Synopsis Part I – Discovery, Physical and Chemical Properties,

1. Synopsis • Part I – Discovery, Physical and Chemical Properties, • Crystal Structure, Stability and Dissociation, • Deposits and Sources, and Global Warming • Impact • Part II – Growing Demand for Natural Gas, • Commercialization, Production, Exploration • and Simulation, R&D Projects, and References • Presentation by • Charles Tracy • Omotayo Asunmo • Yoojin Lee ¤ Information within this presentation is compiled from 20 different resources, of which most are undertaking active methane hydrate research. Brief Overview of Methane Hydrate (Methane Clathrate)The fuel of the future may be ice that burns!

2. In 1964, a Russian drilling crew discovered natural • gas in the "frozen state," or methane hydrate • occurring naturally. The former Soviet Union • intensified interest and sent geologists worldwide. • Glomar Challenger was a oceanographic drilling • and coring vessel, active from 1968 to 1983. It was • equipped with a drilling derrick 140 feet high and • was capable of drilling more than 5,570 feet into the • ocean floor. It investigated some 624 sites in the • Atlantic, Pacific, and Indian Oceans In 1981, the • drilling vessel unexpectedly bored into a methane • hydrate deposit. It was the first research vessel to • obtain core samples from the deep ocean floor • (Shown Top). • Colorado School of Mines, CHR - Methane hydrates • in permafrost zones and near-seafloor offshore • hydrate deposits at Barkley Canyon (Shown Bottom). Part I Discovery, Glomar Challenger, Hydrates in Nature

3. What is Methane Hydrate? • Methane hydrate is often described as "methane gas surrounded by ice." Although this description is easy to understand, it's not completely accurate. A more accurate description would be that methane hydrate is a cage-like lattice of ice (made up of hydrogen bonded water molecules), inside of which are trapped molecules of methane, the chief constituent of natural gas. If you put a match to it, it burns with a soft orange flame (Shown Right). • "Gas hydrates" is the generic term used to describe these hydrates with various gases, and is not unique to methane. Gas hydrates are non-stoichiometric compounds. Most low molecular weight gases including H2, O2, N2, Ar, Kr, Xe, CH4, H2S, SO2, CO2, and CO, as well as some higher hydrocarbons and freons will form hydrate compounds. These "cages“ are unstable when empty, collapsing into conventional ice crystal structure, but they are stabilized by the inclusion of appropriately sized molecules within them. The formation and decomposition of gas hydrates are phase transitions and not chemical reactions.

4. Methane Hydrate “Fiery Ice” – Physical Properties • Synonyms: Methane Hydrate, Methane Clathrate, Methane Ice • Empirical Formula: (CH4)8(H2O)46, 1 mole of CH4 for every 5.75 moles H2O • Molecular Weight, Composition: 957.04 g/mol, H 13.06% C 10.04% O 76.90% • Color, Luster, Hardness: White or Yellow White, Vitreous (Dull), Mohs 2.5 (Finger Nail) • Density, Heat of Formation, Specific Heat:948 kg/m3, 410 kJ/kg, 2 kJ/kgK • Dielectric Constant, Thermal Conductivity, Young’s Modulus: 58, 0.49 W/mK,8.4 GPa • Crystal System, Cavity Radius: Two dodecahedral & Six tetradecahedral cages/unit cell, 0.39-0.47 nm • Environment: 4 - 5°C, 50 atm, can remain stable at temperatures up to 18 °C • Longitudinal Sound Velocity, Poisson’s Ratio: 3.3 km/s, 0.33 • Volumetric Property: Methane hydrate contains 180 m3 of gas per m3 of solid hydrate

5. Methane Hydrate Crystal Structure and Appearance • Structure I & II: Biogenic, Thermogenic • Appearance: Coarse grained “ice rock”

