用一种震源设备实现多波VSP观测的可能性
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摘要
本文通过对新疆几口井的可控震源三分量VSP观测资料的研究表明：在很多地区，水平震源（又称横波可控震源）激发时，不仅可观测到S波，也可观测到能量较强的P波；垂直震源（又称纵波可控震源）激发时，不仅可观测到P波和SV波，也可观测到能量足够强的SH波。经过适当的处理，我们能可靠地分离出水平震源激发时的P波和垂直震源激发时的SH波，分别提取P波和S波的速度参数，作P波、SV波和SH波的成像剖面；利用多波参数作储层分析。这一研究成果克服了通常认为的，只有一种震源（特别是只有垂直震源没有水平震源）难以进行标准的多波勘探的困难，这在实际生产中是很有意义的。一方面它使人们向往的多波勘探易于变为现实，一方面它将大幅度地降低多波勘探的成本，提高勘探效率。另外，这种在一定条件下，利用一种震源设备实现多波勘探的技术，也有可能推广到地面地震勘探，只是地面地震所得到的波场不像VSP观测那样，各种波的特征比较明显、易于识别而已。
The results obtained through studing tricomponent VSP data with vibroseis from wells inXinjiang Uygur Autonomous Region show that in many places when horizontal sources (or S wavevibroseis ) are used S wave can be detected and so can more powerful P wave,when vertical sources(or compressional wave vibroseis ) are used P wave and SV wave can be detected and so cansufficiently powerful SH wave,through proper proecssing P wave in the case of horizontal sourcecan be reliably seperated from SH wave in the case of vertical source,the velocity parameters ofboth P wave and S wave are seperately abstracted,then imaging of P wave,SV wave and SH wavecan be realized, and finally reservoir are analpeed through parameters of multiwave. With thisabove advancement difficulties can be overcome that one kind of source can bardly bc used for us toconduct standard multiwave oxploration. It is very important in that it make multiwave explorationcome true very casily, greatly reduce cost and increase cfficiency. Besides, under certaincircumstances this technique can be applied in surface seismic cxploration and the only differenceIies in that characteristies of waves are comparatively not clear and can not be identified casilyin the wave field obtained in the case of surface seismic oxploration.
The results obtained through studing tricomponent VSP data with vibroseis from wells inXinjiang Uygur Autonomous Region show that in many places when horizontal sources (or S wavevibroseis ) are used S wave can be detected and so can more powerful P wave,when vertical sources(or compressional wave vibroseis ) are used P wave and SV wave can be detected and so cansufficiently powerful SH wave,through proper proecssing P wave in the case of horizontal sourcecan be reliably seperated from SH wave in the case of vertical source,the velocity parameters ofboth P wave and S wave are seperately abstracted,then imaging of P wave,SV wave and SH wavecan be realized, and finally reservoir are analpeed through parameters of multiwave. With thisabove advancement difficulties can be overcome that one kind of source can bardly bc used for us toconduct standard multiwave oxploration. It is very important in that it make multiwave explorationcome true very casily, greatly reduce cost and increase cfficiency. Besides, under certaincircumstances this technique can be applied in surface seismic cxploration and the only differenceIies in that characteristies of waves are comparatively not clear and can not be identified casilyin the wave field obtained in the case of surface seismic oxploration.
引文
[1]何樵登,《地震波理论》,地质出版社,P56～59,1988年。
[2]唐文祥,VSP各波场能量的空间展布,《地球物理技术汇编》,1991年第16期,P109～120,19。
[3]Choro kitsunezaki,Toshiaki Yokoi,Koiehi Okuzumi and Noritoshi Goto,1994,SH-wavegeneration by a vertical force applied close to a pit,First Break,V12,N2,p99-105.
[2]唐文祥,VSP各波场能量的空间展布,《地球物理技术汇编》,1991年第16期,P109～120,19。
[3]Choro kitsunezaki,Toshiaki Yokoi,Koiehi Okuzumi and Noritoshi Goto,1994,SH-wavegeneration by a vertical force applied close to a pit,First Break,V12,N2,p99-105.
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