Divine Fox is a name that evokes imagination. In ancient China, foxes were a mysterious existence. If it were a divine fox, it would be even more unimaginable.
This area is located in the northern part of the South China Sea, on the slope from the continental shelf to the deep sea. It is more than 300 kilometers away from the Pearl River Estuary. The water depth is more than 900 meters, and the deepest point is 1,500 meters.
This has been a traditional fishing ground for Chinese fishermen since ancient times.
However, for thousands of years, people's best understanding of this sea area is the abundance of seafood, and little is known about the seabed that goes hundreds or even thousands of meters below the sea level.
In order to understand the status of my country's resource reserves as much as possible, the China Geological Survey was established in 1999, and immediately organized a new round of special geological surveys such as land and resources surveys, geological and mineral survey assessments, and marine geological surveys.
As the latest discovered energy type, natural gas hydrate, also known as flammable ice as the saying goes, has become one of the key projects of this marine geological survey.
There are basically two technical methods for determining natural gas hydrates in the world. One is the interpretation of geophysical data, such as obtaining the bsr mark, which is the seafloor simulated reflector, gas hydrate-containing sediments and underlying underlying gas hydrates.
The acoustic reflection interface between gas hydrates, and gas hydrates are stable in the marine environment, so analyzing this reflection interface is an important indicator of the presence of gas hydrates.
The other type is a typical seabed methane seepage, or known as a cold seep. Since the main component of natural gas hydrates is methane, detecting a large amount of methane gas seepage on the seabed is also an important indicator of the existence of natural gas hydrates.
Both methods can determine whether flammable ice exists beneath the seafloor.
At the beginning of this century, after the marine geological survey began, geological investigators made a major discovery. They conducted a high-resolution multi-channel geological survey on combustible ice and found that for the first time, seafloor-like reflection (BSR) was discovered in the Xisha area on the northern slope of the South China Sea. This means that this new resource has made zero breakthrough in my country’s waters.
Comprehensive investigations and studies by Chinese marine geologists in the northern South China Sea have confirmed the existence of gas hydrates in my country's waters, and that the northern slopes of the South China Sea have good gas hydrate resource prospects. The most favorable natural gas hydrate resources on the northern slopes of the South China Sea have been preliminarily delineated. target area.
The deep-water area on the northern slope of the South China Sea was immediately listed as one of the three important new areas for the sustainable development of China's oil and gas exploration, and became my country's first choice target for deep-water exploration.
In 2002, while conducting gravity piston sampling on the seafloor, scientific researchers suddenly discovered that the methane content in some places was abnormal, which was important evidence of the decomposition of natural gas hydrates.
Immediately, with the strong support of relevant national departments, China and Germany launched inter-governmental cooperation. In May 2004, a scientific expedition team composed of scientists from China and Germany carried out the distribution of methane and natural gas hydrates on the northern slope of the South China Sea, forming a
and its impact on the environment.
As an internationally advanced platform at the time, the "Sun" oceanographic survey ship became the main force of this maritime scientific research work. Scientists from the two countries discovered a huge carbonate reef in the eastern waters of the Pearl River Mouth Basin.
This is the largest authigenic carbonate rock in the world and is also significant evidence of the existence of natural gas hydrates. It was later named the "Jiulong Methane Reef".
Unfortunately, no samples of shallow superficial gas hydrates were obtained during this scientific expedition, which became a regret for the Chinese and German geologists who participated in this research.
After that, my country successively carried out large-scale gas hydrate resource investigation and research work in the Xisha, Dongsha, Shenhu and Qiongdongnan waters on the northern slope of the South China Sea, and achieved a series of exploration results and theoretical breakthroughs.
In 2007, for the first time, Chinese geological researchers successfully carried out drilling at 8 stations in the Shenhu area of the northern South China Sea. Three stations obtained physical samples of natural gas hydrates. The methane content of the samples obtained was as high as 99.7%, which can be ignited.
combustion.
