Citation: | HUANG Wei, ZHANG Wei, LIANG Jinqiang, SHANG Jiujing, MENG Miaomiao, LIN Lin, XU Mengjie. Characteristics of gas-bearing fluid migration and accumulation system and their control on gas hydrate accumulation in the Jianfengbei Basin of South China Sea[J]. Marine Geology & Quaternary Geology, 2020, 40(4): 148-161. doi: 10.16562/j.cnki.0256-1492.2019091802 |
The Jianfengbei Basin, located on the northern slope of the South China Sea, has high potential of gas hydrate accumulation. There are abundant gas sources and good conditions for migration and accumulation of gas-bearing fluids. In order to reveal the geological characteristics of gas hydrate accumulations in the basin, various types of data, such as high-precision 3D multi-channel seismic data, sub-bottom profiles and multi-beam data are collected and analyzed, and the geological and geophysical characteristics of the deep and shallow pathways for gas-bearing fluid migration and accumulation as well as their controlling effects on gas hydrate accumulation are carefully studied. Morphology, size and distribution patterns of the main gas-bearing fluid migration pathways in both the deep and shallow parts and their controlling factors are described in details. The combination characteristics of the deep and shallow gas-bearing fluid migration pathways and their coupling relationship with gas hydrate distribution are analyzed. Finally, in consideration of the geological conditions for the formation of gas hydrate, accumulation models and influencing factors are discussed. The study shows that the pathways for gas-bearing fluid migration in the Jianfengbei Basin are dominated by faults. All the features, such as bright-spot reflection, reflective blank zone, BSR, acoustic blank, acoustic turbidity and other geophysical characteristics, suggest that gas-bearing fluid migration and gas hydrate mostly occur on the top and/or in the places near the source connected faults, paleo-uplifts associated faults or polygonal faults. Bounded by T3 reflection interface, the gas-bearing fluid migration pathways composed of the faults mentioned above linked vertically the deep gas source layer to the gas hydrate stability zone in the shallow part. Based upon the above, two gas-bearing fluid migration and hydrate accumulation models, “source -connected fault- polygonal fault” and “paleo-uplift associated faults -polygonal fault” are proposed in this paper. The existence of polygonal faults has two functions, On one hand, it promotes gas-bearing fluids “inherited migration” into the shallow layers and controls the accumulation of gas hydrates; on the other hand, in the layer where polygonal faults densely developed, strongly fluid charging may cause the destruction of local temperature and pressure balance which leads to gas hydrate decomposition and leakage, and "intermittent" BSR. The continuing effect of shallow gas leakage will modify the seabed morphology, and lead to the formation of submarine micro-geomorphology, such as seabed slumping, seabed faults, pockmarks and mound-like features.
[1] | Collett T S, Bird K J, Kvenvolden K A, et al. Geologic interrelations relative to gas hydrates within the North Slope of Alaska[R]. Open-File Report 88-389, U.S. Geological Survey-Department of Energy, 1988. |
