【作者】 童思友；

【导师】 李庆忠；

【作者基本信息】 中国海洋大学 ， 海洋地球物理学， 2010， 博士

【摘要】 我国有近300×104 km2的蓝色国土,其中蕴藏着丰富的油气资源。然而,我国对海洋中油气资源的勘探、开发起步较晚,各个海域的油气资源的勘探程度较低,对油气资源的探明程度就更低。各海域中南黄海盆地尤为特殊,是我国目前惟一未发现油气田(藏)的海域。据学者们研究,南黄海盆地处于扬子地块之上,志留系上统和泥盆系下统缺失,中生代和古生代海相碳酸盐岩地层发育较完整,地层发育相对厚、分布区域广,具有较好的含油气勘探前景。然而,由于南黄海盆地勘探程度低,受种种因素的制约,对该海域的地质认识还不够清晰。由于该海域的特殊自然环境和地质现象导致野外采集资料有其特殊性,各种噪音发育、深部反射能量弱、特别严重的是该海域地震资料的各种多次波种类繁多、能量强且多次波的波场特征十分复杂,给后续高质量的室内资料处理带来诸多困难,开展进一步的解释研究工作就更加不易。为此,改善该海域地震资料的品质迫在眉睫,不但要保证野外施工质量,更要在处理中下功夫,尽可能的获得高质量的处理剖面。在该海域地震资料处理中在做好噪音压制的同时,最重要的是要摸清该海域地震资料复杂多次波形成机理、并研究合理有效的多次波压制技术,有的放矢,去伪存真,得好真实可靠的地震剖面,为后续解释研究工作的顺利开展打下坚实的基础。近几年,配合南黄海海域野外采集技术攻关研究,开展了大量的室内处理技术研究以改善地震资料的处理品质,开展了随机噪音压制技术研究、相干噪音压制技术研究和多次波压制技术研究,特别是就严重制约该海域地震资料处理质量的复杂多次波压制技术开展了大量研究工作。该论文重点研究南黄海海域复杂多次波的形成机理及相应的多次波压制技术。本学位论文依托于国家专项之《南黄海综合地球物理补充调查》和国家“863”计划(2006AA09Z339)研究完成的。该论文研究取得了如下几项创新性成果：1.基本摸清了南黄海海域地震资料复杂多次波的形成机理利用搜集的测井资料和他人的研究成果,建立地质模型,采用声波方程和弹性波波动方程正演模拟,作者对比分析了模拟记录的波场特征,特别是多次波的特征,结合实际资料开展综合分析研究,基本摸清了该海域地震资料虚反射、鸣震、强反射界面反射多次波、折射多次波及层间多次波等各种复杂多次波的形成机理,为研究该海域合理的多次波压制技术提供支撑。2.首次采用曲波变换技术有效压制南黄海海域地震资料折射多次波和转换多次波该海域存在T2等多套强反射层的特殊地质现象,入射角极易达到临界角,产生强折射波,进而形成折射多次波,加之采集排列大,入射角范围广,及地下介质的复杂多样,产生复杂的转换波及转换多次波,研究利用E.J.Candes等提出的曲波变换技术有效压制南黄海海域地震资料的折射多次波和转换多次波。3.在南黄海海域地震资料强多次波压制处理中首次采用高精度τ-R变换技术取得显著效果该海域地震资料多次波种类繁多,如虚反射、鸣震、海底及强反射界面全程多次波和层间多次波、转换多次波以及折射多次波发育,波场特征复杂,通过正演模拟分析和实际资料研究,对这些多次波的形成机理有了清晰认识,进而开展有效的多次波压制技术研究。针对该海域强反射界面多次波和层间多次波十分发育的特殊性,综合分析当今国内外各种多次波压制技术优缺点,及这些技术对压制该海域多次波的局限性,首次采用李庆忠院士提出的高精度τ-R变换技术压制多次波,通过对理论模拟记录和实际资料的处理,对强反射界面多次波和层间多次波的压制取得较好的效果,特别对层间多次波的压制有其独到之处。4.形成一套合理压制南黄海海域地震资料复杂多次波的技术方案针对该海域地震资料多次波种类繁多,波场特征复杂的特殊性。综合研究,形成一套合理压制南黄海海域地震资料复杂多次波的技术方案：在合理压制各种噪音的基础上,首先采用自由表面多次波压制技术(SRME)衰减自由表面多次波、接着采用曲波变换技术压制折射多次波和转换多次波、然后结合组合反褶积进一步压制鸣震、继而用高精度τ-R变换技术压制强反射界面全程及层间多次波,在各种多次波得到基本压制后,速度分析精度提高,再在动校正之后采用剔除拟合叠加技术代替常规的叠加技术,将残余多次波进一步压制,获得高质量的处理剖面。以上多项处理技术的研究完善及有机融合,形成一套合理压制南黄海海域地震资料复杂多次波的技术体系和方案,能够很好的压制该海域的复杂多次波。在合理压制掉多次波后,为获得高品质的地震剖面提供保障,为后续研究认识南黄海海域地质特征打下坚实基础。更多还原

