Abstract:Researches were carried out on the origin of gas hydrate samples from the tundra in the Qilian Mountain, Pearl River Mouth Basin in the northern South Sea and the continental slope of Taixinan Basin in China. Gases of the gas hydrate samples from the Jurassic Jiangcang Formation in the Muli County in Qilian Mountain are mainly of oil-derived origin, characterized by self-generation and self-preservation. δ13C1 values range from -52.7‰ to -35.8‰, and the δ13C2 values vary from -42.3‰ to -29.4‰. There was a small amount of coal-derived gases, which might source from the coal-bearing Middle-Jurassic Muli Formation with δ13C1 of -35.7‰ - -31.3‰ and δ13C2 of -27.5‰ - -25.7‰. Gases of the gas hydrate samples from the Pearl River Mouth Basin and Taixinan Basin are dominated by bacterial origin of carbonate reduction, with δ13C1 of -74.3‰ - -56.7‰ and δD1 of -226‰ - -180‰. A trace amount of thermogenic gases were also found in these basins with δ13C1 of -54.1‰ - -46.2‰. This study combined the geochemical data of gas hydrates from 20 areas (basins) in the world, and concluded that thermogenic gases of the gas hydrates in the world can be either of coal-derived or oil-derived origin, but dominated by oil-derived origin. A small amount of coal-derived gas was also found in the Qilian Mountain in China and the Vancouver Island in Canada. The coal-derived gas has relatively heavy δ13C1 ≥ -45‰ and δ13C2 > -28‰, while the oil-derived gas has δ13C1 from -53‰ - -35‰ and δ13C2 < -28.5‰. Gas hydrates in the world mainly belong to bacterial origin of carbonate reduction. Methanogensesis of acetate fermentation was only found in some gas hydrates from the Baikal basin in Russia. Bacterial gases of carbonate reduction have relatively heavy δD1 ≥ -226‰, while gases of acetate fermentation have δD1 < -294‰. The bacterial gas of gas hydrates in the world has the highest δ13C1 value of -56.7‰ and lowest of -95.5‰, with a peak range of -75‰ - -60‰. Gas hydrate in the world has the highest δ13C1 of -31.3‰ and lowest of -95.5‰ and the highest δD1 of -115‰ and lowest of -305‰.
戴金星, 倪云燕, 黄士鹏, 彭威龙, 韩文学, 龚德瑜, 魏伟. 中国天然气水合物气的成因类型[J]. 石油勘探与开发, 2017, 44(6): 837-848.
DAI Jinxing, NI Yunyan, HUANG Shipeng, PENG Weilong, HAN Wenxue, GONG Deyu, WEI Wei. Genetic types of gas hydrates in China. Petroleum Exploration and Development, 2017, 44(6): 837-848.
[1] HAMMERSCHMIDT E G. Formation of gas hydrates in natural gas transmission lines[J]. Industrial and Engineering Chemistry, 1934, 26: 851-855. [2] MAKOGON Y F, TREBIN F A, TROFIMUK A A, et al. Detection of a pool of natural gas in a solid (hydrate gas) state[J]. Doklady Academy of Sciences U.S.S.R.: Earth Science Section, 1972, 196: 197-200. [3] TROFIMUK A A, CHERSKY N V, TSARYOV V P. The role of continental glaciation and hydrate formation on petroleum occurrence[C]//MEYER R F. The future supply of nature-made petroleum and gas. New York: Pergamon Press, 1977: 919-926. [4] 史斗, 郑军卫. 世界天然气水合物研究开发现状和前景[J]. 