The virgin land of uncultivated energy – solid natural gas on the seabed

It seems strange to hear this term, since it is gas, how can it become solid? It turned out that this was a fuel called solid natural gas discovered by scientists in the former Soviet Union under laboratory conditions, and from 1 cubic meter of this solid natural gas, 70 to 220 cubic meters of fully qualified gas fuel can be obtained. Much like compacted ice cream, this solid natural gas can only exist at a certain temperature and pressure, and if this temperature and pressure range is exceeded, the solid natural gas will become water and gas. Therefore, solid natural gas is also called natural gas hydrate - that is, natural gas and water activation, forming a substance containing a certain number of water molecules.

Based on data obtained in the laboratory, soviet scientists predicted that solid natural gas is likely to be buried in rocks that are often cooled, do not exceed 20 degrees Celsius, and are under 200 meters, and are more likely to be buried in glaciers and ocean depths, because these places have the low temperature and high pressure conditions required for solid natural gas. Later, scientists discovered the solid natural gas on the seabed at a depth of 240 meters off the coast of Guatemala in South America.

In 1988, the United States and Canada also announced the discovery of large quantities of solid natural gas on the seabed in coastal areas, with reserves of several hundred trillion cubic meters, which can be exploited for hundreds of years. Core specimens of solid natural gas were later obtained in the Caspian, Black and Okhotsk Seas.

Solid natural gas is also prevalent on land in the northern parts of the planet, where the land freezes deeply. 90% of the world's oceans are likely to form solid natural gas, because the temperature of the seabed is perfectly suitable for the formation of solid natural gas, and the pressure in the depths of the seabed is caused by the huge depth of the water body. In addition, the seabed often deposits many organic matter, such as the carcasses of animals, plants and microorganisms in the sea, and when the corpse decomposes, it releases methane, of which a large part of the methane does not escape from the water, but becomes a hydrate state, which is pressed into the pores of loose sedimentary rock. These sedimentary rocks, filled with hydrate crystals, gradually lie below the new sedimentary layer and sink below the hydrate-forming zone, where the hydrate begins to decompose again because it is pressurized beyond the pressure range, and the decomposed natural gas drills up along the cracks and pores and returns to the hydrate-forming zone. This process, which takes place on the seabed and ocean floor for millions of years, produces solid natural gas mines that can extend for thousands of kilometers and are located a few centimeters to two or three hundred meters above the surface of the seabed.

As a result, the reserves of solid natural gas on the seabed may be tens of times higher than the reserves of oil and gas in all generally produced areas. How to extract solid natural gas on the seabed, there is currently no experience. Some scientists have proposed that solid gas mining farms could be built on the seabed and connected to solid gas receiving vessels on the surface with air lifting pipes. A large bell jar is installed at the lower end of the air lifter, with an automatic mining device in the bell cover, which first crushes the solid natural gas, mixes the crushed solid natural gas with water into a slurry, and then continuously transports it to the receiving ship by the pneumatic hoist. The hydrate decomposes in a heating unit. When the hydrate gradually decomposes into natural gas and water in the lift pipe, the natural gas will form a supplementary traction force, help the pneumatic hoist system, and accelerate the lifting process.

According to rough estimates, there may be as much as 15,000 trillion cubic meters of solid natural gas in seafloor sedimentary rocks and 300 trillion cubic meters on land. But large-scale extraction of solid gas on the seabed and on land, and the formation of commercial-scale solid gas fuels, is not expected to be achieved until the early 2000s, as some complex process issues need to be carefully considered.