地球物理学进展 ›› 2021, Vol. 36 ›› Issue (4): 1769-1777.doi: 10.6038/pg2021EE0266

• 应用地球物理学Ⅱ(海洋、工程、环境、仪器等) • 上一篇    下一篇

一种基于同相轴追踪的炮混叠记录分离方法的研究与应用

尹文笋(), 黄鋆, 刘云, 王晓培, 胡伟   

  1. 中海石油(中国)有限公司上海分公司研究院,上海 200335
  • 收稿日期:2020-09-16 修回日期:2021-06-27 出版日期:2021-08-20 发布日期:2021-09-15
  • 作者简介:尹文笋,男,1989年生,硕士,工程师,主要研究方向为地震信号处理.E-mail: yinws2@cnooc.com.cn
  • 基金资助:
    国家科技重大专项课题“东海深层大型气田勘探评价技术”资助(2016ZX05027-02)

Research and application of blended source separation based on wave tracking

YIN WenSun(), HUANG Jun, LIU Yun, WANG XiaoPei, HU Wei   

  1. CNOOC China Limited-Shanghai, Shanghai 200335, China
  • Received:2020-09-16 Revised:2021-06-27 Online:2021-08-20 Published:2021-09-15

摘要:

海上地震勘探中为提高采集效率会采取连续采集方案,导致地震记录尾端与下一炮起始记录重合,这种现象对浅层地震处理影响不大,但是会完全掩盖深层地震信号.由于混叠噪声与真实信号属于同方向及同震源采集,其频谱完全重叠,常规的噪声压制方法无法完全压制混叠噪声.本文提出了一种基于同相轴追踪的混叠记录分离方法,利用时域上混叠噪声与真实地震信号时距曲线的曲率差异得到混叠噪声的模型,再利用最小平方约束反演方法进行自适应相减,使有效信号误差最小,最终完成混叠炮集分离.通过理论分析与正演测试,混叠衰减的关键在于求取可靠的混叠模型,而自适应衰减则控制细微振幅与相位差异.通过对实际地震资料进行处理,并与F-K滤波方法进行了对比,证实了该方法的有效性.

关键词: 海上地震采集, 同步源采集, 混叠记录, 同相轴追踪, 自适应相减, F-K变换

Abstract:

In marine seismic exploration, a continuous acquisition scheme is adopted to improve the acquisition efficiency, which results in that the record end of the seismic record blends with the initial part of the next record. This phenomenon has little effect on shallow seismic processing, but will completely mask the deep reflection. Because blending noise and real signal are collected in the same direction and by the same source, their frequency spectrum completely overlap, and conventional noise suppression methods cannot efficiently suppress blending noise. This paper approaches a blending records separation method based on wave tracking. The blending noise model is obtained by wave tracking based on the curvature difference in the time-offset curve of the time domain between the blending noise and the real seismic signal, and the least square constraint inversion method is exploited to fit a reliable coefficients of de-blending. Through the theoretical analysis and synthetic experiments, the key point of de-blending is how to extract an accurate noise model, while the adaptive attenuation method controls the subtle amplitude and phase differences between the model and the real data. The method is compared with the F-K trfiltertion, Taking into account that the linear noise cannot be tracked, and as the direct and refract wave in F-K transformation are prone to aliasing, so the linear noise is attenuated in prior to the processing. The application on the filed data shows the apposed method has less noise remained than the F-K transformation on the gathers.

Key words: Marine seismic acquisition, Simultaneous source seismic acquisition, Blending records, Wave tracking, Adaptive subtraction, F-K filter

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