"Shenhai No. 1": Leading oil and gas exploration and development to ultra-deep water
The "Deep Sea No. 1" energy station can supply 3 billion cubic meters of gas stably every year.
The picture shows some facilities of the "Deep Sea No. 1" energy station.
Photo by Xinhua News Agency reporter Zhang Jiansong
Editor's note In the past 2021, all walks of life have followed the development path outlined by the "14th Five-Year Plan", supported by technological innovation, and made solid efforts to achieve one remarkable achievement after another.
This newspaper launched a special plan during the two sessions, focusing on major breakthroughs in energy, aerospace, transportation and other industries, reporting the innovation process behind it, and showing its contribution to economic and social development.
The cumulative production of natural gas exceeds 1 billion cubic meters!
Not long ago, my country's first self-operated 1,500-meter ultra-deep water gas field "Shenhai No. 1" handed over an impressive transcript since it was officially put into operation.
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".
It can extract natural gas at a depth of 1,500 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 1,500-meter deep sea to the stoves of thousands of households, it only takes one day for natural gas to complete this "journey".
But behind this, it is the unremitting exploration of several generations of CNOOC people to "deep blue".
From following up to achieving 3 world-class innovations and a historic lead in 13 domestic pioneering technologies, "Deep Sea No. 1" means a major breakthrough in my country's deepwater oil and gas development and deepwater marine engineering equipment technology.
Find "treasures" in abandoned areas
On June 25, 2021, the commissioning ceremony of the "Shenhai No. 1" ultra-deepwater gas field of China National Offshore Oil Corporation (hereinafter referred to as CNOOC) was held in Beijing and the Nanhai gas field.
The "Shenhai No. 1" gas field is about 150 kilometers away from Sanya City, Hainan Province.
In 2006, CNOOC cooperated with well-known foreign oil companies to explore the Qiongdongnan Basin, and in 2010 drilled the first deepwater well in the central canyon of the block, achieving a breakthrough in deepwater exploration in the western South China Sea.
However, since the single-layer reserves of the deepwater well were too small to be economically developed, and the oil and gas accumulation conditions in the Central Canyon were unclear, well-known foreign oil companies withdrew their exploration rights in this block in 2012. .
The CNOOC people 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 new offshore oil and gas discoveries have exceeded those on land, and the reserves and production have continued to grow. It has become a strategic replacement area for global oil and gas resources.
Starting from the Yinggehai Oil Seedling Survey in 1956, my country's offshore oil industry has gone through more than 60 years of development.
Entering deep water will become the next strategic goal of CNOOC.
On August 18, 2014, a huge orange flame erupted from the combustion arm of the drilling platform, instantly illuminating the South China Sea under the night.
China's first self-designed and built sixth-generation deep-water semi-submersible drilling platform, "Haiyang Shiyou 981", drilled the large gas field "Shenhai No. 1" in the Lingshui 17-2 block, and tested and harvested high-yield oil and gas flow.
This is the first important discovery made in the deep water field since the "Haiyang Shiyou 981" deepwater drilling platform was put into use, and it also proves the huge natural gas resource potential of the Qiongdongnan Basin in the South China Sea.
Since then, CNOOC has successively discovered a number of deep-water gas fields in the waters, and the energy treasures in the depths of the South China Sea are gradually revealed to the world.
The discovery of these deep-sea gas fields benefited from the persistence of my country's offshore oil people in exploration technology theory and basic research.
"In the past, large foreign companies used the traditional Atlantic passive edge theory, which was not applicable to us," said Xie Yuhong, chief scientist of CNOOC. "We inherited the traditional theory of oil and gas exploration technology, strengthened basic geological research, and established a deep-water oil and gas complex. The reservoir model has been improved, the deepwater oil and gas exploration technology has been improved, and the Lingshui 17-2 structural group with large exploration potential has been found in the central canyon waterway of the Qiongdongnan Basin.”