This discovery is the first time that my country has obtained physical samples of natural gas hydrates in the South China Sea, confirming that there are good prospects for hydrate resources in the South China Sea.
This is a strategic breakthrough, and it also makes our country the fourth country after the United States, Japan, and India to obtain physical samples of natural gas hydrate through seabed drilling through national-level research and development programs. It also means that the survey of natural gas hydrate resources in our sea areas has officially entered the
Leading the way in international hydrate exploration.
Subsequently, my country accelerated the pace of natural gas hydrate investigation and research.
The Shenhu Sea Area located in the middle section of the continental slope is among them and has become one of the areas with the most scientific research value. It is also very likely to become a blessed place for my country's flammable ice research work.
In 2013, marine geological survey workers carried out the second natural gas hydrate drilling in the Pearl River Mouth Basin.
A large number of high-purity physical samples of new types of natural gas hydrate were drilled this time. The methane content in the samples reached up to 99%, and they were in the form of blocks, veins, dispersed and other types. They mainly exist in water depths of 600-1100 meters.
The two mineral deposits within 220 meters below the seabed have five characteristics: shallow burial, large thickness, multiple types, high mineral content, and high methane purity, which are rare in the world.
This discovery was the first to obtain a visible physical sample of massive natural gas hydrate in the South my country Sea.
This new discovery fills the gap in visible hydrates in my country's seas and greatly enriches the types of hydrate occurrences in my country's seas. It is a new type of hydrates discovered after the 2007 drilling voyage and has important exploration practices. It has great significance and important scientific research value, and is a milestone breakthrough in the investigation and exploration of hydrate resources in my country's sea areas.
In 2015, marine geological survey workers once again carried out 23 natural gas hydrate drilling wells in the Shenhu waters. This time, the hit rate reached 100%. Natural gas hydrates were found in all 23 wells. The hydrate ore bodies are thick and have large reserves.
, showing high saturation characteristics.
The drilling controlled mineral deposit area is 128 square kilometers, and the controlled resource volume exceeds 150 billion cubic meters. 10 large-scale ore bodies have been circled, including 2 large-scale ore bodies confirmed through drilling and coring. This drilling also discovered type 2 for the first time.
Natural gas hydrates are closely related to deep oil and gas and are of great significance in guiding oil and gas exploration.
This drilling provided an important reference target area for the experimental production of natural gas hydrates in the sea, marking that the investigation of natural gas hydrate resources in my country's seas has reached the world's advanced level.
In the same year, scientific researchers used geophysical data to discover typical seafloor methane seepage (i.e., cold seep) reflection characteristics in the waters near Shenhu, and then used my country's independently developed 4,500-meter unmanned remotely operated submersible "Haima" underwater Robot (rov) performs seafloor observations and real-time methane determination.
The results revealed a large number of chemoautotrophic cold seep organisms - large cold seep ecosystems composed of fungus mats, mussels, tube worms, crabs, etc. and a large number of cold seep carbonate rocks precipitated in a high alkalinity environment, confirming the giant cold seeps.
Group - the existence of seahorse cold seep area.
At the same time, targeted large-scale gravity piston sampling was carried out in the Haima Cold Spring area, and physical samples of seepage-type natural gas hydrate were collected directly from the shallow surface of the seafloor. The results of seafloor observation and sampling verified the results of previous exploration studies on seafloor seepage-type hydrates.
It has made new breakthroughs in the understanding of hydrate resource enrichment patterns in the South China Sea and the seabed ecosystem related to cold seeps, and has important guiding significance for subsequent drilling deployment.
On June 25, 2016, the "China Geological Survey Natural Gas Hydrate Engineering Technology Center" was officially launched in Guangzhou. In the same year, the China Geological Survey discovered more than 100 billion cubic meters of natural gas hydrate in the Shenhu Sea area through drilling.
mineral deposits, and determined the test ore body and target well location for the test mining of natural gas hydrate.
An achievement that will shock the world is in the making.