含CO_2水合物沉积物力学特性研究
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摘要
参照我国南海神狐海域含天然气水合物富集区沉积物的特点,配制近似粒径的泥质粉细砂作为水合物的赋存骨架,利用含天然气水合物多功能设备制备含CO_2水合物泥质粉细砂,进行三轴剪切试验,研究水合物对赋存介质的强度与变形特性的影响。试验结果表明:在净围压相同的情况下,随着水合物饱和度增大,含CO_2水合物沉积物的强度和刚度都增大并出现剪胀现象,土样黏聚力也有明显上升,但对内摩擦角影响不大。在饱和度相同的情况下,随着围压的增大,土样的强度逐渐增强,应变硬化趋势明显,且剪胀趋势减弱。
Referring to the characteristics of sediments in the natural gas hydrate-rich area of the Shenhu sea area in the South China Sea, the Silty fine sand specimens with approximate particle size was prepared as the hydrated skeleton, and the CO_2 hydrate samples was prepared by using the natural gas hydrate triaxial test system. The CO_2-hydrate soil samples were conducted triaxial shear test to study the effects of hydrate on the strength and deformation characteristics for the medium. The experimental results show that with the same net confining pressure, as the hydrate saturation increases, the strength and stiffness of CO_2 hydrate deposits increase and dilatancy occurs, and the cohesion of soil samples also increases significantly. However, it has little effect on the internal friction angle. In the case of the same saturation, as the confining pressure increases, the strength of the soil sample gradually increases, and the strain hardening clearly trend with dilatancy tend to decrease.
Referring to the characteristics of sediments in the natural gas hydrate-rich area of the Shenhu sea area in the South China Sea, the Silty fine sand specimens with approximate particle size was prepared as the hydrated skeleton, and the CO_2 hydrate samples was prepared by using the natural gas hydrate triaxial test system. The CO_2-hydrate soil samples were conducted triaxial shear test to study the effects of hydrate on the strength and deformation characteristics for the medium. The experimental results show that with the same net confining pressure, as the hydrate saturation increases, the strength and stiffness of CO_2 hydrate deposits increase and dilatancy occurs, and the cohesion of soil samples also increases significantly. However, it has little effect on the internal friction angle. In the case of the same saturation, as the confining pressure increases, the strength of the soil sample gradually increases, and the strain hardening clearly trend with dilatancy tend to decrease.
引文
[1] Kvenvoldenk K A.Methane hydrate-a major reservoir of carbon in the shallow geosphere[J].Chemical Geology,1988,71(1/3):41-51.
[2] Li J F,Ye J L,Qin X W,et al.The first offshore natural gas hydrate production test in South China Sea[J].China Geology,2018(1):5-16.
[3] Paull C K,Buelow W J,Ussler W I,et al.Increased continental-margin slumping frequency during sea-level lowstands above gas hydrate bearing sediments[J].Geology,1996,24:143-146.
[4] WSinters W J,Waite W F,Mason D H,et al.Methane gas hydrate effect on sediment acoustic and strength properties[J].Journal of Petroleum Science and Engineering,2007,56:127-135.
[5] Hyodo M,Nakata Y,Yoshimoto N,et al.Basic research on the mechanical behavior of methane hydratesediments mixture[J].Soils Found,2005,45:75-85.
[6] Masui A,Hand H,Ogata Y,et al.Effects of methane hydrate formation on shear strength of synthetic methane hydrate sediments[C]//Proceeding of the Fifteenth International Off-shore and Polar Engineering Conference,Korea,2005:19-24.
[7] Yun T S,Santamarina J C,Ruppel C.Mechanical properties of sand,silt,and clay containing tetrahydrofuran hydrate[J].Journal of Geophysical Research,2007,112,B04106.
[8] 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(2):198-203.
[9] 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.
[10] 刘昌岭,孟庆国,李承峰,等.南海北部陆坡天然气水合物及其赋存沉积物特征[J].地学前缘,2017,24(4):41-50.
[11] Gudmundssong J S.Natural gas hydrate an alternative to liquefied natural gas[J].Petroleum Review,1996,19(5):232-235.
[12] Wait W F,Santamarina J C,Cortes D D,et al.Physical properties of hydrate-bearing sediments[J].Reviews of Geophysics,2009,47:RG4003.
