Geochemical Tracers for Methane Microleakage Activity in the Qiongdongnan Basin

doi:10.11885/j.issn.1674-5086.2017.12.01.01

Abstract

Abstract: To understand methane microleakage activity in the Qiongdongnan Basin of the northern South China Sea, the concentrations of pore water anions and cations, δ¹³C_DIC, and other indices of the core samples HQ-6PC and HQ-38PC were measured using bottom stimulating reflectors (BSR) in the development zone to study the characteristics of methane microleakage. The results showed that sulfate consumption was dominated by organic sulfate reduction (OSR) and anaerobic oxidation of methane (AOM) in the HQ-6PC and HQ-38PC core samples above 5.2 m, whereas the effects of AOM were predominant in the HQ-38PC core sample below 5.2 m. The sulfate-methane transition zone (SMTZ) of the HQ-38PC core sample had a depth of 9.9 m and an upward methane flux of 32 mmol·m^-2·a^-1. The change in Mg/Ca and Sr/Ca depth in the pore water of the two core samples indicated that the authigenic carbonate minerals formed within were primarily high-magnesium calcites. The Cl^- concentration of HQ-6PC was significantly decreased below 3.5 m. Inclusions of low-salinity fluid released from hydrate decomposition are likely present. There is a relatively large salinity anomaly in HQ-38PC between 4.0~5.5 m, suggesting that there might be mixing with high-salinity fluid released during hydrate formation. Thus, there is significant methane microleakage activity in the shallow surface of the two stations and possible hydrate development underneath.

Key words: methane microleakage, pore water, geochemistry, natural gas hydrates, Qiongdongnan Basin

CLC Number:

TE122

FENG Junxi, YANG Shengxiong, SUN Xiaoming, LIANG Jinqiang. Geochemical Tracers for Methane Microleakage Activity in the Qiongdongnan Basin[J]. 西南石油大学学报(自然科学版), 2018, 40(3): 63-75.

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References

[1] 陈多福,陈先沛,陈光谦. 冷泉流体沉积碳酸盐岩的地质地球化学特征[J]. 沉积学报, 2002, 20(1):34-40. doi:10.3969/j.issn.1000-0550.2002.01.007 CHEN Duofu, CHEN Xianpei, CHEN Guangqian. Geology and geochemistry of cold seepage and venting-related carbonates[J]. Acta Sedimentologica Sinica, 2002, 20(1):34-40. doi:10.3969/j.issn.1000-0550.2002.01.007
[2] HOVLAND M, JENSEN S, FICHLER C. Methane and minor oil macro-seep systems:Their complexity and environmental significance[J]. Marine Geology, 2012, 332:163-173. doi:10.1016/j.margeo.2012.02.014
[3] HEGGLAND R. Gas seepage as an indicator of deeper prospective reservoirs:A study based on exploration 3D seismic data[J]. Marine and Petroleum Geology, 1998, 15(1):1-9. doi:10.1016/S0264-8172(97)00060-3
[4] HOVLAND M, SVENSEN H. Submarine pingoes:Indicators of shallow gas hydrates in a pockmark at Nyegga, Norwegian Sea[J]. Marine Geology, 2006, 228(1-4):15-23. doi:10.1016/j.margeo.2005.12.005
[5] BOETIUS A, WENZHÖFER F. Seafloor oxygen consumption fuelled by methane from cold seeps[J]. Nature Geoscience, 2013, 6(9):725-734. doi:10.1038/ngeo1926
[6] POHLMAN J W, RUPPEL C, HUTCHINSON D R, et al. Assessing sulfate reduction and methane cycling in a high salinity pore water system in the northern Gulf of Mexico[J]. Marine and Petroleum Geology, 2008, 25(9):942-951. doi:10.1016/j.marpetgeo.2008.01.016
[7] CHEN Yifeng, USSLER W, HAFLIDASON H, et al. Sources of methane inferred from pore-water δ¹³C of dissolved inorganic carbon in Pockmark G11, offshore MidNorway[J]. Chemical Geology, 2010, 275(3-4):127-138. doi:10.1016/j.chemgeo.2010.04.013
[8] MAZUMDAR A, PEKETI A, JOAO H M, et al. Porewater chemistry of sediment cores off Mahanadi Basin, Bay of Bengal:Possible link to deep seated methane hydrate deposit[J]. Marine and Petroleum Geology, 2014, 49:162-175. doi:10.1016/j.marpetgeo.2013.10.011
[9] BOROWSKI W S, PAULL C K, USSLER W. Marine pore-water sulfate profiles indicate in situ methane flux from underlying gas hydrate[J]. Geology, 1996, 24(7):655-658. doi:10.1130/0091-7613(1996) 024<0655:MPWSPI>2.3.CO;2
[10] BOROWSKI W S, PAULL C K, WU Lili. Global and local variations of interstitial sulfate gradients in deepwater, continental margin sediments:Sensitivity to underlying methane and gas hydrates[J]. Marine Geology, 1999, 159(1):131-154. doi:10.1016/S00253227(99)00004-3
[11] JØRGENSEN B B, KASTEN S. Sulfur cycling and methane oxidation[M]. Berlin:Springer, 2006:271-309.
