Potential versus viability. Research success versus business realities.
The battle continues for gas hydrates and the role they will play in the world’s energy future.
Consider: Even though gas hydrates are considered an extremely challenging research topic, recent small-scale production tests in the Canadian Arctic and North Slope of Alaska have demonstrated that natural gas is producible from hydrate-bearing sands.
These results, combined with other global efforts like the research results from Japan’s MH21 Program, have shown the major potential of gas hydrates – potential that is worth oil companies’ and governments’ time, money and manpower.
And now more data is being entered into the discussion.
AAPG Memoir 89, Natural Gas Hydrates – Energy Resource Potential and Associated Geologic Hazards, is a new publication that confirms the positive progress that gas hydrate research has made over the past several years.
The book comprises the contribution of over 150 authors and includes research findings, graphic data and 39 of the most current peer reviewed articles from gas hydrate experts worldwide.
The editors include AAPG members Tim Collett and Art Johnson, who have made it their job to help shed light on the mysterious but tantalizing potential energy source – and to spread the word.
Collett is a U.S. Geological Survey research geologist in Denver; Johnson is president and chief of exploration for Hydrate Energy International in Kenner, La.
The other editors are AAPG member Ray Boswell, U.S. Department of Energy National Energy Technology Laboratory, Morgantown, W.Va., and Camelia Knapp, assistant professor and director of undergraduate studies, University of South Carolina, Columbia, S.C.
Memoir 89 discusses numerous aspects of the hydrates, including:
- The geologic parameters that control the occurrence and stability of gas hydrates.
- The volume of natural gas stored within gas hydrate accumulations.
- Exploration methods for identifying commercial gas hydrate prospects.
- The technologies needed to economically produce gas from hydrates.
- Possible marine slope stability hazards that can be attributed to the occurrence of gas hydrates.
- The effects of gas hydrate on drilling safety.
Most importantly, the book serves as a publication forum for a number of international gas hydrate research efforts – especially the highly successful gas hydrate research program in Japan, MH21.
Stops and Starts
Memoir 89 was inspired by a 2004 AAPG Hedberg Research Conference on “Natural Gas Hydrates: Energy Resource Potential and Associated Geologic Hazards,” which Johnson and Collett co-chaired.
“By 2004, the science of gas hydrate had progressed to the point where bringing together the top experts in the field from throughout the world was needed and appropriate,” Johnson said.
This was especially important, he continued, because of the “large amount of erroneous information about gas hydrates circulating in the press and on the Internet.”
Now, with the conference in the past and the book in the present, what lies ahead for gas hydrate research?
Boswell said the conference and book have been catalysts for gas hydrate research progression.
“The Hedberg Conference, where the idea of the book originated, clearly marks the point where gas hydrates, at least for me, got real,” he said.
Boswell believes that since the conference, “we have transitioned to a stage where geologists and engineers can now openly talk about hydrate prospects, recoverable volumes, reservoir petrophysics and completion strategies – something that was not going on before, when hydrates were some exotic entity unreachable using current approaches.”
Collett said the goal of the U.S. national program is to have sufficient information and technology to enable commercial production from Arctic reservoirs by 2015, but the U.S. National Petroleum Council reported in 2003 that mass production from gas hydrates is unlikely before 2025.
Collett believes that despite mixed estimates on when production will play a role in world energy, “that it is certainly possible that hydrates will be able to provide a major supply of gas for the world’s future energy needs.”
A positive outlook for gas hydrates in the United States was supported by two assessments completed by the Department of Interior in 2008.
♦ The first, led by Collett and his team at the USGS, was the first to quantify technically recoverable resource volumes from gas hydrate, and reported a mean estimate of 85 Tcf available on the Alaska North Slope with current technologies.
♦ At roughly the same time, the former Minerals Management Service released the results of a comprehensive assessment of gas hydrate potential in the Gulf of Mexico, reporting that a more than 6,700 Tcf in-place resource likely existed in high-concentration accumulations in sand reservoirs.
This assessment received initial validation by a drilling and coring program conducted by a Chevron-led international consortium in partnership with DOE and the USGS in early 2009, which found high concentrations of gas hydrate-bearing in sand reservoirs in four of seven wells drilled.
Still, plans to further capitalize on these positive findings has recently hit some snags:
♦ In the United States, the DOE-Chevron Gulf of Mexico Gas Hydrate Joint Industry Project, under Chevron’s direction, had scheduled a hydrate-pressure coring expedition, Leg III, for the spring of 2011, but the recent ban on leasing and drilling in the Gulf caused the test to be put on hold until 2012.
♦ A large-scale production test in the North Slope at Prudhoe Bay, being planned by BPXA, the DOE and the USGS, also originally set for this winter, has been placed on hold. This test would have been the largest gas-hydrate production test so far, and would have taken 18 months to two years to complete.
On the other hand, the ConocoPhillips gas hydrate carbon dioxide-methane displacement production test remains on the schedule for this winter, and hydrate research is forging ahead in Japan, South Korea and India, with a production test scheduled in Japan for 2012.
When – and Where?
“Fundamentally, it is a matter of economics.”
That’s what Johnson said when asked to give an estimated time frame for gas hydrates to be produced commercially.
Fortunately, he observed, gas hydrate production will not be needed any time soon in the United States, due to increasing production from shale gas and current low gas prices – but he added that nations with limited domestic energy resources may see gas hydrate development as more important.
“Hydrate progress is primarily driven by governments in many countries that are taking a longer view of energy and laying the groundwork for its development,” Johnson said.
“Countries with little domestic energy production usually pay considerably more for their energy needs, because they rely more on imported hydrocarbons, which often come with additional tariffs and transportation expenses,” Collett said, citing Japan, South Korea and India, who all have large gas hydrate research programs.
And sometimes, he added, it is all about location, “such as distance to a conventional energy resource,” which may lead to “the development of an otherwise non-economic unconventional energy resource.”
Collett predicts three scenarios where the first commercial production of gas hydrates might be:
♦ Northern Alaska or the Canadian Mackenize Delta, where hydrate accumulations already are well documented and production testing already has occurred.
♦ The Gulf of Mexico – gas hydrates near these marine basins could be drilled and produced from existing facilities as the conventional oil production declines.
♦ Stand alone gas hydrate production operations, like Japan; these are the most costly and challenging, because these areas have little or no previous oil or gas production to help offset the cost of production facilities.
Since the commercial viability of gas hydrate production remains unproven, is the pace of development will remain uncertain.
“Our understanding of this resource is still evolving,” Collett said. “We do not yet know if these accumulations exist in sufficient concentration to make them economically viable, nor do we know whether even concentrated accumulations can be developed economically.”
Many scientists, however, still see a potential in gas hydrates to provide above and beyond what other resources have.
And with faster rising populations and stronger desires to improve ecological standards, the need to tap the potential may be more of a factor than now realized.
As Boswell commented:
“(Gas hydrates) has the potential to provide many of the world’s most actively growing economies with an increased energy self-sufficiency, which can have numerous positive impacts on everyone.”