6. Why Examine Methane Hydrate's Crystal Structure? • It's because the amount of gas contained in methane hydrate differs depending on whether it has a Type I or a Type II structure. • Among the methods of examining the structure of methane hydrate are the CT Scan, X-ray diffraction, NMR, and Raman spectroscopic methods. • Methane hydrates with Type II structures can hold slightly more gas than methane hydrates with a Type I structure. Consequently, developing a natural methane hydrate deposit with a preponderance of Type II structure methane hydrate is likely to result in the production of more methane. • Methane hydrate as found in a core sample of gravel. The black areas are gravel and sand; the white areas are methane hydrate. The image at bottom right is a CT scan of the same core sample. The dark red areas are gravel. The orange and yellow areas are a mixture of sand and methane hydrate. The green areas are methane hydrate. Using CT technology, we can perform a limited analysis of the distribution of methane hydrate in a core sample (Shown Top).

7. The phase boundary (a pressure temperature line) divides the methane as • hydrate (that is methane ice) to the left of the line from methane that has • dissociated from hydrate on the right. • The hydrothermal gradientindicates the water temperature. The water-sediment • marks the seafloor. • The geothermal gradient indicates the temperature of the sediments, which • increases with depth. • The base of gas hydrate, the sediments become too warm for hydrate to exist. Methane Hydrate Stability Curve

8. Methane hydrate formed in • pure water (Shown Below). Pressure-Temperature Diagram for Methane Hydrate • If conditions fall outside this stability curve on • the PT diagram, the material will dissociate into • its components (Shown Above). • The stability curve shows that methane hydrate • is stable at 0.1 MPa (the pressure at sea • level), if temperatures are low enough and that • it is stable above the melting point of water if • pressures are high enough.

9. At lower temperatures (blue lines), methane • hydrate dissociates rapidly after rapid • depressurization. At warmer temperatures (black • lines), dissociation is complete only after periods • as long as 25 hours (Shown Top). • When heated, methane hydrate dissociates into • methane and water. However, during the • dissociation process, methane hydrate causes an • endothermic reaction by absorbing heat from the • atmosphere. As its temperature falls, the rate at • which it dissociates slows. It is as though the • methane hydrate were saying, "I don't want to • dissociate. This characteristic of methane hydrate • is known as the "self-preservation effect.“ • When gas hydrates dissociate (melt), the • crystalline lattice breaks down into liquid water (or • converts to ice if conditions are below the freezing • point of water) and the gas is released (Shown Bottom). Methane Hydrate: Dissociation and Self-Preservation Effect

10. Thermodynamics– If the methane dissolved concentration • reaches the saturation value for hydrate formation at the local • temperature and pressure conditions, methane and water will • freeze together into methane hydrate or clathrate deposits. • Thermodynamically, the stability of the hydrate is determined • by the temperature and by the availability of methane. At • atmospheric pressure, hydrate is never stable at earth • surface temperatures (Shown Top). • Kinetics– Hydrate can persist at a meta-stable state, several • degrees above its thermodynamic melting temperature, • because of the energy barrier of nucleating small bubbles of • methane gas. Rapid depressurization such as occurs during • core retrieval does lead to melting of hydrate. Several studies • predict inhibition of hydrate formation in fine-grained sediment • caused by the high activation energy of forming small • crystals. This would explain the textures of hydrate as coarse- • grained sediment. Cornell University is simulating the kinetics • of hydrate growth and dissolution in shale-like environments • like the ones in which hydrates exist in ocean (Shown Bottom). Physical Chemistry of Methane Hydrate

11. World Distribution of Methane Hydrate • Originally thought to occur only in the outer regions of the Solar System. On Earth, this ice is widespread in cold sea beds near continental shelves and occurs on land in permafrost and ice sheets. • Estimates on how much energy is stored in methane hydrates range from 350 years supply to 3500 years! • Around the United States, large deposits have been identified and studied in Alaska, the west coast from California to Washington, the east coast, including the Blake Ridge offshore of the Carolinas, and in the Gulf of Mexico. • Worldwide distribution of confirmed or inferred offshore methane hydrate-bearing sediments (Shown Below).

