Asia's first cylindrical floating production, storage and offloading facility, designed and built by China, finished hull construction on Thursday, a breakthrough in the nation's deepwater, ultra-large offshore oil and gas equipment development, said industry experts.

Constructed by China National Offshore Oil Corp, the offshore oil and gas processing plant Haiyang Shiyou 122 has a maximum oil storage capacity of 60,000 metric tons. It is capable of processing 5,600 tons of crude per day and can operate for 15 days in a row, said the company.

The FPSO facility, an offshore oil and gas processing project capable of crude oil production, storage and export, has become the mainstream production facility for global offshore oil and gas development.

The project will next enter the final assembly and integration phase. After its completion next year, it will become a key secondary development project for a deepwater oilfield near the Pearl River Mouth Basin, together with Haiji-2, Asia's first deepwater jacket platform, to jointly develop China's deepwater oil and gas fields.

An analyst said the project represents a key step forward in the development of deepwater exploration equipment in China, and strengthens the country's ability to ensure its energy security.

The project represents a key step forward in the development of deepwater exploration equipment as China looks to expand its offshore oil and gas development, said Lin Boqiang, head of the China Institute for Studies in Energy Policy at Xiamen University.

Many of the discoveries in oil and gas exploration in the global marine sector currently are found in deep sea regions, which makes deep sea oil and gas exploration and development more crucial than ever for safeguarding national energy security, he said.

China has been stepping up offshore oil and gas development in recent years. The country's investments in offshore oil and gas exploration are also expected to continue rising this year, with more than half of this year's domestic oil increment likely to come from offshore, according to a report released by CNOOC.

Shu Wei, general contracting director at Haiyang Shiyou 122, said the company has resolved several world-class technical challenges in the construction of the FPSO, from equipment system design to high-precision construction, achieving several technological breakthroughs, with its precision control reaching advanced international levels.

Li Ziyue, an analyst with BloombergNEF, said China has endeavored to boost deep sea gas production to enhance domestic gas supply security.

With 12 projects being commissioned, China is on the fast track to further exploit deep sea gas resources, Li said.