海底天然气水合物的CSEM响应研究

发布时间：2018-01-02 21:42

本文关键词：海底天然气水合物的CSEM响应研究　出处：《中国海洋大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着经济全球化，人类社会对石油、煤炭等传统能源的消耗越来越大，能源短缺的情况日益严重，寻求一种储量巨大的新型替代能源成为世界各国面临的重大课题。近年来，世界各国相继投入大量的人力、物力来开展新型替代能源的研究。人们发现在海底中蕴藏有丰富的天然气水合物，可作为一种未来的新型、绿色能源。因此，加快海底天然气水合物的勘探、开发和利用对缓解人类社会未来所面临的能源枯竭危机具有十分重大的意义。海上地震勘探是目前最常用的海底天然气水合物探测方法，可以根据地震剖面上的BSR（似海底反射层）来判断海底天然气水合物的存在。但是，BRS并不能完全指示天然气水合物的存在。研究发现，并不是所有存在BSR的地方都含有天然气水合物，存在天然气水合物的地方也不一定含有BSR。而且，地震方法对水合物的饱和度并不敏感。与围岩相比，海底天然气水合物储层是高阻体，其电导率比海底沉积物或海水小的多，海洋CSEM可以根据水合物储层与围岩的电性差异，来比较准确的确定天然气水合物的存在，提高钻井的成功率。海洋CSEM作为一种近年来兴起的新型地球物理勘探方法，将会迅速成为调查海底天然气水合物的重要手段之一。首先，本文针对海底天然气水合物展开了相关的CSEM响应研究，介绍了海洋CSEM的基本原理，根据实际地质资料设计了一维模型，进行了基于振幅比计算的CSEM响应分析，研究了海底天然气水合物的有效异常，完成了基于有效异常的电磁响应分析，分析了水合物储层厚度变化和储层电阻率变化的CSEM响应，证明了拖曳式的发射接收系统在水合物勘探中的有效性。根据实际地质资料设计了不同的一维地电模型，，研究海洋CSEM在不同区域探测海底天然气水合物的适用性。根据现有的实际地质资料设计二维地电模型，讨论了频率变化对CSEM响应结果的影响，以及海底地形起伏对响应结果的影响，研究了相邻两天然气水合物储层模型的CSEM响应特征。对海洋CSEM的横向分辨能力进行了研究，分别讨论了海洋CSEM对单一水合物储层和相邻两天然气水合物储集体相邻一侧边界的横向分辨能力。研究表明海洋CSEM的电场垂直分量有效异常比水平分量大，且其对储层电阻率和厚度变化都很灵敏，海洋CSEM法对海底天然气水合物具有较好的横向分辨能力，综合天然气水合物一维、二维正演模拟的结果，论证了海洋CSEM探测海底天然气水合物的可行性，研究成果可为今后实际的海底天然气水合物勘探提供技术支持。
[Abstract]:With the globalization of economy , the consumption of traditional energy sources , such as petroleum and coal , is becoming more and more serious , and the shortage of energy is becoming more and more serious . In recent years , many countries have invested a large amount of human and material resources to carry out the research of new alternative energy sources . The marine seismic exploration is one of the most commonly used submarine natural gas hydrate detection methods . It can be used to judge the existence of the gas hydrate in the seabed according to the BSR in the seismic section . However , it is not necessary to indicate the existence of the natural gas hydrate completely . The marine CSEM can accurately determine the existence of gas hydrate and improve the success rate of the drilling . Compared with the surrounding rock , the marine CSEM can be used as a new geophysical exploration method in recent years , which will rapidly become one of the important means to investigate the gas hydrate . In this paper , the basic principle of marine CSEM is introduced . Based on the actual geological data , a one - dimensional model is designed . The effect of frequency change on the response of marine gas hydrate is studied . Based on the actual geological data , two - dimensional geoelectric model is designed to study the CSEM response characteristics of marine CSEM . The transverse resolving power of marine CSEM is studied , and the lateral resolution capacity of marine CSEM on the boundary of single hydrate reservoir and adjacent two gas hydrate reservoirs is discussed . The research shows that the effective anomaly of electric field vertical component of ocean CSEM is larger than that of horizontal component , and it is sensitive to reservoir resistivity and thickness variation . The marine CSEM method has better lateral resolution capability and comprehensive natural gas hydrate one - dimensional and two - dimensional forward modeling results . The feasibility of detecting submarine natural gas hydrate by ocean CSEM is demonstrated , and the research results can provide technical support for future exploration of seabed natural gas hydrate .

【学位授予单位】：中国海洋大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P618.13;P744.4

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