The National Methane Hydrates R&D Program
All About Hydrates
History of Hydrate R&D
Phase I - Hydrate as a
laboratory curiosity
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Core recovered from the
Johnson Sealink cruise in the Gulf of Mexico in July 2001.
Photo courtesy Ian McDonald Texas A&M |
Clathrate compounds were first discovered in the early 1800s when two scientists, Humphrey Davy and Michael Faraday, were experimenting with chlorine-water mixtures. As the mixtures cooled, the scientists noticed a solid material forming at temperatures above the normal freezing point of water. Throughout the remainder of the century, many other scientists studied these strange materials, and generally worked out the process by which typically unstable open frameworks of water molecules (and other substances as well) were stabilized by the inclusion, without bonding, of smaller guest molecules into cavities within the structure. Much work was done cataloging the various molecules that could co-exist as hosts (lattice-formers) and guests, and the various conditions at which each variety was stable. However, because natural occurrences were not known, the subject remained largely an academic curiosity.
Phase II - Hydrate as an industrial nuisance
Hydrate research entered a second phase in the 1930s, when E.G. Hammerschmidt determined that hydrate was responsible for plugging natural gas pipelines, particularly those located in cold environments. Subsequently, a small body of researchers led by Dr. Dendy Sloan at the Colorado School of Mines, investigated the physics of various clathrates, including the construction of the first predictive models of their formation. A prime focus of this work was (and continues to be) the development of chemical additives and other methods to inhibit hydrate formation.
Phase III - Hydrate as a naturally-occurring substance
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| Well logs from Northwest Eileen #2 well in Alaska |
In the late 1960s, the global view of clathrate science began to change dramatically when "solid natural gas" or methane hydrate was observed as a naturally-occurring constituent of subsurface sediments in Messoyahka gas field of the Western Siberia basin. Shortly thereafter, hydrate was also found in shallow, sub-permafrost sediments on the North Slope of Alaska. In 1972, hydrate cores and a full well log suite were retrieved at the NW Eileen State #2 well. A limited production test was also conducted, which recovered 92% methane at the surface from a hydrate bearing sandstone at ~2200 feet in depth. The estimated production rate (~4 mcf/d) was clearly uneconomic, and there were no further tests in the region.
By the mid 1970, many scientists, particularly those in the former Soviet Union, began to speculate that the low temperature/high pressure conditions necessary for hydrate formation should exist extensively around the globe, not only in permafrost regions, but also under deep oceans. The global hunt for methane hydrate was on. However, because hydrate quickly dissociates (similar to melting) when removed from its natural environment, no one actually saw marine methane hydrate until 1974 when Soviet scientists recovered large hydrate nodules from the floor of the Black Sea. Then, in the early 1980s, the research vessel Glomar Challenger traveled the globe collecting cores of ocean bottom sediments as part of a renewed round of Deep Sea Drilling Project tests. Many of the samples found chemical evidence for hydrate. However, one core taken off the coast of Guatemala included a one-meter long core composed almost entirely of methane hydrate.
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| The Glomar Challenger |
Portions of this core were sent to the U.S. Geological Survey (USGS), university and industry labs, and the Department of Energy's (DOE) National Energy Technology Laboratory. These studies formed the impetus for the first national R&D program dedicated to naturally occurring hydrate. DOE's initial ten-year methane hydrate program (1982-1992) spent roughly $8 million, and established, in collaboration with numerous other organizations, most notably the USGS, a solid foundation of basic hydrate knowledge. Most notably, the USGS’s work delineated the existence of two primary hydrate accumulation (the “Tarn” and “Eileen” trends) beneath the Alaska North Slope. Hydrates R&D was curtailed in the early 1990s due largely to the suspension of the DOE program; however, work at the USGS continued. In 1995, the USGS provided the first systematic appraisal of domestic hydrate deposits, resulting in an estimate of 320,000 tcf of gas-in-place. This estimate was later reduced to 200,000 tcf following Ocean Drilling Program (ODP) results on the Blake Ridge, which showed typical hydrate concentrations were somewhat less than earlier thought.
