Formation history and physical properties of sediments from the Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope

Abstract The synthesis of available geological information and surface temperature evolution in the Alaska North Slope region suggests that: biogenic and deeper thermogenic gases migrated through fault networks and preferentially invaded coarse-grained layers that have relatively high hydraulic conductivity and low gas entry pressures; hydrate started forming before the beginning of the permafrost; eventually, the permafrost deepened and any remaining free water froze so that ice and hydrate may coexist at some elevations. The single tested specimen (depth 620.47–620.62 m) from the D unit consists of uncemented quartzitic fine sand with a high fraction of fines (56% by mass finer than sieve #200). The as-received specimen shows no evidence of gas present. The surface texture of sediment grains is compatible with a fluvial-deltaic sedimentation environment and shows no signs of glacial entrainment. Tests conducted on sediments with and without THF hydrates show that effective stress, porosity, and hydrate saturation are the major controls on the mechanical and geophysical properties. Previously derived relationships between these variables and mechanical/geophysical parameters properly fit the measurements gathered with Mount Elbert specimens at different hydrate saturations and effective stress levels. We show that these measurements can be combined with index properties and empirical geomechanical relationships to estimate engineering design parameters. Volumetric strains measured during hydrate dissociation vanish at 2–4 MPa; therefore, minimal volumetric strains are anticipated during gas production at the Mount Elbert well. However, volume changes could increase if extensive grain crushing takes place during depressurization-driven production strategies, if the sediment has unexpectedly high in situ porosity associated to the formation history, or if fines migration and clogging cause a situation of sustained sand production.

[1]  T. Lorenson,et al.  Preliminary Assessment of Hydrocarbon Gas Sources from the Mt . Elbert No . 1 Gas Hydrate Test Well , Milne Pt . Alaska , 2008 .

[2]  J. C. Santamarina,et al.  Effect of cementation on the small-strain parameters of sands , 2001 .

[3]  Yu-Hsing Wang,et al.  Specific surface: determination and relevance , 2002 .

[4]  C. Yorath,et al.  Canada’s Continental Margins and Offshore Petroleum Exploration , 1975 .

[5]  J. A. Wolfe,et al.  North American nonmarine climates and vegetation during the Late Cretaceous , 1987 .

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

[7]  T. Ager,et al.  Palynological dating of Upper Cretaceous to middle Eocene strata in the Sagavanirktok and Canning formations, North Slope of Alaska , 1998 .

[8]  J. Burland.  On the compressibility and shear strength of natural clays , 1990 .

[9]  J. Beget,et al.  Late Pliocene to late Pleistocene environments preserved at the Palisades Site, central Yukon River, Alaska , 2003, Quaternary Research.

[10]  R. Spicer,et al.  Late Cretaceous vertebrate fossils from the North Slope of Alaska and implications for dinosaur ecology , 1987 .

[11]  J. Santamarina,et al.  Closure of "Particle Shape Effects on Packing Density, Stiffness, and Strength: Natural and Crushed Sands" , 2006 .

[12]  W. C. Krumbein,et al.  Stratigraphy and sedimentation , 1963 .

[13]  S. Patil,et al.  Resource Characterization and Quantification of Natural Gas-Hydrate and Associated Free-Gas Accumulations in the Prudhoe Bay - Kuparuk River Area on the North Slope of Alaska , 2003 .

[14]  R. McIntosh,et al.  Prudhoe Bay--A 10-Year Perspective , 1980 .

[15]  William P. Dillon,et al.  Natural gas hydrates: occurrence, distribution, and detection , 2001 .

[16]  J. C. Doornkamp,et al.  Atlas of Quartz Sand Surface Textures , 1973 .

[17]  Orlando B. Andersland,et al.  Frozen Ground Engineering , 2003 .

[18]  J. Jenness.  Permafrost in Canada , 1949 .

[19]  Tae Sup Yun,et al.  Mechanical properties of sand, silt, and clay containing tetrahydrofuran hydrate , 2007 .

[20]  Tae Sup Yun,et al.  Observations related to tetrahydrofuran and methane hydrates for laboratory studies of hydrate‐bearing sediments , 2007 .

[21]  W. Mahaney.  Atlas of Sand Grain Surface Textures and Applications , 2002 .

[22]  R. Miller,et al.  Chemical and microbiological properties , 1982 .

[23]  J. A. Wolfe.  Tertiary climatic changes at middle latitudes of western North America , 1994 .

[24]  Kelly Rose,et al.  Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope: Coring operations, core sedimentology, and lithostratigraphy , 2011 .

[25]  B. Anderson,et al.  Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope: Overview of scientific and technical program , 2011 .

[26]  S. Wolf,et al.  Preliminary interpretation of seismic profiles in the Prudhoe Bay area, Beaufort Sea, Alaska , 1972 .

