Conducting Scientific Studies of Natural Gas Hydrates to Support the DOE Efforts to Evaluate and Understand Methane Hydrates

DE-AI26-05NT42496

Goal
The USGS conducts scientific studies of natural gas hydrates to support DOE efforts to evaluate and understand methane hydrates, their potential as an energy resource, and the hazard they may pose to ongoing drilling efforts. This project extends USGS support to the DOE Methane Hydrate Research Program previously supported under DE-AT26-97FT34342 and DE-AT26-97FT34343.

Performer
U.S. Geological Survey at Denver, CO, Woods Hole, MA, and Menlo Park, CA.

Background
The USGS Interagency Agreement (IA) involves laboratory research and international field studies in which DOE/NETL has a significant interest. Geological and geophysical support for these efforts is critical to their success, and the USGS is well and uniquely suited to providing this support. The IA is currently divided into four separate tasks as follows:

• Task 1 – Characterization and Assessment of Natural Gas Hydrates in Permafrost Environments
• Task 2 – Subsurface Gas Hydrate Occurrence in the Gulf of Mexico
• Task 3 – Laboratory Investigations of Gas Hydrates
• Task 4 – International Gas Hydrate Collaboration

USGS research on arctic hydrates supports the US DOE research project with BP Exploration, Alaska (BPXA) and others on resource characterization for the Prudhoe Bay/Kuparuk River region of the Alaska North Slope. The effort (Task 1) utilizes geologic, geochemical, and geophysical (2D and 3D seismic surveys) data from northern Alaska together with other new data sources, including wireline and mud log surveys of wells of opportunity to assess the occurrence and distribution of the known gas hydrate accumulations on the North Slope of Alaska.

USGS research on marine hydrates is coordinated with the US DOE Gulf of Mexico (GoM) Methane Hydrate Joint Industry Project (JIP). This task (Task 2) utilizes geologic, geochemical, seismic, electrical, geothermal, and bottom photography to understand the occurrence and potential hazard to drilling of subsurface gas hydrates in the northern GoM and to extend this understanding regionally. For this task, laboratory studies compliment the field studies by making measurements in controlled environments. Laboratory studies include complete analysis of the JIP core samples and investigation of techniques to create hydrate from dissolved methane.

Task 3 supports research at the USGS Gas Hydrate Petrophysics Laboratory in Menlo Park, California and at the Gas Hydrate and Sediment Testing Laboratory Instrument (GHASTLI) in Woods Hole, Massachusetts. The physical states of hydrates in marine sediments are important in assessing the effects of hydrates on sediment properties, such as sediment thermal and mechanical stability. Computed X-ray tomography (CT) has proven to be a powerful tool for investigating the distribution of gas hydrates in sediment cores down to the grain and pore scale. Scanning Electron Microscopy (SEM), powder x-ray diffraction (XRD), and neutron scattering (NS) are three other powerful techniques for investigating the gas hydrate distribution, grain and pore texture and also hydrate mineralogy (sI, sII and/or sH). The Task 3 sample characterization effort will utilize these techniques and others to compliment on-board and post-drilling studies.

Task 4, recently added in fiscal year 2006, supports the multinational cooperative project between the U.S. and international partners. In collaboration with the Directorate General of Hydrocarbons (DGH) of India, the USGS is working to develop more accurate assessments of Indian marine gas hydrates for potential future production tests. A major drilling program, conducted during the summer of 2006, gathered data that will be used to assess the energy resource potential of gas hydrates offshore of India. This task will provide the necessary equipment and expertise for geotechnical and geochemical studies for the drilling program.

Potential Impact
The technical depth of USGS scientists and engineers brings an additional important dimenension to the research activities of the DOE Methane Hydrate R&D Program. In the Arctic, decades of geological and geophysical investigation are brought to bare to help understand the full extend of the hydrate resource. These efforts in collaboration with DOE and industry partners such as BP Exploration, Alaska (BPXA) are making important contributions to our understanding of how arctic hydrates may some day be developed as a source of natural gas.

USGS research on marine hydrates is currently coordinated with the US DOE Gulf of Mexico (GoM) Methane Hydrate Joint Industry Project (JIP). This work is making important advances in our understanding of the occurrence and potential hazard to drilling of subsurface gas hydrates in the northern GoM and extending this understanding regionally. This information will provide industry with better tools and data as oil and gas development moves into areas where gas hydrates could present potential hazards. As we gain a better understanding of the nature and distribution of marine gas hydrates, USGS and DOE scientists and engineers, along with industry, will some day work together to develop this valuable resource.

