Haiji-2, the first deepwater jacket in Asia designed and built independently by China National Offshore Oil Corp, completed construction in Zhuhai on Tuesday.

This is a testament to the fact that the independent design and construction capability of China's deepwater ultra-large jacket platform has reached world-class levels, CNOOC said.

The jacket platform is the "foundation" for supporting and fixing the huge body of an offshore oil and gas platform.

Completion of the project is of great significance in promoting the development of deepwater oil and gas energy in China and accelerating the high level of energy science and technology self-reliance, it said.

With a total height of 338.5 meters and a total weight of 37,000 metric tons, the jacket of Haiji-2 uses more than 20,000 tons of high-strength steel, making it the first case of large-scale application of domestically produced high-strength steel in marine engineering.

The project has broken multiple records in Asia in terms of structural height, weight, operating depth and construction speed, signifying that China has developed advanced capability in independently designing and constructing deepwater super-large jacket platforms.

CNOOC said that with the continuous development of offshore oil and gas resources, the deepwater area below 200 meters has become an important battlefield for offshore oil and gas development in China.

Deepwater jacket platform Haiji-2 will play an increasingly important role in the development of deep-sea oil and gas resources in China, it said.

An analyst said China's investment in offshore oil and gas exploration is expected to rise further, with more than half of this year's domestic oil increment likely to come from offshore sources.

China's offshore oil and gas production is expected to increase in 2024, while its continuous upstream investment and production commitment will play a critical role in the country's energy supply security, said Li Ziyue, an analyst with BloombergNEF.

According to Wang Zhen, head of the CNOOC Energy Economics Institute, China's offshore oil production investment rose last year, with the steady promotion of key development projects, and offshore oil and gas production reaching new highs.

Growth in the oil and gas sector this year will come mostly from offshore resources, which is expected to become an important energy growth driver in the future, he said.

According to the institute, renewable energy sources are also witnessing more opportunities in the offshore sector, as offshore wind has developed on a large scale in the country.