地球科学进展, 1999, 14(4): 330-339. SHI Dou, ZHENG Junwei. The status and prospects of research and exploitation of natural gas hydrate in the world[J]. Advance in Earth Sciences, 1999, 14(4): 330-339. [5] 肖钢, 白玉湖. 天然气水合物: 能燃烧的冰[M]. 武昌: 武汉大学出版社, 2012: 173-176. XIAO Gang, BAI Yuhu. Natural gas hydrates: Flammable ice[M]. Wuchang: Wuhan University Press, 2012: 173-176. [6] STOLL R D, EWING J, BRYAN G M. Anomalous wave velocities in sediments containing gas hydrates[J]. Journal of Geophysical Research, 1971, 76(8): 2090-2094. [7] BILY C, DICK J W L. Naturally occurring gas hydrates in the Mackenzie Delta, N.W.T[J]. Bulletin of Canadian Petroleum Geology, 1974, 22(3): 340-352. [8] KVENVOLDEN K A. Methane hydrate: A major reservoir of carbon in the shallow geosphere?[J]. Chemical Geology, 1988, 71(1): 41-51. [9] KVENVOLDEN K A. Potential effects of gas hydrate on human welfare[J]. Proceedings of the National Academy of Sciences of the United States of America, 1999, 96(7): 3420-3426. [10] COLLETT T S. Natural gas hydrates of the Prudhoe Bay and Kuparuk River area, North Slope, Alaska[J]. AAPG Bulletin, 1993, 77(5): 793-812. [11] DALLIMORE S R, COLLETT T S. Intrapermafrost gas hydrates from a deep core hole in the Mackenzie Delta, Northwest Territories, Canada[J]. Geology, 1995, 23(6): 527. [12] COLLETT T S, JOHNSON A T, KNAPP C C, et al. Natural gas hydrates: Energy resource potential and associated geologic hazards[M]. Tulsa: AAPG, 2009: 146-219. [13] 叶乐峰. 我国南海可燃冰试开采60天圆满成功[N]. 光明日报, 2017-07-10(8). YE Lefeng. Trial mining of natural gas hydrates achieves a complete success[N]. Guangming Daily, 2017-07-10(8). [14] 金庆焕, 张光学, 杨木壮, 等. 天然气水合物资源概论[M]. 北京: 科学出版社, 2006: 4-6. JIN Qinghuan, ZHANG Guangxue, YANG Muzhuang, et al. Introduction to natural gas hydrates resources[M]. Beijing: Science Press, 2006: 4-6. [15] MATVEEVA T, SOLOVIEV V, WALLMANN K, et al. Geochemistry of gas hydrate accumulation offshore NE Sakhalin Island (the Sea of Okhotsk): Results from the KOMEX-2002 cruise[J]. Geo-Marine Letters, 2003, 23(3/4): 278-288. [16] COLLETT T S, AGENA W F, LEE M W, et al. Assessment of gas hydrate resources on the North Slope, Alaska, 2008[EB/OL]. (2016-11-29)[2017-10-10]. http://energy.usgs.gov/fs/2008/30731. [17] DALLIMORE S R, COLLETT T S. Scientific results from the Mallik 2002 gas hydrate production research well program, Mackenzie Delta, Northwest Territories, Canada[J]. Bulletin of the Geological Survey of Canada, 2002, 585: 957. [18] 邹才能, 陶士振, 侯连华, 等. 非常规油气地质[M]. 2版. 北京: 科学出版社, 2013: 327-330. ZOU Caineng, TAO Shizhen, HOU Lianhua, et al. Unconventional oil and gas geology[M]. 2nd ed. Beijing: Science Press, 2013: 327-330. [19] 张光学, 陈芳, 沙志彬, 等. 南海东北部天然气水合物成藏演化地质过程[J]. 地学前缘, 2017, 24(4): 15-23. ZHANG Guangxue, CHEN Fang, SHA Zhibin, et al. The geological evolution process of natural gas hydrate reservoirs in the northeastern South China Sea[J]. Earth Science Frontiers, 2017, 24(4): 15-23. [20] 黄霞, 刘晖, 张家政, 等. 祁连山冻土区天然气水合物烃类气体成因及其意义[J]. 地质科学, 2016, 51(3): 934-945. HUANG Xia, LIU Hui, ZHANG Jiazheng, et al. Gnetic-type and its significance of hydrocarbon gases from permafrost-associated gas hydrate in Qilian Mountain[J]. Chinese Journal of Geology, 2016, 51(3): 934-945. [21] 卢振权, 祝有海, 张永勤, 等. 