Formation Mechanism and Phase State of Hydrates in Fractured Layers of Permafrost
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摘要: 天然气水合物广泛充填于冻土地层裂隙中,钻探冻土地层裂隙中的天然气水合物需要先对其合成、分布和相态进行研究。基于祁连山地区裂隙性地层特征制作了人工岩心,进行了天然气水合物的形成及相平衡实验;利用A.H.Mohammadi提出的天然气水合物热力学模型,预测了NaCl和KCl溶液中天然气水合物的相平衡条件,并分析其在含盐低温钻井液条件下的相平衡偏移问题。实验得出,天然气水合物主要分布在岩心的裂隙面及端面;压力为4 MPa时,质量分数为5%和10%的NaCl溶液中天然气水合物的相平衡温度分别降低了约2.2 K和4.6 K,质量分数为10%的KCl溶液中天然气水合物的相平衡温度降低了3.4 K。研究结果表明:冻土地层裂隙中的天然气水合物由大量块状水合物和极少量孔隙充填型水合物组成,其相平衡条件与宏观水相中一致,在相同盐度下NaCl对天然气水合物相平衡的影响大于KCl。Abstract: Natural gas hydrate is widely distributed in the fractured layers of permafrost. In order to explore gas hydrate in the fractured layers of permafrost, it is necessary to study its formation, distribution and phase state. In this paper, the formation and phase equilibrium experiments of gas hydrate were conducted on the artificial cores which were prepared in reference to the characteristics of fractured layers in the area of Qilian Mountains. The phase equilibrium of hydrate in NaCl and KCl solutions were predicted according to the gas hydrate thermodynamic model created by A.H.Mohammadi, and the phrase equilibrium migration of hydrate in drilling fluids under the conditio of low temperature and salt bearing was discussed. It is shown by experimental results that gas hydrate is mainly distributed at the fracture surface and end surface of samples. When the pressure is 4 MPa, the phase equilibrium temperature of hydrate in NaCl solutions that have mass fraction of 5% and 1% declined about by 2.2 K and 4.6 K, respectively, and that in KCl solution with mass fraction of 10% decreased by 3.4 K. Research results indicated that the gas hydrate in fractured layers of permafrost is mostly in the massive form and slightly filled in the pores, and its phase equilibrium condition is consistent with that in macroscopic water phase. And under the same salinity, the effect of NaCl on the phase equilibrium of gas hydrate is greater than that affected by KCl.
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Keywords:
- natural gas hydrate /
- fracture /
- permafrost /
- drilling fluid /
- phase equilibrium
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[1] SLOAN E D.Fundamental principles and applications of natural gas hydrates[J].Nature,2003,426:353-359.
[2] MOHAMMADI A H,AFZAL W,RICHON D.Gas hydrates of methane,ethane,propane,and carbon dioxide in the presence of single NaCl,KCl,and CaCl2 aqueous solutions:experimental measurements and predictions of dissociation conditions[J].The Journal of Chemical Thermodynamics,2008,40(12):1693-1697.
[3] MAEKAWA T.Equilibrium conditions for clathrate hydrates formed from methane and aqueous propanol solutions[J].Fluid Phase Equilibria,2008,267(1):1-5.
[4] NAJIBI H,CHAPOY A,HAGHIGHI H,et al.Experimental determination and prediction of methane hydrate stability in alcohols and electrolyte solutions[J].Fluid Phase Equilibria,2009,275(2):127-131.
[5] 孙始财,业渝光,刘昌岭,等.石英砂中甲烷水合物稳定条件研究[J].化学学报,2011,69(9):1135-1140. SUN Shicai,YE Yuguang,LIU Changling,et al.Stable conditions for methane hydrate in quartz sand[J].Acta Chimica Sinica,2011,69(9):1135-1140. [6] 张金华,魏伟,魏兴华,等.我国主要冻土区天然气水合物形成条件及成藏模式探讨[J].中国石油勘探,2013,18(5):74-78. ZHANG Jinhua,WEI Wei,WEI Xinghua,et al.Discussion about natural gas hydrate formation conditions and accumulation pattern in China’s major permafrost regions[J].China Petroleum Exploration,2013,18(5):74-78. [7] 祝有海,张永勤,文怀军.祁连山冻土区天然气水合物科学钻探工程概况[J].地质通报,2011,30(12):1816-1822. ZHU Youhai,ZHANG Yongqin,WEN Huaijun.An overview of the scientific drilling project of gas hydrate in Qilian Mountain permafrost,Northwestern China[J].Geological Bulletin of China,2011,30(12):1816-1822. [8] PARTY S S.Drilling gas hydrates on hydrate ridge,Cascadia continental margin:ODP Leg 204 Preliminary Report[R].Texas:Texas AM University,2002.
