Michael D. Max

Economic geology of natural gas hydrate

Why Gas Hydrate?.- Physical Chemical Characteristics of Natural Gas Hydrate.- Oceanic Gas Hydrate Character, Distribution, and Potential for Concentration.- Natural Gas Hydrate: A Diagenetic Economic Mineral Resource.- State of Development of Gas Hydrate as an Economic Resource.- Oceanic Gas Hydrate Localization, Exploration, and Extraction.- Gas Production from Unconfined Class 2 Oceanic Hydrate Accumulations.- Regulatory and Permitting Environment for Gas Hydrate.- Conclusions and Summary.

The state, potential distribution, and biological implications of methane in the Martian crust

The search for life on Mars has recently focused on its potential survival in deep (>2 km) subpermafrost aquifers where anaerobic bacteria, similar to those found in deep subsurface ecosystems on Earth, may have survived in an environment that has remained stable for billions of years. An anticipated by-product of this biological activity is methane. The detection of large deposits of methane gas and hydrate in the Martian cryosphere, or as emissions from deep fracture zones, would provide persuasive evidence of indigenous life and confirm the presence of a valuable in situ resource for use by future human explorers.

Initiation of Martian outflow channels: Related to the dissociation of gas hydrate?

We propose that the disruption of subpermafrost aquifers on Mars by the thermal- or pressure-induced dissociation of methane hydrate may have been a frequent trigger for initiating outflow channel activity. This possibility is raised by recent work that suggests that significant amounts of methane and gas hydrate may have been produced within and beneath the planets cryosphere. On Earth, the build-up of overpressured water and gas by the decomposition of hydrate deposits has been implicated in the formation of large blowout features on the ocean floor. These features display a remarkable resemblance (in both morphology and scale) to the chaotic terrain found at the source of many Martian channels. The destabilization of hydrate can generate pressures sufficient to disrupt aquifers confined by up to 5 kilometers of frozen ground, while smaller discharges may result from the water produced by the decomposition of near-surface hydrate alone.

Oceanic Gas Hydrate

Many gas hydrates are stable in deep-ocean conditions, but methane hydrate is by far the dominant type, making up >99% of hydrate in the ocean floor (Chapter 2). The methane is almost entirely derived from bacterial methanogenesis, predominantly through the process of carbon dioxide reduction. In some areas, such as the Gulf of Mexico, gas hydrates are created by the rmogenically-formed hydrocarbon gases, and other clathrate-forming gases such as hydrogen sulfide and carbon dioxide. Such gases escape from sediments at depth, rise along faults, and form gas hydrate at or just below the seafloor, but on a worldwide basis these are of minor volumetric importance compared to microbial and the rmogenic methane. Methane hydrate exists in several forms in marine sediments. In coarse grained sediments it often forms as disseminated grains and pore fillings, whereas in finer silt/clay deposits it commonly appears as nodules and veins. Gas hydrate also is observed as surface crusts on the sea floor. Methane hydrate samples have been obtained by drilling.

Introduction, Physical Properties, and Natural Occurrences of Hydrate

In the early 1820’s, John Faraday, working in England, was investigating the newly discovered gas, chlorine. He easily repeated the earlier experiments of Humphrey Davy (Davy, 1811) in which gaseous chlorine and water formed solid chlorine hydrate upon cooling in the “- late cold weather -”. Faraday’s lab curiosity chlorine hydrate has water as the host molecule, and chlorine molecules as the guest. These pioneering syntheses experiments are the first reported reference to a class of associative compounds now known as gas hydrates (Faraday, 1823, wvusd. 2000). Chlorine hydrate has persisted as a laboratory curiosity (Pauling et al., 1994) in part because its ease of formation lends it to laboratory demonstration. A variety of other molecules can form hydrates specifically and a variety of clathrates in general. The non-bonding uniqueness of clathrates as “chemicals” has interested scientists for almost two centuries.

The U.S. Atlantic Continental Margin; the Best-Known Gas Hydrate Locality

One of the few attempts to date to map gas hydrate over a large area has been made on the Atlantic continental margin of the United States (Dillon et al., 1993, 1994, 1995). This work has resulted in the production of an extensive data base of seismic reflection lines including both single and multichannel lines, and complete GLORIA sidescan sonar coverage. This work was part of the assessment of the U.S. EEZ and was carried out by the U.S. Geological Survey. Earlier efforts were made by Tucholke et al. (1977) and Shipley, et al. (1979). Research along the U.S. SE continental margin of the U.S. is continuing.

