的质量控制,Normal,Abnormal,wrong record sequence,Signal clipping,Reset parameter and reshot,A circuit was setup between DSD and FDU on the vibrator to eliminate clipping.,HFVS 辅助道的质量控制,Signal distortion,一些辅助道出现错误的例子,需要重新放炮,小结优点:1）应用地面力信号解矩阵方程，求取地层反射系数 2）点激发、点接收，可以实现高密度空间采样 3）施工效率高,操作难点:1)大道数:超级排列 2)能记录震源的震动性能信号(参考、力、重锤、平板）3)LAUR和LRU通讯问题 4)对现场处理要求高,HFVS(High Fidelity Vibratory Seismic)-基于高保真技术的高效采集,欢迎各位提出您的意见和看法!,谢谢！,