In the 1970s, American geologists drilling in the ocean discovered what looked like ordinary dry ice. When it was salvaged from the ocean floor, the “ice” quickly became bubbling mud and water. And those bubbles were accidentally ignited, and these bubbles are methane.
According to the research, these grayish-white substances, like dry ice, are solid mixtures formed by the crystallization of natural gas and water under high pressure and low-temperature conditions. This substance contains more than 99% methane molecules. It can therefore burn when exposed to fire.
Pure natural gas hydrate is white in appearance. It can be ignited directly like solid alcohol. For this reason, it is often referred to as “combustible ice”. Scientists have shown that the energy density of combustible ice is very high. 1 cubic meter of combustible ice can release 164 cubic meters of natural gas.
“Combustible ice” is widely distributed around the world. It has a high resource value. Therefore, it has become a long-term research hotspot in the oil and gas industry.
Since the 1960s, several countries, including the United States, Japan, Germany, China, Korea, and India, have developed research programs for gas hydrate exploration and development. So far, more than 230 hydrate occurrences have been discovered in offshore waters and permafrost zones, and a large number of gas hydrate hotspots have emerged.
Current scientific research results indicate that combustible ice exists only on the seafloor or within the terrestrial tundra. It is mainly distributed in the unconsolidated sediment domain in specific areas of deep water. Or the polar shelf waters below 100~250m water depth.
Comprehensive studies have shown that gas hydrate resources are enormous. According to conservative estimates, the conversion of gas hydrates into methane gas in the world’s oceans has exceeded 200 million cubic meters. This is equivalent to more than twice the total amount of known coal, oil, and natural gas in the world. It is the world’s largest known alternative energy source that has not yet been developed.
Natural gas hydrates are also the largest fossil energy source on the planet that is awaiting development. Moreover, according to the results of current exploration surveys, gas hydrates in the oceans are tens of times more abundant than those stored in terrestrial tundra.
The world’s vast reserves of conventional oil and gas will soon be exhausted. Scientists estimate that on the seafloor alone, combustible ice covers an area of 40 million square kilometers. A quarter of the Earth’s total ocean area.
In 2011, flammable ice was found in 116 locations around the world. The thickness of the mineral layer and large scale are incomparable to conventional gas fields. Scientists estimate that there is enough flammable ice on the ocean floor for at least 1,000 years.
At present, the energy resources available for human exploitation, such as oil and coal, are decreasing. Many countries are looking for new alternative energy sources. The discovery of combustible ice immediately raised concerns.
In particular, the main component of gas hydrates is methane. After burning almost no pollution, is a new kind of green energy. From the perspective of its large reserves, wide distribution, and good application prospects, it is the best alternative energy after oil, natural gas, coal, and other traditional energy.