降压开采过程中含水合物沉积物的力学特性研究
|
摘要
天然气水合物是一种潜在的能源资源,开采过程中,水合物的分解会造成工程和地质等安全隐患。为研究降压开采过程中多因素综合影响条件下沉积物的力学性质,在自主研发的低温高压三轴仪上进行了不同围压条件下含水合物沉积物的剪切试验。试验结合常规三轴剪切及一个试样多级加荷的方法,并加入了水合物的降压分解过程。结果表明:水合物的存在可以显著提高沉积物的抗剪强度。在降压分解过程中,含水合物沉积物试样的力学强度受到有效围压和孔隙中水合物含量的综合影响。前期试样由于孔隙压力降低导致有效围压大幅增加,试样抗剪强度增大,后期由于水合物含量的大幅降低,试样在较高有效围压下抗剪强度下降。有效围压对含水合物沉积物试样的体积应变有较大的影响,较高的有效围压会导致含水合物试样产生显著的剪缩现象。
Natural gas hydrate is anticipated to be a potential energy resource. During the mining process from methane hydrate reservoir, the decomposition of methane hydrate can cause risks threatening the safety of engineering and geology. A series of shear tests under different confining pressure conditions was carried out using self-developed low-temperature and high-pressure triaxial apparatus to investigate the mechanical properties of sediments containing methane hydrate under different conditions. The experiment combined with conventional triaxial shear method and multi-stage loading tests was focused on the hydrate decomposition process. It was found that the strength of the sediments was significantly increased due to the presence of hydrates. In the process of depressurization, the strength of sediments was found to be affected by the variations of effective confining pressure and the hydrate saturation. At the early stage, due to the decrease of pore pressure, the effective confining pressure significantly increased, and the shear strength increased as well. In the later stage, the shear strength of samples decreased under high effective confining pressure due to the decrease of hydrate content. The effective confining pressure had a great effect on volumetric strain of the hydrate sediments, and higher effective confining pressure led to obvious shear shrinkage.
Natural gas hydrate is anticipated to be a potential energy resource. During the mining process from methane hydrate reservoir, the decomposition of methane hydrate can cause risks threatening the safety of engineering and geology. A series of shear tests under different confining pressure conditions was carried out using self-developed low-temperature and high-pressure triaxial apparatus to investigate the mechanical properties of sediments containing methane hydrate under different conditions. The experiment combined with conventional triaxial shear method and multi-stage loading tests was focused on the hydrate decomposition process. It was found that the strength of the sediments was significantly increased due to the presence of hydrates. In the process of depressurization, the strength of sediments was found to be affected by the variations of effective confining pressure and the hydrate saturation. At the early stage, due to the decrease of pore pressure, the effective confining pressure significantly increased, and the shear strength increased as well. In the later stage, the shear strength of samples decreased under high effective confining pressure due to the decrease of hydrate content. The effective confining pressure had a great effect on volumetric strain of the hydrate sediments, and higher effective confining pressure led to obvious shear shrinkage.
引文
[1]DENDY SLOAN E.Clathrate hydrates of natural gas[M].[S.l.]:M.Dekker,1998.
[2]王南,裴玲,雷丹凤,等.中国非常规天然气资源分布及开发现状[J].油气地质与采收率,2015,(1):26-31.WANG Nan,PEI Ling,LEI Dan-feng,et al.Analysis of unconventional gas resources distribution and development status in China[J].Petroleum Geology and Recovery Efficiency,2015,(1):26-31.
[3]安青,许维秀.天然气水合物开采研究现状[J].河南化工,2008,25(6):10-12.AN Qing,XU Wei-xiu.Research status on exploitation of natural gas hydrate[J].Henan Chemical Industry,2008,25(6):10-12.
[4]WOO‐YEOL J,VOGT P R.Effects of bottom water warming and sea level rise on Holocene hydrate dissociation and mass wasting along the Norwegian-Barents Continental Margin[J].Journal of Geophysical Research Atmospheres,2004,109(B6):225-239.