12. Hydrate Deposits and Sources • Arctic and Ocean Deposits – hydrate deposits can be 1000-2000 feet thick and cover large areas • Biogenic Source – hydrates formed by microbial activity in the upper several hundred meters of deep-sea sediment • Thermogenic Source – hydrates formed by geological processes and thermal breakdown of organic material at greater depths

13. Beneath permafrost- • In areas close to the North and • South poles, strata of earth • remain frozen even in summer. • These strata are known as • permafrost. Under this permafrost • are the types of low-temperature, • high-pressure environments in • which methane hydrate can exist • in its natural state. Environments in Which Methane Hydrate is Present • In strata beneath deep ocean floors- Water near the bottom of extremely deep oceans is as cold as 0 to 4°C. • Moreover, the weight of the water above means that the seafloor is under high • pressure. Accordingly, the earth under the seafloor in deep oceans is the type • of low-temperature, high-pressure environment in which methane hydrate can • exist naturally.

14. Methane Hydrate Produced in Laboratory • At the Norwegian University of Science and Technology methane hydrate was produced in a high-pressure reactor operated at 50-70 bars and 2-10°C. The 600 cm3 CSTR was filled with 100 cm3 of liquid water and the remaining natural gas mixture containing, 92 mol % methane, 5 mol % ethane and 3 mol % propane. Hydrate formation was started by agitation with a magnetic stirrer at 500 rpm. The reactor was then tipped upside down to separate the liquid water and solid hydrate (Shown Below). • The hydrate was stored in a freezer at -18°C. From the experiment the heat of formation was 410 KJ/ kg and the specific heat was 2 KJ/ kgK, and the density was 948 kg/ m3.

15. Global Warming: CH4 could be far worse than CO2 • There are enormous quantities of naturally occurring greenhouse gasses trapped in ice-like structures in the permafrost at the bottom of the oceans. These clathrates contain 3,000 times as much methane as in the atmosphere. • Methane is about twenty times stronger as a greenhouse gas than carbon dioxide. However, whereas it takes around 50 to 100 years for carbon dioxide to break down, methane breaks down around 12 years. • Since arctic warming seems to proceed faster than expected, a temperature increase of a few degrees would cause these gases to volatilize into the atmosphere, which would further raise temperatures, which would release more methane, and so on. There's 400 gigatons of methane locked in the frozen arctic tundra - enough to start this chain reaction. • The most recent of these catastrophes occurred about 55 million years ago in what geologists call the Paleocene-Eocene Thermal Maximum (PETM), when methane burps caused rapid warming and massive die-offs, disrupting the climate for more than 100,000 years.

16. Titan, Mars Methane May Be On Ice • The planet Mars and Saturn's moon Titan appear to have nothing in common but their color. But the atmospheres of both worlds contain an unlikely molecule, methane. Because ultraviolet sunlight easily breaks up methane, its detection implies a recent source, such as volcanic eruptions and/or hydrothermal vents. Researchers suggest methane ice may feed atmospheres (Shown Top). • NASA/ESA Cassini and Huygens probes landed on Titan, revealing a spectacular landscape carved by what many believe to be liquid methane rivers. One of the spacecraft's instruments punched into the moon's soil and detected methane gas from below. The scientists suggest methane clathrate forms a crust above an internal water-ammonia ocean (Shown Bottom). • Many believe Mars has been in a warm interglacial period for the past 400,000 years. If clathrates exist beneath eroding glaciers, ice loss at the surface may lower the pressure enough to make them unstable, uncorking the gas within them. A slow, long-term, climate-driven release may account for all of Mars' methane.