USGS laboratory scientists also support the program by investigating the physical states of hydrates in arctic and marine settings. These studies are important in assessing the effects of hydrates on sediment properties, such as sediment thermal and mechanical stability, and ultimately in developing cost-effective production methods. USGS laboratory work is employing computed X-ray tomography (CT), Scanning Electron Microscopy (SEM), powder x-ray diffraction (XRD), and neutron scattering (NS) to characterize hydrates and hydrate sediment mixtures. This work complements the field projects.

USGS support for multinational cooperative projects adds to the comprehensive understanding of the geologic occurrence of gas hydrates along continental margins and in the assessment of the energy resource potential of gas hydrates in globally.

Accomplishments

Task 1 – Characterization and Assessment of Natural Gas Hydrates in Permafrost Environments
This task addresses the critical issues associated with potential production of gas hydrates (and associated free-gas) in the Prudhoe-Kuparuk area. The primary focus is to assess the geophysical characteristics of in-situ natural gas hydrates and support US DOE-funded extended gas hydrate production tests of the Eileen and Tarn gas-hydrate/free-gas accumulations.

USGS worked directly with BPXA and their contractors to design and implement the North Slope of Alaska Mt. Elbert 1 Gas Hydrate Test Well, which was spudded on February 3, 2007. This included planning for the acquisition of 400-600 ft of wireline core, a research-level well log program, and performing multiple low-volume sampling/pressure testing using a Modular Formation Dynamics Tester (MDT).

The USGS coordinated and participated in wellsite coring and sampling during drilling of the Mt. Elbert gas hydrate stratigraphic test well effort between BPXA and the US DOE at Milne Point, Alaska. The 22-day drilling program cored to a depth of 760 meters, logged to a depth of 914 meters, and tested for gas hydrate response at four depth intervals using MDT. From the coring program, there was 85 % recovery, with ~250 samples selected for laboratory analyses and 11 gas-hydrate samples preserved in either liquid nitrogen or pressure vessels for analysis.

The major scientific achievement at this site is that two high-saturation gas hydrate-bearing intervals were identified, as predicted from pre-drilling geological and geophysical analysis using prospecting methods developed by USGS. The two units were an upper 14-m thick gas-hydrate bearing reservoir of sandstone (unit “D”) and a lower 16-m thick unit, also a reservoir. Both units had gas hydrate saturations of 60 – 75 %. Two technological firsts were also achieved: (a) conducting wireline retrievable coring in the relatively unconsolidated sub-permafrost sediments in the North Slope and (b) conducting open-hole MDT testing within gas-hydrate bearing intervals. For more information see the BP Exploration Alaska project, “Alaska North Slope Gas Hydrate Reservoir Characterization" (DE-FC26-01NT41332).

The wireline logging produced an outstanding dataset for permafrost and gas hydrate properties. The open-hole MDT testing also produced an outstanding dataset for gas hydrate response during testing. Work is now progressing to analyze the physical formation properties from the Mt. Elbert samples and to compare the detailed drilling results with pre-drilling models so that the models can be refined and improved. A Mt. Elbert data set is also being developed as a case study to be utilized in the DOE-funded International Effort to Compare Methane Hydrate Reservoir Simulators.

The USGS is also working with the Bureau of Land Management to process and analyze 3D seismic grids and related 2D seismic and well data from the National Petroleum Reserve-Alaska (NPRA) in order to identify gas hydrate prospects. The work focuses on gathering existing geologic and geophysical data to construct a new gas hydrate stability map for the eastern portion of the NPRA. The work has been recently expanded to include a new North Slope Alaska gas stability field map as interpreted from the USGS “Borehole Temperature Logs from Arctic Alaska." These data have been released on the following web site, http://esp.cr.usgs.gov/data/bht/alaska/ [external site].

Task 2 – Subsurface Gas Hydrate Occurrence in the Gulf of Mexico
This task seeks to understand the physical, geological, and chemical conditions in which gas hydrates exist in the GoM, and to estimate the concentrations and behaviors of gas hydrate deposits during drilling. Part of the strategy of this task is to first use detailed studies from areas where the ChevronTexaco JIP has drilled (in April, 2005) and to extrapolate this understanding to assess hydrate occurrence and hazard in a regional context.

