Walk-away VSP和3D-VSP自适应静校正方法研究  

Walk-away VSP and 3D-VSP self-adapted static correction method

作　　者：张山[1,2,3] 朱海龙[1,2] 王家映[1] 顾汉明[1] 

机构地区：[1]中国地质大学(武汉)地球物理与空间信息学院,武汉430074 [2]中石化南京石油物探技术研究院,南京210014 [3]南京捷诺科技有限公司,南京210035

出　　处：《地球物理学进展》2011年第5期1755-1762,共8页Progress in Geophysics

摘　　要：目前Walk-away VSP和3D-VSP处理中尚缺乏有效的静校正手段,主要是借用面地震静校正量.本文根据Walk-away VSP和3D-VSP观测系统和数据特点提出了自适应静校正的思路.主要包括自适应高程静校正和自适应剩余静校正,自适应高程静校正的要点是通过VSP初至时间和激发点高程差,求出替换速度,然后根据高程计算静校正量;剩余静校正的要点是利用VTI各向异性速度模型计算出理论初至时间,实际初至时间与理论初至时间的差即为静校正量,本方法将目的层以上地层均校正为横向均匀介质,不但消除了地表、低速带、降速带横向变化的影响,而且消除了浅部基岩横向变化对目的层的影响.实例表明,按本方法进行静校正后,所得结果更符合沉积理论,对VSP资料的精细处理和正确解释起到了积极作用.Now there is still lacked a effective static correction method in walk away VSP and 3D-VSP processing. Therefor the surface seismic static correction quantity has been used in VSP process. In this article a self-adapted static correction idea and method is proposed based on walk away VSP and 3D-VSP layout and the data characteristics. It mainly includes the self-adapted elevation static correction and the self-adapted residual static correction. The key point of self-adapted elevation static correction aims at caculating replacing velocity via the break times of VSPs and elevation differences of shotpoints, and eomputating elevation statics by elevation and replacing velocity. The residual static correction＇s main point is that calculating the first-arrival times theoretically based on the VTI anisotropy model, then caculating residual statics by substracting actual first-arrival times from theoretical times. By correcting strata above interest to a lateral isotopic media, this method not only eliminates the influences induced by lateral changes of the surface, the low velocity zone, and the fall speed belt, but also eliminates the influences to interest by the lateral changes of uper bedrocks. The example indicates that carring on the static correction after this method, the obtained result conforms to the deposition theory. It is positive for VSP data fine processing and correct interpratation.

关 键 词：Walk—away VSP 3D-VSP 静校正 自适应 各向异性 

分 类 号：P631[天文地球—地质矿产勘探]