Cable-Laying Barge Completes Its First Subsea Venture in Oil & Gas After Offshore Wind Projects (Gallery)

China-headquartered subsea cable vessel owner and operator Fulan Offshore has crossed the finish line at an oilfield project in the Bohai Sea with one of its cable lay barges (CLBs), which previously worked on offshore wind projects.

According to the Chinese player, its CLB Ailan YiHao (AL-1) made its first work commitment in the oil and gas industry by completing the installation of a subsea cable for the Jinzhou 23-2 oilfield development project. With a total length of 35 kV, the composite cable is about 41 km—said to be the longest one-length inter-platform connection in Bohai Bay by far.

According to China’s State-owned Assets Supervision and Administration Commission of the State Council (SASAC), this oilfield development project is the first offshore multi-layer heavy oil thermal recovery project in the Asian country. The construction started in Qingdao, North China’s Shandong Province, on August 4, 2023. The drilling activities followed suit in May 2024.

Once it comes online, the project will meet the needs of 1 million for 3.5 years. Located in the Liaodong Bay of the Bohai Sea, the Jinzhou 23-2 oilfield is said to feature a ‘layered cake’ structure of multiple layers of sand-rich heavy oil reservoirs.

With a project area of about 3,600 square meters and a weight of about 16,000 tons, the two thermal recovery platforms, which were under construction in Qingdao, are about 31 meters high, representing—what has been described as—the largest offshore heavy oil thermal recovery platforms constructed in China to date.

The construction of the thermal recovery platforms for the project was planned to be completed before October 2024, with full-scale production expected by the end of the same year, after the platforms arrived at the Jinzhou 23-2 oil field in the Bohai Sea.

CLB Ailan YiHao (AL-1) at oilfield development project offshore China; Source: Fulan Offshore

Four months ago, the same vessel tucked another milestone under its belt with a 330kV high voltage alternative current (HVAC) power cable installation thanks to the Yangjiang Qingzhou-6 OWF export cable construction in Guangdong Province. This is described as the biggest offshore wind farm project in China being developed by China Three Gorges Corporation, a Chinese state-owned power company. The 35 km simultaneous lay and burial down to 3 – 4 m depth was completed within four days.

Equipped with the six-point mooring system, Ailan Yihao also finished its cable laying part of operations at the Integrated Waste Management Facilities (IWMF) project in Hong Kong. The work is now being continued with one of Fulan Offshore’s CLVs.

After Keppel Seghers Hong Kong (Keppel Seghers HK) and Zhen Hua Engineering (Zhen Hua) won the contract to design, build, and operate the IWMF project off the coast of Shek Kwu Chau, the former hired the heavy lift specialist Sarens to assist with barge transport, load-out, and weighing of over 17 modules from the fabrication yard to the installation site in Hong Kong.

The 17 modules were loaded out from the COOEC Fluor Heavy Industries yard in China and transported on barges by sea to Hong Kong. These modules included six prefabricated modules weighing 6,000 tons each and six more prefabricated modules weighing 2,500 tons each, alongside five prefabricated modules having a maximum weight of 500 tons.

Afterward, the modules were loaded in at the newly-built artificial island in Hong Kong waters. The temporary steel casing around the modules was removed and replaced with the permanent steelwork, followed by installation on the foundations.

The 100.65 meters long, 27.45 meters wide, and 6.41 meters deep Ailan No. 1 is a cable lay barge operated by Fulan Offshore and classified by the China Classification Society. Equipped with a cable turntable with a diameter of 26 meters, it can carry up to 6,000 tons of cable.