For the first time, an international research program involving the Department of the Interior's U.S. Geological Survey has proven that it is technically feasible to produce gas from gas hydrates. Gas hydrates are a naturally occurring "ice-like" combination of natural gas and water that have the potential to be a significant new source of energy from the world's oceans and polar regions.
Today at a symposium in Japan, the successful results of the first modern, fully integrated production testing of gas hydrates are being discussed by an international gathering of research scientists. The international consortium, including the USGS, the Department of Energy, Canada, Japan, India, Germany, and the energy industry conducted test drilling at a site known as Mallik, in the Mackenzie Delta of the Canadian Arctic. This location was chosen because it has one of the highest concentrations of known gas hydrates in the world.
The United States is committed to participating in international research programs such as this one to advance the understanding of natural gas hydrates and the development of these resources. Even though gas hydrates are known to occur in numerous marine and Arctic settings, little was known before the Mallik project about the technology necessary to produce gas hydrates.
The successful results from this research form the world's most detailed scientific information about the occurrence and production characteristics of gas hydrates.
The estimated amount of natural gas in the gas hydrate accumulations of the world greatly exceeds the volume of all known conventional gas resources. While gas hydrates hold great potential as an "environmentally-friendly" fuel for the 21st Century, the technical challenges of realizing them as a resource are substantial. Additional research is required to understand and develop new techniques to quantify their distribution in nature.
Depressurization and thermal heating experiments at the Mallik site were extremely successful. The results demonstrated that gas can be produced from gas hydrates with different concentrations and characteristics, exclusively through pressure stimulation. The data supports the interpretation that the gas hydrates are much more permeable and conducive to flow from pressure stimulation than previously thought. In one test, the gas production rates were substantially enhanced by artificially fracturing the reservoir.
So how big a deal is this as compared to other fossil fuels energy sources? Gas hydrates reserves estimates vary quite a bit. But some of the estimates are pretty high.
The technology may take between 10 and 15 years to develop, but will help us tap gas hydrate reserves, estimated to be "more than double the known reserves of fossil fuel," said C.N.R.Rao, Founder and Honorary President of the Jawaharlal Nehru Centre for Advanced Scientific Research, and A.Kuznetsov, Director, Institute of Inorganic Chemistry, in Russia.
Interest in hydrate E&P has soared in recent years because of growing evidence that more hydrocarbon exists in hydrate deposits than the combined oil, gas and coal reserves worldwide. According to the U.S. Energy Information Agency in its just-released Natural Gas 1998: Issues and Trends, "Recovery of only 1% of hydrates would more than double the domestic gas resource base." A report from Ocean Drilling Program Leg 164, which investigated the huge Blake Ridge offshore the Carolinas, estimated U.S. methane hydrate reserves at 200,000 Tcf.
That really puts gas hydrates in the big leagues because there is an enormous amount of fossil fuel energy stored in coal.
The estimate was refined in 1997 to a more conservative 200,000 trillion cubic feet. Even this lower estimate is significant when compared to the 1,400 trillion cubic feet in the nation's conventional gas reserves. On a world-wide basis, it is estimated that methane hydrate reserves are 400 million trillion cubic feet, compared with 5,000 trillion feet in known gas reserves.
Well, there may not be enough hydrocarbons available to bring on global warming from conventional fossil fuels reserves. But if the technology to extract methane gas hydrates can be made cost-effective then humanity might need to refrain from using as much fossil fuel as it can burn.
In one science fiction novel whose title escapes me (anyone remember the story?) some event (nukes exploded on the ocean floor by accident or by terrorists?) caused all the gas hydrates to come to the surface and this caused an enormous hot house effect that melted all the ice and let lose massive hurricanes (or am I mixing up different science fiction novels? they all blend together after a while). The point here is that it would be a bad thing if all the gas hydrates came to the surface in an incontrolled manner. They constitute a pretty large amount of hydrocarbons.
Update: MIT's Technology Review has an article covering pretty much the same ground as covered in the other links above.
As a source for natural gas, hydrate today is about where coal bed methane was 15 years ago, says Michael Max, a hydrate expert formerly with the Naval Research Laboratory in Washington, D.C. “Coal bed methane was a classic, unconventional gas play,” with more than a few doubters, Max says. “Now it supplies around eight percent of the U.S natural gas supply. We think hydrate has a similar trajectory.”
Natural gas frm hydrates may well become a much higher percentage of the total energy mix if oil field production starts to decline within 10 years as some predict.
|Share |||Randall Parker, 2003 December 10 11:46 PM Energy Fossil Fuels|