青海祁连山冻土区天然气水合物的气体成因研究[J]. 现代地质, 2010, 24(3): 581-588. LU Zhenquan, ZHU Youhai, ZHANG Yongqin, et al. Study on genesis of gases from gas hydrate in the Qilian Mountain Permafrost, Qinghai[J]. Geoscience, 2010, 24(3): 581-588. [22] 黄霞, 祝有海, 王平康, 等. 祁连山冻土区天然气水合物烃类气体组分的特征和成因[J]. 地质通报, 2011, 30(12): 1851-1856. HUANG Xia, ZHU Youhai, WANG Pingkang, et al. Hydrocarbon gas composition and origin of core gas from the gas hydrate reservoir in Qilian Mountain permafrost[J]. Geological Bulletin of China, 2011, 30(12): 1851-1856. [23] CHEN B, XU J B, LU Z Q, et al. Hydrocarbon source for oil and gas indication associated with gas hydrate and its significance in the Qilian Mountain permafrost, Qinghai, Northwest China[J/OL]. Marine and Petroleum Geology, 2017, In press [2017-10-10]. https:// doi:org/10.1016/j.marpetgeo.2017.02.019. [24] FU X G, WANG J, TAN F W, et al. Gas hydrate formation and accumulation potential in the Qiangtang Basin, northern Tibet, China[J]. Energy Conversion and Management, 2013, 73(5): 186-194. [25] ZHAO X M, DENG J, LI J P, et al. Gas hydrate formation and its accumulation potential in Mohe permafrost, China[J]. Marine and Petroleum Geology, 2012, 35(1): 166-175. [26] 周幼吾, 郭东信, 邱国庆, 等. 中国冻土[M]. 北京: 科学出版社, 2000. ZHOU Youwu, GUO Dongxin, QIU Guoqing, et al. Frozen soil in China[M]. Beijing: Science Press, 2000. [27] 祝有海, 刘亚玲, 张永勤. 祁连山多年冻土区天然气水合物的形成条件[J]. 地质通报, 2006, 25(1/2): 58-63. ZHU Youhai, LIU Yaling, ZHANG Yongqin. Formation conditions of gas hydrates in permafrost of the Qilian Mountains, Northwest China[J]. Geological Bulletin of China, 2006, 25(1/2): 58-63. [28] 谭富荣, 刘世明, 崔伟雄, 等. 木里煤田聚乎更矿区天然气水合物气源探讨[J]. 地质学报, 2017, 91(5): 1158-1167. TAN Furong, LIU Shiming, CUI Weixiong, et al. Origin of gas hydrate in the Juhugeng mining area of Muli coalfield[J]. Acta Geologica Sinica, 2017, 91(5): 1158-1167. [29] 刘昌岭, 贺行良, 孟庆国, 等. 祁连山冻土区天然气水合物分解气碳氢同位素组成特征[J]. 岩矿测试, 2012, 31(3): 489-494. LIU Changling, HE Xingliang, MENG Qingguo, et al. Carbon and hydrogen isotopic compositions characteristics of the released gas from natural gas hydrates in the Qilian Mountain Permafrost[J]. Rock and Mineral Analysis, 2012, 31(3): 489-494. [30] LIU C L, MENG Q G, HE X L, et al. Comparison of the characteristics for natural gas hydrate recovered from marine and terrestrial areas in China[J]. Journal of Geochemical Exploration, 2015, 152: 67-74. [31] 杨胜雄, 沙志彬. “南海天然气水合物研究进展”专辑特别主编致读者[J]. 地学前缘, 2017, 24(4): 扉页. YANG Shengxiong, SHA Zhibin. “Research advancement of natural gas hydrate in South China Sea” album: The chief editor to readers [J]. Earth Science Frontiers, 2017, 24(4): The title page. [32] 杨胜雄, 梁金强, 陆敬安, 等. 南海北部神狐海域天然气水合物成藏特征及主控因素新认识[J]. 地学前缘, 2017, 24(4): 1-14. YANG Shengxiong, LIANG Jinqiang, LU Jingan, et al. New understandings on the characteristics and controlling factors of gas hydrate reservoirs in the Shenhu area on the northern slope of the South China Sea[J]. Earth Science Frontiers, 2017, 24(4): 1-14. [33] 吴庐山, 杨胜雄, 梁金强, 等. 