[12] REGNIER P, DALE A W, ARNDT S, et al. Quantitative analysis of anaerobic oxidation of methane (AOM) in marine sediments:A modeling perspective[J]. EarthScience Reviews, 2011, 106(1-2):105-130. doi:10.1016/j.earscirev.2011.01.002
[13] MEISTER P, LIU B, FERDELMAN T G, et al. Control of sulphate and methane distributions in marine sediments by organic matter reactivity[J]. Geochimica et Cosmochimica Acta, 2013, 104:183-193. doi:10.1016/j.gca.2012.11.01
[14] SEITER K, HENSEN C, SCHRÖTER J, et al. Organic carbon content in surface sediments-defining regional provinces[J]. Deep Sea Research Part I:Oceanographic Research Papers, 2004, 51(12):2001-2026. doi:10.1016/j.dsr.2004.06.014
[15] LEVIN L A, SIBUET M. Understanding continental margin biodiversity:A new imperative[J]. Annual Review of Marine Science, 2012, 4:79-112. doi:10.1146/annurevmarine-120709-142714
[16] LUFF R, WALLMANN K. Fluid flow, methane fluxes, carbonate precipitation and biogeochemical turnover in gas hydrate-bearing sediments at Hydrate Ridge, Cascadia Margin:Numerical modeling and mass balances[J]. Geochimica et Cosmochimica Acta, 2003, 67(18):3403-3421. doi:10.1016/S0016-7037(03)00127-3
[17] LIANG Qianyong, HU Yu, FENG Dong, et al. Authigenic carbonates from newly discovered active cold seeps on the northwestern slope of the South China Sea:Constraints on fluid sources, formation environments, and seepage dynamics[J]. Deep Sea Research Part I:Oceanographic Research Papers, 2017, 124:31-41. doi:10.1016/j.dsr.2017.04.015
[18] YANG Tao, JIANG Shaoyong, GE Lu, et al. Geochemical characteristics of pore water in shallow sediments from Shenhu area of South China Sea and their significance for gas hydrate occurrence[J]. Chinese Science Bulletin, 2010, 55(8):752-760. doi:10.1007/s11434-009-0312-2
[19] YANG Tao, JIANG Shaoyong, GE Lu, et al. Geochemistry of pore waters from HQ-1PC of the Qiongdongnan Basin, northern South China Sea, and its implications for gas hydrate exploration[J]. Science China Earth Sciences, 2013, 56(4):521-529. doi:10.1007/s11430-012-4560-7
[20] 邬黛黛,吴能友,张美,等. 东沙海域SMI与甲烷通量的关系及对水合物的指示[J]. 地球科学中国地质大学学报, 2013, 38(6):1309-1320. doi:10.3799/dqkx.2013.000 WU Daidai, WU Nengyou, ZHANG Mei, et al. Relationship of sulfate-methane interface (SMI), methane flux and the underlying gas hydrate in the Dongsha Area, northern South China Sea[J]. Earth Science-Journal of China University of Geosciences, 2013, 38(6):1309-1320. doi:10.3799/dqkx.2013.000
[21] WU L S, YANG S X, LIANG J Q, et al. Variations of pore water sulfate gradients in sediments as indicator for underlying gas hydrate in Shenhu Area, the South China Sea[J]. Science China Earth Sciences, 2013, 56(4):530-540.doi:10.1007/s11430-012-4545-6
[22] YE Hong, YANG Tao, ZHU Guorong, et al. Pore water geochemistry in shallow sediments from the northeastern continental slope of the South China Sea[J]. Marine and Petroleum Geology, 2016, 75:68-82. doi:10.1016/j.marpetgeo.2016.03.010
