苏里格地区转换波初至识别方法研究

THE METHOD STUDY ON IDENTIFYING P-SV FIRST ARRIVAL IN SULIGE

P-SV转换波静校正是转换波处理中的一个难题,常规的纵波静校正方法不能用于转换波处理。利用初至波进行纵波静校正取得了很好的效果,但是由于转换波初至识别和拾取困难,针对转换波的折射静校正方法一直没有得到较好的应用。对转换波初至的组成和特点进行了讨论,通过推导共检波点道集中初至的时距曲线得到了共检波点道集中P-P-P波初至和P-P-SV波初至在一定偏移据范围内平行的结论。根据这一结论,提出了共检波点域初至波叠加法确定转换波初至的算法,并对苏里格地区的转换波资料进行了转换波初至识别,取得了满意的效果。

The static correction of P-SV converted wave is difficult for converted wave processing,the common P-wave static correction method cannot be used for converted wave process.A satisfactory result is achieved by using first arrival wave to carry out P-wave static correction,but the fraction static correction method for converted wave has not been well used due to the difficulty of identification and collection of converted wave.The composition and characteristics of first arrival of converted wave are discussed.The conclusion is given that the first arrival of P-P-P wave is parallel with the first arrival of P-P-SV wave in CRP by deriving the equation of first arrival P-SV waves travel time.According to the conclusion,the receiver domain of the beginning of a total wave superposition method is applied to determine the conversion wave,and the algorithm is put forward.Through the algorithm,the converted wave data from Sulige area are used to identify the first arrival of converted wave,and a satisfactory consequence is achieved.