时频域稀疏优化谐波噪声压制方法及其在准噶尔盆地高密度地震勘探中的应用

Harmonic noise suppression in the time-frequency domain via sparse optimization and application to high-density seismic exploration in Junggar Basin,China

(1.中国石油天然气股份有限公司新疆油田分公司勘探开发研究院地球物理研究所,新疆乌鲁木齐830013;2.西安交通大学电子与信息工程学院,陕西西安710049)

(1.Institute of Geophysics,Research Institute of Exploration and Development,Xinjiang Oil Field Branch Company,PetroChina Co Ltd.,Urumchi 830013,China;2.School of Electronic and Information Engineering,Xi'an Jiaotong Univeristy,Xi'an 710049,China)

谐波噪声是可控震源滑动扫描采集过程中产生的主要干扰,有效压制此类噪声是实现高精度、高分辨率地震数据叠前、叠后反演及属性分析的前提。讨论了时频域稀疏优化谐波噪声压制方法的技术关键,即有效信号及谐波干扰噪声稀疏表示字典的构造,给出了稀疏表示字典主要参数的确定方法。将时频域稀疏优化谐波噪声压制方法应用于准噶尔盆地玛湖地区三维典型单炮记录谐波噪声压制,并与工业界常用的频率域振幅异常噪声压制方法(FDNAT)进行了对比。典型单炮数据处理结果对比、单道数据对比、反褶积及其多道数据平均归一化振幅谱分析表明,时频域稀疏优化方法能在压制谐波噪声的同时具有良好的保真性能。

Severe harmonic noise often interferes with seismic records from vibroseis slip-sweep acquisition,greatly reducing the signal-to-noise ratio of shot gathers.Therefore,effectively suppressing harmonic noise is a precondition for high-precision and high-resolution seismic data prestack,post-stack inversion,and attribute analysis.Based on different time-frequency distributions of the effective signal and harmonic noise,this paper presents a novel method to separate harmonic noise from seismic records.The key step is the construction of redundant waveform dictionaries,which can provide a sparse representation of signal and harmonic noise.A scheme is proposed for determining the main parameters of the sparse representation dictionary.The proposed method was applied to a typical single shot record of three-dimensional seismic data in the Ma Lake area of Junggar Basin,China.The results showed that the proposed method can suppress harmonic noise effectively while maintaining good fidelity compared with conventional frequency-dependent noise attenuation (FDNAT).

国家自然科学基金(41774135,41504092,41504093)、中国博士后科学基金(2016T90925,2015M572567)及中央高校基本科研业务费专项资金联合资助。

10.3969/j.issn.1000-1441.2018.01.011