[23] JIANG Shaoyong, YANG Tao, GE Lu, et al. Geochemistry of pore waters from the Xisha Trough, northern South China Sea and their implications for gas hydrates[J]. Journal of Oceanography, 2008, 64(3):459-470. doi:10.1007/s10872-008-0039-8
[24] HU Y, FENG D, LIANG Q, et al. Impact of anaerobic oxidation of methane on the geochemical cycle of redoxsensitive elements at cold-seep sites of the northern South China Sea[J]. Deep Sea Research Part Ⅱ:Topical Studies in Oceanography, 2015, 122:84-94. doi:10.1016/j.dsr2.2015.06.012
[25] 梁金强,付少英,陈芳,等. 南海东北部陆坡海底甲烷渗漏及水合物成藏特征[J]. 天然气地球科学, 2017, 28(5):761-770. doi:10.11764/j.issn.1672-1926.2017.02.006 LIANG Jinqiang, FU Shaoying, CHEN Fang, et al. Characteristics of methane seepage and gas hydrate reservior in the northeastern slope of South China Sea[J]. Natural Gas Geoscience, 2017, 28(5):761-770. doi:10.11764/j.issn.1672-1926.2017.02.006
[26] 张光学,梁金强,陆敬安,等. 南海东北部陆坡天然气水合物藏特征[J]. 天然气工业, 2014, 34(11):1-10. doi:10.3787/j.issn.1000-0976.2014.11.001 ZHANG Guangxue, LIANG Jinqiang, LU Jing'an, et al. Characteristics of natural gas hydrate reservoirs on the northeastern slope of the South China Sea[J]. Natural Gas Industry, 2014, 34(11):1-10. doi:10.3787/j.issn.10000976.2014.11.001
[27] 吴庐山,杨胜雄,梁金强,等. 南海北部琼东南盆地HQ-48PC站位地球化学特征及对天然气水合物的指示意义[J]. 现代地质, 2010, 24(3):534-544. doi:10.3969/j.issn.1000-8527.2010.03.018 WU Lushan, YANG Shengxiong, LIANG Jinqiang, et al. Geochemical characteristics of sediments at site HQ48PC in Qiongdongnan Area, the north of the South China Sea and their implication for gas hydrates[J]. Geoscience, 2010, 24(3):534-544. doi:10.3969/j.issn.10008527.2010.03.018
[28] 姚伯初. 南海的天然气水合物矿藏[J]. 热带海洋学报,2001,20(2):20-28. doi:10.3969/j.issn.1009-5470.2001.02.004 YAO Bochu. The gas hydrate in the South China Sea[J]. Journal of Tropical Oceanography, 2001, 20(2):20-28. doi:10.3969/j.issn.1009-5470.2001.02.004
[29] 梁金强,王宏斌,苏新,等. 南海北部陆坡天然气水合物成藏条件及其控制因素[J]. 天然气工业, 2014, 34(7):128-135. doi:10.3787/j.issn.1000-0976.2014.07.022 LIANG Jinqiang, WANG Hongbin, SU Xin, et al. Natural gas hydrate formation conditions and the associated controlling factors in the northern slope of the South China Sea[J]. Natural Gas Industry, 2014, 34(7):128-135. doi:10.3787/j.issn.1000-0976.2014.07.022
[30] 陈多福,姚伯初,赵振华,等. 珠江口和琼东南盆地天然气水合物形成和稳定分布的地球化学边界条件及其分布区[J]. 海洋地质与第四纪地质, 2001, 21(4):73-78. doi:10.16562/j.cnki.0256-1492.2001.04.014 CHEN Duofu, YAO Bochu, ZHAO Zhenhua, et al. Geochemical constraints and potential distributions of gas hydrates in Pearl River Mouth Basin and Qiongdongnan Basin in the northern margin of the South China Sea[J]. Marine Geology and Quaternary Geology, 2001, 21(4):73-78. doi:10.16562/j.cnki.0256-1492.2001.04.014
[31] 陈多福,李绪宣,夏斌. 南海琼东南盆地天然气水合物稳定域分布特征及资源预测[J]. 地球物理学报, 2004, 47(3):483-489. doi:10.3321/j.issn:0001-5733.2004.03.018 CHEN Duofu, LI Xuxuan, XIA Bin. Distribution of gas hydrate stable zones and resource prediction in the Qiongdongnan Basin of the South China Sea[J]. 2004, 47(3):483-489. doi:10.3321/j.issn:0001-5733.2004.03.018
