Measurement of Thermal Conductivity and Saturation of Gas Hydrates in Sediment by Thermal Pulse Probe-Time Domain Reflection Technique
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摘要: 我国在海洋和冻土区都已发现天然气水合物资源区并成功获取实物样品。含水合物沉积物的热导率是估算水合物资源量、设计合理开采方案的关键性数据之一。受水合物稳定条件和测量技术的限制,水合物热导率测定尚不完善。本文通过自主研制的天然气水合物热物理参数测量系统,开展了海洋沉积物中天然气水合物热导率与饱和度测量研究。实验使用取自南海神狐海域的沉积物作为反应介质,在压力7.8 MPa、温度2℃的条件下合成甲烷水合物,并利用热脉冲探针与时域反射技术联合测量的方式获得沉积物中水合物形成过程的热导率和饱和度等实验数据。结果表明,当水合物饱和度从0增加至49%时,体系热导率出现了先升高后降低的变化趋势。分析发现体系热导率随水合物饱和度的变化特征与水合物在沉积物中的填充方式有关,在实验选用的南海沉积物中,水合物优先选择在颗粒孔隙间成核生长,并最终与沉积物颗粒胶结共存。Abstract: So far, gas hydrates not only have been explored in marine and frozen areas of China, but also have been sampled successfully. The thermal conductivity of sediments with gas hydrates is a key parameter for estimating the resource and designing a proper exploitation plan. Restricted to the stable conditions for hydrates and their measurement technique, much more work need to be done on the thermal conductivity investigation of hydrates. In this paper, a description of the measurement technique of the thermal conductivity and saturation of gas hydrates formed in marine sediment is given. Marine sediment collected from the Shenhu area of the South China Sea was taken as the porous media. The methane hydrates in them were synthesized under the conditions of 7.8 MPa pressure and 2℃ temperature. The thermal conductivity and saturation were measured by thermal pulse probe technique coupled with time domain reflection method. Based on the results, when the hydrate saturation changed from 0 to 49%, the thermal conductivity appeared to be initially increase and then decrease. It was deduced that the relationship between thermal conductivity and saturation was controlled by the hydrate filling pattern. In this experiment, gas hydrates priority selection in particle void nucleation and growth, and gradually cement with sediments.
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Key words:
- hydrates /
- thermal pulse probe /
- time domain reflection technology /
- thermal conductivity /
- saturation
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[1] 许红,黄君权,夏斌,蔡乾忠.最新国际天然气水合物研究现状与资源潜力评估(上)[J].天然气工业,2005, 25(5): 21-25. http://www.cnki.com.cn/Article/CJFDTOTAL-TRQG200505006.htm
[2] 许红,黄君权,夏斌,蔡乾忠.最新国际天然气水合物研究现状及资源潜力评估(下)[J].天然气工业,2005, 25(6): 18-23. http://www.cnki.com.cn/Article/CJFDTOTAL-TRQG200506005.htm
[3] Sloan E D, Bloys J B, Hydrate Engineering[M]. USA: Society of Petroleum Engineers, 2000: 148-152.
[4] Winters W J, Pecher I A, Waite W F, Mason D H. Physical properties and rock physics models of sediment containing natural and laboratory-formed methane gas hydrate[J]. American Mineralogist, 2004, 89(8-9): 1221-1231. doi: 10.2138/am-2004-8-909
[5] Winters W J, Waite W F, Mason D H, Gilbert L Y, Pecher I A. Methane gas hydrate effect on sediment acoustic and strength properties[J]. Journal of Petroleum Science and Engineering,2007, 56(1-3): 127-135. doi: 10.1016/j.petrol.2006.02.003
[6] 金春爽,汪集旸.天然气水合物的地热研究进展[J].地球科学进展,2001, 16(4): 540-543. http://www.cnki.com.cn/Article/CJFDTOTAL-DXJZ200104015.htm
[7] Stoll R D, Bryan G M. Physical properties of sediments containing gas hydrates[J]. Journal of Geophysical Research, 1979, 84(B4): 1629-1634. doi: 10.1029/JB084iB04p01629
[8] Waite W F. Thermal conductivity measurements in porous mixtures of methane hydrate and quartz sand[J]. Geophysical Research Letters, 2002, 29(24): 2229-2235.
[9] Rosenbaum E J, Niall J, Johnson J K, Shaw D W, Warzinski R P. Thermal conductivity of methane hydrate from experiment and molecular simulation[J]. The Journal of Physical Chemistry B,2007, 111(46): 13194-13205. doi: 10.1021/jp074419o
[10] 刁少波,业渝光,岳英杰,张剑,陈强,胡高伟.多孔介质中水合物的热物理参数测量[J].岩矿测试,2008, 27(3): 165-168. http://www.cnki.com.cn/Article/CJFDTOTAL-YKCS200803006.htm
[11] 任图生,邵明安,巨兆强, Horton R.利用热脉冲-时域反射技术测定土壤水热动态和物理参数Ⅰ.原理[J].土壤学报,2004, 41(2): 225-229. doi: 10.11766/trxb200305160210
[12] 任图生,邵明安,巨兆强, Horton R.利用热脉冲-时域反射技术测定土壤水热动态和物理参数Ⅱ.应用[J]. 土壤学报,2004, 41(4): 523-529. doi: 10.11766/trxb200305160405
[13] Campbell G, Calissendorff C, Williams J. Probe for measuring soil specific heat using a heat-pulse method[J]. Soil Science Society of America Journal,1991, 55(1): 291-293. doi: 10.2136/sssaj1991.03615995005500010052x
[14] Tarara J M, Ham J M. Measuring soil water content in the laboratory and field with dual-probe heat-capacity sensors[J]. Agronomy Journal,1997, 89(4): 535-542. doi: 10.2134/agronj1997.00021962008900040001x
[15] Wright J, Nixon F, Dallimore S, Matsubayashi O.A method for direct measurement of gas hydrate amounts based on the bulk dielectric properties of laboratory test media [C]//The Fourth International Conference on Gas Hydrate, ICGH-Ⅳ. Japan: Yokohama, 2002: 745-749.
[16] 胡高伟,业渝光,刁少波,张剑,刘昌岭.时域反射技术测量海洋沉积物含水量的研究[J].现代地质,2010, 24(3): 622-626. http://www.cnki.com.cn/Article/CJFDTOTAL-XDDZ201003030.htm
[17] 陈强,业渝光,刘昌岭.多孔介质体系中甲烷水合物生成动力学的模拟实验[J].海洋地质与第四纪地质, 2007,27(1): 111-116. http://www.cnki.com.cn/Article/CJFDTOTAL-HYDZ200701019.htm
[18] Dalmazzone D, Hamed N, Dalmazzone C. DSC measurements and modelling of the kinetics of methane hydrate formation in water-in-oil emulsion[J]. Chemical Engineering Science, 2009, 64(9): 2020-2026. doi: 10.1016/j.ces.2009.01.028
[19] 胡高伟.南海沉积物的水合物声学特性模拟实验研究[D].武汉:中国地质大学, 2010.