Molecular and stable isotope compositions of natural gas hydrates : A revised global dataset and basic interpretations in the context of geological settings

Abstract A global dataset of molecular and stable isotope compositions of gases released from 209 different specimens of natural gas hydrate is presented and discussed. The 26 hydrate-bearing areas from 21 geographic regions are grouped into high gas flux (HGF) settings, low gas flux (LGF) settings and hydrated gas accumulations (HGA). Methane (CH4) is the most abundant hydrate-bound gas, while CO2 and C2+ hydrocarbon gases are frequently present in small amounts. Non-hydrocarbon gases, such as H2S, are uncommon. The stable isotope composition of hydrate-bound gases varies significantly (e.g., δ13C of CH4 from −74.7 to −39.6‰), suggesting that gases of both microbial and thermogenic origin form gas hydrates. Hydrate-bound gases are derived from autochthonous [located predominantly within the gas hydrate stability zone (GHSZ)] and allochthonous (located in deep sediments) sources. The occurrence and concentration of gas hydrates in sediments are controlled not by the origin of gases, but rather by their sources, which in turn strongly depend on geological setting. Allochthonous gases (microbial and/or thermogenic) dominate in HGF and HGA settings where they are focused in the shallow GHSZ along faults, within mud volcanoes, in permeable carrier beds and other geological features from underlying petroleum systems. Relatively high concentrations of gas hydrate (average 5–15% of pores and locally up to 100% of volume) occurring over small areas are typical of HGF and HGA settings. In contrast, autochthonous and diffuse allochthonous gases (mostly microbial) occur in stratigraphically and structurally simple LGF settings and result in relatively low concentrations of gas hydrate (average ∼2% of pores in the GHSZ) spread over large areas. The major implication of this finding is that successful prediction of resource and geohazard potential of gas hydrates is possible only if regional petroleum systems extending well below the GHSZ are properly evaluated. In addition to the diagnosis of origins and sources of hydrate-bound gases, molecular and isotopic data help to better identify hydrate-bearing intervals and provide valuable insights into the dynamics of hydrate-bearing sites.

[1]  F. Gradstein,et al.  Initial Reports of the Deep Sea Drilling Project, 76 , 1983 .

[2]  B. Katz,et al.  Petroleum Systems of South Atlantic Margins , 2000 .

[3]  M. Winfrey,et al.  Temperature limitation of methanogenesis in aquatic sediments , 1976, Applied and environmental microbiology.

[4]  T. Hirano,et al.  Occurrence, structure, and composition of natural gas hydrate recovered from the Blake Ridge, northwest Atlantic , 2000 .

[5]  A. Duchkov,et al.  THE FIRST FIND OF GAS-HYDRATES IN THE SEDIMENTARY ROCKS OF LAKE BAIKAL , 1998 .

[6]  R. Hillis,et al.  Subsurface Sediment Mobilization , 2003 .

[7]  J. Chanton,et al.  Thermogenic gas hydrates in the northern Cascadia margin , 2004 .

[8]  W. Borowski,et al.  Effects of core retrieval and degassing on the carbon isotope composition of methane in gas hydrate - and free gas - bearing sediments from the blake ridge , 2000 .

[9]  Keith A. Kvenvolden,et al.  A review of the geochemistry of methane in natural gas hydrate , 1995 .

[10]  D. Archer,et al.  Global inventory of methane clathrate: sensitivity to changes in the deep ocean , 2004 .

[11]  Timothy S. Collett,et al.  Intrapermafrost gas hydrates from a deep core hole in the Mackenzie Delta, Northwest Territories, Canada , 1995 .

[12]  S. W. Taylor,et al.  Bacteriogenic Ethane in Near-Surface Aquifers: Implications for Leaking Hydrocarbon Well Bores , 2000 .

[13]  James M. Brooks,et al.  Association of Oil Seeps and Chemosynthetic Communities with Oil Discoveries, Upper Continental Slope, Gulf of Mexico , 1993 .

[14]  Alexei V. Milkov,et al.  Preliminary assessment of resources and economic potential of individual gas hydrate accumulations in the Gulf of Mexico continental slope , 2003 .

[15]  K. Kvenvolden,et al.  32. GAS HYDRATES OF THE PERUVIAN OUTER CONTINENTAL MARGIN1 , 1990 .

[16]  J. Zachos,et al.  Early Cenozoic decoupling of the global carbon and sulfur cycles , 2003 .

[17]  G. Dickens.  Rethinking the global carbon cycle with a large, dynamic and microbially mediated gas hydrate capacitor , 2003 .

[18]  T. Collett.  Natural Gas Hydrates of the Prudhoe Bay and Kuparuk River Area, North Slope, Alaska , 1993 .

[19]  L. Cathles,et al.  A compositional kinetic model of hydrate crystallization and dissolution , 2004 .