南海北部神狐海域沉积物中烃类气体的地球化学特征[J]. 海洋地质前沿, 2011(6): 1-10. WU Lushan, YANG Shengxiong, LIANG Jinqiang, et al. Geochemical characteristics of hydrocarbon gases in sediments in Shenhu area, the northern South China Sea[J]. Marine Geology Frontiers, 2011(6): 1-10. [34] 付少英, 陆敬安. 神狐海域天然气水合物的特征及其气源[J]. 海洋地质动态, 2010, 26(9): 6-10. FU Shaoying, LU Jing’an. The characteristics and origin of gas hydrate in Shenhu area, South China Sea[J]. Marine Geology Letter, 2010, 26(9): 6-10. [35] LIU C L, MENG Q G, HE X L, et al. Characterization of natural gas hydrate recovered from Pearl River Mouth basin in South China Sea[J]. Marine and Petroleum Geology, 2015, 61(61): 14-21. [36] 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. LIU Changling, MENG Qingguo, LI Chengfeng, et al. Characterization of natural gas hydrate and its deposits recovered from the northern slope of the South China Sea[J]. Earth Science Frontiers, 2017, 24(4): 41-50. [37] 梁劲, 王静丽, 陆敬安, 等. 台西南盆地含天然气水合物沉积层测井响应规律特征及其地质意义[J]. 地学前缘, 2017, 24(4): 32-40. LIANG Jin, WANG Jingli, LU Jing’an, et al. The characteristics of logging response of the gas hydrate formation in Taixinan Basin and its geological significance[J]. Earth Science Frontiers, 2017, 24(4): 32-40. [38] 戴金星, 裴锡古, 戚厚发. 中国天然气地质学: 卷一[M]. 北京: 石油工业出版社, 1992: 5-92. DAI Jinxing, PEI Xigu, QI Houfa. Natural gas geology in China: Vol.1[M]. Beijing: Petroleum Industry Press, 1992: 5-92. [39] DAI J X. Identification of various alkane gases[J]. Science in China(Series B), 1992, 35(10): 1246-1257. [40] 戴金星. 天然气碳氢同位素特征和各类天然气鉴别[J]. 天然气地球科学, 1993(2/3): 1-40. DAI Jinxing. Characteristics of carbon and hydrogen isotopes of natural gas and its identification[J]. Natural Gas Geoscience, 1993(2/3): 1-40. [41] 戴金星, 倪云燕, 黄士鹏, 等. 煤成气研究对中国天然气工业发展的重要意义[J]. 天然气地球科学, 2014, 25(1): 1-22. DAI Jinxing, NI Yunyan, HUANG Shipeng, et al. Significant function of coal-derived gas study for natural gas industry development in China[J]. Natural Gas Geoscience, 2014, 25(1): 1-22. [42] 徐永昌, 沈平, 刘文汇, 等. 天然气成因理论及应用[M]. 北京: 科学出版社, 1994: 334-375. XU Yongchang, SHEN Ping, LIU Wenhui, et al. Genesis theory of natural gas and its application[M]. Beijing: Science Press, 1994: 334-375. [43] 徐永昌, 沈平. 中原, 华北油气区《煤型气》地化特征初探[J]. 沉积学报, 1985, 3(2): 37-46. XU Yongchang, SHEN Ping. A preliminary study on geochemical characteristics of coal-type gas in Zhongyuan-Huabei oil-gas area[J]. Acta Sedimentologica Sinica, 1985, 3(2): 37-46. [44] 刘文汇, 徐永昌. 天然气成因类型及判别标志[J]. 沉积学报, 1996, 14(1): 110-116. LIU Wenhui, XU Yongchang. Genetic indicators for natural gases[J]. Acta Sedimentologica Sinica, 1996, 14(1): 110-116. [45] 刘文汇, 陈孟晋, 关平, 等. 天然气成烃、成藏三元地球化学示踪体系及实践[M]. 北京: 科学出版社, 2009: 150-171. LIU Wenhui, CHEN Mengjin, GUAN Ping, et al. Genesis and formation of natural gas: Ternary geochemistry trace system and practice[M]. Beijing: Science Press, 2009: 150-171. [46] 傅家谟, 刘德汉, 盛国英. 煤成烃地球化学[M]. 北京: 科学出版社, 1990: 86-88, 103-113, 287-304. FU Jiamo, LIU Dehan, SHENG Guoying. Geochemistry of coal-generated hydrocarbons[M]. Beijing: Science Press, 1990: 86-88, 103-113, 287-304. [47] 彭平安, 邹艳荣, 傅家谟. 