[27]  W. Ayrton.  Canadian Society of Petroleum Geologists: GEOLOGIC NOTES , 1977 .

[28]  Yukio Nakata,et al.  MICROSCOPIC PARTICLE CRUSHING OF SAND SUBJECTED TO HIGH PRESSURE ONE-DIMENSIONAL COMPRESSION , 2001 .

[29]  S. Elias,et al.  Arctic North American seasonal temperatures from the latest Miocene to the Early Pleistocene, based on mutual climatic range analysis of fossil beetle assemblages , 2002 .

[30]  Marlan W. Downey.  Evaluating Seals for Hydrocarbon Accumulations , 1984 .

[31]  Jerry A. Yamamuro,et al.  DRAINED SAND BEHAVIOR IN AXISYMMETRIC TESTS AT HIGH PRESSURES , 1996 .

[32]  Gye-Chun Cho,et al.  Gas hydrate dissociation in sediments: Pressure‐temperature evolution , 2008 .

[33]  A. Page.  Methods of soil analysis. Part 2. Chemical and microbiological properties. , 1982 .

[34]  M. Roy,et al.  RESPONSE OF PARTICULATE MATERIALS AT HIGH PRESSURES , 1973 .

[35]  J. C. Santamarina,et al.  Mechanical and electromagnetic properties of northern Gulf of Mexico sediments with and without THF hydrates , 2008 .

[36]  K. Rose,et al.  Pore fluid geochemistry from the Mount Elbert gas hydrate stratigraphic test well, Alaska North Slope , 2011 .

[37]  S. Eittreim,et al.  Geology and tectonic development of the continental margin north of Alaska , 1979 .

[38]  L. Ellis,et al.  Evidence for biodegradation and evaporative fractionation in West Sak, Kuparuk and Prudhoe Bay field areas, North Slope, Alaska , 2001 .

[39]  K. Rose,et al.  Physical properties of sediment from the Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope , 2011 .

[40]  Julio R. Valdes,et al.  Particle Clogging in Radial Flow: Microscale Mechanisms , 2006 .

[41]  V. Lunardini.  Permafrost Formation Time , 1995 .

[42]  Timothy S. Collett,et al.  In-situ gas hydrate hydrate saturation estimated from various well logs at the Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope , 2011 .

[43]  A. Lachenbruch,et al.  Permafrost, heat flow, and the geothermal regime at Prudhoe Bay, Alaska , 1982 .

[44]  J. Santamarina,et al.  THE IMPACT OF HYDRATE SATURATION ON THE MECHANICAL, ELECTRICAL, AND THERMAL PROPERTIES OF HYDRATE-BEARING SAND, SILTS, AND CLAY , 2008 .

[45]  Gye-Chun Cho,et al.  Spatial Variability in Soils: High Resolution Assessment with Electrical Needle Probe , 2004 .

[46]  Gye-Chun Cho,et al.  DETERMINATION OF CRITICAL STATE PARAMETERS IN SANDY SOILS - SIMPLE PROCEDURE , 2001 .

[47]  R. G. McCrossan.  The Future Petroleum Provinces of Canada – Their Geology and Potential , 1973 .

[48]  G. Carman,et al.  Geology and Regional Setting of Kuparuk Oil Field, Alaska , 1983 .

[49]  J. Carlos Santamarina,et al.  Volume change associated with formation and dissociation of hydrate in sediment , 2010 .

[50]  Roger James Evan Brown,et al.  Permafrost in Canada: Its Influence on Northern Development , 1970 .

[51]  A. Grantz,et al.  Geologic Framework of the Alaskan Continental Terrace in the Chukchi and Beaufort Seas , 1975 .

[52]  J. A. Wolfe.  Tertiary climates and floristic relationships at high latitudes in the northern hemisphere , 1980 .

[53]  Nicholas John Anderson,et al.  Holocene thermal maximum in the western Arctic (0-180°W) , 2004 .

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

[55]  D. J. Taylor,et al.  Seismic Prospecting for Gas-hydrate and Associated Free-gas Prospects in the Milne Point Area of Northern Alaska , 2009 .

[56]  R. Spicer,et al.  Climate change and the evolution of high-latitude terrestrial vegetation and floras. , 1990, Trends in ecology & evolution.

[57]  T. Collett,et al.  Molecular and isotopic analyses of the hydrocarbon gases within gas hydrate-bearing rock units of the Prudhoe Bay-Kuparuk River area in northern Alaska , 1992 .

[58]  K. Bird,et al.  Geologic interrelations relative to gas hydrates within the North Slope of Alaska , 1988 .

[59]  J. Santamarina,et al.  Particle transport in a nonuniform flow field : Retardation and clogging , 2007 .

[60]  J. Gosink,et al.  Variations in permafrost thickness in response to changes in paleoclimate , 1991 .