深水陡坡带绕射多次波压制方法研究

在深水陡坡带和复杂海底构造区域,即使采用长电缆,由绕射产生的自由表面相关多次波因为传播方向的异变,仍然难以避免在自由表面发生下行反射的反射点位置位于电缆长度范围之外,造成预测多次波的近偏移距信息不足或者负偏移距信息缺失等问题,以致不能准确地预测和压制陡坡带的绕射多次波.本文在常规反馈迭代自由表面多次波压制方法的基础上做出相应改进,将邻炮的炮记录依照炮点、检波点互换原理引入到反馈迭代循环当中,补充绕射多次波预测所需要的近偏移距和负偏移距信息.经过Sigsbee2b模型和实际资料测试,达到较好压制深水陡坡带的自由表面相关绕射多次波的目地.

Study of diffracted multiple elimination on steep slope zone in deep water

steep slope zone of deep water and rugged water-bottom area, even with long acquisition cable, because of the direction of propagation of diffracted multiple, it is hard to avoid the reflected point out of the cable, which makes diffracted multiples prediction without enough near offset and negative offset information, so that we cannot predict and suppress diffracted multiple exactly. This has been a big problem for us on diffracted multiple elimination in deep water steep slope zone. This paper presents a new method based on the feedback iteration model, introduces the adjacent shot record into the feedback iteration model, to supplement the near offset and negative offset data information. According to Sigsbee2b model data and field data test, the new method ultimately achieved the purpose of better prediction and elimination of free-surface related diffracted multiple.