物理化学学报 >> 2011, Vol. 27 >> Issue (12): 2773-2778.doi: 10.3866/PKU.WHXB20112773

热力学，动力学和结构化学 上一篇    下一篇

氯盐溶液中甲烷水合物高压分解条件及影响因素

孙始财1,2,3, 刘昌岭2,3, 业渝光2,3, 姜倩1   

  1. 1. 山东科技大学土木建筑学院, 山东省土木工程防灾减灾重点实验室, 山东青岛 266510;
    2. 国土资源部海洋油气资源与环境地质重点实验室, 山东青岛 266071;
    3. 青岛海洋地质研究所, 山东青岛 266071
  • 收稿日期:2011-07-28 修回日期:2011-09-21 发布日期:2011-11-25
  • 通讯作者: 孙始财 E-mail:qdsunsc@163.com
  • 基金资助:

    国土资源部公益性行业科研专项经费(201111026-3), 国家重点基础研究发展规划(973) (2009CB219503)和山东省自然科学基金(ZR2009FQ017)资助项目

Dissociation Conditions and Influencing Factors of Methane Hydrate in Chloride Salt Solution under High Pressure

SUN Shi-Cai1,2,3, LIU Chang-Ling2,3, YE Yu-Guang2,3, JIANG Qian1   

  1. 1. Shandong Provincial Key Laboratory of Civil Engineering Disaster Prevention and Mitigation, College of Civil Engineering andArchitecture, Shandong University of Science and Technology, Qingdao 266510, Shandong Province, P. R. China;
    2. The KeyLaboratory of Marine Hydrocarbon Resources and Environmental Geology, Ministry of Land and Resources, Qingdao 266071,Shandong Province, P. R. China;
    3. Qingdao Institute of Marine Geology, Qingdao 266071, Shandong Province, P. R. China
  • Received:2011-07-28 Revised:2011-09-21 Published:2011-11-25
  • Contact: SUN Shi-Cai E-mail:qdsunsc@163.com
  • Supported by:

    The project was supported by the Ministry of Land and Resources Research of China in the Public Interest (201111026-3), National Key Basic Research Program of China (973) (2009CB219503), and Natural Science Foundation of Shandong Province, China (ZR2009FQ017).

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摘要： 向水合物储层注入盐类溶液是水合物常规开采技术之一, 所以必须掌握储层压力条件下盐类溶液中水合物分解条件及其影响因素. 本文研究了NaCl、MgCl2、CaCl2氯盐溶液中甲烷水合物分解条件, 结果表明NaCl(2.0、1.0、0.5 mol·L-1)、MgCl2 (1.0、0.5 mol·L-1)和CaCl2 (1.0、0.5 mol·L-1)溶液中甲烷水合物的分解温度比纯水中分别降低了(4.8、2.4、1.0 K (NaCl))、(5.3、1.5 K (MgCl2))和(4.3、1.8 K (CaCl2)). 以van der Waals 和Platteeuw 热力学模型为基础, 结合电解质溶液中水的活度方程(Pitzer-Mayorga 方程)，给出了氯盐溶液中水合物分解条件热力学模型, 进而比较了模型计算值与实验值, 结果显示两者非常吻合. 分析表明, 氯盐溶液中离子静电作用产生的水分子溶剂化效应和盐析效应降低了水的活度而导致水合物分解温度降低.

关键词: 甲烷水合物, 氯盐溶液, 分解条件, 盐析效应, 水的活度

Abstract: A method that can be used for gas hydrate exploitation is the injection of a brine solution into hydrate reservoir, therefore, the hydrate dissociation conditions and the influencing factors in brine solution should be investigated under reservoir pressure. In this paper, methane hydrate dissociation conditions in NaCl, MgCl2, and CaCl2 solutions were investigated. The results show that the dissociation temperature depressions are (4.8, 2.4, 1.0 K (NaCl)), (5.3, 1.5 K (MgCl2)), (4.3, 1.8 K (CaCl2)) in NaCl (2.0, 1.0, 0.5 mol· L-1), MgCl2 (1.0, 0.5 mol·L-1), and CaCl2 (1.0, 0.5 mol·L-1) solutions, respectively, relative to those in pure water. The experimental values were in good agreement with the calculated values based on the van der Waals and Platteeuw thermodynamic model and the Pitzer-Mayorga equation for the water activity of electrolyte solution. In chloride salt solution the water molecule solvent effect and the salting-out effect that is caused by an electrostatic field decreases the water activity resulting in a depression of the hydrate dissociation temperature.

Key words: Methane hydrate, Chloride salt solution, Dissociation condition, Salting-out effect, Water activity