Study on Features of Water Soluble Hydrocarbon Components and Carbon-hydrogen Isotopes of Methane in the Kaixinling-Wuli Permafrost Region on the Northern Margin of Qiangtang Area

doi:10.19657/j.geoscience.1000-8527.2019.06.16

Abstract

Abstract:

Several cold springs bear water soluble alkanes along the concealed faults in the Kaixinling-Wuli permafrost region on the northern margin of Qiangtang area. Based on analyses of the water soluble hydrocarbon components, stable carbon-hydrogen isotopes of methane, the genesis of the water soluble alkanes was studied. The results showed that the methane (CH₄) volume fraction ratio in the water soluble hydrocarbon components reached as high as 99.83%-99.96% in the Kaixinling-Wuli permafrost region, accompanied by a small amount of ethane (C₂H₆), propane (C₃H₈), trace amounts of ethylene (C₂H₄) and propylene (C₃H₆). In water soluble hydrocarbon, methane δ ¹³C_PDB values range in -46.5‰ to -55.1‰ with δD_VSMOW values of -281.0‰ to -342.0‰ in the Kaixinling permafrost area. In water soluble hydrocarbon, methane δ ¹³C_PDB values are -47.8‰ to -58.9‰, and δD_VSMOW values are -339.0‰ to -346.0‰ in the Wuli permafrost area. These features indicate that in water soluble hydrocarbon, methane is of organic origin, but the gas origin is relatively complex. Methane mainly belongs to microbial gas, secondarily pyrolysis gas, mixed with a small amount of oil-associated gas, discriminated by the genesis diagrams of δ¹³C_CH₄-δD_CH₄ vs. δD_CH₄ and δ¹³C₁ vs. C₁/ (C₂+C₃). It is inferred that methane is mainly originated from the hydrocarbon gases or sub-microbial gases, decomposed from the organic matters under the action of microorganisms, in connection with the coal-bearing hydrocarbon source rocks in Nayixiong Formation of the Late Permian. Gas condition implies that at depths from 200 to 500 meters, it is conducive to form methane hydrate with microbial gas in this permafrost region.

Key words: water soluble hydrocarbon component, methane carbon-hydrogen isotope, genesis, gas hydrate, Kaixinling-Wuli permafrost region, northern margin of Qiangtang area

CLC Number:

WANG Jinshou, LU Zhenquan, WANG Fuchun, CHEN Jing, XUE Wanwen, ZHANG Zhiqing. Study on Features of Water Soluble Hydrocarbon Components and Carbon-hydrogen Isotopes of Methane in the Kaixinling-Wuli Permafrost Region on the Northern Margin of Qiangtang Area[J]. Geoscience, 2019, 33(06): 1306-1313.

Figures/Tables 7

Fig.1 Geological diagram of Kaixinling-Wuli permafrost region

Table 1 Results of water soluble hydrocarbon alkane gas composition in frozen cold spring from Kaixinling-Wuli permafrost region

样号	采样地	烃类气体成分和含量/(μL/L)						碳数比例/%
样号	采样地	CH₄	C₂H₆	C₂H₄	C₃H₈	C₃H₆	总烃	C₁	C₂	C₃
D603S3	乌丽	629.16	0.25	0.08	0.00	0.10	629.60	99.93	0.05	0.02
D767S1^*	乌丽	834.23	0.15	0.04	0.02	0.13	834.58	99.96	0.02	0.02
D773S3^*	乌丽	1 113.21	1.38	0.17	0.06	0.13	1 114.95	99.84	0.14	0.02
D774S3	开心岭	583.22	0.79	0.17	0.01	0.04	584.24	99.83	0.17	0.01
D777S2	开心岭	743.76	0.18	0.05	0.02	0.04	744.05	99.96	0.03	0.01
D778S1	开心岭	667.91	0.19	0.04	0.02	0.04	668.20	99.96	0.03	0.01
D780S6	开心岭	342.23	0.08	0.02	0.01	0.02	342.36	99.96	0.03	0.01
平均值		701.96	0.43	0.08	0.02	0.07	702.57	99.92	0.07	0.01

Table 2 Results of carbon, hydrogen isotope tests of water soluble hydrocarbon gas from frozen cold spring

样号	δ¹³C_PDB/‰			δ $D V SMOW$ /‰		C₁/ (C₂+C₃)
样号	CH₄	C₂H₆	C₃H₈	H₂	CH₄	C₁/ (C₂+C₃)
D603S3	-58.9	未检出	未检出	未检出	-339.0	1 463
D767S1	-55.6	未检出	未检出	未检出	-342.0	2 453
D773S3	-47.8	未检出	未检出	未检出	-346.0	640
D774S3	-48.4	未检出	未检出	未检出	-342.0	578
D777S2	-53.6	未检出	未检出	未检出	-340.0	2 565
D778S1	-55.1	未检出	未检出	未检出	-334.0	2 303
D780S6	-46.5	未检出	未检出	未检出	-281.0	2 633
平均值	-52.3				-331.9	1 805

