A GEOLOGICAL MODEL FOR SHALLOW GAS HYDRATES ACCUMULATION ASSOCIATED WITH MUD VOLCANO
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摘要:
深海环境泥火山活动为甲烷从深部向浅部迁移提供了搬运介质和通道,泥火山附近天然气水合物成藏具有独特的形成过程和富集规律。泥火山型水合物资源潜力和环境影响的理论假设已被提出,而在工程实施阶段的论述相对较少。本次研究通过调研世界范围内典型海域泥火山-天然气水合物系统研究进展和赋存规律,结合我国海域泥火山的调查成果,归纳出泥火山型天然气水合物赋存地质模型。之后分析该模型组成要素的地质记录,获得识别泥火山型天然气水合物的3G异常标志,总结出该类型水合物实用的勘探思路。
Abstract:The mud volcanism in deep-water setting may provide transporting media and migration pathway for methane movement from the deep to the shallow, that may provide unique opportunities for gas hydrate to form and accumulate near the mud volcanoes. Some theoretical hypotheses concerning the resource potential and the climatic impact of such gas hydrates have been reported, but less discussion is available concerning its engineering aspects. This study made a review on the research progress and the accumulating mechanism of some typical marine mud volcano-gas hydrate systems around the world. Combined with the survey results in China's sea territory, we worked out in this paper a geological model for the gas hydrate accumulations associated with mud volcanoes. The geological records of the elements of the model are worked out, and the signatures of 3G anomalies, which indicate the gas hydrates associated with the mud volcano, are acquired. Upon the basis, some suggestions are summed up for practical exploration of this type of gas hydrates in the sea.
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Key words:
- mud volcano /
- gas hydrate /
- 3G anomalies /
- accumulation geological model
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图 1 Håkon Mosby泥火山-水合物系统模式图,水热过程和交代过程分别在泥火山中央部分(a)和周围(b)较为显著(据文献[10]修改)
Figure 1.
图 2 日本海典型地震剖面及随钻测井数据(据文献[21]修改)
Figure 2.
图 3 哥斯达黎加海域Mound 11泥火山流体运移模式(据文献[22]修改)
Figure 3.
图 4 鄂霍茨克海LV39-25H采样观察到的水合物(据文献[25]修改)
Figure 4.
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