VSP资料在转换波层位标定中的应用

Application of VSP data in calibrating converted wave horizons

(1.成都理工大学研究生院，四川成都610059；2.中国石油四川石油地球物理勘探公司物探研究中心，四川成都610213)

College of Postgraduate, Chengdu University of Technology, Chengdu 610059, China

利用VSP资料可以较好地解决地面多分量转换波的层位标定问题,其基本原理和方法是：首先利用水平分量的下行横波获得横波初至，利用水平分量的上行转换波获得上行转换波的双程时间剖面，利用垂直分量剖面获得纵波初至；然后由纵波初至和横波初至得到转换波的时-深关系；再通过转换波的时-深关系和双程时间剖面对过井转换波剖面进行层位标定。应用该方法对广安地区05GA3C04线过GA101井的地面三分量转换波偏移剖面进行了层位标定，并将标定结果用于纵波与转换波的联合解释和岩性剖面解释，得到的结果与工区内的钻井结果吻合。

VSP data can be used to solve the horizon calibration problem of ground three component converted wave well. The basic principle is that the two-way time of converted wave is the sum of P-wave first break and S-wave first break. Firstly, the down-going S-wave of horizontal component is used to obtain the first break of S-wave; the up-going S-wave of horizontal component is used to gain the two-way time profile of up-going converted wave; the vertical component section is used to get the accurate first break of P-wave. Then, the time-depth relationship of converted-wave is obtained from the first break of P-wave and S-wave. Finally, horizon calibration is carried out on cross-well converted wave sections through time-depth relationship and two-way time profile. The method was applied to the horizon calibration of ground three-component converted wave migration profile through well ga101, 05GA3C04 line in Guang’an area. The result was applied to the joint interpretation and lithologic profile interpretation of P-wave and converted wave. The interpretation result coincides with the drilling information of the area.