[20]  Alla Yu Lein,et al.  Geological, geochemical, and microbial processes at the hydrate-bearing Håkon Mosby mud volcano: a review , 2004 .

[21]  G. Rehder,et al.  Noble gases and radiocarbon in natural gas hydrates , 2002 .

[22]  J. Brooks,et al.  Light hydrocarbons in recent Texas continental shelf and slope sediments , 1978 .

[23]  D. Grauls.  Gas hydrates: importance and applications in petroleum exploration , 2001 .

[24]  T. Lorenson,et al.  Chemistry, isotopic composition, and origin of a methane-hydrogen sulfide hydrate at the Cascadia subduction zone , 1998 .

[25]  J. Brooks,et al.  Asphalt Volcanism and Chemosynthetic Life in the Campeche Knolls, Gulf of Mexico , 2004, Science.

[26]  J. Brooks,et al.  Geochemistry of Hydrate Gas and Water from Site 570, Deep Sea Drilling Project Leg 84 , 1985 .

[27]  A. V. Egorov,et al.  Chemical and isotopic evidence for the nature of the fluid in CH4-containing sediments of the Håkon Mosby Mud Volcano , 1999 .

[28]  R. Berner,et al.  Organic carbon losses during burial and thermal maturation of normal marine shales , 1987 .

[29]  R. Cunningham,et al.  AAPG Memoir 73, Chapter 8: Seismic Evidence for Widespread Gas Hydrate Formation, Offshore West Africa , 2000 .

[30]  G. Wefer,et al.  New chronology for the late Paleocene thermal maximum and its environmental implications , 2000 .

[31]  I. Fung,et al.  Potential distribution of methane hydrates in the world's oceans , 1994 .

[32]  V. Soloviev,et al.  Gas hydrate accumulation in the subsurface sediments of Lake Baikal (Eastern Siberia) , 2003 .

[33]  L. A. Barnard,et al.  Gas Hydrates of the Blake Outer Ridge Site 533, Deep Sea Drilling Project Leg 76 , 1983 .

[34]  A. Milkov.  Global estimates of hydrate-bound gas in marine sediments: how much is really out there? , 2004 .

[35]  J. Charlou,et al.  Physical and chemical characterization of gas hydrates and associated methane plumes in the Congo-Angola Basin , 2004 .

[36]  D. Grauls,et al.  Dynamics of gas hydrate: case of the Congo continental slope , 2004 .

[37]  B. Buffett,et al.  Sources of methane for marine gas hydrate: inferences from a comparison of observations and numerical models , 2003 .

[38]  Carolyn A. Koh,et al.  Clathrate hydrates of natural gases , 1990 .

[39]  Alexei V. Milkov,et al.  Thermogenic gas hydrates and hydrocarbon gases in complex chemosynthetic communities, Gulf of Mexico continental slope , 1999 .

[40]  A. Gorman,et al.  Migration of methane gas through the hydrate stability zone in a low-flux hydrate province , 2002 .

[41]  R. Huene,et al.  Initial Reports of the Deep Sea Drilling Project, 84 , 1985 .

[42]  T. Lorenson.  Gas composition and isotopic geochemistry of cuttings, core, and gas hydrate from the JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well , 1999 .

[43]  D. Rice,et al.  Generation, Accumulation, and Resource Potential of Biogenic Gas , 1981 .

[44]  J. Wright,et al.  A case for a comet impact trigger for the Paleocene/Eocene thermal maximum and carbon isotope excursion , 2003 .

[45]  E. Sloan,et al.  Geochemistry of a naturally occurring massive marine gas hydrate , 1984 .

[46]  Gerald R. Dickens,et al.  Direct measurement of in situ methane quantities in a large gas-hydrate reservoir , 1997, Nature.

[47]  Martin Schoell,et al.  Genetic Characterization of Natural Gases , 1983 .

[48]  M. Hovland,et al.  Gas hydrate and sedimant gas composition, Hole 892A , 1995 .

[49]  B. Katz.  16. GEOCHEMICAL INVESTIGATION OF SITES 1108 AND 1109, LEG 180 , 2001 .

[50]  L. Harvey,et al.  Evaluation of the potential impact of methane clathrate destabilization on future global warming , 1995 .

[51]  Alexei V. Milkov,et al.  Gas hydrate systems at Hydrate Ridge offshore Oregon inferred from molecular and isotopic properties of hydrate-bound and void gases , 2005 .

[52]  L. Magoon,et al.  The Petroleum System: From Source to Trap , 1994 .

[53]  L. Cathles,et al.  A kinetic model for the pattern and amounts of hydrate precipitated from a gas steam: Application to the Bush Hill vent site, Green Canyon Block 185, Gulf of Mexico , 2003 .