[2] | Hornbach M J, Saffer D M, Holbrook W S, et al. Three-dimensional seismic imaging of the Blake Ridge methane hydrate province: evidence for large, concentrated zones of gas hydrate and morphologically driven advection [J]. Journal of Geophysical Research, 2008, 113(B7): B07101. |
[3] | Zhang W, Liang J Q, Yang X L, et al. The formation mechanism of mud diapirs and gas chimneys and their relationship with natural gas hydrates: insights from the deep-water area of Qiongdongnan Basin, northern South China Sea [J]. International Geology Review, 2020,62(7-8):789-810. doi: 10.1080/00206814.2018.1491014 |
[4] | Milkov A V, Sassen R. Thickness of the gas hydrate stability zone, Gulf of Mexico continental slope [J]. Marine and Petroleum Geology, 2000, 17(9): 981-991. doi: 10.1016/S0264-8172(00)00051-9 |
[5] | Freifeld B, Kneafsey T, Pruess J, et al. X-ray scanner for ODP Leg 204: drilling gas hydrates on hydrate ridge, Cascadia continental margin[R]. Berkeley: Lawrence Berkeley National Laboratory, 2002. |
[6] | Tinivella U, Loreto M F, Accaino F. Regional versus detailed velocity analysis to quantify hydrate and free gas in marine sediments: the South Shetland Margin case study[M]//Long D, Lovell M A, Rees J R, et al. Sediment-Hosted Gas Hydrates: New Insights on Natural and Synthetic Systems. Geological Society, London, Special Publications, 2009. |
[7] | Makogon Y F. Natural gas hydrates – A promising source of energy [J]. Journal of Natural Gas Science and Engineering, 2010, 2(1): 49-59. doi: 10.1016/j.jngse.2009.12.004 |
[8] | Taylor M H, Dillon W P, Pecher I A. Trapping and migration of methane associated with the gas hydrate stability zone at the Blake Ridge Diapir: new insights from seismic data [J]. Marine Geology, 2000, 164(1-2): 79-89. doi: 10.1016/S0025-3227(99)00128-0 |
[9] | Løseth H, Gading M, Wensaas L. Hydrocarbon leakage interpreted on seismic data [J]. Marine and Petroleum Geology, 2009, 26(7): 1304-1319. doi: 10.1016/j.marpetgeo.2008.09.008 |
[10] | Berndt C. Focused fluid flow in passive continental margins [J]. Philosophical Transactions of the Royal Society A, 2005, 363(1837): 2855-2871. doi: 10.1098/rsta.2005.1666 |
[11] | Gay A, Lopez M, Cochonat P, et al. Isolated seafloor pockmarks linked to BSRs, fluid chimneys, polygonal faults and stacked Oligocene-Miocene turbiditic palaeochannels in the Lower Congo Basin [J]. Marine Geology, 2006, 226(1-2): 25-40. doi: 10.1016/j.margeo.2005.09.018 |
[12] | López C, Spence G, Hyndman R, et al. Frontal ridge slope failure at the northern Cascadia margin: margin-normal fault and gas hydrate control [J]. Geology, 2010, 38(11): 967-970. doi: 10.1130/G31136.1 |
[13] | 李磊, 裴都, 都鹏燕, 等. 海底麻坑的构型、特征、演化及成因——以西非木尼河盆地陆坡为例[J]. 海相油气地质, 2013, 18(4):53-58 doi: 10.3969/j.issn.1672-9854.2013.04.008 LI Lei, PEI Du, DU Pengyan, et al. Architecture, character, evolution and genesis of seabed pockmarks: a case study to the continental slope in Rio Muni basin, West Africa [J]. Marine Origin Petroleum Geology, 2013, 18(4): 53-58. doi: 10.3969/j.issn.1672-9854.2013.04.008 |
