.5 billion years ago, the Earth was in the first period of the Paleozoic era, that is, Cambrian . When it comes to Cambrian, we will immediately think of " Cambrian Life Explosion ".
Yes, it was from this time that the earth became lively. In a relatively short period of time, the species on earth suddenly flourished, and a large number of invertebrates appeared in the Cambrian oceans. However, the opposite of life is death. The emergence of a large number of creatures means that a large number of wreckage will fall at the bottom of the ocean. As expected, as time goes by, the wreckage of organisms accumulates on the seabed like mud and sand. Over time, the seabed becomes a treasure house of organic matter.
Facing the increasing number of organic matter on the seabed, the happiest thing is the decompositionists living here.
These anaerobic bacteria are constantly decomposing day and night, but they still cannot keep up with the supply speed. However, it doesn’t matter. Here, there is already a lack of oxygen , and the decomposition of protein further aggravates the hypoxia status on the seabed, so organic matter can be preserved well. With the further increase of organic matter, the previous organic matter gradually consolidated under compaction, and finally formed an extremely thin layer-like structure, that is, shale. Shale is a very interesting thing. It has a large number of cracks and pores that can be used to store combustible gases such as methane. On the other hand, it contains a large amount of organic matter itself, so it can produce methane itself.
Shale is a geological structure integrating gas storage and gas production.
In shale, organic matter will be transformed into a substance called " kerogen ", an extremely complex polymer compound , which is considered to be the predecessor of petroleum and natural gas . This substance can produce methane gas after undergoing thermal degradation and secondary cracking. The initially generated methane gas will adsorb in micro-nano pores. When the adsorption amount of these pores reaches saturation, the gas will further float into the micro-cracks of the shale. Over time, a shale gas well will form.
Shale gas is a promising clean energy, but it is not a new thing. The earliest human beings began to use shale gas back to the 19th century.
However, although humans have been using shale gas for a long time, they have not had corresponding mining technology in the past, so they cannot obtain gas buried deep underground. They can only collect some methane gas leaked from the surface through geological movements. But the situation is completely different now. The United States has the highest total shale gas output in the world, with an annual output of hundreds of billions of cubic meters. In recent years, my country has paid more and more attention to the mining of shale gas.
As we all know, China pays great attention to the development and utilization of clean energy, so naturally it will not ignore the clean energy of shale gas.
At present, my country's shale gas mining technology is very mature. Shale gas mining blocks mainly in Fuling , Zhaotong and other places have been built, and shale gas production is steadily increasing. At present, my country mainly uses horizontal wells and hydraulic technology and rotational guidance technology to mine shale gas. Simply put, it is to use the ground high-pressure pump group to pump a large amount of fracturing fluid into the well, creating high pressure at the bottom of the well, so that the gas can be transported outward from the reservoir. Generally speaking, the life of a shale gas well can usually reach more than 20 years.