[13] Davi M K,Zatespina O Y,Buffettb B A.Mathane solubility in marine hydrate environments[J].Marine Geology,2004,203(1/2):177-184.
[14] Stern L A,Kirby S H,Durham W B.Polycrystalline methane hydrate:Synthesis from superheated ice and lowtemperature mechanical properties[J].Energy Fules,1998,12:201-211.
[15] Wait W F,Winters W J,Mason D H.Methane hydrate formation in partially water-saturated Ottawa sand[J].American Mineralogist,2004,89(8/9):1202-1207.
[16] Timothy J K,Liviu T,George J M,et al.Methane hydrate formation and dissociation in a partially saturated core-scale sand sample[J].Journal of Petroleum Science and Engineering,2007,56:108-126.
[17] 中华人民共和国建设部.土工试验方法标准:GB/T 50123—1999[S].北京:中国计划出版社,1999.
[18] Sloan E D,Koh C A.Clathrate Hydrates of Natural Gases[M].NewYork:CRC Press,2008.
[19] Turner D J.Clathrate hydrate formation in water-in-oil dispersions[D].Colorado:Colorado School of Mines,2005.
[20] Hossein G,Jocelyn L G.Strength behavior of methane hydrate bearing sand in undrained triaxial testing[J].Marine and Petroleum Geology,2013,43:310-319.
[2] Li J F,Ye J L,Qin X W,et al.The first offshore natural gas hydrate production test in South China Sea[J].China Geology,2018(1):5-16.
[3] Paull C K,Buelow W J,Ussler W I,et al.Increased continental-margin slumping frequency during sea-level lowstands above gas hydrate bearing sediments[J].Geology,1996,24:143-146.
[4] WSinters W J,Waite W F,Mason D H,et al.Methane gas hydrate effect on sediment acoustic and strength properties[J].Journal of Petroleum Science and Engineering,2007,56:127-135.
[5] Hyodo M,Nakata Y,Yoshimoto N,et al.Basic research on the mechanical behavior of methane hydratesediments mixture[J].Soils Found,2005,45:75-85.
[6] Masui A,Hand H,Ogata Y,et al.Effects of methane hydrate formation on shear strength of synthetic methane hydrate sediments[C]//Proceeding of the Fifteenth International Off-shore and Polar Engineering Conference,Korea,2005:19-24.
[7] Yun T S,Santamarina J C,Ruppel C.Mechanical properties of sand,silt,and clay containing tetrahydrofuran hydrate[J].Journal of Geophysical Research,2007,112,B04106.
[8] 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(2):198-203.
[9] 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.
[10] 刘昌岭,孟庆国,李承峰,等.南海北部陆坡天然气水合物及其赋存沉积物特征[J].地学前缘,2017,24(4):41-50.
[11] Gudmundssong J S.Natural gas hydrate an alternative to liquefied natural gas[J].Petroleum Review,1996,19(5):232-235.
[12] Wait W F,Santamarina J C,Cortes D D,et al.Physical properties of hydrate-bearing sediments[J].Reviews of Geophysics,2009,47:RG4003.
[13] Davi M K,Zatespina O Y,Buffettb B A.Mathane solubility in marine hydrate environments[J].Marine Geology,2004,203(1/2):177-184.
[14] Stern L A,Kirby S H,Durham W B.Polycrystalline methane hydrate:Synthesis from superheated ice and lowtemperature mechanical properties[J].Energy Fules,1998,12:201-211.
[15] Wait W F,Winters W J,Mason D H.Methane hydrate formation in partially water-saturated Ottawa sand[J].American Mineralogist,2004,89(8/9):1202-1207.
[16] Timothy J K,Liviu T,George J M,et al.Methane hydrate formation and dissociation in a partially saturated core-scale sand sample[J].Journal of Petroleum Science and Engineering,2007,56:108-126.
[17] 中华人民共和国建设部.土工试验方法标准:GB/T 50123—1999[S].北京:中国计划出版社,1999.
[18] Sloan E D,Koh C A.Clathrate Hydrates of Natural Gases[M].NewYork:CRC Press,2008.
[19] Turner D J.Clathrate hydrate formation in water-in-oil dispersions[D].Colorado:Colorado School of Mines,2005.
[20] Hossein G,Jocelyn L G.Strength behavior of methane hydrate bearing sand in undrained triaxial testing[J].Marine and Petroleum Geology,2013,43:310-319.