The Marjan oil and gas collection and transportation platform Photo: Courtesy of CNOOC

China's heaviest offshore oil and gas platform destined for overseas markets was completed and delivered at a production facility in Qingdao, East China's Shandong Province, major Chinese oil company CNOOC said on Monday, the day of delivery.

The completion of the Marjan oil and gas collection and transportation platform marks a breakthrough in China's capacity for the construction of large-scale offshore oil and gas equipment.

The platform, weighing more than 17,200 tons, is one of the world's largest. It is taller than a 24-story building with a deck area equivalent to 15 basketball courts.

The platform was officially delivered after a construction period lasting 34 months, and it will set sail at the end of August on a large transport ship to its designated installation area some 6,400 nautical miles away.

The Marjan platform is a complex system formed through a network of pipelines as well as chemical treatment and operational control systems designed for collecting and transporting offshore oil and gas to land for processing, serving as a main terminal for offshore oilfields.

The platform can collect and transport 24 million tons of crude oil and 7.4 billion cubic meters of gas annually, making it the leading capacity platform of its kind globally. 

The platform's size, pipeline length and system complexity have all set international records for similar platforms, CNOOC confirmed.

The Marjan platform of Saudi's state-run oil giant Aramco will be installed in Saudi waters to assist the Marjan oilfield to ramp up annual output to 24 million tons.

Experts said that bilateral cooperation such as the Marjan project highlights the high-level complementarity between China and Saudi Arabia amid enhanced and deepened cooperation under the Belt and Road Initiative.

"The cooperation taps into China's technological, manufacturing and engineering capacity in large offshore platforms, and it brought the energy cooperation to a deeper level," Jin Lei, a professor at the China University of Petroleum, told the Global Times on Monday.

The delivery comes as China and Saudi Arabia strengthen energy cooperation.

Aramco CEO Amin Nasser said in a recent post-earnings call that Aramco is looking to invest in more chemical plants in China over the near term, the South China Morning Post reported on Friday.

Aramco, the world's largest crude export company, is targeting additional facilities that can transform oil into chemicals to leverage growing demand from China's emerging green industries, Nasser said. 

According to Chinese financial news portal caijing.com, China's energy cooperation with Saudi Arabia previously focused on traditional energy sources but has evolved to include new-energy sector.

In 2023, Saudi Aramco entered into deals worth a total of $8 billion with Chinese partners in the mid-stream and downstream sectors of the petroleum industry.