转换波静校正方法研究与应用

发布时间：2018-12-25 15:51

【摘要】：转换波处理与常规纵波处理有很大的不同,其中转换横波的静校正问题作为影响转换波成像结果质量好坏的关键步骤之一,被认为是公认的难题。转换波的传播路径是不对称的,上行的反射波为横波,由于横波速度在近地表处比纵波低很多,且横向变化剧烈,使得同一检波点处的横波静校量较纵波静校正量大得多,导致常规纵波静校正方法难以直接推广应用于转换波静校正问题。为此,本文开展了转换波静校正方法的应用研究。本文从转换波静校正的基本概念入手,介绍了现有的各种转换波静校正方法的国内外研究现状,着重研究了基于反射波的转换波静校正方法和基于折射波的转换波静校正方法。共检波点叠加道相关法和纵波构造时间控制法都是基于反射波的转换波静校正方法,是生产上最常用的方法。纵波构造时间约束法主要求取检波点长波长静校正量,而优化的共检波点叠加道相关法求取的是检波点的短波长静校正量;改进的转换波延迟时法是基于折射波的转换波静校正方法,该方法在共检波点叠加剖面上拾取互相关时差,可较好地解决转换波的长波长和短波长静校正问题。由单一的转换波静校正方法难以完全消除转换波静校正问题,需要根据工区实际情况,对方法进行组合,逐步消除转换波静校正量。通过对苏里格2D3C地震数据的处理,证实了转换波延迟时法与共检波点叠加道相关法相结合求解转换波检波点静校正量在厚风化层地区能取得了较好的应用效果。针对国外M工区3D3C地震数据近地表由厚度不规则变化的冰川沉积物构成导致风化层静校正问题非常严重的问题,本文利用三维折射波静校正方法与基于互相关的剩余静校正方法相结合求取纵波静校正量作为P-SV转换波数据的炮点静校正量;对于检波点静校正量,本文利用纵波构造约束法求取检波点的长波长静校正量,采用共检波点叠加道相关法求取检波点短波长静校正量。通过对对国外M工区实际资料的应用结果表明,组合静校正方法能较好的解决检波点静校正问题,具有实际应用价值。
[Abstract]:The conversion wave processing is very different from the conventional P-wave processing. The statics of the converted shear wave is regarded as one of the key steps to affect the quality of the converted wave imaging results, and it is considered to be a recognized problem. The propagating path of the converted wave is asymmetric, and the upstream reflected wave is a shear wave. Because the velocity of the shear wave is much lower than that of the longitudinal wave near the surface, and the lateral variation is severe, the static correction of the shear wave at the same detection point is much larger than that of the longitudinal wave static correction. It is difficult to apply the conventional P-wave statics method directly to the conversion wave statics problem. Therefore, the application of the conversion wave statics method is studied in this paper. Starting with the basic concept of converted wave statics, this paper introduces the present research status of various converted wave statics methods at home and abroad, and emphatically studies the converted wave statics methods based on reflection waves and refraction wave statics methods. The common detection point stacking channel correlation method and the P-wave construction time control method are the most commonly used methods in the production of converted wave statics based on reflected waves. The time constraint method of P-wave construction is mainly used to calculate the long-wavelength statics of the detection points, while the optimized co-detection point stack correlation method is used to calculate the short-wavelength statics of the detection points. The improved converted wave delay time method is based on refraction wave conversion wave statics. This method can pick up the cross-correlation time difference on the stacking section of common detection point, which can solve the problem of long wavelength and short wavelength statics of converted wave. It is difficult to completely eliminate the problem of converted wave statics by a single converted wave statics method. It is necessary to combine the method according to the actual situation of the working area and gradually eliminate the converted wave statics. Through the processing of Sulige 2D3C seismic data, it is proved that the converted-wave delay time method and the co-detection point stacking correlation method can be used to solve the static correction of the converted wave detection points in the thick weathered zone. In view of the serious problem of static correction of weathered beds caused by glacial sediments with irregular thickness near the surface of 3D3C seismic data in M working area abroad, In this paper, three dimensional refraction static correction method and residual static correction method based on cross-correlation are combined to calculate the P-wave statics as the shot statics of P-SV converted wave data. For the static correction of the detection point, the long wavelength static correction of the detection point is obtained by using the P-wave structure constraint method, and the short wavelength statics value of the detection point is obtained by the common detection point stack correlation method. Through the application of the practical data in M area abroad, it is shown that the combined static correction method can solve the problem of detection point statics well and has practical application value.
【学位授予单位】：中国石油大学(华东)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P631.4

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