Table 2 Results of carbon, hydrogen isotope tests of water soluble hydrocarbon gas from frozen cold spring

样号	δ¹³C_PDB/‰			δ $D V SMOW$ /‰		C₁/ (C₂+C₃)
样号	CH₄	C₂H₆	C₃H₈	H₂	CH₄	C₁/ (C₂+C₃)
D603S3	-58.9	未检出	未检出	未检出	-339.0	1 463
D767S1	-55.6	未检出	未检出	未检出	-342.0	2 453
D773S3	-47.8	未检出	未检出	未检出	-346.0	640
D774S3	-48.4	未检出	未检出	未检出	-342.0	578
D777S2	-53.6	未检出	未检出	未检出	-340.0	2 565
D778S1	-55.1	未检出	未检出	未检出	-334.0	2 303
D780S6	-46.5	未检出	未检出	未检出	-281.0	2 633
平均值	-52.3				-331.9	1 805

Fig.2 Relationships of methane carbon isotope vs.C1/(C2+C3) of water soluble hydrocarbon (after references[33-34] )

Fig.3 Genetic diagram of water soluble hydrocarbon gas (after reference [29,35] )

Fig.4 Diagram of carbon isotope and composition of water soluble hydrocarbon methane (after reference [34]])

Fig.5 δ13CCH4-δDCH4 genetic discrimination diagram of water soluble hydrocarbon gas (after reference [35] )