[14] | Cathles L M, Su Z, Chen D F. The physics of gas chimney and pockmark formation, with implications for assessment of seafloor hazards and gas sequestration [J]. Marine and Petroleum Geology, 2010, 27(1): 82-91. doi: 10.1016/j.marpetgeo.2009.09.010 |
[15] | Cartwright J, Santamarina C. Seismic characteristics of fluid escape pipes in sedimentary basins: implications for pipe genesis [J]. Marine and Petroleum Geology, 2015, 65: 126-140. doi: 10.1016/j.marpetgeo.2015.03.023 |
[16] | Paganoni M, Cartwright J A, Foschi M, et al. Relationship between fluid-escape pipes and hydrate distribution in offshore Sabah (NW Borneo) [J]. Marine Geology, 2018, 395: 82-103. doi: 10.1016/j.margeo.2017.09.010 |
[17] | Lonergan L, Cartwright J, Jolly R. The geometry of polygonal fault systems in Tertiary mudrocks of the North Sea [J]. Journal of Structural Geology, 1998, 20(5): 529-548. doi: 10.1016/S0191-8141(97)00113-2 |
[18] | Dewhurst D N, Cartwright J A, Lonergan L. The development of polygonal fault systems by syneresis of colloidal sediments [J]. Marine and Petroleum Geology, 1999, 16(8): 793-810. doi: 10.1016/S0264-8172(99)00035-5 |
[19] | Cartwright J, Wattrus N, Rausch D, et al. Recognition of an early Holocene polygonal fault system in Lake Superior: implications for the compaction of fine-grained sediments [J]. Geology, 2004, 32(3): 253-256. doi: 10.1130/G20121.1 |
[20] | Hustoft S, Mienert J, Bünz S, et al. High- resolution 3D-seismic data indicate focussed fluid migration pathways above polygonal fault systems of the mid-Norwegian margin [J]. Marine Geology, 2007, 245(1-4): 89-106. doi: 10.1016/j.margeo.2007.07.004 |
[21] | Sun Q L, Wu S G, Lü F L, et al. Polygonal faults and their implications for hydrocarbon reservoirs in the southern Qiongdongnan Basin, South China Sea [J]. Journal of Asian Earth Sciences, 2010, 39(5): 470-479. doi: 10.1016/j.jseaes.2010.04.002 |
[22] | 孙启良, 吴时国, 陈端新, 等. 南海北部深水盆地流体活动系统及其成藏意义[J]. 地球物理学报, 2014, 57(12):4052-4062 doi: 10.6038/cjg20141217 SUN Qiliang, WU Shiguo, CHEN Duanxin, et al. Focused fluid flow systems and their implications for hydrocarbon and gas hydrate accumulations in the deep-water basins of the northern South China Sea [J]. Chinese Journal of Geophysics, 2014, 57(12): 4052-4062. doi: 10.6038/cjg20141217 |
[23] | 杨涛涛, 吴敬武, 王彬, 等. 琼东南盆地华光凹陷构造特征及沉积充填[J]. 海洋地质与第四纪地质, 2012, 32(5):13-18 YANG Taotao, WU Jingwu, WANG Bin, et al. Structural pattern and sediment filling in Huaguang sag of southern Qiongdongnan basin [J]. Marine Geology & Quaternary Geology, 2012, 32(5): 13-18. |
[24] | 吴能友, 杨胜雄, 王宏斌, 等. 南海北部陆坡神狐海域天然气水合物成藏的流体运移体系[J]. 地球物理学报, 2009, 52(6):1641-1650 doi: 10.3969/j.issn.0001-5733.2009.06.027 WU Nengyou, YANG Shengxiong, WANG Hongbin, et al. Gas-bearing fluid influx sub-system for gas hydrate geological system in Shenhu Area, Northern South China Sea [J]. Chinese Journal of Geophysics, 2009, 52(6): 1641-1650. doi: 10.3969/j.issn.0001-5733.2009.06.027 |
[25] | Nigmatulin R I, Shagapov V S, Syrtlanov V R. Self-similar problem of decomposition of gas hydrates in a porous medium upon depression and heating [J]. Journal of Applied Mechanics and Technical Physics, 1998, 39(3): 421-427. doi: 10.1007/BF02468125 |
