Q偏移技术在陵水凹陷气云模糊区地震资料处理中的应用研究  

Application and Research of Q Migration Technology in Seismic Data Processing in Gas Cloud Fuzzy Area of Lingshui Sag

作　　者：蒋亚洲 Jiang Yazhou(Institute of Geophysical Erploration,Geophysical-China Oil field Services Limit,Zhanjiang Guangdong 524057,China)

机构地区：[1]中海油田服务股份有限公司物探事业部物探研究院,广东湛江524057

出　　处：《工程地球物理学报》2023年第5期645-651,共7页Chinese Journal of Engineering Geophysics

基　　金：中海石油海南分公司生产科研项目(编号:CCL2020HNFN0043B03)。

摘　　要：深水石油勘探要求更高品质的地震成像数据作为基础,然而气云区、气烟囱及其他速度异常体等高吸收异常构造的存在,造成深层地震波振幅变弱,频率降低,严重影响目标构造成像精度。本文以陵水凹陷气云模糊区为目标靶区,系统分析工区地震资料品质特点,针对性地采用Q(Geological Quality Factor,地质品质因子)偏移技术补偿浅层气云造成的吸收衰减。首先采用谱比法建立初始的等效Q场;然后基于等效Q场进行Q层析反演建立准确的异常Q场模型;最后基于高精度Q场进行克希霍夫Q叠前深度偏移。实际资料表明,重处理后浅层气云低速异常造成的能量吸收、频率衰减现象得到解决,目的砂体横向连续性更好,有效频带拓宽30%,气云下方模糊区的成像质量得到明显改善,为工区砂体展布落实及后续圈闭目标研究提供了高品质基础资料。Deep-water oil exploration requires higher-quality seismic imaging data as support.However,the existence of high-absorption anomalous zones such as shallow gas clouds,gas chimneys and other low-velocity anomalous bodies causes the amplitude of deep seismic waves to weaken and the frequency to decrease,which seriously affects the imaging accuracy of target structure.In this paper,the gas cloud fuzzy area in Lingshui sag is taken as the target area,and the quality characteristics of seismic data in the work area are systematically analyzed.The absorption attenuation of seismic data is compensated by Q migration technology.Firstly,the initial equivalent Q field is established by spectral ratio method.Secondly,based on the equivalent Q field,Q tomography inversion is carried out to establish an accurate abnormal Q field model.Finally,Kirchhoff Q prestack depth migration is carried out based on high-precision Q field.The field data show that the energy absorption and frequency attenuation caused by the low velocity anomaly of shallow gas cloud are solved after reprocessing.The lateral continuity of the target sand body is better,the effective frequency band is widened by 30 %,and the imaging quality of the fuzzy area under the gas cloud is obviously improved,which provides high quality basic data for the implementation of sand body distribution and subsequent trap target research in the work area.

关 键 词：深水勘探 陵水凹陷 气云模糊区 Q偏移 Q层析 谱比法 

分 类 号：P631.4[天文地球—地质矿产勘探]