ROC Oil's operations in the Bohai Bay of China have managed to withstand the region's coldest winter in more than 40 years, with the company's Zhao Dong oil field avoiding the shutdowns being experienced by other platforms in the region.

David Slack-Smith, a spokesman for Sydney-based Roc, told The Australian the company's experience in the region meant it was well prepared to deal with the recent weather extremes.

Mr Slack-Smith said the company had previously taken steps to protect Zhao Dong from the harsh winter conditions, including the installation of pipelines to replace barges that had previously unloaded oil from the production platform. The company and its partners in the field had also contracted an icebreaker vessel for the duration of the winter. "It's slightly more extreme than usual this year, but it's not impacting on our daily production at all," he said.

Chinese oil and gas giant CNOOC has had to call in a fleet of 13 icebreakers to help ensure that production can continue at its fields in Bohai Bay.