[9] LEE M W,COLLETT T S.Integrated analysis of well logs and seismic data to estimate gas hydrate concentrations at Keathley Canyon,Gulf of Mexico[J].Marine and Petroleum Geology,2008,25(9):924-931.
[10] LEE M W.COLLETT T S.Pore and fracture filling gas hydrate reservoirs in the gulf of Mexico gas hydrate joint industry project legⅡ Green Canyon 955 H Well[J].Marine and Petroleum Geology,2012,34(1):62-71.
[11] COLLETT T S,RIEDEL M,COCHRAN J,et al.Geologic controls on the occurrence of gas hydrates in the Indian Continental Margin:results of the Indian National Gas Hydrate Program (NGHP) Expedition 01 Initial Reports[R].2008.
[12] PARK K P,BAHK J J,KWON Y,et al.Korean National Program expedition confirms rich gas hydrate deposits in the Ulleung Basin,East Sea,Fire in the Ice[R].US DOE-NETL Newsletter,2008.
[13] 王平康,祝有海,卢振权,等.祁连山冻土区天然气水合物岩性和分布特征[J].地质通报,2011,30(12):1839-1850. WANG Pingkang,ZHU Youhai,LU Zhenquan,et al.Gas hydrate in the Qilian Mountain permafrost and its distribution characteristics[J].Geological Bulletin of China,2011,30(12):1839-1850. [14] 祝有海,张永勤,文怀军,等.祁连山冻土区天然气水合物及其基本特征[J].地球学报,2010,31(1):7-16. ZHU Youhai,ZHANG Yongqin,WEN Huaijun,et al.Gas hydrates in the Qilian Mountain permafrost and their basic characteristics[J].Acta Geoscientica Sinica,2010,31(1):7-16. [15] LEE M W,COLLETT T S.Characteristics and interpretation of fracture-filled gas hydrate-an example from the Ulleung Basin,East Sea of Korea[J].Marine and Petroleum Geology,2013,47(3):168-181.
[16] MANTEGHIAN M,MOUSAVI SAFAVI S M,MOHAMMADI A.The equilibrium conditions,hydrate formation and dissociation rate and storage capacity of ethylene hydrate in presence of 1,4-dioxane[J].Chemical Engineering Journal,2013,217:379-384.
[17] 郑艳红.甲烷水合物在盐、醇类介质中相平衡研究[D].兰州:中国科学院研究生院(兰州地质研究所),2002. ZHENG Yanhong.Hydrate phase equilibrium of methane in the aqueous solutions of salts and methanol medium[D].Lanzhou:Graduate School of the Chinese Academy of Sciences(Lanzhou Institute of Geology),2002. [18] ADISASMITO S,FRANK R J,SLOAN E D.Hydrates of Carbon dioxide and methane mixtures[J].Journal of Chemical and Engineering Data,1991,36(1):68-71.
[19] SEO Y W,LEE H.Hydrate phase equilibria of the ternary CH4+NaCl+water,CO2+NaCl+water and CH4+CO2+water mixtures in silica gel pores[J].Journal of Physical Chemistry B,2003,107(3):889-894.
[20] 苗建宇,祝总祺,刘文荣,等.济阳坳陷古近系-新近系泥岩孔隙结构特征[J].地质论评,2012,49(3):330-336. MIAO Jianyu,ZHU Zongqi,LIU Wenrong,et al.Characteristics of pore structures of Paleogene-Neogene argillaceous rocks in the Jiyang depression[J].Geological Review,2012,49(3):330-336. [21] TURNER D J,CHERRY R S,SLOAN E D.Sensitivity of methane hydrate phase equilibria to sediment pore size[J].Fluid Phase Equilibria,2005,228/229:505-510.
[22] 孙始财,刘昌岭,业渝光,等.氯盐溶液中甲烷水合物高压分解条件及影响因素[J].物理化学学报,2011,27(12):2773-2778. SUN Shicai,LIU Changling,YE Yuguang,et al.Dissociation conditions and influencing factors of methane hydrate in chloride salt solution under high pressure[J].Acta Physico-Chimica Sinica,2011,27(12):2773-2778. [23] 黄子卿.电解质溶液理论导论[M].北京:科学出版社,1983:151. HUANG Ziqing.Introduction to the electrolyte solution theory[M].Beijing:Science Press,1983:151. -
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