"The inner liner of the thermos" achieves an international first
1500 meters is 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, every step in the depth is "as difficult as going to the sky" - every 1 meter of water depth increases, the pressure, temperature, current and other conditions will change dramatically.
A set of equipment installed at a depth of 1,500 meters underwater, the pressure is equivalent to standing on a fingernail weighing 300 pounds.
Moreover, deepwater development has extremely high requirements on technology, equipment capabilities and key design indicators.
Only a few large oil companies in the world have deep water development technical capabilities.
Therefore, when the "Shenhai No. 1" ultra-deepwater gas field was discovered in 2014, the response of most people was to cooperate with foreign countries and jointly exploit them.
But at that time, the international oil price was falling sharply, and the international oil companies retreated one after another.
Coupled with other objective reasons, the "Deep Sea No. 1" energy station has embarked on the road of independent innovation.
The difficulty and the task are heavy, what should I do?
At that time, CNOOC had mastered the development of oil and gas fields with a water depth of 300 meters, but it had little practical experience for deep-water gas fields, from "shallow" to "deep".
In the autumn of 2014, the design of the development scheme was put on the agenda.
35-year-old Li Da became the deputy project manager and the person in charge of the floating body.
"We started research in October 2014 and proposed the option of building a semi-submersible production platform with oil storage in May 2015," Li Da said.
The industry was in an uproar.
Few people would have imagined that CNOOC people who had never done deep-water design independently before and had "answered questions independently" for the first time would choose a path that even foreign deep-water counterparts have never thought of -- drawing on the principle of "thermo flask liner" , creating a world precedent for column oil storage on semi-submersible platforms.
According to the conventional design of similar oil and gas fields in the world, it is a technically feasible solution to build a new condensate oil pipeline.
But this will increase the cost of about 800 million yuan.
Can a platform be designed that can both meet the production needs of the gas field and temporarily store a small amount of condensate?
A new idea came to the design team.
They set up 5,000 cubic meters of condensate oil tanks in the four floating body columns of the platform, and installed tailor-made "body armor" for the oil tanks, which can not only solve the problem of condensate oil storage, but also avoid the oil body Risk of collision leakage.
This innovation, known as "U-shaped isolation and safe storage technology for condensate oil", has created a world precedent for column oil storage on semi-submersible platforms.
Subsequently, "Deep Sea No. 1" was born with two other world firsts: the large deformation and semi-floating precision closing technology of 50,000-ton super-large structures, and the lateral transfer technology of pre-inclined back-to-positive load for the world's largest ton-level open structure.
At the same time, it uses 13 domestic pioneering technologies, including the design and installation technology of polyester mooring system in 1500-meter-level water depth, and the design and detection technology of floating structure fatigue that has not been docked for 30 years.
"Dive into" the deep sea
The commissioning of "Shenhai No. 1" is a major breakthrough in my country's deepwater oil and gas development and marine engineering equipment technology, marking the historic leap in my country's offshore oil exploration and development capabilities from 300 meters deep water to 1,500 meters ultra-deep water.
The successful production of "Shenhai No. 1" gas field of 1 billion cubic meters verifies the advanced nature and reliability of the complete technical system of deepwater oil and gas exploration, development, production, operation and maintenance independently created by my country, and also marks that my country has entered the advanced stage of deepwater oil and gas exploration and development. National ranks.
After the "Shenhai 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 will supply 3 billion cubic meters of gas to Guangdong, Hong Kong, 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 the trillion-dollar gas region in the South China Sea from blueprint to reality, so as to improve It can well meet the growing demand for clean energy in the Guangdong-Hong Kong-Macao Greater Bay Area and the Hainan Free Trade Zone (Hong Kong).
What is more valuable is that the deep-water projects represented by the "Deep Sea No. 1" large gas field have not only driven the development of my country's national industries such as shipbuilding, steel, and electromechanical, but also made CNOOC a high-quality joint construction of the "Belt and Road", deepening A firm practitioner of international energy cooperation.
Our reporter Cao Xiuying