[54]  R. Sassen,et al.  Exclusion of 2-methylbutane (isopentane) during crystallization of structure II gas hydrate in sea-floor sediment, Gulf of Mexico , 2000 .

[55]  T. Lorenson,et al.  Gas content and composition of gas hydrate from sediments of the southeastern North American continental margin , 2000 .

[56]  A. Milkov.  Worldwide distribution of submarine mud volcanoes and associated gas hydrates , 2000 .

[57]  J. Tse,et al.  Laboratory analysis of a naturally occurring gas hydrate from sediment of the Gulf of Mexico , 1986 .

[58]  W. Borowski,et al.  7. ISOTOPIC COMPOSITION OF CH 4 , CO 2 SPECIES, AND SEDIMENTARY ORGANIC MATTER WITHIN SAMPLES FROM THE BLAKE RIDGE: GAS SOURCE IMPLICATIONS 1 , 2000 .

[59]  F. Rostek,et al.  Fluid flow in and around a mud volcano field seaward of the Barbados accretionary wedge: Results from Manon cruise , 1996 .

[60]  T. Uchida,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 , 1999 .

[61]  K. Kvenvolden,et al.  Potential effects of gas hydrate on human welfare. , 1999, Proceedings of the National Academy of Sciences of the United States of America.

[62]  J. Brooks,et al.  Thermogenic Gas Hydrates in the Gulf of Mexico , 1984, Science.

[63]  A. James,et al.  Microbial Alteration of Subsurface Natural Gas Accumulations , 1984 .

[64]  Takashi Uchida,et al.  Subsurface Occurrence of Natural Gas Hydrate in the Nankai Trough Area: Implication for Gas Hydrate Concentration , 2004 .

[65]  W. Borowski,et al.  In situ methane concentrations at Hydrate Ridge, offshore Oregon: New constraints on the global gas hydrate inventory from an active margin , 2003 .

[66]  James H. Knapp,et al.  Geophysical evidence for gas hydrates in the deep water of the South Caspian Basin, Azerbaijan , 2001 .

[67]  A. Malthe-Sørenssen,et al.  Release of methane from a volcanic basin as a mechanism for initial Eocene global warming , 2004, Nature.

[68]  R. Sassen,et al.  Two-dimensional modeling of gas hydrate decomposition in the northwestern Gulf of Mexico: significance to global change assessment , 2003 .

[69]  J. Brooks,et al.  Gas hydrate that breaches the sea floor on the continental slope of the Gulf of Mexico , 1994 .

[70]  J. Brooks,et al.  Observations of gas hydrates in marine sediments, offshore northern California , 1991 .

[71]  I︠u︡. F. Makogon.  Hydrates of Hydrocarbons , 1997 .

[72]  Jeffery B. Klauda,et al.  Predictions of gas hydrate phase equilibria and amounts in natural sediment porous media , 2003 .

[73]  M. Hovland,et al.  Potential Influence of Gas Hydrates on Seabed Installations , 2013 .

[74]  R. Littke,et al.  Hydrocarbon gas in the Costa Rica subduction zone: primary composition and post-genetic alteration , 2002 .

[75]  C. Clayton.  Source volumetrics of biogenic gas generation , 1992 .

[76]  R. M. Owen,et al.  Dissociation of oceanic methane hydrate as a cause of the carbon isotope excursion at the end of the Paleocene , 1995 .

[77]  K. Kvenvolden,et al.  Gas hydrates in oceanic sediment , 1988 .

[78]  James P. Kennett,et al.  Methane hydrates in Quaternary climate change : the clathrate gun hypothesis , 2003 .

[79]  C. Clayton.  Carbon isotope fractionation during natural gas generation from kerogen , 1991 .

[80]  J. Curiale,et al.  26. GAS HYDRATES IN SEDIMENTS OF HOLES 497 AND 498A, DEEP SEA DRILLING PROJECT LEG 67 , 2006 .

[81]  L. Pinheiro,et al.  Mud volcano gas hydrates in the Gulf of Cadiz , 2002 .

[82]  Alexei V. Milkov,et al.  Economic geology of offshore gas hydrate accumulations and provinces , 2002 .

[83]  Michael D. Max,et al.  Natural gas hydrate : in oceanic and permafrost environments , 2000 .

[84]  G. Etiope,et al.  A new estimate of global methane flux from onshore and shallow submarine mud volcanoes to the atmosphere , 2004 .

[85]  G. Ivanova,et al.  GAS HYDRATES OF THE SOUTHERN CASPIAN , 1992 .

[86]  K. Wallmann,et al.  Fluid expulsion related to mud extrusion off Costa Rica¿A window to the subducting slab , 2004 .

[87]  Michael J. Whiticar,et al.  Carbon and hydrogen isotope systematics of bacterial formation and oxidation of methane , 1999 .