[5]MASUI AKIRA,MIYAZAKI KUNIYUKI,HANEDAHIRONORI,et al.Mechanical properties of natural gas hydrate bearing sediments retrieved from eastern Nankai Trough[C].[S.l.]:Congres Geologique International,2008.
[6]HYODO MASAYUKI,NAKATA YUKIO,YOSHIMOTO NORIMASA,et al.Shear behaviour of methane hydrate-bearing sand[J].Human Resource Development Review,2007,11(1):77-96.
[7]WINTERS W J,PECHER I A,BOOTH J S.Properties of samples containing natural gas hydrate from the JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well,determined using gas hydrate and sediment test laboratory instrument(GHASTLI)[J].Bulletin of the Geological Survey of Canada,1999,(544):241-250.
[8]HYDE HYODO M,NAKATA A F L,YOSHIMOTO Y,et al.Triaxial compressive strength of methane hydrate[C]//International Offshore and Polar Engineering Conference.Kitakyushu,Japan:[s.n.],2002.
[9]HYODO MASAYUKI,NAKATA YUKIO,YOSHIMOTO NORIMASA,et al.Basic research on the mechanical behavior of methane hydrate-sediments mixture[J].Journal of the Japanese Geotechnical Society Soils&Foundation,2005,45(1):75-85.
[10]李洋辉,宋永臣,于锋,等.围压对含水合物沉积物力学特性的影响[J].石油勘探与开发,2011,38(5):637-640.LI Yang-hui,SONG Yong-chen,YU Feng,et al.Effect of confining pressure on mechanical behavior of methane hydrate-bearing sediments[J].Petroleum Exploration and Development.2011,38(5):637-640.
[11]张旭辉,王淑云,李清平,等.天然气水合物沉积物力学性质的试验研究[J].岩土力学,2010,31(10):3069-3074.ZHANG Xu-hui,WANG Shu-yun,LI Qing-ping,et al.Experimental study of mechanical properties of gas hydrate deposits[J].Rock and Soil Mechanics,2010,31(10):3069-3074.
[12]孙晓杰.天然气水合物地层物理力学性质实验研究[D].青岛:中国石油大学(华东),2011.SUN Xiao-jie.Physical and mechanical properties research on natural gas hydrate bearing sediments[D].Qingdao:China University of Petroleum(East China),2011.
[13]孙中明,张剑,刘昌岭,等.沉积物中甲烷水合物饱和度测定及其力学特性研究[J].实验力学,2013,28(6):747-754.SUN Zhong-ming,ZHANG Jian,LIU Chang-ling,et al.On the determination of methane hydrate saturation and mechanical properties of sediments containing methane hydrate[J].Journal of Experimental Mechanics,2013,28(6):747-754.
[14]李实,宁伏龙,余义兵,等.含水合物沉积物力学性质:方法、特性与定量关系[J].地质科技情报,2014,(1):9-18.LI Shi,NING Fu-long,YU Yi-bing,et al.Mechanical properties of natural gas-hydrate-bearing sediments:Areview[J].Geological Science and Technology Information,2014,(1):9-18.
[15]YANG Jing,WEN Wei,ZHANG Xiu-hua,et al.Mechanical and dissociation properties of methane hydrate-bearing sand in deep seabed[J].Soils and Foundations,2013,53(2):299-314.
[16]SONG Yong-chen,YU Feng,LI Yang-hui,et al.Mechanical property of artificial methane hydrate under triaxial compression[J].Journal of Natural Gas Chemistry,2010,19(3):246-250.
[17]魏厚振,颜荣涛,陈盼,等.不同水合物含量含二氧化碳水合物砂三轴试验研究[J].岩土力学,2011,32(增刊2):198-203.WEI Hou-zhen,YAN Rong-tao,CHEN Pan,et al.Deformation and failure behavior of carbon dioxide hydrate-bearing sands with different hydrate contents under triaxial shear tests[J].Rock and Soil Mechanics,2011,32(Supp.2):198-203.