[26] | Golmshtok A Y. The impact of faulting on the stability conditions of gas hydrates in Lake Baikal sediments [J]. Izvestiya, Physics of the Solid Earth, 2014, 50(4): 528-542. doi: 10.1134/S106935131404003X |
[27] | Jones A T, Greinert J, Bowden D A, et al. Acoustic and visual characterisation of methane-rich seabed seeps at Omakere Ridge on the Hikurangi Margin, New Zealand [J]. Marine Geology, 2010, 272(1-4): 154-169. doi: 10.1016/j.margeo.2009.03.008 |
[28] | Chun J H, Ryu B J, Son B K, et al. Sediment mounds and other sedimentary features related to hydrate occurrences in a columnar seismic blanking zone of the Ulleung Basin, East Sea, Korea [J]. Marine and Petroleum Geology, 2011, 28(10): 1787-1800. doi: 10.1016/j.marpetgeo.2011.06.006 |
[29] | Hovland M, Svensen H, Forsberg C F, et al. Complex pockmarks with carbonate-ridges off mid-Norway: products of sediment degassing [J]. Marine Geology, 2005, 218(1-4): 191-206. doi: 10.1016/j.margeo.2005.04.005 |
[30] | Pilcher R, Argent J. Mega-pockmarks and linear pockmark trains on the West African continental margin [J]. Marine Geology, 2007, 244(1-4): 15-32. doi: 10.1016/j.margeo.2007.05.002 |
[31] | 栾锡武, 刘鸿, 岳保静, 等. 海底冷泉在旁扫声纳图像上的识别[J]. 现代地质, 2010, 24(3):474-480 doi: 10.3969/j.issn.1000-8527.2010.03.009 LUAN Xiwu, LIU Hong, YUE Baojing, et al. Characteristics of cold seepage on side scan sonar sonogram [J]. Geoscience, 2010, 24(3): 474-480. doi: 10.3969/j.issn.1000-8527.2010.03.009 |
[32] | 苏丕波, 梁金强, 沙志彬, 等. 南海北部神狐海域天然气水合物成藏动力学模拟[J]. 石油学报, 2011, 32(2):226-233 doi: 10.7623/syxb201102006 SU Pibo, LIANG Jinqiang, SHA Zhibin, et al. Dynamic simulation of gas hydrate reservoirs in the Shenhu area, the northern South China Sea [J]. Acta Petrolei Sinica, 2011, 32(2): 226-233. doi: 10.7623/syxb201102006 |
[33] | 钟广见, 易海, 林珍, 等. 尖峰北盆地地质构造及油气勘探潜力[J]. 海洋地质与第四纪地质, 2008, 28(1):105-110 ZHONG Guangjian, YI Hai, LIN Zhen, et al. Geologic structure of Jianfengbei basin and its prospect for petroleum exploration [J]. Marine Geology & Quaternary Geology, 2008, 28(1): 105-110. |
[34] | 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 |
[35] | 钟志洪, 施和生, 朱明, 等. 珠江口盆地构造-地层格架及成因机制探讨[J]. 中国海上油气, 2014, 26(5):20-29 ZHONG Zhihong, SHI Hesheng, ZHU Ming, et al. A discussion on the tectonic-stratigraphic framework and its origin mechanism in Pearl River Mouth basin [J]. China Offshore Oil and Gas, 2014, 26(5): 20-29. |
[36] | 龚再升. 中国近海含油气盆地新构造运动与油气成藏[J]. 地球科学——中国地质大学学报, 2004, 29(5):513-517 GONG Zaisheng. Neotectonics and petroleum accumulation in offshore Chinese basins [J]. Earth Science—Journal of China University of Geosciences, 2004, 29(5): 513-517. |
[37] | 吴时国, 孙启良, 董冬冬. 深水盆地中多边形断层的几何特征与形成机制探讨[J]. 地质力学学报, 2008, 14(3):231-240 doi: 10.3969/j.issn.1006-6616.2008.03.005 WU Shiguo, SUN Qiliang, DONG Dongdong. The geometrical characteristics and formation mechanism of polygonal faults in deep-water basin [J]. Journal of Geomechanics, 2008, 14(3): 231-240. doi: 10.3969/j.issn.1006-6616.2008.03.005 |
[38] | CHEN D X, WU S G, WANG X J, et al. Seismic expression of polygonal faults and its impact on fluid flow migration for gas hydrates formation in deep water of the South China Sea [J]. Journal of Geological Research, 2011, 2011: 1-7. |