The primary focus of this task has been on the archiving and interpretation of geological and geophysical data from the 2005 JIP drill sites. Logging and drilling results provide the opportunity to correlate the occurrence of gas hydrate with seismic signature and then extrapolate hydrate distribution around the site-survey seismic grid. In addition, the drilling results provide lithologic, thermal, chemical, and other geological information essential for interpreting depositional environment, age, and other factors that influence hydrate formation. The results of this effort will be reported in the JIP Scientific Results manuscript reports. The first volume report describes the seismic and bottom photography transect across the two Atwater Valley mounds studied at the Atwater drilling site. The second report covers the seismic stratigraphy and geologic characterization of the Keathley Canyon drill site.

The USGS has led an effort to review and assess drilling targets for the planned 2008 JIP logging-while-drilling (LWD) expedition. During the summer of 2007 five meetings were held to review the data and to discuss recommendations for optimal target sites. The group considered eight sites throughout the northern Gulf of Mexico and eliminated four of them from further consideration, including one of the sites originally designated as a potential priority gas hydrates site (AC857). More than a dozen drilling targets have been identified in the AC818 site (the most mature in our analysis). A final meeting was held October 19, 2007 where three sites were recommended for drilling in 2008: AC818 (eighteen drilling targets identified), GC955 (nine drilling targets identified), and WR313 (eight drilling targets identified).

Task 3 – Laboratory Investigations of Gas Hydrates
As part of this task, the USGS uses knowledge gained from the drilling expeditions to better plan and conduct laboratory experiments that reproduce the physical property and hydrate formation results obtained through drilling. Flow tests were completed in December 2006 using the Gas Hydrate and Sediment Testing Laboratory Instrument (GHASTLI) to investigate hydrate formation from dissolved-phase methane. Preliminary analysis of the data began in February 2007. Early findings show that for low saturation levels, both the acoustic and shear failure responses of the sample mimicked results from water-saturated sand samples in which no methane or hydrate was present. This is in agreement with studies from Georgia Tech suggesting pore-space hydrate saturations must exceed about 40% before significant physical property changes occur in the sample.

The second of three planned dissolved phase hydrate formation tests was completed in mid-November 2007. In the first test, a fixed temperature in the sample was used. Hydrate formation appeared to be rapid, but localized in the region right around where methane-rich water entered the sample. In the second test, the sample temperature was cycled. When the sample was warm, methane-rich water was pumped through the sample. The sample was then isolated and cooled, to promote hydrate formation throughout the sample from the methane-rich water. The process was repeated several times, in hopes of adding hydrate with each cycle. In fact it appears hydrate forming during a cooling cycle dissolved again when the sample was warmed in preparation for adding new methane-rich water. No measurable net growth occurred.

Using GHASTLI consolidation, acoustic, and shear strength properties were also successfully measured on sediment recovered during the 2005 Gulf of Mexico JIP field program. This sample is unique because it is the first pressure core transferred into a Parr vessel and sealed with a new ball-valve system that preserved initial pressure during shipment to Woods Hole. Hence, the sample was depressurized only once, immediately before the transfer into GHASTLI. This sample provided an important benchmark for GHASTLI regarding how to handle and transfer samples that have never been depressurized. Lessons learned on this sample were applied to the transfer of pressure samples collected during the Indian National Gas Hydrate Progam (NGHP) Expedition 01 drilling.

The USGS Gas Hydrates Petrophysics Laboratory utilizes a number of techniques to study the physical states of hydrates in marine sediments and the effects of hydrates on sediment properties, such as sediment thermal and mechanical stability. Recently, the laboratory has developed an apparatus to prepare hydrate samples from saturated sand packs in a more uniform manner than has been previously possible. The new apparatus allows slow rotation of samples during the reaction process to avoid water pooling, thus allowing investigation of the effects of higher levels of hydrate saturation in pore space. The work under this task work is complementary to on-board and post-drilling studies from DOE-funded and international field drilling and coring efforts such as the Integrated Ocean Drilling Study (IODP) Expedition 311, ChevronTexaco JIP and the Indian NGHP recent expedition.

The USGS is also conducting work to investigate the properties of gas hydrate samples developed in the lab. Depressurization/repressurization (d/r) tests for thermal properties using hydrate-bearing, gas rich Ottawa sand with 20% and 43% of the pore space saturated with hydrate have been completed. These studies have confirmed that the water content near the central axis of the sample is lower than the value near the outer surface of the sample, a variation meriting further investigation. The increase in thermal conductivity resulting from a d/r cycle for 20% pore space saturation with hydrate is ~6%, as compared with a ~14% increase seen in the 43% hydrate saturation sample. This experiment and the same experiment conducted in the Gas Hydrate and Sediment Testing Laboratory Instrument (GHASTLI) on elastic properties are intended to investigate the simulated transfer of natural core from a pressurized corer to a storage and transfer vessel.

