Shale gas is actually related to volcanic ash from the dinosaur era

Recently, American scientists published a paper stating that "the volcanic ash of the Cretaceous period may have eutrophicated seawater, leading to the proliferation of algae and the accumulation of hydrocarbons, forming some of the shale oil and gas reserves in North America today.

Researchers from Rice University in the United States have found that shale oil and gas fields from Texas to Montana in the United States are related to Cretaceous volcanic ash approximately 145 to 65 million years ago. This conclusion may also apply to shale oil and gas formed in other periods and regions.

What is shale gas? Is its formation actually related to volcanic ash from the dinosaur era? Recently, the intern reporter of Science and Technology Daily interviewed researcher Fu Bihong from the Institute of Remote Sensing and Digital Earth of the Chinese Academy of Sciences and asked him to help solve the mystery.

Algae reproduction after the mass extinction of organisms

In relevant papers, researchers pointed out that some of these oil and gas fields in North America were formed approximately 100 to 90 million years ago, during the late dinosaur era, when Earth's volcanic activity was very active, resulting in high atmospheric carbon dioxide content and a warm climate. Most of the western part of North America today was shallow sea at that time, and volcanic ash deposited on the seafloor, forming rocks.

This study explains the relationship between shale gas formation and the Cretaceous extinction, which is the fifth major extinction in Earth's history. Fu Bihong affirmed the scientific value of the related research. According to his explanation, the formation of shale gas is directly related to several major extinctions in history, including the late Ordovician period 449 million years ago

The Late Devonian period 377 million years ago, the Late Permian period 251 million years ago, the Late Triassic period 195 million years ago, and the Cretaceous period confirmed this time. This is the latest well documented biological extinction related to shale gas formation, "said Fu Bihong.

According to Fu Bihong, the formation of black shale during these five periods was similar: volcanic magma activity and submarine magma eruption led to an increase in seawater temperature, ocean acidification, and the extinction of a large number of marine organisms. The large amount of carbon dioxide generated by the eruption caused suffocation and extinction of organisms. After a period of extinction events, algal organisms proliferate in large numbers in the ocean or lakes, with huge biomass. After burial, they form black shale rich in organic matter. In this reducing environment, not only oil and gas are formed, but metal minerals are also formed. Black shale can be peeled off layer by layer, like pages of a book. Shale gas generally refers to the natural gas generated and accumulated in this black shale, "said Fu Bihong.

The main component of shale gas is methane, which is the same as conventional natural gas. However, after the formation of conventional natural gas, it will migrate to other reservoirs, while shale gas is different in that it is adsorbed in oil shale and exists in the form of gas or oil, which brings great difficulty to extraction.

The 'Shale Gas Revolution' will rewrite the energy landscape

China is one of the countries with abundant recoverable shale gas reserves in the world, and is also the third largest shale gas production area after the United States and Canada. Currently, the annual production has reached nearly 10 billion cubic meters. As one of the top energy consuming countries in the world, shale gas extraction has revolutionary significance in improving China's energy shortage and increasing the use of clean energy.

Shale gas extraction in the United States has a century of history, but due to high technical requirements, breakthroughs have only been made in the past decade, greatly reducing the cost of extraction. Shale gas extraction in China has been a recent decade. Since 2009, China has officially included shale gas development in its energy supply map, with a late start but rapid development speed.

Shale gas is adsorbed inside the shale, and during mining, the shale must be crushed and high-pressure fluid (water) injected to destroy the shale layer in order to release the adsorbed shale gas, "explained Fu Bihong. At present, a large amount of shale gas extracted in China has been formed since the end of the Ordovician period. The black shale, mainly composed of the Longmaxi Formation of the Lower Silurian, has a wide distribution area, large thickness, abundant shale gas reserves, and high industrial extraction value.

With the increasing demand in the energy market and the strengthening of environmental protection measures such as' coal to gas', China's demand for clean energy such as natural gas is increasing. Through learning, introduction, and digestion, shale gas extraction technology is constantly maturing. The black shale in Southwest China, Hubei, and Hunan regions is widely distributed and thick, and state-owned enterprises such as' two barrels of oil 'have strong funding and advanced technology investment. These are all favorable factors for the development of China's shale gas industry Fu Bihong said.

The world's shale gas resources amount to 457 trillion cubic meters, which is equivalent to conventional natural gas resources. Among them, the recoverable resources of shale gas technology are 187 trillion cubic meters. China has abundant shale gas resources, with a technically recoverable resource of 36 trillion cubic meters, which has great potential for large-scale development.

According to China's shale gas development plan, with sufficient policy support and smooth market development, we aim to achieve shale gas production of 30 billion cubic meters by 2020 and 80 to 100 billion cubic meters by 2030.

The successful development of shale gas has had a profound impact on the US natural gas market and the global energy supply and demand structure. From scratch to the third place in production, the future "shale gas revolution" will also rewrite China's energy landscape.