[18]颜荣涛,韦昌富,魏厚振,等.水合物形成对含水合物砂土强度影响[J].岩土工程学报,2012,34(7):1234-1240.YAN Rong-tao,WEI Chang-fu,WEI Hou-zhen,et al.Effect of hydrate formation on mechanical strength of hydrate-bearing sand[J].Chinese Journal of Geotechnical Engineering,2012,34(7):1234-1240.
[19]石要红,张旭辉,鲁晓兵,等.南海水合物黏土沉积物力学特性试验模拟研究[J].力学学报,2015,47(3):521-528.SHI Yao-hong,ZHANG Xu-hui,LU Xiao-bing,et al.Experimental study on the static mechanical properties of hydrate-bearing silty-clay in the South China Sea[J].Chinese Journal of Theoretical and Applied Mechanics,2015,47(3):521-528.
[20]于锋.甲烷水合物及其沉积物的力学特性研究[D].大连:大连理工大学,2011.YU Feng.Studay on mechanical properties of methane hydrate and sediments[D].Dalian:Dalian University of Technology,2011.
[21]李洋辉,宋永臣,刘卫国,等.温度和应变速率对水合物沉积物强度影响试验研究[J].天然气勘探与开发,2012,35(1):50-53.LI Yang-hui,SONG Yong-chen,LIU Wei-guo,et al.Effects of temperature and strain rate on strength of hydrate sediment[J].Natural Gas Exploration and Development,2012,35(1):50-53.
[22]于锋,宋永臣,李洋辉,等.含冰甲烷水合物的应力与应变关系[J].石油学报,2011,32(4):687-692.YU Feng,SONG Yong-cheng,LI Yang-hui,et al.Astuady on stress-strain relations of methane hydrate[J].Acta Petrolet Sinica,2011,32(4):687-692.
[23]孙晓杰,程远方,李令东,等.天然气水合物岩样三轴力学试验研究[J].石油钻探技术,2012,40(4):52-57.SUN Xiao-jie,CHENG Yuan-fang,LI Ling-dong,et al.Triaxial compression test on synthetic core sample with simulated hydrate-bearing sediments[J].Petroleum Drilling Techniques,2012,40(4):52-57.
[24]中华人民共和国水利部.GB/T 50123-1999土工试验方法标准[S].北京:中国计划出版社,1999.The Ministry of Water Resources of the People’s Republic of China.GB/T 50123-1999 Standards for soil test method[S].Beijing:China Planning Publishing House,1999
[25]GHIASSIAN H,GROZIC J L H.Strength behavior of methane hydrate bearing sand in undrained triaxial testing[J].Marine and Petroleum Geology,2013,43:310-319.
[26]HYODO MASAYUKI,LI YANG-HUI,YONEDA JUN,et al.Effects of dissociation on the shear strength and deformation behavior of methane hydrate-bearing sediments[J].Marine&Petroleum Geology,2014,51(2):52-62.
[27]BERGE L I,JACOBSEN K A,SOLSTAD A.Measured acoustic wave velocities of R11(CCl 3 F)hydrate samples with and without sand as a function of hydrate concentration[J].Journal of Geophysical Research Solid Earth,1999,104(B7):15415-15424.
[28]YUN T S,FRANCISCA F M,SANTAMARINA J C,et al.Compressional and shear wave velocities in uncemented sediment containing gas hydrate[J].Geophysical Research Letters,2005,32(10):153-174.
[2]王南,裴玲,雷丹凤,等.中国非常规天然气资源分布及开发现状[J].油气地质与采收率,2015,(1):26-31.WANG Nan,PEI Ling,LEI Dan-feng,et al.Analysis of unconventional gas resources distribution and development status in China[J].Petroleum Geology and Recovery Efficiency,2015,(1):26-31.