[32] SCHULZ H D. Quantification of early diagenesis:Dissolved constituents in pore water and signals in the solid phase[M]//SCHULZ H D, ZABEL M Eds. Marine Geochemistry. Berlin:Springer, 2006:73-124.
[33] LI Yuanhui, GREGORY S. Diffusion of ions in sea water and in deep-sea sediments[J]. Geochimica et Cosmochimica Acta, 1974, 38(5):703-714. doi:10.1016/0016-7037(74)90145-8
[34] Shipboard Scientific Party. Site 1146. In:WANG P X, PRELL W L, BLUM P, et al. Proceedings of the Ocean Drilling Program, Initial Reports Volume 184[R]. College Station, Texas:Texas A & M University (Ocean Drilling Program), 2000:1-101.
[35] HESSE R, HARRISON W E. Gas hydrates (clathrates) causing pore-water freshening and oxygen isotope fractionation in deep-water sedimentary sections of terrigenous continental margins[J]. Earth and Planetary Science Letters, 1981, 55(3):453-462. doi:10.1016/0012821X(81)90172-2
[36] USSLER W, PAULL C K. Effects of ion exclusion and isotopic fractionation on pore water geochemistry during gas hydrate formation and decomposition[J]. Geo-Marine Letters, 1995, 15(1):37-44. doi:10.1007/BF01204496
[37] HESSE R. Pore water anomalies of submarine gas-hydrate zones as tool to assess hydrate abundance and distribution in the subsurface:What have we learned in the past decade?[J]. Earth-Science Reviews, 2003, 61(1):149-179. doi:10.1016/S0012-8252(02)00117-4
[38] DÄHLMANN A, DE LANGE G J. Fluid-sediment interactions at Eastern Mediterranean mud volcanoes:A stable isotope study from ODP Leg 160[J]. Earth and Planetary Science Letters, 2003, 212(3-4):377-391. doi:10.1016/S0012-821X(03)00227-9
[39] ALOISI G, DREWS M, WALLMANN K, et al. Fluid expulsion from the Dvurechenskii mud volcano (Black Sea):Part I. Fluid sources and relevance to Li, B, Sr, I and dissolved inorganic nitrogen cycles[J]. Earth and Planetary Science Letters, 2004, 225(3-4):347-363. doi:10.1016/S0012-821X(04)00415-7
[40] ZHU Youhai, HUANG Yongyang, MATSUMOTO R, et al. Geochemical and stable isotopic compositions of pore fluids and authigenic siderite concretions from site 1146, ODP Leg 184:implication for gas hydrate[R]. In:Prell W L, Wang P, Rea D K, Clemans S C, eds. Proceedings of the ODP, Scientific Results, 2002, 184:1-15. doi:10.2973/odp.proc.sr.184.202.2003
[41] 杨涛,蒋少涌,葛璐,等. 南海北部陆坡西沙海槽XS-01站位沉积物孔隙水的地球化学特征及其对天然气水合物的指示意义[J]. 第四纪研究, 2006, 26(3):442-448. doi:10.3321/j.issn:1001-7410.2006.03.017 YANG Tao, JIANG Shaoyong, GE Lu, et al. Geochemical characteristics of sediment pore water from site XS-01 in the Xisha Trough of South China Sea and their significance for gas hydrate occurrence[J]. Quaternary Sciences, 2006, 26(3):442-448. doi:10.3321/j.issn:1001-7410.2006.03.017
