气力提升法海洋渗漏型天然气水合物开采技术研究

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	气力提升法海洋渗漏型天然气水合物开采技术研究
其他题名	Studies of the production process of offshore seepage gas hydrate by airlifting
	沈志远
导师	冯自平
	2007-06-06
学位授予单位	中国科学院广州能源研究所
学位授予地点	广州能源研究所
学位名称	硕士
关键词	天然气水合物渗漏系统气力提升多相流数值模拟
摘要	自从认识到在永久冻土带和海底存在大量的水合物资源后，发展水合物藏商业开采方法以及对开采过程的可行性与经济性评价就成为一个热点课题。目前已经提出的开采思路大多是结合传统的油气开采技术，包括：热力开采、降压开采、注化学剂开采等。这些开采方法都存在能耗大、开采效率低、对环境影响大等难以避免的缺点。探索新的开采方法对利用水合物中的天然气资源有着重要的意义。本文针对海洋渗漏型天然气水合物含量高、成藏浅、产出集中的特点，结合深海锰结核开采的研究现状，提出了气力提升开采水合物新技术。运用多相流体动力学数值模拟方法，同时考虑了提升过程中固态水合物的分解效应，建立了气力提升管内多相流动的漂移流动模型。数值模拟程序采用了基于有限体积法和交错网格技术的SIMPLER算法求解。通过数值模拟结果，获得了提升管内多相流动特性，分析了由于固态水合物分解产生的“自提升效应”对提升过程的影响。同时对提升系统主要工艺参数对提升动态特性的影响规律也进行了分析。在此基础上，利用模型对一实际规模的水合物藏进行了模拟，得到了在一定的开采能力要求下，具有最高能量效率的注气参数，对气力提升技术的能量效率进行了评估。在提升海底3000m处的水合物时，即使水合物含量低至30%，其最高能量效率可高达30。最后对比了气力提升开采方法与常规的注热开采、降压开采和注化学剂开采的能量效率与经济性，结果表明，该气力提升水合物开采技术具有产量大、能量效率高的突出优点。
其他摘要	As a potential strategic energy resource, natural gas hydrate (NGH), which maybe the substitution of petroleum and natural gas in the future, is getting more and more attention. Methods being proposed for NGH recovery including thermal treatment, depressurization and inhibitor addition. But these methods cannot be economically or effective to NGH from the deep ocean floor. Therefore, the new technology is expected. Due to the features of high concentration and shallow buried depth, the seepage gas hydrate is considered as a kind of rich reservoir with high potential productivity. In this paper, a new production method of seepage gas hydrate has been provided，that is, the air-lifting technology, referring to the production of manganese nodes from deep sea . The purposes of this work are to develop a method of numerical simulation for gas-liquid-solid three-phase flow systems and to confirm a method of estimating performance of air-lifting for seepage gas hydrate. Finite difference equations for the numerical analysis were derived by integration of the partial differential equations based on the drift flux model for steady three-phase flow takes account of the dissociation of gas hydrate. The method of the numerical procedure is based on the SIMPLER algorithm. Flow characteristics of air-lift were presented. Effects of several factors, such as physical properties and delivered concentration of solid particals; inner diameter, length of each section of conveying pipe; volumetric flux of supplied air on flow characteristics were discussed. And the optimum operating conditions has been found. The results shows that this technology has very high productivity with only a little energy consumption. For hydrate under 3000m depth，the energy ratio can approach to 30 even with only 30％concentration of hydrate. This ratio is much higher than that of the traditional thermal stimulation method．
页数	75
语种	中文
文献类型	学位论文
条目标识符	http://ir.giec.ac.cn/handle/344007/4003
专题	中国科学院广州能源研究所
推荐引用方式 GB/T 7714	沈志远. 气力提升法海洋渗漏型天然气水合物开采技术研究[D]. 广州能源研究所. 中国科学院广州能源研究所,2007.

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