D/R tests in GHASTLI showed that both wave speeds and amplitudes increase after d/r in both Ottawa sand samples. The effect of a d/r cycle on the acoustic signal and the connection between the acoustic signal and wave propagation processes are not yet fully understood and are the subjects of ongoing studies by Dr. Myung Lee (USGS, Denver) and researchers at the Georgia Institute of Technology. Preliminary results are being integrated with X-Ray Computed Tomography from Dr. Tim Kneafsey (Lawrence Berkeley National Laboratory) and natural sample measurements by Dr. Santamarina's group at Georgia Tech using their Instrumented Pressure Testing Chamber (IPTC). Collectively, the findings of these efforts should present a more complete picture of the extent and process by which a d/r cycle alters core properties.

Task 4 – International Gas Hydrate Collaboration
This task has facilitated USGS field participation and some post-cruise geochemical and geotechnical analysis of samples recovered during drilling in May to August 2006 along the Indian continental margins. USGS scientists supported the drilling operations for the 3-leg cruise by coordinating the outfitting of the ship, staffing scientific specialists, operational logistics, and decisions about prioritizing drill sites. While the bulk of the USGS support occurred at sea where more than 20 research wells were drilled, the effort also includes post-cruise analysis of pressure cores as well as distribution of pressure cores to other laboratories for future analysis.

Current Status

Task 1 – Characterization and Assessment of Natural Gas Hydrates in Permafrost Environments
USGS continues to coordinate science research and reporting activities in support of the BPXA/DOE Mt. Elbert Gas Hydrate Stratigraphic Test Well. A scientific/engineering results meeting for drilling results will be hosted by USGS on March 4-7, 2008. Work is progressing on a well test program Decision Support Package, which is expected to be delivered to BP in October 2008.

Task 2 – Subsurface Gas Hydrate Occurrence in the Gulf of Mexico
USGS efforts are currently directed at working with JIP personnel to begin operational and logistics planning for the 2008 LWD program.

Task 3 – Laboratory Investigations of Gas Hydrates
The USGS is utilizing controlled laboratory experiments to improve future field protocols for core handling and measurement and to inform modeling studies of critical parameters regarding the physical states of hydrates in marine sediments and the effects of hydrates on sediment properties, such as sediment thermal and mechanical stability.

The third dissolved phase hydrate formation test began in late November 2007. In this test a continuous flow of methane-rich water will be put through the sample. The sample temperature will be reduced over a 4-week period with the intent of identifying the critical temperature at which hydrate begins forming, then tracking the growth rate. Like the second test, this third test utilizes the 12-mm long Star-Oddi pressure/temperature loggers used in the Indian NGHP Expedition 01 and Mt. Elbert field projects. These measurement "pills," being embedded within the sample itself, permit tracking of internal temperature and pressure gradients, the latter being a means of identifying where hydrate forms and reduces the local permeability. In test 2, the pills did not record a time-dependent pressure gradient, further suggesting the lack of sustained hydrate growth, but the temperature profile during the heating and cooling phases were clearly measured.

Based on lessons learned from the Gulf of Mexico JIP test, three existing ball-valve samples from the 2006 Indian NGHP Expedition 01 program were successfully transferred into GHASTLI. Despite several fractures in the first Indian NGHP Expedition 01 sample observed after depressurization, it was successfully consolidated and sheared. The second sample adhered to the membrane during transfer due to its plastic nature, had to be removed, reformed, and finally transferred into GHASTLI. Although both samples were disturbed prior to consolidation, they produced very similar shear strength versus strain results and pore-pressure behavior. Because of an initially higher water content, more disturbance caused by depressurization, and a sub-vertical very thin sand lense, the final “pristine” sediment pressure-core sample was weaker than two previously tested pressure-core samples. These tests provide an opportunity to understand the effects of dissociation on physical properties and to compare the properties measured using GHASTLI with those determined during the later part of 2006 in Singapore on continuously-pressurized cores. However, initial reports of sample heterogeneity may make this challenging. In addition to strengthening ties with the National Gas Hydrate Program of India, this project may provide clues on behavior changes induced by in situ production tests. Results were incorporated into an abstract submitted for the February 2008 Indian NGHP Expedition 01 symposium in New Delhi.