[3]安青,许维秀.天然气水合物开采研究现状[J].河南化工,2008,25(6):10-12.AN Qing,XU Wei-xiu.Research status on exploitation of natural gas hydrate[J].Henan Chemical Industry,2008,25(6):10-12.
[4]WOO‐YEOL J,VOGT P R.Effects of bottom water warming and sea level rise on Holocene hydrate dissociation and mass wasting along the Norwegian-Barents Continental Margin[J].Journal of Geophysical Research Atmospheres,2004,109(B6):225-239.
[5]MASUI AKIRA,MIYAZAKI KUNIYUKI,HANEDAHIRONORI,et al.Mechanical properties of natural gas hydrate bearing sediments retrieved from eastern Nankai Trough[C].[S.l.]:Congres Geologique International,2008.
[6]HYODO MASAYUKI,NAKATA YUKIO,YOSHIMOTO NORIMASA,et al.Shear behaviour of methane hydrate-bearing sand[J].Human Resource Development Review,2007,11(1):77-96.
[7]WINTERS W J,PECHER I A,BOOTH J S.Properties of samples containing natural gas hydrate from the JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well,determined using gas hydrate and sediment test laboratory instrument(GHASTLI)[J].Bulletin of the Geological Survey of Canada,1999,(544):241-250.
[8]HYDE HYODO M,NAKATA A F L,YOSHIMOTO Y,et al.Triaxial compressive strength of methane hydrate[C]//International Offshore and Polar Engineering Conference.Kitakyushu,Japan:[s.n.],2002.
[9]HYODO MASAYUKI,NAKATA YUKIO,YOSHIMOTO NORIMASA,et al.Basic research on the mechanical behavior of methane hydrate-sediments mixture[J].Journal of the Japanese Geotechnical Society Soils&Foundation,2005,45(1):75-85.
[10]李洋辉,宋永臣,于锋,等.围压对含水合物沉积物力学特性的影响[J].石油勘探与开发,2011,38(5):637-640.LI Yang-hui,SONG Yong-chen,YU Feng,et al.Effect of confining pressure on mechanical behavior of methane hydrate-bearing sediments[J].Petroleum Exploration and Development.2011,38(5):637-640.
[11]张旭辉,王淑云,李清平,等.天然气水合物沉积物力学性质的试验研究[J].岩土力学,2010,31(10):3069-3074.ZHANG Xu-hui,WANG Shu-yun,LI Qing-ping,et al.Experimental study of mechanical properties of gas hydrate deposits[J].Rock and Soil Mechanics,2010,31(10):3069-3074.
[12]孙晓杰.天然气水合物地层物理力学性质实验研究[D].青岛:中国石油大学(华东),2011.SUN Xiao-jie.Physical and mechanical properties research on natural gas hydrate bearing sediments[D].Qingdao:China University of Petroleum(East China),2011.
[13]孙中明,张剑,刘昌岭,等.沉积物中甲烷水合物饱和度测定及其力学特性研究[J].实验力学,2013,28(6):747-754.SUN Zhong-ming,ZHANG Jian,LIU Chang-ling,et al.On the determination of methane hydrate saturation and mechanical properties of sediments containing methane hydrate[J].Journal of Experimental Mechanics,2013,28(6):747-754.
[14]李实,宁伏龙,余义兵,等.含水合物沉积物力学性质:方法、特性与定量关系[J].地质科技情报,2014,(1):9-18.LI Shi,NING Fu-long,YU Yi-bing,et al.Mechanical properties of natural gas-hydrate-bearing sediments:Areview[J].Geological Science and Technology Information,2014,(1):9-18.
[15]YANG Jing,WEN Wei,ZHANG Xiu-hua,et al.Mechanical and dissociation properties of methane hydrate-bearing sand in deep seabed[J].Soils and Foundations,2013,53(2):299-314.
[16]SONG Yong-chen,YU Feng,LI Yang-hui,et al.Mechanical property of artificial methane hydrate under triaxial compression[J].Journal of Natural Gas Chemistry,2010,19(3):246-250.