17. Part IIThe Growing U.S. Demand for Natural Gas • The United States will consume increasing volumes of natural gas well into the 21st century. U.S. annual natural gas consumption is expected to increase from about 22 trillion cubic feet today to nearly 31 trillion cubic feet in 2025 - a projected increase of over 40 percent. U.S. energy consumption by type (Shown Top). • In 1995, the U.S. Geological Survey completed its most detailed assessment of U.S. gas hydrate resources. The study estimated the in-place gas resource within the gas hydrate of the United States ranges from 112,000 trillion cubic feet to 676,000 trillion cubic feet, with a mean value of 320,000 trillion cubic feet of gas. • If only one percent of the methane hydrate resource could be made technically and economically recoverable, the United States could more than double its domestic natural gas resource base. • Worldwide, estimates of the natural gas potential of methane hydrate approach 400 million trillion cubic feet -- a staggering figure compared to the 5,500 trillion cubic feet that make up the world's currently proven gas reserves. World natural gas and gas hydrate resources (Shown Bottom).

18. Natural Gas and Methane Hydrate • City gas consists of a combustible gas known as "natural gas" that is extracted from between the earth's strata, and then supplied to homes around the country. While the principle component of natural gas is methane, it also contains other hydrocarbons. For this reason, although city gas is mostly methane, it also includes traces of these other hydrocarbons. • Methane hydrate is also trapped between the earth's strata. But while natural gas takes the form of a gas, methane hydrate is a solid. The development of methane hydrate entails breaking down these methane hydrate solids and extracting the methane and other hydrocarbons. Future Methane Hydrate Proposed Infrastructure (Shown Below).

19. Drilling rigs are found in three general types: • Jack-up rigs, Semi-submersible rigs, and Drill • ships. Efforts are currently underway to apply • these deep-sea oil and natural gas drilling • techniques to drilling for methane hydrate- • bearing layers. • As many as 60,000 wells are drilled annually to • extract oil and natural gas. No wells have been • drilled to date with the purpose of extracting • methane hydrate. The problems and challenges • posed by methane hydrate drilling are drilling in • deep waters, drilling in unstable formation, • preventing methane hydrate dissociation, and • strong ocean currents. Commercialization- Methane Hydrate Drilling • However, because methane hydrate is a solid, it is unlikely to flow out in the same way as oil • and natural gas. But if we could devise some method to make methane hydrate dissociate • underground and generate methane gas, it would be possible to apply the same techniques • used in the production of oil and natural gas. Consequently, finding an efficient, safe method • of triggering the dissociation of methane hydrate is an important factor in production. Next are • three methods used for oil and natural gas production and currently being explored.

20. Thermal Recovery Method (Top) - • Methane gas is extracted by circulating hot water or • steam down through the well to the methane • hydrate-bearing layer, causing the methane hydrate • to decompose. • Depressurization Method (Bottom) - • Methane gas is extracted by reducing the pressure • inside the well by reducing the specific gravity or • amount of the drilling mud, causing the methane • hydrate to decompose. • Inhibitor Injection Method (Not Shown) - • Introducing an additive alters the temperature and • pressure at which methane hydrate forms and • dissociates. These additives are known as • "inhibitors." Free gas is extracted by injecting an • inhibitor into the methane hydrate-bearing layer. • Methanol, MEG and DEG are well-known methane • hydrate inhibitors. Methane Hydrate Production

21. Seismic surveys are used in oil and natural gas prospecting to study the • distribution of oil or natural gas bearing sediment. Seismic survey uses • artificially generated vibrations to conduct geological surveys. These • vibrations are also known as acoustic waves, and seismic survey is • sometimes referred to as acoustic exploration. Exploration for Methane Hydrate • Air guns generate acoustic waves by • firing compressed air into the water. • Acoustic waves bounce off the seafloor, • which marks the boundary between the • sea and the sediment underneath, and off • the boundaries between different • layers of sediment, before returning to • the ocean surface, where they are picked • up by sensors located inside a streamer • cable. Seismic survey involves analyzing • the strength of these waves and the time • it takes for them to reach the sensors. • The results of this analysis indicate the • makeup of the layers of sediment beneath • the seafloor.