As part of an ongoing effort by Dr. Myung Lee (USGS, Denver) to predict hydrate-saturation in a sand pack based on acoustic waveforms, a sand pack with ~50% of the pore space saturated with ice was constructed, and the compressional and shear wave signals through the sample measured. Acoustic waveform signals obtained through aluminum rods of varying length and diameter are used by Dr. Lee to construct a mathematical description of the "normal mode" wave packet to help analyze acoustic waveforms measured in cemented sand packs in GHASTLI. The shear waveforms show the same unexpected energy pulse observed in both the hydrate-cemented and ice-cemented sand packs tested in GHASTLI. Using the measured waveforms through the aluminum rods, Dr. Lee has developed the mathematical formalism for describing the acoustic normal modes in the aluminum rods. A manuscript is in preparation, and the work is being extended to describe hydrate- or ice-cemented sands.

Task 4 – International Gas Hydrate Collaboration
Much of the recent work under this task has been dedicated to finishing the Initial Results volume for the 2006 India Gas Hydrates Drilling Program. The final volume includes sections on methods, operational summaries, chapters on each of the 21 sites, together with extensive appendices with data summaries and downhole log data. In addition, work progressed on organizing the post-drilling science results symposium in New Delhi, India, February 6-10, 2008. Here interpretations of the drilling data will be shared by all participants and plans finalized for chapters to be included in the science results volume. This meeting will include all cruise participants plus representatives of the major gas hydrates drilling projects from around the world.

Project Start: April 11, 2005
Project End: May 31, 2008

DOE Contribution: $1,363,000
Performer Contribution: na

Contact Information:
NETL – Robert Vagnetti (robert.vagnetti@netl.doe.gov or 304-285-1334)
USGS – Deborah R. Hutchinson (dhutchinson@usgs.gov or 508-457-2263)

Additional Information
In addition to the information provided here, a full listing of project related publications and presentations as well as a listing of funded students can be found in the Methane Hydrate Program Bibliography [PDF].

USGS Hydrate From Ice (HyFI) Test System [external site - USGS]

Mount Elbert Science Team, 2007, Alaska North Slope well successfully cores, logs, and tests gas-hydrate-bearing reservoirs: Fire in the Ice, DOE/NETL Newsletter, Winter, 2007, p. 1-4

Press Release: Petroleum News, February 25, 2007, North Slope gas hydrate well hits target – BP-operated Mount Elbert well confirms presence of gas hydrate accumulation and enables coring and testing of gas hydrate zone, by Alan Bailey, http://www.petroleumnews.com/pntruncate/608307478.shtml.

2008 ICGH Paper - Seeding Hydrate Formation in Water-Saturated Sand with Dissolved-Phase Methane Obtained from Hydrate Dissolution: a Progress Report [PDF] - August, 2008

2008 ICGH Paper - Geologic and Engineering Controls on the Production of Permafrost-Associated Gas Hydrate Accumulations [PDF] - August, 2008

2008 ICGH Paper - Indian Continental Margin Gas Hydrate Prospects: Results of the Indian National Gas Hydrate Program (NGHP) Expedition 01 [PDF] - August, 2008

2008 ICGH Paper - Physical Properties of Repressurized Samples Recovered During the 2006 National Gas Hydrate Program Expedition Offshore India [PDF] - August, 2008

2008 ICGH Paper - Seismic Mapping of Gas Hydrate Deposits in the Krishna-Godhavari Basin Offshore India [PDF] - August, 2008

2008 ICGH Paper - Site Selection for DOE/JIP Gas Hydrates Drilling in the Northern Gulf of Mexico [PDF] - August, 2008

2008 ICGH Paper - Investigation of Gas Hydrate-Bearing Sandstone Reservoirs at the "Mount Elbert" Stratigraphic Test Well, Milne Point, Alaska [PDF]- August, 2008

Pertinent Publications
The publications listed below are those published in 2004 and after. For a complete listing of publications and presentations related to this project access the Methane Hydrates Bibliography .

Peer-Reviewed Publications
Chand, S., T. A. Minshull, J. A. Priest, A. I. Best, C. R. Clayton, and W. F. Waite, 2006, An effective medium inversion algorithm for gas hydrate quantification and its application to laboratory and borehole measurements of gas hydrate-bearing sediments, Geophysical Journal International, 166, doi: 10.1111/j.1365-246X.2006.03038.x, p. 543-552.

