面向海洋剩余多次波衰减方法的研究

The method of marine residual multiple attenuation

随着近几年长排列大容量震源地震勘探技术的广泛采用,勘探目标逐渐趋向于中深部地层,使其成为目前研究南海深部构造的主要研究手段之一。但由于一些剩余多次波的影响,一直成为中深层成像与解释的瓶颈。针对南海某海域的实际资料,在采用SRME技术与高精度Radon变换等常规衰减技术的基础上,仍会存在一些残余多次波,主要为崎岖海底或者复杂构造引起的绕射多次波。针对剩余多次波的特点,在不同的频带范围内,通过径向中值滤波评估得到不同的"含信因子"用于异常噪音的衰减,同时为了提高数据保真度,引入逐步衰减的处理机制,层层检验衰减效果,最后结果表明,数据中剩余多次波能量被较好压制,提高了中深层的信噪比,基底以下的深部构造得到了较好地展示。

Because of using expanding spread and big source seismic acquisition,exploration targets gradually tend towards mid-depth strata,it will be an important research method for deep seated structure in South China Sea.But due to much interferences of residual multiple,that always disturb imagination and interpretation of mid-depth strata.In this paper,we apply actual data in south china sea,and the data always contain more residual multiples after using SRME technique and high accuracy Radon transform,which are diffractions of rough seafloor and complex construct.Based on the features of residual multiple,in the different extent of frequency band,this method will apply radial median filtering in calculating＂signal-bearing factor＂to attenuate the anomaly noise.Moreover,in order to improve the quality of data,we import a multistep attenuation processing mechanism to examine the attenuation effect.The final results indicate that residual multiples have been suppressed,and have enhanced signal-to-noise ratio of mid-depth strata,the deep seated structures beyond the basement have been better displayed.