【Abstract】 China has nearly 300x104km2 blue lands, which is rich in oil and gas resources. However, the exploration and development of China’s oil and gas resources in the ocean started late. The exploration degree of oil and gas resources in all waters is lower and the proven degree of oil and gas resources is much lower. The South Yellow Sea Basin is particularly special, which is the only sea area without oil and gas (reservoir) in China at present. According to scholars’study, the South Yellow Sea Basin is above the Yangtze block, where the upper Silurian and lower Devonian is missing, and Mesozoic and Paleozoic marine carbonate rocks develop completely. The stratigraphic development is relatively thick, and the distribution of area is wide, which has good oil and gas exploration prospects. However, due to the low level of exploration of the South Yellow Sea Basin, affected by various factors, the geological knowledge of the waters is also not clear enough. The acquired seismic data has its own particularity because of the special natural environment and geological phenomena of the area. There is all kinds of noise and deep reflection energy is weak, which is especially serious is that there are various multiple-waves that have high energy and complex wave field characteristics on seismic data of the area. It brings many difficulties to the high-quality indoor data processing and to carry out further interpretation research work is even more difficult. So it is imminent to improve the quality of seismic data of the area, which is not only to ensure the wild construction quality, but also to improve the process method to acquire high-quality processing profile. When suppressing noise in seismic data processing of the area, the most important problem is to find out that the mechanism of the complex multiple-waves on seismic data of the area, and to consider reasonable and effective multiple suppression techniques. Eliminate the false and retain the true to get well real and reliable seismic profiles and lay a solid foundation for the following interpretation work. In recent years, with the South Yellow Sea field acquisition technology research study, we carried out a large number of indoor processing technology research to improve the processing quality of seismic data and carried out technical studies to suppress random noise, coherent noise suppression technology research and multiple suppression technology research, especially doing a lot of research on complex multiple suppression technologies which severely constrained the seismic data processing quality of the waters. The paper focuses on the South Yellow Sea complex multiple wave formation mechanism and the corresponding multiple-wave suppression technology. This dissertation relies on the National project, "Integrated geophysical supplementary investigations in Southern Yellow Sea" and the National "863" program (2006AA09Z339) study.The thesis has made a number of innovative achievements as follows:1. Basically found out the formation mechanism of complex multiple wave on seismic data of South Yellow Sea.Establish a geological model by using of log data collected and other people’s research results. The author analyze comparatively wave field characteristics of analog records, especially the multiple wave characteristics by using acoustic wave equation and the elastic wave equation forward modeling. By developing an integrated analysis with practical seismic data, basically find out the formation mechanism of virtual reflection, reverberation, reflection multiple wave on strong reflection interface, refraction multiple, interbed multiple and other complex multiple wave on the seismic data of this area, which provides support for the study of the reasonable multiple-wave suppression technology of the area.2. Curvelet transform technology was used to effectively suppress the refraction multiple wave and converted multiple wave on seismic data of South Yellow Sea for the first time.The existence of special geological phenomenon of many sets of strong reflective layers such as T2 of the sea making the incident angle easily achieve the critical angle, resulted in strong refraction and formed refraction multiple-wave. At the same time, converted wave and converted multiple-wave of the sea developed because the collection array was large, the large range of the incident angle and the complexity of the underground media, effectively suppress the refracted multiple wave and converted multiple-wave by using Curvelet Transform Technology proposed by E.J.Candes on the South Yellow Sea seismic data.3. The high-precisionτ-R Transform technology was firstly used to effectively suppress strong multiple waves of the South Yellow Sea seismic data.There are various multiple-waves on the South Yellow Sea seismic data, such as the virtual reflection, reverberation, the whole multiple waves of submarine and strong reflective interface, interbed multiple waves, converted waves and refracted multiple waves. The wave field characteristics are complex. There is a clear understanding of the formation mechanism of these multiple waves through the forward modeling analysis and the studies of practical data, and thus to carry out research on effective multiple-wave suppression technology. Against the special nature of the development of strong reflection multiple and interbed multiple, by the comprehensive analysis of advantages and disadvantages of current multiple suppression technology at home and abroad and the limitations of these technologies on repression of multiple waves of the waters, we proposed to suppress multiple reflections by using high-precisionτ-R transformation technology proposed by Li Qingzhong Fellow. Through the processing of theoretical analog records and the actual data, there was a good result on the repression of multiple waves of strong reflecting interface and interbed multiple waves. It has its own unique especially for the repression of interbed multiple waves.4. Form a reasonable technical program to suppress the complex multiple wave of the South Yellow Sea seismic data.Against the particularity that there are various multiple waves the complex wave field characteristics on seismic data of the sea. Through comprehensive study, we formed a reasonable technical solution to suppress the complex multiple wave of the South Yellow Sea seismic data:on the basic of the reasonable suppression of a variety of noise, first use the free surface multiple suppression techniques (SRME) with deconvolution to attenuate the free surface multiple reflections, and then use curvelet transform technique to suppress refracted multiple wave and converted multiple waves, followed by using high-precisionτ-R transform technique to suppress whole and interbed multiple reflections on strong reflection interface. After a variety of multiples to be suppressed, the velocity analysis precision was improved, and then use deletion fitting stacking technique to replace conventional stacking technique after normal moveout correction to further suppress the residual multiple reflections and to acquire high-quality processing profile.The improvement of many kinds of processing technology above and the formation of a reasonable technology system and program to suppress the complex multiple wave of South Yellow Sea seismic data can effectively suppress the multiple reflections in the waters. After reasonably suppressing the multiple reflections, provide protection for obtaining high-quality seismic profiles and lay a solid foundation for the follow-up study of the geological features of the South Yellow Sea.更多还原