初至波层析反演技术在浅水气云区成像的应用——以渤海湾某油气田为例  

Application of First Break Tomography to Shallow Water Gas Cloud Area A Case Study in Bohai Bay

作　　者：程耀[1] 张明强[1] 朱金强 宋鑫 Cheng Yao;Zhang Mingqiang;Zhu Jinqiang;Song Xin(Geophysical Research Institute,Geophysical-COSL,Tianjin 300451,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,天津300451

出　　处：《工程地球物理学报》2024年第5期890-897,共8页Chinese Journal of Engineering Geophysics

基　　金：中国海油集团公司科研项目(编号:CNOOC-KJ145ZDXM02 YF2021-01)。

摘　　要：深度域速度建模是地震成像的关键环节。当前主流的反射波层析技术在浅水气云区资料应用时,由于受到浅层气强烈的吸收及散射作用影响,难以得到准确的速度模型。利用初至波受气云影响较小、容易识别且易于拾取的特点,将初至波层析反演技术成功应用到渤海湾某大型油气田实际资料的速度建模中。结果表明:初至波层析反演可以建立高精度的中浅层速度模型。与常规反射波层析反演速度模型及偏移成果相比,该方法可以准确刻画气云区低速异常,显著提升气云区成像效果,消除由于速度不准导致的同相轴扭曲等构造假象。证明了初至波层析反演技术可以在气云区弱振幅和低信噪比条件下得到可靠的中浅层速度模型,为浅层存在显著速度异常体区域的速度建模提供了很好的解决方案。Velocity modeling is a key step in seismic imaging.The current mainstream reflection tomography technique faces challenges in obtaining accurate velocity models due to strong absorption and scattering effects from shallow gas.In this paper,we successfully applied the first break tomography technique to the velocity model building of a large oil and gas field in Bohai Bay,taking advantage of the characteristics of first break that are less affected by gas clouds,easy identification and easy picking up.The results show that first break tomography can establish a high-precision medium-to-shallow velocity model.Compared with the conventional reflection wave tomography,this method can accurately describe the low-velocity anomalies in the gas cloud area,significantly improve imaging quality of the gas cloud area and eliminate the structural twist.It also proves that the first break tomography technique can obtain reliable velocity models in the middle and shallow layers under the condition of weak amplitude and low SNR in the gas cloud area,which provides a good solution for the velocity model building of the area with significant velocity anomaly in the shallow layer.

关 键 词：气云区 速度建模 初至波层析 

分 类 号：P631.4[天文地球—地质矿产勘探]