[39] | Cartwright J. Diagenetically induced shear failure of fine-grained sediments and the development of polygonal fault systems [J]. Marine and Petroleum Geology, 2011, 28(9): 1593-1610. doi: 10.1016/j.marpetgeo.2011.06.004 |
[40] | Andresen K J, Huuse M. ‘Bulls-eye’ pockmarks and polygonal faulting in the Lower Congo Basin: relative timing and implications for fluid expulsion during shallow burial [J]. Marine Geology, 2011, 279(1-4): 111-127. doi: 10.1016/j.margeo.2010.10.016 |
[41] | Sun Q L, Wu S G, Yao G S, et al. Characteristics and formation mechanism of polygonal faults in qiongdongnan basin, northern south china sea [J]. Journal of Earth Science, 2009, 20(1): 180-192. doi: 10.1007/s12583-009-0018-z |
[42] | 何玉林, 匡增桂, 徐梦婕. 北康盆地第四纪块体搬运沉积地震反射特征及成因机制[J]. 地质科技情报, 2018, 37(4):258-268 HE Yulin, KUANG Zenggui, XU Mengjie. Seismic reflection characteristics and triggering mechanism of mass transport deposits of quaternary in Beikang basin [J]. Geological Science and Technology Information, 2018, 37(4): 258-268. |
[43] | 王建桥, 祝有海, 吴必豪, 等. 南海ODP1146站位烃类气体地球化学特征及其意义[J]. 海洋地质与第四纪地质, 2005, 25(3):53-60 WANG Jianqiao, ZHU Youhai, WU Bihao, et al. Geochemistry of hydrocarbon gases from site 1146, ODP leg 184, the south china sea and the implications [J]. Marine Geology & Quaternary Geology, 2005, 25(3): 53-60. |
[44] | 何家雄, 马文宏, 祝有海, 等. 南海北部边缘盆地天然气成因类型及运聚规律与勘探新领域[J]. 海洋地质前沿, 2011, 27(4):1-10 HE Jiaxiong, MA Wenhong, ZHU Youhai, et al. Genetic types, migration and accumulation of gas in the north marginal basins of south china sea and new exploration targets [J]. Marine Geology Frontiers, 2011, 27(4): 1-10. |
[45] | 吴时国, 孙启良, 吴拓宇, 等. 琼东南盆地深水区多边形断层的发现及其油气意义[J]. 石油学报, 2009, 30(1):22-26, 32 doi: 10.3321/j.issn:0253-2697.2009.01.004 WU Shiguo, SUN Qiliang, WU Tuoyu, et al. Polygonal fault and oil -gas accumulation in deep-water area of Qiongdongnan Basin [J]. Acta Petrolei Sinica, 2009, 30(1): 22-26, 32. doi: 10.3321/j.issn:0253-2697.2009.01.004 |
[46] | 王力峰, 沙志彬, 梁金强, 等. 晚期泥底辟控制作用导致神狐海域SH5钻位未获水合物的分析[J]. 现代地质, 2010, 24(3):450-456 doi: 10.3969/j.issn.1000-8527.2010.03.005 WANG Lifeng, SHA Zhibin, LIANG Jinqiang, et al. Analysis of gas hydrate absence induced by the late-stage diapir domination in the borehole SH5 of Shenhu area [J]. Geoscience, 2010, 24(3): 450-456. doi: 10.3969/j.issn.1000-8527.2010.03.005 |
a. The location of study area, b. Multi-beam topographic map of the study area, c. Partialy enlarged (b)
A sub-bottom profile showing typical micro-geomorphic and acoustic response characteristics of the seabed in the Jianfengbei Basin
The multi-channel seismic profile showing source -connected faults in the Jianfengbei Basin
The multi-channel seismic profile showing paleo-uplift associated faults in the Jianfengbei Basin
The multi-channel seismic profile showing polygonal faults in the Jianfengbei Basin
A multi-channel seismic profile showing BSR distribution in the Jianfengbei Basin
The multi-channel seismic profile showing gas-bearing fluid migration combination between deep and shallow layers in the Jianfengbei Basin
Distribution patterns of shallow gas-bearing fluid migration and BSR distribution as well as the comprehensive response of seabed micro-geomorphology
Gas hydrate accumulation model of the Jianfengbei Basin.