The cumulative production of natural gas exceeds 1 billion cubic meters!
Not long ago, the mainland's first self-operated 1500-meter ultra-deep-water atmospheric field "Deep Sea No. 1" handed over an impressive report card since it was officially put into production.
In the Lingshui Waters of Hainan, the world's first 100,000-ton deep-water semi-submersible production and storage platform, "Deep Sea No. 1", stands proudly above the blue ocean like a super-large "Big Mac".
Image courtesy of CNOOC.
It can extract natural gas up to 1500 meters underwater, connect it to the national natural gas pipeline network through submarine pipelines, and transport the separated condensate to land through tankers.
From the 1500-meter deep sea to the stoves of thousands of households, natural gas takes only 1 day to complete this "journey". Behind this is the unremitting exploration of several generations of Chinese offshore oil people to "deep blue".
From following the run to achieving 3 world-class innovations and 13 domestic pioneering technologies, "Deep Sea No. 1" means a major breakthrough in the development of deep-water oil and gas in the mainland and the equipment technology of deep-water marine engineering.
1
Find "treasures" in abandoned areas
On June 25, 2021, the commissioning ceremony of the "Deep Sea No. 1" ultra-deepwater atmospheric field of China National Offshore Oil Corporation (hereinafter referred to as CNOOC) was held in Beijing and the South China Sea gas field.
The "Deep Sea No. 1" field is about 150 kilometers away from Sanya City, Hainan Province, with a water depth of 1220 meters to 1560 meters in the sea area, and the east-west horizontal span of the gas field reaches 50 kilometers.
In 2006, CNOOC cooperated with well-known foreign oil companies to explore the Qiongdongnan Basin, and in 2010 drilled the first deep-water well in the central canyon of the block, achieving a breakthrough in deep-water exploration in the western part of the South China Sea.
However, since then, due to the small scale of the single-layer reserves of the deepwater well, the lack of development economy, and the lack of understanding of the oil and gas accumulation conditions in the central canyon, the well-known foreign oil company withdrew from the exploration interest of the block in 2012.
The People of China Offshore Oil who dared to be the first did not give up. From a global perspective, since the beginning of the new century, the pace of global offshore oil and gas exploration and development has accelerated significantly, the total reserves of newly discovered offshore oil and gas have exceeded that of land, and the storage and production have continued to grow, which has become a strategic replacement area for global oil and gas resources.
If you count from the 1956 Yingge sea oil seedling survey, the mainland offshore oil industry has gone through more than 60 years of development. Entering deep water will be the next strategic goal of China National Offshore Oil.
On August 18, 2014, a huge orange flame erupted from the burning arm of the rig, instantly illuminating the South China Sea in the dark. China's first self-designed and constructed sixth-generation deepwater semi-submersible drilling platform, "Offshore Oil 981", drilled a large gas field "Deep Sea No. 1" in Block 17-2 of Lingshui to test and harvest high-yield oil and gas flows.
This is the first important discovery in the deep-water field since the "Offshore Oil 981" deepwater drilling platform was put into use, and at the same time proves the huge natural gas resource potential of the Qiongdongnan Basin in the South China Sea. Subsequently, CNOOC has successively explored and discovered a number of deep-water gas fields in the sea, and the energy treasures in the depths of the South China Sea have gradually appeared in front of the eyes of the world.
The discovery of these deep-sea fields has benefited from the persistence of continental offshore oil people in exploration technology theory and basic research.
"In the past, large foreign companies used the traditional Atlantic passive fringe theory, which did not apply to us." Xie Yuhong, chief scientist of CNOOC, said, "We have inherited the traditional theory of oil and gas exploration technology, strengthened basic geological research, established a deep-water oil and gas accumulation model, improved the deepwater oil and gas exploration technology, and found the tectonic group of Lingshui 17-2 large exploration potential in the central canyon waterway of the Qiongdongnan Basin." ”
2
"Thermos bottle liner" has achieved international firsts
1500 meters, usually defined internationally as the dividing line between deep water and ultra-deep water. Although the ultra-deep water area is rich in oil and gas resources, each step of the deep is "as difficult as ascending to the sky" - for every 1 meter increase in water depth, pressure, temperature, inrush and other conditions will change drastically. A set of equipment and facilities installed at 1500 meters underwater is subjected to pressure equivalent to a person weighing 300 pounds standing on a fingernail cover. Moreover, the requirements for deepwater development on technology, equipment capabilities, and key design indicators are extremely high. Only a few large oil companies in the world have the technical capabilities of deepwater development.
