基于虚反射走时和道集相干联合的电缆等浮校正方法  

Method of cable floating correction based on combination of gather coherence and ghost reflection traveltime

作　　者：颜中辉 王小杰 徐华宁[1,2] 陈珊珊 杨佳佳[1,2] 杨传胜 YAN Zhonghui;WANG Xiaojie;XU Huaning;CHEN Shanshan;YANG Jiajia;YANG Chuansheng(Qingdao Institute of Marine Geology,China Geological Survey,Qingdao,Shandong 266237,China;Laboratory for Marine Mineral Resources,Laoshan Laboratory for Marine Science and Technology,Qingdao,Shandong,266237,China)

机构地区：[1]中国地质调查局青岛海洋地质研究所,山东青岛266237 [2]崂山实验室海洋矿产资源评价与探测技术功能实验室,山东青岛266237

出　　处：《石油地球物理勘探》2023年第6期1365-1373,共9页Oil Geophysical Prospecting

基　　金：国家自然科学基金项目“基于多分辨HHT时频分析的南黄海中深层弱地震反射补偿研究”(42106208)和“东海陆架盆地长排列地震数据高精度叠前逆时深度偏移成像”(42106207);山东省自然科学面上基金项目“跨频段融合天然气水合物储层检测研究”(ZR2021MD118)和“东海陆架及邻域海底流体渗漏系统的识别及其形成机制研究”(ZR202111260092);崂山实验室科技创新项目“中国海域重点盆地发育时空差异及其深部过程”(LSKJ202203401);中国地质调查局项目“深海调查-测量”(DD20230643、DD20191003)联合资助

摘　　要：海洋高分辨率小道距地震勘探中,因设备固有问题引起电缆不等浮效应,造成了地震道集上同相轴动校正不平,甚至弯曲抖动现象,影响同相叠加的效果,降低了地震成像精度。常规的剩余时差校正方法难以准确识别由电缆不等浮引起的时差,在校正结果上产生误差。为此,提出一种基于虚反射走时和道集相干联合的电缆等浮校正方法。首先,采用交互拾取虚反射走时方法获得实时的电缆沉放深度,计算初始的剩余时差;然后,基于模型参考道进行道集之间的二维相干分析,获取参考的剩余时差;最后,取上述两个时差的加权平均得到修正的电缆不等浮剩余时差,应用后达到同相叠加的效果,从而提升地震资料成像品质。在模型数据和实际数据的测试分析中,通过与常规的互相关电缆等浮校正方法进行对比表明,该校正方法的精度更高、效果更好。In the high-resolution and small trace distance marine acquisition,due to the inherent problems of equipment,the cable unequal floating effect will be caused,there are some problems,for instance,phase axistremor and uneven NMO correction will be shown on the gather,which cannot achieve the effect of in-phase superposition,and reduce the imaging accuracy of seismic data.The conventional residual moveout correction method is difficult to accurately identify whether residual moveout is caused by the unequal floating of the cable,which will cause errors in the correction results.This paper presents a cable floating correction method based on combination of gather coherence and ghost reflection traveltime.Firstly,the sinking depth of the actual cable is calculated by using the interactive pick-up ghost reflection travel time,and then the initial moveout correction is obtained.Then the reference moveout correction is obtained by the gather coherence and the model reference trace.Finally,the moveout correction is weighted selected by the cross-correlation analysis between the two,and the moveout is applied after smoothing,the phase axis of the data achieves the effect of phase stacking,in order to improve the resolution and imaging accuracy of seismic data.In this paper,combined with the test analysis of model data and actual processing,compared with the conventional cross-correlation cable float correction method,the results show that the correction method in this paper is more accurate and effective in float correction.

关 键 词：小道距采集 电缆等浮校正 剩余时差 互相关分析 虚反射走时 

分 类 号：P631[天文地球—地质矿产勘探]