Circone, S., S. Kirby, and L. Stern, 2006, Thermodynamic calculations of the system CH4-H2O and methane hydrate phase equilibria, Journal of Physical Chemistry B, Volume 110, p. 8232-8239.

Circone, S., L. Stern, and S. Kirby, 2004a, The role of water in hydrate dissociation, Journal of Physical Chemistry B, Volume 108, p. 5747-5755.

Circone, S., L. Stern, and S. Kirby, 2004b, Effect of Elevated Methane Pressure on Methane Hydrate Dissociation Behavior, American Mineralogist, Volume 89, p. 1192-1201.

Dvorkin, J., Helgerud, M.B., Waite, W.F., Kirby, S.H. and Nur, A., 2000, Introduction to Physical Properties and Elasticity Models, Chapter 20 in Max, M.D., ed., Natural Gas Hydrate in Oceanic and Permafrost Environments: Kluwer Academic Publishers, Netherlands, p. 245-260.

Lee, M., T. Collett, M. Whiticar, in review, Integration of vertical seismic, surface seismic and well log data at the Mallik 2L-38 gas hydrate research well, Mackenzie Delta, Canada, in Collett, T., A. Johnson, C. Knapp and R. Boswell, eds., Natural Gas Hydrates: Energy Resource and Associated Geologic Hazards, The American Association of Petroleum Geologists Hedberg Special Publication.

Lorenson, T., T. Collett, M. Whiticar, in review, Hydrocarbon gas composition and origin of gas hydrate from Alaska North Slope, USA, in Collett, T., A. Johnson, C. Knapp and R. Boswell, eds., Natural Gas Hydrates: Energy Resource and Associated Geologic Hazards, The American Association of Petroleum Geologists Hedberg Special Publication.

Paull, C., W. Ussler, T. Lorenson, W. Winters, and J. Dougherty, 2005, Geochemical constraints on the distribution of gas hydrates in the Gulf of Mexico, Geo-marine Letters, Volume 25, p. 273-280.

Rehder, G., S. Kirby, W. Durham, P. Brewer, L. Stern, E. Peltzer, and J. Pinkston, 2004, Dissolution Rates of Pure Methane Hydrate and Carbon Dioxide Hydrate in Undersaturated Seawater at 1000 M Depth, Geochemistry et Cosmochimica Acta, Volume 68, p. 285-292.

Stern, L., S. Kirby, S. Circone, and W. Durham, 2004, Scanning Electron Microscopy (SEM) Investigations of Laboratory-Grown Gas Hydrates from Melting Ice, and Comparison to Natural Hydrates, American Mineralogist, Volume 89, p. 1162-1175.

Stern, L., S. Kirby, and W. Durham, 2005, Scanning electron microscope imaging of grain structure and phase distribution within gas-hydrate-bearing intervals from JAPEX/JNOC/GSC et al., Mallik 5L-38: what can we learn from comparisons with laboratory synthesized samples?, Geological Survey of Canada Bulletin 585.

Waite, W., L. Gilbert, W. Winters, and D. Mason, 2006, Estimating thermal diffusivity and specific heat from needle probe thermal conductivity data, Review of Scientific Instruments, 77, 044904, doi:10.1063/1.2194481.

Waite, W., C. Ruppel, and S. Kirby, 2006, Comment on “Thermal and visual time-series at a seafloor gas hydrate deposit on the Gulf of Mexico slope,” by MacDonald, I., L. Bender, M. Vardaro, B. Bernard, and J. Brooks [Earth Planet. Sci. Lett. 233 (2005) 49 59], Earth and Planetary Science Letters, 245, 481- 482.

Waite, W., W. Winters, and D. Mason, 2004, Methane Hydrate Formation in Partially Water-Saturated Ottawa Sand, American Mineralogist, Volume 89, p. 1202-1207.

Waite, W.F., deMartin, B.J., Kirby, S.H., Pinkston, J. and Ruppel, C.D., 2002, Thermal Conductivity Measurements in Porous Mixtures of Methane Hydrate And Quartz Sand: Geophysical Research Letters, vol. 29, no. 24, 2229, doi:10.1029/2002GL015988, pp. 82(1)-82(4).

