Gas Hydrates on Alaska's North Slope

Jessica Robertson: Hello and welcome to USGS CoreCast. I'm Jessica Robertson. The US Geological Survey estimates that there is 85.4 trillion cubic feet of undiscovered technically recoverable gas from natural gas hydrates on the Alaska North Slope. This resource could add significantly to the US energy mix according to the first ever resource estimate of technically recoverable gas from gas hydrates.

Today, we are joined by the Director of the USGS, Mark Myers, and USGS scientist, Timothy Collett, to discuss this assessment. Thank you for joining us today, Mark and Tim. So, Mark, first can you tell us what the USGS is announcing?

Mark Myers: Yes, Jessica. Today we're announcing the USGS estimates for technically recoverable undiscovered natural gas hydrates from onshore and state waters on the North Slope in Alaska, and those numbers are substantial. The mean estimate is 85.4 trillion cubic feet of natural gas coming from these hydrates. And this is the first assessment of technically recoverable natural gas hydrates in the world.

Today all other assessments have been on the in-place resource rather than how much of that might be technically recoverable.

01:08

Jessica Robertson: Tim, can you tell us what are gas hydrates and what does it mean that they are technically recoverable?

Timothy Collett: Thank you, Jessica. Gas hydrates, very simply put at, an ice-like mixture of gas and water in which gas molecules were actually trapped in a solid framework or cage or water molecules. Gas hydrates occur under a very limited range of temperature and pressure conditions such as areas in the north and in the permafrost environments of Northern Alaska and Canadian Arctic. Also occur in deep marine environments and water depths greater than 400 or 500 meters.

Hydrates have been long looked at as unconventional potential resource no-production. In this assessment, for the first time we're looking at the technically recoverability of gas hydrates. What that basically means is we're looking at how much of this gas can be produced from hydrates with existing technology.

02:02

Jessica Robertson: And Mark, what does this mean for hydrate science and our energy resource base?

Mark Myers: Well, natural gas hydrates are the largest known resource of natural gas in the world. And as we struggle to find alternatives to our traditional energy resources, these unconventional resources have huge potential for our society for the future. So, this assessment means that we believe, using existing technology, a certain percentage of those resources are in fact recoverable.

And in the future, with additional testing, might demonstrate commerciality. So, this is a big step forward in our understanding of natural gas hydrates. It's a culmination of about 25 years of research in USGS to get to this point such it's been a good investment in science, and today we're seeing the actual results of the next step of understanding how much of the resource that we've identified with partners is in fact potentially recoverable using existing technology.

While this assessment has occurred only on the Alaska North Slope and again on onshore areas and the state waters out the three mile limit, there is a large resource base on the offshore which MMS is doing an assessment on as well as a large deposits of hydrates worldwide including in the Gulf of Mexico and known off both are the Atlantic and the Pacific coasts. So, what we've learned from this study can be applied to other areas.

03:20

Jessica Robertson: And Mark, can you tell us how might these hydrates be an important resource for our country in the future?

Mark Myers: First of all, natural gas is a critical energy source for our country. It's a large power source for the electricity that's generated for heating our homes and increasingly important is the transportation fuel. So, natural gas also has a very low carbon footprint. So, it's a very positive fuel with respect to decreasing our emissions of CO2 into the atmosphere.

The United States is challenged to meet its increased growing demand for natural gas. Today we're increasing the reliant on imported liquefied natural gas. So, because the United States has a substantial endowment of in-placed hydrates, this could be an important substitute fuel to replace other fuel sources that are less environmentally friendly and also provide a greater percentage of domestic energy for our country.

04:10

Jessica Robertson: So, Tim, can you tell us a little bit about the science behind this research?

Timothy Collett: Yes. Our projects in gas hydrate research started more than 25 years ago. What we've been able to do is get a strong understanding about the trends of hydrates, the geologic controls. We've also been able to assess the size and distribution of different accumulations of gas hydrates.

And this has really been a very positive project for the last five years with access to data from the Bureau of Land Management. For the first time it's allowed us map hydrates in areas with our firstly unexplored on the north slope. With that information at hand, we've been able to develop a probability estimate with the amount of gas hydrates there are in the north slope in different geologic settings.

In turn, we've also worked in a number of projects through out the world where we've been actually able to test and produce gas hydrates particularly projects from Mackenzie Delta called the Mallik Project and the Mt. Albert Project from the north slope of the Alaska with the Department of Energy and British Petroleum.

05:14

That test in turn has been used in production modeling programs, and these modeling programs give us ability to predict hydrate production in various settings under different geologic conditions. All of these work have given us direct insights to the produceability of gas hydrates and in turn allowed us to make this assessment of the technical recoverable hydrates on the north slope.

Jessica Robertson: So, Tim, where is the Alaska North Slope and who owns the land where these resources could potentially occur?

Timothy Collett: North Slope of Alaska is generally defined as near in north of the Brooks Range extending to the Beaufort Sea. We see within our assessment, we actually predicted about 85.4 trillion cubic feet of gas to curl within the gas hydrates of that total line.

06:01

We see about 56% being a federally managed land, about 49% on land to water is managed by the State of Alaska and the remaining 4% occurring on native lands.

Jessica Robertson: Is there anything else, both of you, want to share with us regarding this assessment? Mark?

Mark Myers: Well, I think putting this assessment in the context that has significant information that's of great societal benefit. It fits into our - one of our key goals in our science strategy in terms of energy and also could provide significant new energy in the future, as we said before, that is very clean burning energy. So, again, it show the relevance of the USGS Science strategy.

It also shows the relevance of the long term investment in hydrate science the USGS has done. It shows the need for a long term investment science and the fact that USGS has performed admirably with respect to the strategic investment necessary to get to this point at a time when the country badly needs this new source of preferred energy.

07:01

Jessica Robertson: And Tim, is there anything else you'd like to add?

Timothy Collett: Yes, when we look at gas hydrates, it's been looked at as a unconventional resource with its potential production far off into the future for a number of years. That view point, in recent years has began to change. The reason for that change is an increased understanding about the geologic controls on gas hydrates, a number of projects throughout the world including on the north slope of Alaska where we're looking at the produceability of the hydrates themselves.

The geologic data combined with engineering data has allowed us to make a better assessment of what the future of gas hydrates are as a potential resource. That data sets have mainly been developed through partnerships. And those partnerships have been critical including working with the oil and gas companies acting as operators on the north slope, also university partners such as the University of Alaska and other.

But, most important are some of our federal partners including the Department of Energy. In the last five years, particularly, is the Bureau of Land Management. In the access to data we've had through BLM, we've been able to do very detailed analysis with the geologic occurrences of gas hydrates giving us direct insights to the geologic controls and in turn giving us an appreciation of the produceability of hydrates.

08:24Jessica Robertson: Well, it's been a pleasure speaking with both of you and thank you for joining us. And thanks to all of you for listening to this episode of CoreCast. To learn more about the USGS research on natural gas hydrates and to see results of the gas hydrate assessment in northern Alaska, please visit energy.usgs.gov. As always, CoreCast is a product of the US Geological Survey Department of the Interior.