Phase IV - International R&D efforts to test the
production potential of natural methane hydrate
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| Photo of the Mallik Well
--Photo courtesy Tom Mroz , NETL geologist
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In the mid-90s, Japan and India, two countries with large energy needs but limited domestic energy resources, began aggressive, well-funded hydrate programs in preparation for commercial production of methane. It soon became clear that continued neglect of the hydrate issue threatened to put the United States well behind the lead in potentially critical technology development. At the same time, continued environmental concerns rapidly escalated the demand for natural gas, giving rise to concerns of the long-term sustainability of gas supplies. In response to these and other issues, a report by the President's Council of Advisors for Science and Technology (PCAST, 1997) strongly recommended renewed and significant funding for hydrate R&D. In 1998 and 1999, international efforts resulted in the drilling of the first two wells designed specifically to investigate methane hydrate-bearing strata. The first well (the Mallik 3L-18C) was drilled into hydrate-bearing strata below permafrost on the McKenzie River delta in the Northwest Territories of Canada. The second location was drilled by a consortium of Japanese government agencies and commercial interests in 3,100 feet of water off the southeastern Japanese coast adjacent to a deep ocean trench known as the Nankai Trough. Both wells showed the presence of highly concentrated methane hydrate. Production testing was not performed on either well. The Japanese discovery was particularly significant, as the well showed hydrate concentrations of up to 80% in specific confined reservoirs sandstones, a finding in stark contrast to the dispersed, shale incased, and low saturation accumulations described from the Blake Ridge.
Phase V -
A coordinated and balanced National Methane Hydrate Program
By 1999, the growing recognition of the size and extent of the global methane hydrate resource gave rise
to a number of critical scientific and public policy issues. One set of questions centered around
the role that methane hydrate plays in the natural environment - including its interaction
with sea-bottom life forms, ocean-floor stability, the global carbon cycle, and long-term climate change.
A second set of concerns dealt with the hazards that hydrate-bearing sediments pose to conventional oil and gas
drilling operations as they expand into ever-deeper water. In light of these issues, and in the face
of emerging natural gas supply shortages, aggressive environmental goals, and increasing reliance on
foreign energy, the U.S. Congress offered legislation in 1999 that culminated in the signing into law
of the Methane Hydrate Research and Development Act of 2000.
This law set the structure, goals, and timetables for a DOE-led National Methane Hydrate R&D program.
This program has recently been re-authorized for another five-year installment. Please see our National R&D Program pages for more information on past and ongoing hydrate R&D projects within this program.
Critical Findings: 2000 to 2005.
The successes of field programs at both Nankai and at Mallik lead to a second research program at Mallik (the Mallik 2002 consortium) with the goal of investigation hydrate formation producibility. A series of field experiments tested the Mallik reservoir's response to both thermal stimulation and depressurization. Both methods resulted in hydrate dissociation and the release of gas, thereby confirming the technical feasibility of methane production from hydrate that has been suggested by the 1972 tests at the Eileen well.
In early 2004, Japan's Ministry of Economy, Trade, and Industry returned to the Nankai Trough, drilling 15 additional wells, including one horizontal well, into hydrate bearing units in water depths ranging from 700 to 2000 meters. Well results from this drilling program continue to be analyzed.
Domestically, the Hydrate R&D program has significantly advanced the
understanding of hydrate physical and chemical science through a variety of
laboratory and field studies. Most notably, a DOE project in cooperation with BP Exploration (Alaska), has developed an exploration methodology that has resulted in the identification of more than a dozen high-potential hydrate prospects with the Milne Point unit of the greater Prudhoe Bay production complex. Integrated Ocean Drilling Program cruises to the Pacific Northwest, and a
DOE/industry JIP cruise in the Gulf of Mexico have further confirmed the close link between marine hydrate accumulations and reservoir quality. Ongoing and integrated field, modeling, and laboratory efforts have demonstrated that methane production at viable rates from certain naturally-occurring hydrate deposits should be possible using tailored applications of already existing drilling, completion and stimulation technologies. The task at hand now is to 1) develop the means to find and assess formations remotely, particularly in the marine environment; 2) determine the likely scale of the recoverable marine resource; and 3) demonstrate specific production technologies through long-term field tests at a variety of relevant sites.
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