Waite, W.F., L.A. Stern, S.H. Kirby, W.J. Winters, D.H. Mason, 2007. Simultaneous determination of thermal conductivity, thermal diffusivity and specific heat in sI methane hydrate, Geophysical Journal International, 169, doi: 10.1111/j.1365-246X.2007.03382.x, p. 767-774.

Winters, W., W. Waite, and D. Mason, in review, Effects of methane hydrate on the physical properties of sediment in Collett, T., A. Johnson, C. Knapp and R. Boswell, eds., Natural Gas Hydrates: Energy Resource and Associated Geologic Hazards, The American Association of Petroleum Geologists Hedberg Special Publication.

Winters, W., W. Waite, D. Mason, L. Gilbert and I. Pecher, 2007, Methane gas hydrate effect on sediment acoustic and strength properties, Journal of Petroleum Science and Engineering – Natural Gas Hydrate/Clathrate (Elsevier), edited by D. Mahajan, C. Taylor and G. Ali Mansoori, Volume 56, Issues 1-3, March.

Winters, W., W. Waite, and D. Mason, 2004, Strength and Acoustic Properties of Ottawa Sand Containing Laboratory-Formed Methane Gas Hydrate in Taylor, C., and J. Kwan, eds., Recent Advances in the Study of Gas Hydrates, American Institute of Chemical Engineers and Kluwer Academic/Plenum Publishers, p. 213-226.

Winters, W., I. Pecher, W. Waite, and D. Mason, 2004, Physical Properties and Rock Physics Models of Sediment Containing Natural and Laboratory-Formed Methane Gas Hydrate, American Mineralogist, Volume 89, p. 1221-1227.

Winters, W., S. Dallimore, T. Collett, B. Medioli, R. Matsumoto, J. Katsube, and P. Brennan-Alpert, 2005, Relationships of Sediment Physical Properties from the JAPEX/JNOC/GSC Mallik 5L-38 Gas Hydrate Production Research Well in Dallimore, S. and T. Collett, eds., Scientific Results from Mallik 2002 Gas Hydrate Production Research Well Program, Mackenzie Delta, Northwest Territories, Canada, Geological Survey of Canada Bulletin 585.

Government Reports
Collett, T., 2004, Alaska North Slope gas hydrate energy resources, U.S. Geological Survey Open-File Report 2004-1454.

Hutchinson, D., 2005, Final Technical Report to the Department of Energy, National Energy Technology Lab Interagency Agreement, Task DE-AT26-97FT34343, September 8, 1997- April 30, 2005..

Lee, M., and T. Collett, 2005, Controls on the Physical Properties of Gas-Hydrate-Bearing Sediments Because of the Interaction between Gas Hydrate and Porous Media, U. S. Geological Survey Scientific Investigations Report 2005-5143.

Winters, W., T. Lorenson, and C. Paull, eds., in press, Initial report of the IMAGES VIII/PAGE 127 Gas Hydrate and Paleoclimate Cruise on the RV Marion Dufresne in the Gulf of Mexico, 2-18 July, U.S. Geological Survey Open File Report 2004-1358.

Other Publications
Stern, L., S. Kirby, and S. Circone, 2002, Interagency group “zooms in” on methane hydrate pore structures, U.S. DOE-NETL Fire in the Ice Newsletter, Summer.

Presentations
Chuvilin, E., E. Kozlova, O. Boldina, and W. Winters, 2004, Stability of methane gas hydrate formed in marine sediment from the northern Gulf of Mexico, St. Petersburg, Russia, Minerals of the Ocean – Integrated Strategies, April 25-30.

Collett, T., 2004, Arctic gas hydrate resources, Tromso, Norway, Proceedings of the Conference on Arctic Geologic, Resources, and Environmental Challenges, May 24-26.

Dugan, B., J. Germaine, W. Winters, and P. Flemings, 2004, Laboratory constraints and models of pressure, hydrate, and stability in shallow Mississippi Canyon sediments (MC 855), deepwater Gulf of Mexico, Dallas, TX, The American Association of Petroleum Geologists Annual Meeting, April 18-21.

Ellis, M., R. Evans, D. Hutchinson, and P. Hart, 2005, An electromagnetic survey of the JIP drill sites in Atwater Valley, paper OS31D-07, American Geophysical Union Fall Meeting, December 5-9.

Gilbert, L., W. Waite, W. Winters, and D. Mason, 2004, Characterization of Gulf of Mexico sediment in hydrate and non-hydrate bearing cores using specific surface area, San Francisco, CA, American Geophysical Union Fall Meeting, December 13-17.

