琼东南盆地深水绕射多次波地震资料特征与衰减方法

The Formation and Attenuation Methods of Deep Water Diffracted Multiple, Qiongdongnan Basin

琼东南盆地是一个比较典型的深水含油气盆地,其中央凹陷深水区具有海底崎岖多变、浅部欠压实地层发育、广泛分布残洼隆起等地质地震特征,这些因素使得地震资料多次波异常发育,绕射多次波更较其他区域复杂。常规的衰减方法,诸如Radon、SRME等方法衰减绕射多次波困难。然而这些绕射多次波常常与中深层烃源岩、裂隙垂向运移通道等地震资料叠合在一起,对地质研究工作产生困难。本文从该区域深水绕射多次波形成的机理原因开展研究,根据绕射多次波的类型特征,提出两种不同的绕射多次波概念;针对“地层相关”“构造相关”的绕射多次波,提出基于分频处理精细衰减和线性多次波衰减为核心的绕射多次波衰减方法(RDMA),结合深水常用的多次波衰减方法,形成针对性绕射多次波衰减流程。地震资料实际处理结果表明,本文提出的深水绕射多次波衰减方法效果较好。

The deepwater area of the Qiongdongnan Basin formed a rugged submarine,shallow strata undercompression,extensive distribution of the depression in the uplift area.However,conventional methods such as 2D-SRME and RADON are difficult to effectively attenuate,which seriously affect the evaluation of medium and deep source rock and the vertical migration channel.In this paper,the causes of the diffraction multiple development in the Qiongdongnan Basin deepwater area are systematically analyzed,and the concept of“formation causes”and“structure causes”diffraction multiple are proposed.For these two different diffraction multiple,(RDMA)is studied by frequency-separated amplitude attenuation and linear diffraction multiple decay as the core.The method and technique are combined with the conventional method to form the multiple attenuation of he Qiongdongnan Basin deepwater area.The effect of the actual data indicates that the method is effective.