22. HWHydrate Simulation • includes a wide range of • PVT calculations covering • systems with gas hydrates • (Below). Simulation Study of Production Performance • Because production tests are so expensive, production is simulated on • computers using known facts and results from previous tests. Computers • are used to simulate the pressure, temperature, and other conditions in • the vicinity of a well, and the results used as basic data for actual production.

23. Research for Methane Hydrate Global Environment and Climate Processes on Methane Hydrate program will collect data in both the marine and arctic environments to enable: • Improved understanding to related ecosystems associated with gas hydrates and methods to minimize those impacts • Developing predictive models of methane generation, oxidation, and migration, as well as natural hydrate formation and dissociation • Measuring and interpreting the timing, magnitude, distribution, and ultimate fate of past methane releases • Determining background fluxes of gases between sea floor sediments, hydrate, the water column, and the atmosphere • Numerical modeling of the impacts among hydrate-related phenomena, global carbon cycling, and climate change • Studying hydrate’s role in the development and stability of continental shelves and slopes

24. Alaska: Project on the North Slope • DOE and BP have been working for four years to delineate and characterize more than a dozen discrete methane hydrate accumulations within the Milne Point Area, near Prudhoe Bay, on the Alaska North Slope. University of Alaska, University of Arizona, and the U.S. Geological Survey have assisted in the laboratory, geophysical, and modeling studies. • The DOE-BP Alaska Project plans drilled a vertical stratigraphic test well in one of the accumulations using ice pad in Milne Point Field in February 2007. The Stratigraphic test confirmed significant hydrate deposits that have been predicted based on seismic tests, well data, and modeling. A production test may be scheduled based on the analysis of the well data.

25. Gulf of Mexico: Project for Deep Water Drilling • A partnership enterprise between DOE and Chevron is developing technology and data to assist in the characterization of naturally occurring gas hydrate in the deep water Gulf of Mexico. The project reflects industry’s need to better understand the safety issues related to conventional oil and gas operations (drilling, producing, and gathering oil and gas) in areas prone to hydrate occurrence. • The ability to safely drill the surface hole, set, set surface casing, and maintain the integrity of the surface pipe as the entire well is drilled is of primary importance. Information gained from these studies will also help locate and produce potentially commercial hydrate deposits.

26. Gulf of Mexico: Project for Seafloor Monitoring • Methane hydrate formations on or near the seafloor may vary in extent over a span of months. These changes have implications for possible shifts in seafloor sediment, which could damage facilities- including production platforms, sub sea wellheads, pipelines, and for the potential release of methane to the atmosphere. • A project jointly funded by DOE, USGS, NOAA, and NETL will enable DOE and partners to monitor changes in gas hydrate at a seafloor observatory currently being installed in the Gulf of Mexico. Developed by a consortium of 15 academic groups, headed by University of Mississippi. • The observatory will allow continuous collection of data within the hydrate stability zone and monitor the interactions between hydrate, seafloor sediments, the water column, and the atmosphere.

27. References • Research Consortium for Methane Hydrate Resources in Japan • Norwegian University of Science and Technology • U.S. Department of Energy - Office of Fossil Energy • Heriot Watt University - Institute of Petroleum Engineering • Cornell University – Chemical and Biomolecular Engineering • National Oceanic and Atmospheric Administration • University of Chicago - Geophysical Sciences • Methane Hydrate Research Laboratory • Lawrence Livermore National Laboratory • Center for Gas Hydrate Research • Colorado School of Mines, CHR • U.S. Geological Survey • Oak Ridge National Laboratory • Hydrate Energy International • Science & Technology Review • National Science Foundation • Astronomy Magazine • NASA / ESA • World of Chemistry • Wikipedia WHAT IS THAT! Scientists Discover Methane Ice Worms on Gulf of Mexico Sea Floor (Shown Right)