|A photo of Combustible ice, or gas hydrate, usually found in ocean beds and permafrost zones (File Photo)|
First results from exploratory drilling have confirmed the presence of a considerable exploitable reserve of high-purity gas hydrates in the eastern sea near the coast of Guangdong's Pearl River Mouth Basin, according to a report from the Chinese government network on December 17.
China’s Ministry of Land and Resources released the exploration results at a conference on Tuesday in Beijing, confirming that a Chinese marine geology scientific and technical team have obtained samples of high-purity gas hydrates (commonly known as combustible ice). They found a considerable reserve during a three-month underwater drilling operation that began in June this year.
After analyzing the gas hydrate samples and the results from the 23 drilling wells, experts have forecast that the 55 km2 range of reserves in the sea off Guangdong could contain the equivalent of 100-150 billion cubic meters natural gas.
The newly found reserve is under a shallow layer of sea bed but is of substantial depth and contains various types of high purity gas hydrate rock, according to Che Changbo, the deputy director of the geological exploration division of Chinese Ministry of Land and Resources.
Following 15 years of research, Chinese experts are forecasting a rich resource of combustible ice in China. The South China Sea region is expected to have combustible ice stocks equivalent to 68 billion tons of oil. In addition, gas hydrate reserves have been found in Qinghai, equivalent to 35 billion tons of oil. Taking as yet unproven reserves in Tibetan Plateau into account, China is expected to have rich source of combustible ice.
Despite leading the world in research in the field, China still has a long way to go in researching and developing the relevant technologies. But with the prospect of such large-scale gas hydrate reserves, commercial development has become a hot topic of discussion. Technical problems and the cost of combustible ice extraction are the bottleneck that many counties have faced in the exploitation of natural gas hydrates.
Statistics shows that China has been a net importer of oil for the last 20 years. In 2012, up to 56% of crude oil came from imports, making China the world's second largest crude oil importer and second largest oil consumer.
"China is expected to employ combustible ice for commercial use as a replacement for traditional energy sources by 2030," said Che. As the depletion of existing energy sources has become an increasingly prominent issue, so the search for alternative energy has become a primary concern of economies all over the world.
Methane hydrate is an attractive energy source due to its high energy density: one cubic meter of combustible ice contains about 164 cubic meters of regular natural gas. However, researchers are still investigating the most appropriate way to extract the fuel for commercialization.
Combustible ice has already been discovered in more than 100 countries, buried in both the Arctic permafrost and beneath the sea bed. As well as China, countries including the US, Japan, and the Republic of Korea have plans to tap the natural gas hydrates buried in their territories.
Gas hydrate, an ice-like substance, is also known as combustible ice. Containing methane and ice crystals that can supply energy, it can literally be lit on fire and burned as fuel. It is regarded as a potential alternative to coal and oil. But rather than dig up the substance, excavators would probably melt the ice underground first, and then extract the methane gas.
Because methane is a potent greenhouse gas, researchers are also concerned about the environmental effects of extracting methane hydrate. However, compared with conventional fuels like coal, one of the main advantages of using combustible ice is its relatively minor impact on people and the environment.
"Burning coal may be cheap, but it is a major source of air pollution and causes respiratory disease in ordinary people,” says Han Xiaoping, chief information officer of China Energy Network. “It makes more sense to spend money on clean energy than on doctors. "