SEEDING HYDRATE FORMATION IN WATER-SATURATED SAND WITH DISSOLVED-PHASE METHANE OBTAINED FROM HYDRATE DISSOLUTION: A PROGRESS REPORT

An isobaric flow loop added to the Gas Hydrate And Sediment Test Laboratory Instrument (GHASTLI) is being investigated as a means of rapidly forming methane hydrate in watersaturated sand from methane dissolved in water. Water circulates through a relatively warm source chamber, dissolving granular methane hydrate that was pre-made from seed ice, then enters a colder hydrate growth chamber where hydrate can precipitate in a water-saturated sand pack. Hydrate dissolution in the source chamber imparts a known methane concentration to the circulating water, and hydrate particles from the source chamber entrained in the circulating water can become nucleation sites to hasten the onset of hydrate formation in the growth chamber. Initial results suggest hydrate grows rapidly near the growth chamber inlet. Techniques for establishing homogeneous hydrate formation throughout the sand pack are being developed.

National workshop on gas hydrates

The range of present knowledge on the subject of gas hydrates and related federal research programs was the topic of discussion at the National Workshop on Gas Hydrates, April 23–24. The intention of the meeting was to provide the impetus for an expanded and broader-based national research program in both academia and government. Held at the U.S. Geological Survey National Center, Reston, Va., the workshop was organized by Michael D. Max, Naval Research Laboratory, Washington, D.C.; William P. Dillon, USGS, Woods Hole, Mass.; and Rodney D. Malone, U.S. Department of Energy, Morgantown Energy Technology Center, Morgantown, W.Va. The 33 attendees represented academia (33%), federal agencies (58%), and industry (9%).

Hydrocarbon System Analysis for Methane Hydrate Exploration on Mars

The recent detection of plumes of methane venting into the Martian atmosphere indicates the probable presence of a substantial subsurface hydrocarbon reservoir. Whatever the immediate source of this methane, its production (whether by biogenic or abiogenic process) almost certainly occurred in association with the presence of liquid water in the deep (5+ km [3+ mi]) subsurface, where geothermal heating is thought to be sufficient to raise crustal temperatures above the freezing point of water. Indeed, a geologic evidence that the planet once possessed vast reservoirs of subpermafrost groundwater that may persist to the present day exists. If so, then methane generation has likely spanned a similar period of time, extending over a considerable part of the geologic history of Mars. As on Earth, the venting of natural gas on Mars indicates that substantial amounts of gas are likely present, either dissolved in groundwater or as pockets of pore-filling free gas beneath the depth where the pressure-temperature conditions permit the formation of gas hydrate. Hydrate formation requires the presence of either liquid water or ice. The amount of water on Mars is unknown; however, the present best geologic estimates suggest that the equivalent of a global layer of water 0.5–1 km (0.3–0.6 mi) deep may be stored as ground ice and groundwater beneath the surface. The detection of methane establishes the subsurface of Mars as a hydrocarbon province, at least in the vicinity of the plumes. Hydrocarbon system analysis indicates that methane gas and hydrate deposits may occur in the subsurface to depths ranging from approximately 10 m (30 ft) to 20 km (10 mi). The shallow methane deposits may constitute a critical potential resource that could make Mars an enabling stepping stone for the sustainable exploration of the solar system. They provide the basis for constructing facilities and machines from local Martian resources and for making higher energy-density. chemical rocket fuels for both return journeys to Earth and for more distant exploration.

Control of Gas Hydrate Formation Using Surfactant Systems: Underlying Concepts and New Applications

Abstract: We describe some new approaches to the rapid formation of gas hydrates using surfactant systems that form reverse micelles. The thermodynamics of hydrate formation in surfactant containing reverse micellar systems indicate the possibility of controlling hydrate deposition. The use of reverse micellar systems also allows the deposition of hydrates in the form of small crystallites that do not aggregate. Surfactants also appear to displace agglomerated hydrates from surfaces, thereby facilitating flow. Direct injection of water into gas saturated liquid hydrocarbons leads to rapid hydrate formation. On the other hand, water droplets injected into liquid carbon dioxide indicate a gradual conversion to the hydrate form with the initial formation of a hydrate skin. An interesting application of rapid hydrate formation is its use in the restriction of inorganic nanocluster growth.