海底电缆双检资料陆检微分合并技术

Merging method using the derivative of geophone data in OBC dual-sensor seismic processing

海底电缆(OBC)技术是滩浅海地震勘探的重要手段,其采集特点是将炮点沉放在水下一定深度,而检波器铺设在海底,这就使得地震波在海水层中震荡产生鸣震,因此水陆双检采集方式应运而生.在OBC双检数据的资料处理中,如何实现水检和陆检的一致性融合是关键,其目的是利用水检和陆检对有效波和鸣震的不同响应来压制鸣震干扰.常用的合并方式基于水检和陆检波场相同的假设,将两者进行能量匹配后直接合并,造成有效波受到损害,鸣震压制效果差.本文提出一种陆检微分合并新技术,将陆检资料进行微分处理后,根据其与水检资料的能量关系确定尺度变换因子,然后将陆检微分结果与水检进行合并.模型测试以及实际资料应用效果验证了陆检微分合并技术能够在保护有效波的前提下,消除鸣震干扰,拓宽频带,提高分辨率.

Ocean Bottom Cable（OBC） technology is an important means of offshore seismic exploration,whose acquisition method is,sinking shotpoints underwater,putting detectors on the seabed,this will make the seismic wave shock in seawater layer leading to ghost wave,so the dual-sensor acquisition method came into being. The merging method is the key problem in OBC dual-sensor data processing,which aims to suppress the ghost on the basis of its opposite response characteristics in hydrophone P and geophone Z data. In commonly used merging methods,the P and Z data are summed directly by energy matching according to hypothesis of the same wavefield in dual-sensor data, resulting in the damage of effective wave and bad suppression of ghost. In this paper,we have proposed a new merging method using P data and the derivative of Z data by some scale calibration to implement the ghost suppression.Compared with two common methods（direct summation and summation with phase adjustment）,our merging method using the derivative of geophone can remove the ghost,broaden the frequency band and improve the resolution of dual-sensor data under the premise of protecting the effective wave for the model test and real dataset of KDD area.