[42] 吴能友,张海啟,杨胜雄,等. 南海神狐海域天然气水合物成藏系统初探[J]. 天然气工业, 2007, 27(9):1-6. doi:10.3321/j.issn:1000-0976.2007.09.001 WU Nengyou, ZHANG Haiqi, YANG Shengxiong, et al. Preliminary discussion on natural gas hydrate (NGH) reservoir system of Shenhu Area, north slope of South China Sea[J]. Natural Gas Industry, 2007, 27(9):1-6. doi:10.3321/j.issn:1000-0976.2007.09.001
[43] LUO Min, CHEN Linying, TONG Hongpeng, et al. Gas hydrate occurrence inferred from dissolved Cl^- concentrations and δ¹⁸O values of pore water and dissolved sulfate in the shallow sediments of the Pockmark Field in Southwestern Xisha Uplift, Northern South China Sea[J]. Energies, 2014, 7(6):3886-3899. doi:10.3390/en7063886
[44] 祝有海,饶竹,刘坚,等. 南海西沙海槽S14站位的地球化学异常特征及其意义[J]. 现代地质, 2005, 19(1):39-44. doi:10.3969/j.issn.1000-8527.2005.01.006 ZHU Youhai, RAO Zhu, LIU Jian, et al. Geochemical anomalies and their implication from site 14, the Xisha Trough, the South China Sea[J]. Geoscience, 2005, 19(1):39-44. doi:10.3969/j.issn.1000-8527.2005.01.006
[45] CHUANG Peichuan, DALE A W, WALLMANN K, et al. Relating sulfate and methane dynamics to geology:Accretionary prism offshore SW Taiwan[J]. Geochemistry, Geophysics, Geosystems, 2013, 14(7):2523-2545. doi:10.1002/ggge.20168
[46] 何家雄,卢振权,苏丕波,等. 南海北部天然气水合物气源系统与成藏模式[J]. 西南石油大学学报(自然科学版),2016,38(6):8-24. doi:10.11885/j.issn.16745086.2016.09.03.01 HE Jiaxiong, LU Zhenquan, SU Pibo, et al. Source Supply System and Reservoir Forming Model Prediction of Natural Gas Hydrate in the Deep Water Area of the Northern South China Sea[J]. Journal of Southwest Petroleum University (Science & Technology Edition), 2016, 38(6):8-24. doi:10.11885/j.issn.16745086.2016.09.03.01
[47] TORRES M E, WALLMANN K, TRÉHU A M, et al. Gas hydrate growth, methane transport, and chloride enrichment at the southern summit of Hydrate Ridge, Cascadia margin off Oregon[J]. Earth and Planetary Science Letters, 2004, 226(1-2):225-241. doi:10.1016/j.epsl.2004.07.029
[48] MALINVERNO A, POHLMAN J W. Modeling sulfate reduction in methane hydrate-bearing continental margin sediments:Does a sulfate-methane transition require anaerobic oxidation of methane?[J]. Geochemistry, Geophysics, Geosystems, 2011, 12(7):Q07006. doi:10.1029/2011GC003501
[49] MASUZAWA T, HANDA N, KITAGAWA H, et al. Sulfate reduction using methane in sediments beneath a bathyal "cold seep" giant clam community off Hatsushima Island, Sagami Bay, Japan[J]. Earth and Planetary Science Letters, 1992, 110(1-4):39-50. doi:10.1016/0012821X(92)90037-V
[50] LUO Min, CHEN Linying, WANG Shuhong, et al. Pockmark activity inferred from pore water geochemistry in shallow sediments of the pockmark field in southwestern Xisha Uplift, northwestern South China Sea[J]. Marine and Petroleum Geology, 2013, 48:247-259. doi:10.1016/j.marpetgeo.2013.08.018
[51] SNYDER G T, HIRUTA A, MATSUMOTO R, et al. Pore water profiles and authigenic mineralization in shallow marine sediments above the methane-charged system on Umitaka Spur, Japan Sea[J]. Deep Sea Research Part Ⅱ:Topical Studies in Oceanography, 2007, 54(11-13):1216-1239. doi:10.1016/j.dsr2.2007.04.001