Hart, P., T. Lorenson, A. Grantz, B. Herman, 2006, Gas hydrate and associated free gas across the Alaskan Beaufort Sea outer continental margin (abs.), Edinburgh, Scotland, 5th International Workshop on Methane Hydrate Research and Development, October 9-12 – submitted.

Helgerud, M., W. Waite, L. Stern, and S. Kirby, 2005, Effects of fracture and crack healing in sI methane and sII methane-ethane hydrate, paper OS43A-0605, American Geophysical Union Fall Meeting, December 5-9.

Hunter, R., Digert, S., Wilson, S., Collett, T.S., and Boswell, R., 2007, Gas hydrate resource potential (abs.): AAPG Annual Meeting, Long Beach, CA., April, 2007, http://www.searchanddiscovery.com/documents/2007/07018annual_abs_lngbch/abstracts/lbHunter.htm [external site].

Lorenson, T., W. Winters, C. Paull, and W. Ussler, 2006, Is gas hydrate and the Storegga Slide offshore Norway connected to an active petroleum system?, Houston, TX, The American Association of Petroleum Geologists Annual Meeting, April 9-12.

Stern, L., 2006, Gas hydrates: an overview of our 10+ years of laboratory research on these unusual compounds, U.S. Geological Survey Earthquake Hazards Team seminar, January 25.

Stern, L., W. Durham, S. Kirby, S. Circone, and M. Helgerud, 2004, Experimental Observations Pertinent to the Mechanical and Thermal Stability of sI Methane Hydrate/Sand Aggregates, Dallas, TX, The American Association of Petroleum Geologists Annual Meeting, April 16-21.

Stern, L., and S. Kirby, 2006, Gas hydrates in sediments imaged by cryogenic SEM (CSEM): Insights from lab experiments on synthetic hydrates as interpretive guides (abs.), Bremerhaven, Germany, Physics and Chemistry of Ice (PCI) Conference, July 23-28.

Ussler, W., C. Paull, Y. Chen, R. Matsumoto, T. Lorenson, and W. Winters, 2005, The consequences of methane oxidation at the sulfate-methane interface in a methane-rich core from the northern Gulf of Mexico, Trondheim, Norway, Fifth International Conference on Gas Hydrates, June 12-16.

Waite, W., L. Stern, W. Winters, and D. Mason, 2006, Simultaneous determination of thermal conductivity, thermal diffusivity and specific heat in sI methane hydrate, American Geophysical Union Conference Fall Meeting, December 11-15..

Waite, W., C. Santamarina, T. Yun, T. Kneafsey, C. Ruppel, W. Winters, and D. Mason, 2006, Mechanical and thermal property changes in hydrate-bearing sediment resulting from a brief depressurization, American Geophysical Union Fall Meeting, December 11-15.

Waite, W., T. Kneafsey, J. Santamarina, W. Winters, T. Yun, D. Mason, and C. Ruppel, 2006, Physical property changes in hydrate-bearing sediment samples due to depressurization/repressurization, American Geophysical Union Fall Meeting, December 11-15.

Waite, W., L. Gilbert, W. Winters, and D. Mason, 2005, Thermal property measurements in Tetrahydrofuran (THF) hydrate and hydrate-bearing sediment between -25 and +4C and their application to methane hydrate, 5th International Conference on Gas Hydrates, June 12-16.

Waite, W., L. Gilbert, W. Winters, and D. Mason, 2004, Thermal property measurements in Tetrahydofuran (THF) hydrate between -25 and +4C and their application to methane hydrate, San Francisco, CA, American Geophysical Union Fall Meeting, December 13-17.

Winters, W., W. Waite, and D. Mason, 2006 (in press), Grain size effects on acoustic and strength behavior of sediments containing natural- and laboratory-formed methane gas hydrate, Kauai, HI, Workshop on Science and Technology Issues in Methane Hydrate Research and Development, March 5-9.

Winters, W., W. Waite, and D. Mason, 2005, Effects of Methane gas hydrate formation on pore pressure response, shear strength, and acoustic properties of sediment, paper OS43A-0607, American Geophysical Union Fall Meeting, December 5-9.

Winters, W., W. Waite, B. Dugan, D. Mason, and I. Pecher, 2004, Strength and physical properties of sediment containing laboratory-formed and natural gas hydrate, Dallas, TX, The American Association of Petroleum Geologists Annual Convention, April 18-21.