[88]  Alexei V. Milkov,et al.  Estimate of gas hydrate resource, northwestern Gulf of Mexico continental slope , 2001 .

[89]  G. Bohrmann,et al.  Hydrocarbon gases in deposits from mud volcanoes in the Sorokin Trough, north-eastern Black Sea , 2003 .

[90]  S. Dallimore,et al.  Permafrost-Associated Gas Hydrate , 2000 .

[91]  G. Dickens.  The potential volume of oceanic methane hydrates with variable external conditions , 2001 .

[92]  T. Collett.  Seismic- and well-log-inferred gas hydrate accumulations on Richards Island , 1999 .

[93]  William R. Bryant,et al.  Association of gas hydrates and oil seepage in the Gulf of Mexico , 1986 .

[94]  S. Qadri,et al.  Novel results on structural investigations of natural minerals of clathrate hydrates , 2004 .

[95]  Hitoshi Tomaru,et al.  Ethane enrichment and propane depletion in subsurface gases indicate gas hydrate occurrence in marine sediments at southern Hydrate Ridge offshore Oregon , 2004 .

[96]  W. Borowski,et al.  Co-existence of gas hydrate, free gas, and brine within the regional gas hydrate stability zone at Hydrate Ridge (Oregon margin): evidence from prolonged degassing of a pressurized core , 2004 .

[97]  E. McDade.  Geology and Geochemistry of Gas Hydrates, Central Gulf of Mexico Continental Slope , 1999 .

[98]  Alexei V. Milkov,et al.  Thickness of the gas hydrate stability zone, Gulf of Mexico continental slope , 2000 .

[99]  E. Dlugokencky,et al.  Stable carbon isotopic composition of atmospheric methane: A comparison of surface level and free tropospheric air , 1999 .

[100]  J. Greinert,et al.  Gas hydrate destabilization: enhanced dewatering, benthic material turnover and large methane plumes at the Cascadia convergent margin , 1999 .

[101]  G. Dickens,et al.  Noble gases in methane hydrate from the Blake Ridge , 2000 .

[102]  M. Hovland,et al.  Organic geochemistry of gases, fluids, and hydrates at the Cascadia Margin accretionary margin , 1995 .

[103]  M. Vanneste,et al.  Sublacustrine mud volcanoes and methane seeps caused by dissociation of gas hydrates in Lake Baikal , 2002 .

[104]  K. Kvenvolden,et al.  Methane and other Hydrocarbon Gases in Marine Sediment , 1983 .

[105]  G. MacDonald.  The Future of Methane as an Energy Resource , 1990 .

[106]  V. A. Soloviev,et al.  Gas hydrate accumulation at the Håkon Mosby Mud Volcano , 1999 .

[107]  R. Sassen,et al.  Thermogenic vent gas and gas hydrate in the Gulf of Mexico slope: Is gas hydrate decomposition significant? , 2001 .

[108]  S. Dallimore,et al.  Scientific Results from JAPEX/JNOC/GSC Mallik 2L-38 Gas Hydrate Research Well, Mackenzie Delta, Northwest Territories, Canada , 1999 .

[109]  N. Ross Chapman,et al.  The origin of thermogenic gas hydrates on the northern Cascadia Margin as inferred from isotopic (13C/12C and D/H) and molecular composition of hydrate and vent gas , 2005 .

[110]  D. Valentine,et al.  Water column methane oxidation adjacent to an area of active hydrate dissociation, Eel river Basin , 2001 .

[111]  G. Rehder,et al.  Correction to “Noble gases and radiocarbon in natural gas hydrates” by Gisela Winckler, Werner Aeschbach‐Hertig, Johannes Holocher, Rolf Kipfer, Ingeborg Levin, Christian Poss, Gregor Rehder, Erwin Suess, and Peter Schlosser , 2002 .

[112]  Harry H. Roberts,et al.  Massive vein-filling gas hydrate: relation to ongoing gas migration from the deep subsurface in the Gulf of Mexico , 2001 .

[113]  B. Buffett,et al.  metastability of gas hydrate , 1999 .

[114]  L. Cathles,et al.  The geochemical signatures of variable gas venting at gas hydrate sites , 2004 .

[115]  M. Vanneste,et al.  Evidence of near-surface sediment mobilization and methane venting in relation to hydrate dissociation in Southern Lake Baikal, Siberia. , 2003 .

[116]  T. Lorenson,et al.  Gas hydrates from the continental slope, offshore Sakhalin Island, Okhotsk Sea , 1993 .

[117]  W. Borowski,et al.  Sources of Biogenic Methane to Form Marine Gas Hydrates In Situ Production or Upward Migration? a , 1993 .

[118]  J. M. Coleman,et al.  Initial Reports of the Deep Sea Drilling Project, 96 , 1986 .