【作者】 臧成印；

【导师】 贺振华； 黄德济；

【作者基本信息】 成都理工大学 ， 地球探测与信息技术， 2009， 硕士

【摘要】 滩浅海地区地表复杂,采集的地震资料干扰波种类繁多、分布广泛;由于震源和检波器差异,造成相同区块的地震资料动力学属性存在较大差异。本文首先分析了滩浅海地区地震资料特征(指导后续的匹配工作)和几种主要干扰波(多次波、面波、50Hz工业干扰等)的特征:①多次波的特征:在道集上与同时间的一次波相比速度较低,层间多次呈周期性出现;②面波的特征:主频和视速度较低,具有一定的相干性,能量很强,一般随时间的推移和炮检距的增加而衰减;③50Hz工业干扰的特征:频率固定为50Hz,能量较强,在单炮上分布广泛但无规律,但固定分布在靠近高压线的检波点上。然后,针对滩浅海地震资料上的这些干扰波的特征,提出了一系列的有针对性的方法技术,用于有效地克服这些干扰的影响:①滩浅海地震资料的多次波压制技术。常规的地震资料的多次波压制方法主要采用抛物线Radon变换方法压制多次波,受多种因素影响,这种常规方法压制效果不太理想,并且会破坏道间振幅的相对关系。根据线性Radon变换原理,本论文提出的“两步法”线性Radon变换压制多次波技术,通过模型试验和实际资料处理表明,可以很好地压制多次波,但会对有效波有轻微损伤。此外,针对常规的多次波压制方法不能在压制多次波的同时保留振幅的AVO特性,本文采用李庆忠提出了“剔除拟合法”有效地进行了滩浅海地震资料的多次波压制,模型和实际资料的处理结果证明了该方法在压制多次波并同时保留AVO振幅特性方面的有效性。在滩浅海地震资料处理中,可以根据实际的需要选择多次波压制方法。②滩浅海地震资料的面波压制技术。常用的压制面波的方法是基于面波和有效波之间视速度和频率差异的F_K域滤波法,F_X域相干噪音压制法(Fxcns)和基于面波和有效波之间振幅能量差异的区域异常噪音衰减(ZAP)压制面波方法,前两种方法是将地震数据分别转换到F_K域和F_X域,以便于将面波和有效波进行分离;ZAP方法是将振幅分解到四种域内,找出并剔除振幅异常值。本文通过对三种面波压制方法进行效果对比,得出了F_X域相干噪音压制法压制面波后,较之其它两种面波压制方法,资料的频带展的更宽,能量较强,信噪比更高,是针对滩浅海地区资料理想的面波压制方法的结论。③滩浅海地震资料的50Hz工业干扰压制技术。根据50Hz工业干扰在实际地震资料处理过程中分布较广但在炮域内分布无规律的特点,本文提出了一种有效压制50HZ工业干扰的方法——检波点域分离法。该方法将原始数据抽道集到检波点域,然后根据资料深层有效波能量微弱,几乎全部是50Hz工业干扰的特点,用深层资料估计出50Hz工业干扰后,将其从原始资料中减去,达到提高信噪比的目的。实际资料的处理结果证明了检波点域压制50Hz工业干扰技术效率更高,效果更好,大大提高了资料的信噪比;并且可以根据地震资料的实际情况,在控制窗口内对50Hz工业干扰进行压制,最大限度地保护有效信号。运用本论文所述的噪音压制技术,对滩浅海地震资料进行处理,大大提高了地震资料的信噪比,为后续的高精度偏移成像和解释工作奠定了基础。更多还原

【Abstract】 The surface structure of beach shallow sea area is complex, so the noise in the seismic data which collected at this area is very diverse and distributes widely. Due to the big differences in sources and detectors, the dynamic attributions of the seismic data collected in the same exploratory area are different. At first, We analyzed the differences in energy, frequency, phase and the wavelet of the seismic data of this area,guiding the follow-up matching works. Also, for building a foundation for noise suppression, we had analyzed the generation, propagation, and the characteristic of the noise of the seismic data collected at beach shallow sea area :①the characteristics of multiple: the velocity of multiple is lower than effective signal’s at the same time in the seismic data. Internal multiples appear periodically.②the characteristics of surface wave: the frequency and apparent velocity of surface wave is low; surface wave is a type of coherent noise; the energy of surface wave is very strong, but it will attenuate along with the passage of time and the increase of offset.③the characteristics of 50Hz industrial interference: its value of frequency is 50 Hz, not changed; its energy is strong; it distributes widely and irregularly, It exists in the stable receiver which nearby the high-tension wire.Aim at the characteristics of interference wave of seismic data in beach and shallow sea, we has provided a series of specific methods and techniques which could overcome the impact of these disturbances and instruct the following matching works.①Multiple suppression technique of seismic data in beach shallow sea area: Conventional multiple suppressing method of seismic data is mainly the parabolic Radon transform. Affected by many factors, this kind of conventional method of suppressing is not ideal, and will destroy the relative relations of amplitude. Through the processing of a model gather and actual data, proved that the "two-step" linear Radon Transform in this paper can suppress multiples effectively, but has the minor damage to the significant wave. According to the conventional processing technique can not retain AVO phenomenon when it removes multiples, the Deletion Fitting method was developed by LiQingzhong. The processing of a model gather and actual data confirms this method can remove multiples and random noise efficiently but retain AVO phenomenon. We can choose the suitable multiple suppression method according to the need in beach shallow sea area seismic data processing.②Surface wave suppression technique of seismic data in beach shallow sea area: The staple surface wave attenuation methods is F_K domain filtering and F_X Coherent Noise Suppression based on apparent velocity and frequency, the ZAP method based on amplitude difference between signal and noise. For separating the signal and the surface wave, the first two methods transform the seismic data to F_K domain or F_X domain. The principle of ZAP is decompose the amplitude of seismic data to four different domains, finding out the abnormal value of the amplitude and remove it in each four domains. Through the contrast effect on the three methods for suppressing surface wave, concluded that after suppressing surface wave using Fxcns, compared with two other methods of surface wave suppression, the seismic data show a wider frequency band, a stronger energy and the higher signal-noise ratio, this method is an ideal surface wave suppression method in the area.③50Hz industrial disturbance suppression technique of seismic data in beach shallow sea area:In accordance with the characteristic of the broad distribution in actual seismic data processing and hard to elimination of the 50Hz industrial disturbance, a method for suppressing effectively 50Hz industry disturbance-separation in geophone domain is developed. This method is based on the characteristic that the energy of signal is weak but the energy of 50Hz industrial disturbance is very strong in deep seismic data. For increasing the signal-noise ratio for further data processing, we predict the 50Hz industrial disturbance using deep seismic data, remove it from seismic data. The processing results of actual data have proved that the technology of suppressing the 50Hz industrial interference in geophone domain is more efficient and better, and improved the signal-to-noise ratio of seismic data greatly; according to the actual seismic data, this technology can suppress the 50Hz industrial disturbance in the control window for maximize to protect the effective signal.We have processed the beach shallow sea area seismic data applying the noise suppression techniques introduced in this paper, it improved the signal-to-noise ratio of seismic data greatly. This working builds a foundation for follow-up high precision migration and interpretation更多还原