煤成气生成动力学研究进展[J]. 石油勘探与开发, 2009, 36(3): 297-306. PENG Ping’an, ZOU Yanrong, FU Jiamo. Progress in generation kinetics studies of coal-derived gases[J]. Petroleum Exploration and Development, 2009, 36(3): 297-306. [48] 王庭斌. 中国含煤-含气(油)盆地[M]. 北京: 地质出版社, 2014: 77-90. WANG Tingbin. Coal- and gas-(oil-) bearing basins in China[M]. Beijing: Geological Publishing House, 2014: 77-90. [49] 王廷栋, 蔡开平. 生物标志物在凝析气藏天然气运移和气源对比中的应用[J]. 石油学报, 1990, 11(1): 25-31. WANG Tingdong, CAI Kaiping. The application of biomarkers in the study of natural gas migration and gas reservoir-source rock correlation[J]. Acta Petrolei Sinica, 1990, 11(1): 25-31. [50] 刘全有, 金之钧, 张殿伟, 等. 塔里木盆地天然气地球化学特征与成因类型研究[J]. 天然气地球科学, 2008, 19(2): 234-237. LIU Quanyou, JIN Zhijun, ZHANG Dianwei, et al. Geochemical characteristics and genesis of natural gas in Tarim Basin[J]. Natural Gas Geoscience, 2008, 19(2): 234-237. [51] 王世谦. 四川盆地侏罗系—震旦系天然气的地球化学特征[J]. 天然气工业, 1994, 14(6): 1-5. WANG Shiqian. Geochemical characteristics of Jurassic-Sinian gas in Sichuan Basin[J]. Natural Gas Industry, 1994, 14(6): 1-5. [52] 李剑, 李志生, 王晓波, 等. 多元天然气成因判识新指标及图版[J]. 石油勘探与开发, 2017, 44(4): 503-512. LI Jian, LI Zhisheng, WANG Xiaobo, et al. New indexes and charts for genesis identification of multiple natural gases[J]. Petroleum Exploration and Development, 2017, 44(4): 503-512. [53] WHITICAR M J. Carbon and hydrogen isotope systematics of bacterial formation and oxidation of methane[J]. Chemical Geology, 1999, 161(1/2/3): 291-314. [54] BOURRY C, CHAZALLON B, CHARLOU J L, et al. Free gas and gas hydrates from the Sea of Marmara, Turkey: Chemical and structural characterization[J]. Chemical Geology, 2009, 264(1/2/3/4): 197-206. [55] KIDA M, HACHIKUBO A, SAKAGAMI H, et al. Natural gas hydrates with locally different cage occupancies and hydration numbers in Lake Baikal[J]. Geochemistry Geophysics Geosystems, 2013, 10(5): 3093-3107. [56] POHLMAN J W, CANUEL E A, CHAPMAN N, et al. The origin of thermogenic gas hydrates inferred from isotopic ( 13 C/ 12 C and D/H) and molecular composition of hydrate and vent gas[J]. Organic Geochemistry, 2005, 36(5): 703-716. [57] HACHIKUBO A, KRYLOV A, SAKAGAMI H, et al. Isotopic composition of gas hydrates in subsurface sediments from offshore Sakhakin Island, Sea of Okhotsk[J]. Geo-Marine Letters, 2010, 30(3): 313-319. [58] PAPE T, BAHR A, RETHEMEYER J, et al. Molecular and isotopic partitioning of low-molecular-weight hydrocarbons during migration and gas hydrate precipitation in deposits of a high-flux seepage site[J]. Chemical Geology, 2010, 269(3/4): 350-363. [59] LORENSON T D, WHITICAR M J, WASEDA A, et al. Gas composition and isotopic geochemistry of cuttings, core and gas hydrate from the JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well[C]//Scientific results from JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well, Mackenzie Delta, Northwest Territories, Canada. Ottawa: Geological Survey of Canada, 1999: 143-164. [60] UCHIDA T, MATSUMOTO R, WASEDA A, et al. Summary of physicochemical