References 45

[1]	周幼吾, 郭东信, 邱国庆, 等. 中国冻土[M]. 北京: 科学出版社, 2000: 145-353.
[2]	吴青柏, 施斌, 刘永智. 青藏公路沿线冻土与公路相互作用研究[J]. 中国科学: D辑 , 2002,32(6):514-520.
[3]	王进寿, 潘彤, 曾小平, 等. 青海乌丽冻土区冷泉水溶烃对形成天然气水合物的指示意义[J]. 地质科技情报, 2015,34(5):53-57.
[4]	王进寿, 郑有业, 黄朝晖, 等. 陆域天然气水合物形成条件理论研究及其对青南多年冻土区水合物勘查的启示[J]. 地质科技情报, 2016,35(5):139-147.
[5]	徐学祖, 程国栋, 俞祁浩. 青藏高原多年冻土区天然气水合物的研究前景和建议[J]. 地球科学进展, 1999,14(2):201-204.
[6]	卢振权, 吴必豪, 饶竹, 等. 青藏铁路沿线多年冻土区天然气水合物的地质、地球化学异常[J]. 地质通报, 2007,26(8):1029-1040.
[7]	LIU S Q, JIANG Z X, LIU H, et al. The natural-gas hydrate exploration prospects of the Nayixiong Formation in the Kaixinling-Wuli permafrost, Qinghai-Tibet Plateau[J]. Marine and Petroleum Geology, 2016,72:179-192. DOI URL
[8]	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.
[9]	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(9):3-6.
[10]	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(1):7-16, 130.
[11]	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. DOI URL
[12]	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.
[13]	李小豫, 龚建明, 陈小慧, 等. 青藏高原乌丽冻土区二叠纪煤系烃源岩特征[J]. 现代地质, 2013,27(6):1384-1391.
[14]	青海省地质矿产局. 青海省岩石地层[M]. 武汉: 中国地质大学出版社, 1997: 112-287.
[15]	吴军虎. 青海乌丽—开心岭地区晚二叠世构造演化与聚煤规律作用分析[J]. 中国煤炭地质, 2011,23(6):9-13.
[16]	卢振权, SULTAN N, 金春爽, 等. 青藏高原多年冻土区天然气水合物形成条件模拟研究[J]. 地球物理学报, 2009,52(1):157-168.
[17]	卢振权, 吴必豪, 祝有海. 南海潜在天然气水合物藏的成因及形成模式初探[J]. 矿床地质, 2002,21(3):232-239.
[18]	ABRAMS M A. Significance of hydrocarbon seepage relative to petroleum generation and entrapment[J]. Marine and Petroleum Geology, 2005,22(4):457-477. DOI URL
[19]	狄永军, 郭正府, 李凯明, 等. 天然气水合物成因探讨[J]. 地球科学进展, 2003,18(1):138-143.
[20]	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.
[21]	ABRAJANO T A, STURCHIO N C, BOHLKE J K, et al. Methane-hydrogen gas seeps, Zambales ophiolite, Philippines: Deep or shallow origin?[J]. Chemical Geology, 1988,71(1):211-222. DOI URL
[22]	SCHOELL M. Multiple origins of methane in the earth[J]. Chemical Geology, 1988,71(1):1-10. DOI URL
[23]	KVENVOLDEN K A. Gas hydrates as a potential energy resource: a review of their methane content [R]. HOWELL D G. The Future of Energy Gases, Geology Survey Profession Paper U S, 1993,1570:555-561.
[24]	COLLETT T S. Natural gas hydrates of the Prudhoe Bay and Kuparuk River area, North Slope, Alaska[J]. American Association of Petroleum Geologists Bulletin, 1993,77(5):793-812.
[25]	COLLETT T S. Energy resource potential of natural gas hydrates[J]. AAPG, 2002,86(11):1971-1992.
[26]	COLLETT T S, AGENA W F, LEE M W, et al. Assessment of gas hydrate resources on the North Slope, Alaska[R/OL]. 2008 Geological Survey Fact Sheet, U.S. http://pubs.usgs.gov/fs/2008/3073/ , 2008-3073, 4.
[27]	刘朝露, 李剑, 方家虎, 等. 水溶气运移成藏物理模拟实验技术[J]. 天然气地球科学, 2004,15(1):32-36.
[28]	戴金星. 云南省腾冲县硫磺塘天然气的碳同位素组成特征和成因[J]. 科学通报, 1988,33(15):1168-1170.
[29]	戴金星. 各类烷烃气的鉴别[J]. 中国科学: B辑, 1992(2):185-193.
[30]	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.
[31]	戴金星, 宋岩, 戴春生, 等. 中国东部无机成因气及其气藏形成条件[M]. 北京: 科学出版社, 1995: 1-100.
[32]	WHITICAR M J, FABER E, SCHOELL M. Biogenic methane formation in marine and freshwater environments: CO₂ reduction vs.acetate fermentation 2 isotope evidence[J]. Geochimica et Cosmochimica Acta, 1986,50(5):693-709. DOI URL
[33]	BUDWILL K. Microbial methano genesis and its role in enhancing coalbed methane recovery (Canadian coals)[R]. CSEG Recorder, 2003: 41-43.
[34]	陈践发, 徐永昌, 黄第藩. 塔里木盆地东部地区天然气地球化学特征及成因探讨(之一)[J]. 沉积学报, 2000,18(4):606-609.
[35]	SHEN P, XU Y. Isotopic compositional characteristics of terrigenous natural gases in China[J]. Chinese Journal of Geochemistry, 1993,12(1):14-24. DOI URL
[36]	YAKUSHEV V S, CHUVILIN E M. Natural gas and gas hydrate accumulations within permafrost in Russia[J]. Cold Regions Science and Technology, 2000,31:189-197. DOI URL
[37]	BERNARD B, BROOKS J M, SACKETT W M. A geochemical model for characterization of hydrocarbon gas sources in marine sediments[M]// Proceedings of the Offshore Technology Conference 1977,OTC’77,Houston,USA. 1977: 435-438.
[38]	戴金星, 戚厚发, 宋岩, 等. 我国煤层气组份、碳同位素类型及其成因和意义[J]. 中国科学: B缉, 1986,12:1317-1326.
[39]	MIYAZAKI S, KORSCH R J. Coalbed methane resources in the Permian of eastern Australia and their tectonic setting[J]. The APPEA Journal, 1993,33:161-175. DOI URL
[40]	秦勇, 唐修义, 叶建平, 等. 中国煤层甲烷稳定碳同位素分布及成因探讨[J]. 中国矿业大学学报, 2000,29:113-119.
[41]	张金川, 徐波, 聂海宽, 等. 中国页岩气资源勘探潜力[J]. 天然气工业, 2008,28(6):136-140.
[42]	邹才能, 董大忠, 杨桦, 等. 中国页岩气形成条件及勘探实践[J]. 天然气工业, 2011,31(12):26-39.
[43]	LORNSON T D, COLLETT T S, HUNTER R B. Gas geochemistry of the Mount Elbert gas hydrate stratigraphic test well, Alaska North Slope: Implications for gas hydrate exploration in the Arctic[J]. Marine and Petroleum Geology, 2011,28:343-360. DOI URL
[44]	COLLETT T S, LEE M W, AGENA W F, et al. Permafrost-associated natural gas hydrate occurrences on the Alaska North Slope[J]. Marine and Petroleum Geology, 2011,28:279-294. DOI URL
[45]	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, 2015,61:14-21. DOI URL