A subsidiary of ConocoPhillips said on Tuesday that all operations at an oilfield in northern China's Bohai Bay have been shut down, as ordered by China's marine authority.
China's State Oceanic Administration (SOA) last Friday ordered ConocoPhillips China to halt injection, drilling and production at the Penglai 19-3 oilfield because it had failed to seal leaks that have lasted for nearly three months.
"Operations are currently stopped at 181 producing wells and 54 injecting wells," ConocoPhillips China said on its website.
The Penglai 19-3 oilfield is the country's largest offshore oilfield, with total output of 8.4 million tonnes per year (168,000 bpd), about 20 per cent of total crude oil production in Bohai Bay.
ConocoPhillips has a 49-per-cent stake in the oilfield and acts as operator, while CNOOC Ltd , China's top offshore oil and gas producer, has a 51-per-cent stake.
ConocoPhillips China said it would continue to work with CNOOC to develop a plan to reduce reservoir pressure to ensure the safety of the field.
The company added that it was preparing a new marine environmental impact report for the oil field that would be submitted to the marine authority.