properties of natural gas hydrate and associated gas-hydrate-bearing sediments, JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well, by the Japanese research consortium[J]. Bulletin of the Geological Survey of Canada, 1999, 544: 205-228. [61] VAULAR E N, BARTH T, HAFLIDASON H. The geochemical characteristics of the hydrate-bound gases from the Nyegga pockmark field, Norwegian Sea[J]. Organic Geochemistry, 2010, 41(5): 437-444. [62] SASSEN R, LOSH S L, CATHLES L, et al. Massive vein-filling gas hydrate: Relation to ongoing gas migration from the deep subsurface of the Gulf of Mexico[J]. Marine and Petroleum Geology, 2001, 18(5): 551-560. [63] SASSEN R, SWEET S T, MILKOV A V, et al. Thermogenic vent gas and gas hydrate in the Gulf of Mexico slope: Is gas hydrate decomposition significant?[J]. Geology, 2001, 29: 107-110. [64] SASSEN R, ROBERTS H H, CARNEY R, et al. Free hydrocarbon gas, gas hydrate, and authigenic minerals in chemosynthetic communities of the northern Gulf of Mexico continental slope: Relation to microbial processes[J]. Chemical Geology, 2004, 205(3/4): 195-217. [65] MACDONALD I R, BOHRMANN G, ESCOBAR E, et al. Asphpalt volcanism and chemosynthetic life, Campeche Knolls, Gulf of Mexico[J]. Science, 2004, 304: 999-1002. [66] MILKOV A V. Molecular and stable isotope compositions of natural gas hydrates: A revised global dataset and basic interpretations in the context of geological settings[J]. Organic Geochemistry, 2005, 36(5): 681-702. [67] STERN L A, LORENSON T D, PINKSTON J C. Gas hydrate characterization and grain-scale imaging of recovered cores from the Mount Elbert gas hydrate stratigraphic test well, Alaska North Slope [J]. Marine and Petroleum Geology, 2011, 28(2): 394-403. [68] SASSEN R, CURIALE J A. Microbial methane and ethane from gas hydrate nodules of the Makassar Strait, Indonesia[J]. Organic Geochemistry, 2006, 37(8): 977-980. [69] CHOI J Y, KIM J H, TORRES M E, et al. Gas origin and migration in the Ulleung Basin, East Sea: Results from the Second Ulleung Basin Gas Hydrate Drilling Expedition (UBGH2)[J]. Marine and Petroleum Geology, 2013, 47(47): 113-124. [70] STERN L A, LORENSON T D. Grain-scale imaging and compositional characterization of cryo-preserved India NGHP 01 gas-hydrate-bearing cores[J]. Marine and Petroleum Geology, 2014, 58: 206-222. [71] WASEDA A, UCHIDA T. Origin of methane in natural gas hydrates from Mackenzie Delta and Nankai Trough[R]//Yokohama, Japan: Fourth International Conference on Gas Hydrates, 2002. [72] 唐世琪, 卢振权, 饶竹, 等. 祁连山冻土区天然气水合物岩心顶空气组分与同位素的指示意义: 以DK-9孔为例[J]. 地质通报, 2015, 34(5): 961-971. TANG Shiqi, LU Zhenquan, RAO Zhu, et al. The indicative significance of gas composition and isotopes of headspace gases from the gas hydrate drilling core in the Qilian Mountain permafrost: A case study of well DK-9[J]. Geological Bulletin of China, 2015, 34(5): 961-971. [73] 王佟, 刘天绩, 邵龙义, 等. 青海木里煤田天然气水合物特征与成因[J]. 