A third major leak at a CNOOC plant has ended 2011 on a down beat for China's oil giant.
The leak occurred at CNOOC's Zhuhai Hengqin gas processing terminal and was believed have come from the plant's subsea pipeline. The leak was initially discovered by fishermen in mid-December and the Zhuhai Maritime Safety Administration subsequently reported the accident to CNOOC.
A major incident plan was put in place and the situation was brought under control, according to CNOOC, after the pipeline system was depressurised for 48 hours. The whole terminal then underwent an continued, accelerated depressurisation process to ensure the leak did not re-appear. Repair work continued towards the end of December to repair the damaged pipeline.
The cause of the incident is still under investigation, however, as part of the control process, the Company was forced to release the remaining natural gas in the pipeline. In a slightly confused picture, flames were seen on the sea's surface which were believed have been a deliberate part of the process to burn off the escaping gas.
The Zhuhai Terminal is located in Hengqin island of Zhuhai city and is a joint development project of Panyu-Huizhou gas processing terminal. Panyu 30-1 gas field itself is located in Southeast 240 km China Hong Kong in some 200m of water depth. The gas is carried via a 20 inch steel sea tube to to the Huizhou 21-1 gas field and then through a 232.5 km long pipeline to the Zhuhai terminal.
The shutdown has reduced CNOOC's net production by approximately 160 mcf per day, around 26,700 boe, daily. The latest incident is the third major oil or gas leak from CNOOC operations this year.