[52] KIM J H, PARK M H, CHUN J H, et al. Molecular and isotopic signatures in sediments and gas hydrate of the central/southwestern Ulleung Basin:High alkalinity escape fuelled by biogenically sourced methane[J]. GeoMarine Letters, 2011, 31(1):37-49. doi:10.1007/s00367010-0214-y
[53] HONG Weili, TORRES M E, KIM J H, et al. Carbon cycling within the sulfate-methane-transition-zone in marine sediments from the Ulleung Basin[J]. Biogeochemistry, 2013, 115(1-3):129-148. doi:10.1007/s10533-0129824-y
[54] BOROWSKI W S, HOEHLER T M, ALPERIN M J, et al. Significance of anaerobic methane oxidation in methanerich sediments overlying the Blake Ridge gas hydrates[C]. Proceedings of the Ocean Drilling Program, Scientific Results, 2000, 164:87-99. doi:10.2973/odp.proc.sr.164.214.2000
[55] 陈法锦,陈建芳,金海燕,等. 南海表层沉积物与沉降颗粒物中有机碳的δ¹³C对比研究及其古环境再造意义[J]. 沉积学报,2012,30(2):340-345. doi:10.14027/j.cnki.cjxb.2012.02.013 CHEN Fajin, CHEN Jianfang, JIN Haiyan, et al. Correlation of δ¹³Corg in surface sediments with sinking particulate matter in South China Sea and implication for reconstructing paleo-environment[J]. Acta Sedimentologica Sinica, 2012, 30:340-345. doi:10.14027/j.cnki.cjxb.2012.02.013
[56] WU Daidai, WU Nengyou, YE Ying, et al. Early diagenesis records and pore water composition of methane-seep sediments from the Southeast Hainan Basin, South China Sea[J]. Journal of Geological Research, 2011. doi:10.1155/2011/592703
[57] NÖTHEN K, KASTEN S. Reconstructing changes in seep activity by means of pore water and solid phase Sr/Ca and Mg/Ca ratios in pockmark sediments of the Northern Congo Fan[J]. Marine Geology, 2011, 287(1-4):1-13. doi:10.1016/j.margeo.2011.06.008
[58] PECKMANN J, THIEL V. Carbon cycling at ancient methane-seeps[J]. Chemical Geology, 2004, 205(3-4):443-467. doi:10.1016/j.chemgeo.2003.12.025
[59] SCHRAG D P, HIGGINS J A, MACDONALD F A, et al. Authigenic carbonate and the history of the global carbon cycle[J]. Science, 2013, 339(6119):540-543. doi:10.1126/science.1229578
[60] SUN X, TURCHYN A V. Significant contribution of authigenic carbonate to marine carbon burial[J]. Nature Geoscience, 2014, 7(3):201-204. doi:10.1038/ngeo2070
[61] BURTON E A. Controls on marine carbonate cement mineralogy:Review and reassessment[J]. Chemical Geology, 1993, 105(1-3):163-179. doi:10.1016/00092541(93)90124-2
[62] PECKMANN J, REIMER A, LUTH U, et al. Methanederived carbonates and authigenic pyrite from the northwestern Black Sea[J]. Marine Geology, 2001, 177(1):129-150. doi:10.1016/S0025-3227(01)00128-1
[63] GIESKES J, MAHN C, DAY S, et al. A study of the chemistry of pore fluids and authigenic carbonates in methane seep environments:Kodiak Trench, Hydrate Ridge, Monterey Bay, and Eel River Basin[J]. Chemical Geology, 2005, 220(3-4):329-345. doi:10.1016/j.chemgeo.2005.04.002