Therefore, when the Deepsea One ultra-deepwater field was discovered in 2014, most people reacted by cooperating with the outside world and jointly mining.
But at that time, international oil prices were falling off a cliff, and international oil companies were retreating. Coupled with other objective reasons, the "Deep Sea One" energy station embarked on the road of independent innovation.
Difficult and heavy tasks, what to do? CNOOC had mastered the development of 300-meter-deep oil and gas fields at that time, but it had little practical experience in deep-water gas fields, from "shallow" to "deep".
In the autumn of 2014, the development plan design work was put on the agenda. Li Da, 35, became deputy project manager and floating body leader.
"We started our research in October 2014 and in May 2015 we proposed the option of building a semi-submersible production platform with oil storage." Li Da said.
The industry is in an uproar. Few people can imagine that CNOOC people, who have never independently carried out deep-water design and "answered questions independently" for the first time, will choose a path that even foreign deep-water counterparts have not thought of - drawing on the principle of "thermos bottle inner tank" to create a world precedent for semi-submersible platform column oil storage.
According to the conventional design of similar oil and gas fields in the world, the construction of new condensate pipelines is a technically feasible solution. But this will increase the cost of about 800 million yuan.
Can you design a platform that can meet the production needs of the gas field while temporarily storing a small amount of condensate? A new idea flashed through the design team.
They set up 5,000 cubic meters of condensate tanks in the 4 floating columns of the platform, and equipped the oil tank with tailor-made "protective body armor", which not only solved the problem of condensate storage, but also avoided the risk of oil body collision and leakage.
Known as "condensate U-shape isolation and safe storage technology," this innovation sets a world precedent for semi-submersible platform column storage.
Subsequently, "Deep Sea No. 1" gave birth to two other world firsts: 50,000-ton superstructure large deformation semi-floating precision Helong technology, the world's largest tonnage open structure pre-oblique return positive load lateral transfer technology. At the same time, it uses 13 domestic pioneering technologies, such as the design and installation technology of the 1500-meter water depth polyester cable anchorage system, and the design and detection technology of floating structure fatigue that has not been docked for 30 years.
3
The footsteps of "diving" into the deep sea do not stop
The commissioning of "Deep Sea No. 1" is a major breakthrough in the mainland's deep-water oil and gas development and marine engineering equipment technology, marking a historic leap from 300 meters deep water to 1500 meters of ultra-deep water in the mainland's offshore oil exploration and development capabilities.
The successful production of the "Deep Sea No. 1" gas field reached a production capacity of 1 billion cubic meters, which verified the advanced nature and reliability of the complete technical system of exploration, development, production, operation and maintenance of deepwater oil and gas resources independently created by the mainland, and also marked that the mainland had entered the ranks of advanced countries in deep-sea oil and gas exploration and development.
After the "Deep Sea No. 1" energy station is put into operation, the natural gas produced will be connected to the national natural gas pipeline network through the submarine pipeline, and 3 billion cubic meters of gas will be stably supplied to Guangdong, Hong Kong and qiong and other places every year.
At present, with "Deep Sea No. 1" as an important hub, CNOOC is actively promoting the development of gas fields such as "Deep Sea No. 2" (Lingshui 25-1) and promoting the construction of trillion atmospheric areas in the South China Sea from blueprint to reality, so as to better meet the growing demand for clean energy in the Guangdong-Hong Kong-Macao Greater Bay Area and the Hainan Free Trade Zone (Port).
What is more valuable is that the deep-water project represented by the "Deep Sea One" atmospheric field has not only driven the development of national industries such as shipbuilding, steel, mechanical and electrical engineering in the mainland, but also made CNOOC a firm practitioner of high-quality joint construction of the "Belt and Road" and deepening international energy cooperation.
Source: WeChat public account "Science and Technology Daily", the original title: "Deep Sea No. 1" how good is it?
Author: Cao Xiuying
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