[17]魏厚振,颜荣涛,陈盼,等.不同水合物含量含二氧化碳水合物砂三轴试验研究[J].岩土力学,2011,32(增刊2):198-203.WEI Hou-zhen,YAN Rong-tao,CHEN Pan,et al.Deformation and failure behavior of carbon dioxide hydrate-bearing sands with different hydrate contents under triaxial shear tests[J].Rock and Soil Mechanics,2011,32(Supp.2):198-203.
[18]颜荣涛,韦昌富,魏厚振,等.水合物形成对含水合物砂土强度影响[J].岩土工程学报,2012,34(7):1234-1240.YAN Rong-tao,WEI Chang-fu,WEI Hou-zhen,et al.Effect of hydrate formation on mechanical strength of hydrate-bearing sand[J].Chinese Journal of Geotechnical Engineering,2012,34(7):1234-1240.
[19]石要红,张旭辉,鲁晓兵,等.南海水合物黏土沉积物力学特性试验模拟研究[J].力学学报,2015,47(3):521-528.SHI Yao-hong,ZHANG Xu-hui,LU Xiao-bing,et al.Experimental study on the static mechanical properties of hydrate-bearing silty-clay in the South China Sea[J].Chinese Journal of Theoretical and Applied Mechanics,2015,47(3):521-528.
[20]于锋.甲烷水合物及其沉积物的力学特性研究[D].大连:大连理工大学,2011.YU Feng.Studay on mechanical properties of methane hydrate and sediments[D].Dalian:Dalian University of Technology,2011.
[21]李洋辉,宋永臣,刘卫国,等.温度和应变速率对水合物沉积物强度影响试验研究[J].天然气勘探与开发,2012,35(1):50-53.LI Yang-hui,SONG Yong-chen,LIU Wei-guo,et al.Effects of temperature and strain rate on strength of hydrate sediment[J].Natural Gas Exploration and Development,2012,35(1):50-53.
[22]于锋,宋永臣,李洋辉,等.含冰甲烷水合物的应力与应变关系[J].石油学报,2011,32(4):687-692.YU Feng,SONG Yong-cheng,LI Yang-hui,et al.Astuady on stress-strain relations of methane hydrate[J].Acta Petrolet Sinica,2011,32(4):687-692.
[23]孙晓杰,程远方,李令东,等.天然气水合物岩样三轴力学试验研究[J].石油钻探技术,2012,40(4):52-57.SUN Xiao-jie,CHENG Yuan-fang,LI Ling-dong,et al.Triaxial compression test on synthetic core sample with simulated hydrate-bearing sediments[J].Petroleum Drilling Techniques,2012,40(4):52-57.
[24]中华人民共和国水利部.GB/T 50123-1999土工试验方法标准[S].北京:中国计划出版社,1999.The Ministry of Water Resources of the People’s Republic of China.GB/T 50123-1999 Standards for soil test method[S].Beijing:China Planning Publishing House,1999
[25]GHIASSIAN H,GROZIC J L H.Strength behavior of methane hydrate bearing sand in undrained triaxial testing[J].Marine and Petroleum Geology,2013,43:310-319.
[26]HYODO MASAYUKI,LI YANG-HUI,YONEDA JUN,et al.Effects of dissociation on the shear strength and deformation behavior of methane hydrate-bearing sediments[J].Marine&Petroleum Geology,2014,51(2):52-62.
[27]BERGE L I,JACOBSEN K A,SOLSTAD A.Measured acoustic wave velocities of R11(CCl 3 F)hydrate samples with and without sand as a function of hydrate concentration[J].Journal of Geophysical Research Solid Earth,1999,104(B7):15415-15424.
[28]YUN T S,FRANCISCA F M,SANTAMARINA J C,et al.Compressional and shear wave velocities in uncemented sediment containing gas hydrate[J].Geophysical Research Letters,2005,32(10):153-174.