煤田地质与勘探, 2009, 37(6): 26-30. WANG Tong, LIU Tianji, SHAO Longyi, et al. Characteristics and origins of the gas hydrates in the Muli coalfield of Qinghai[J]. Coal Geology and Exploration, 2009, 37(6): 26-30. [74] WANG T. Gas hydrate resource potential and its exploration and development prospect of the Muli coalfield in the northeast Tibetan plateau[J]. Energy Exploration and Exploitation, 2010, 28(3): 147-158. [75] 曹代勇, 刘天绩, 王丹, 等. 青海木里地区天然气水合物形成条件分析[J]. 中国煤炭地质, 2009, 21(9): 3-6. CAO Daiyong, LIU Tianji, WANG Dan, et al. Analysis of formation conditions of natural gas hydrate in Muli coalfield, Qinghai Province[J]. Coal Geology of China, 2009, 21(9): 3-6. [76] 曹代勇, 王丹, 李靖, 等. 青海祁连山冻土区木里煤田天然气水合物气源分析[J]. 煤炭学报, 2012, 37(8): 1364-1368. CAO Daiyong, WANG Dan, LI Jing, et al. Gas source analysis of natural gas hydrate of Muli coalfield in Qilian Mountain permafrost, Qinghai Province, China[J]. Journal of China Coal Society, 2012, 37(8): 1364-1368. [77] DAI J X, XIA X Y, QIN S F, et al. Origins of partially reversed alkane δ 13 C values for biogenic gases in China[J]. Organic Geochemistry, 2004, 35(4): 405-411. [78] DAI J X, NI Y Y, HUANG S P, et al. Secondary origin of negative carbon isotopic series in natural gas[J]. Journal of Natural Gas Geoscience, 2016, 1(1): 1-7. [79] 戴金星. 天然气中烷烃气碳同位素研究的意义[J]. 天然气工业, 2011, 31(12): 1-6. DAI Jinxing. Significance of the study on carbon isotopes of alkane gases[J]. Natural Gas Industry, 2011, 31(12): 1-6. [80] DAI J X, ZOU C N, LI J, et al. Carbon isotopes of Middle-Lower Jurassic coal-derived alkane gases from the major basins of northwestern China[J]. International Journal of Coal Geology, 2009, 80(2): 124-134. [81] HU Anping, LI Jian, ZHANG Wenzheng, et al. Geochemical characteristics and genetic types of natural gas from Upper Paleozoic, Lower Paleozoic and Mesozoic reserviors in the Ordos Basin, China[J]. SCIENCE CHINA Earth Sciences, 2008, 51(s1): 183-194. [82] 贺行良, 王江涛, 刘昌岭, 等. 天然气水合物客体分子与同位素组成特征及其地球化学应用[J]. 海洋地质与第四纪地质, 2012, 32(3): 163-174. HE Xingliang, WANG Jiangtao, LIU Changling, et al. Guest molecular and isotopic compositions of natural gas hydrates and its geochemical applications[J]. Marine Geology and Quaternary Geology, 2012, 32(3): 163-174. [83] WASEDA A, UCHIDA T. The geochemical context of gas hydrate in the eastern Nankai Trough[J]. Resource Geology, 2004, 54(1): 69-78. [84] MILLER D J, KETZER J M, VIANA A R, et al. Natural gas hydrates in the Rio Grande Cone (Brazil): A new province in the western South Atlantic[J]. Marine and Petroleum Geology, 2015, 67: 187-196. [85] BLINOVA V N, IVANOV M K, BOHRMANN G. Hydrocarbon gases in deposits from mud volcanoes in the Sorokin Trough, north-eastern Black Sea[J]. Geo-Marine Letters, 2003, 23(3): 250-257. [86] STADNITSKAIA A, IVANOV M K, POLUDETKINA E N, et al. Sources of hydrocarbon gases in mud volcanoes from the Sorokin Trough, NE Black Sea, based on molecular and carbon isotopic compositions[J]. Marine and Petroleum Geology, 2008, 25(10): 1040-1057. [87] CHARLOU J L, DONVAL J P, FOUQUET Y, et al. Physical and chemical characterization of gas hydrates and associated methane plumes in the Congo-Angola Basin[J]. Chemical Geology, 2004, 205(3): 405-425.