Alaska and the Gulf of Mexico - 1980-2023 Current Status of Methane Hydrate Development

Alaska and the Gulf of Mexico - 1980-2023 Current Status of Methane Hydrate Development

In the United States, methane hydrate is attracting attention as an important future energy resource. The main areas of reserves are the permafrost in northern Alaska, the Gulf of Mexico, and the continental slope off the East Coast. In particular, huge reserves of more than 85 trillion cubic meters have been identified in the North Slope of Alaska. In the Gulf of Mexico, more than 100 million cubic meters per square kilometer of hydrate is estimated to exist, and the geological structure is characterized by sandy layers that are easy to mine.

The U.S. began researching methane hydrate in the 1980s, and the Department of Energy (DOE) has led the development of the technology. 2007 test mining was conducted on the North Slope of Alaska, producing approximately 5,000 cubic meters of gas per day. 2012 saw the development of a technology to recover methane using carbon dioxide. In 2012, a technology to recover methane using carbon dioxide was tested, and this test produced approximately 6,000 cubic meters of gas per day. This technology attracted attention as an environmentally friendly approach to sequestering the greenhouse gas CO₂ underground.

Furthermore, in October 2023, a long-term production test was started in Alaska in cooperation with Japan's JOGMEC. The test aims to produce approximately 300,000 cubic meters of natural gas per year and is an important technological demonstration for commercialization.

The technology development includes a depressurization method to reduce pressure on the seafloor and recover the gas, a chemical injection method to accelerate hydrate cracking, and a CO₂ exchange method that uses carbon dioxide to replace methane. The CO₂ exchange method is said to have the potential to reduce the cost per cubic meter from about $100 to $50.

On the other hand, challenges remain. Mining costs are high compared to existing natural gas, currently requiring about $50 to $100 per cubic meter. In addition, the risk of global warming due to methane leakage and the possibility of submarine landslides have been pointed out. This calls for technological innovation to minimize environmental risks.

While addressing these issues, the United States has positioned methane hydrate as an important resource from the perspective of energy security. By promoting international cooperation and technological innovation, we aim to overcome high mining costs and environmental risks, and to commercialize methane hydrate in the future.