The British Department of Energy and Climate Change announced Total officials had informed them of the start of a so-called dynamic kill operation late Tuesday. The company announced the leak was stopped 12 hours later.
The incident was first reported March 25. Gas was leaking at a rate 7 million cubic feet per day but had slowed to around 2.1 million cubic feet per day. The well intervention involved the pumping of heavy mud into the leaking well.
Total President of Exploration and Production Yves-Louis Darricarrere said Wednesday's announcement was a major turning point in the incident response.
"Since March 25th, we have been working closely with the authorities and we have communicated transparently and will continue to do so," he said in a statement. "We shall now fully complete the ongoing task and take into account the lessons learned from this incident."
None of the natural gas from the Elgin platform had reached shore, and there were few reports of major environmental damage.