The amount of gas leaking from Total's
The latest scientific flights, modelling and platform visits this week confirm a decrease in the gas leak rate, to around one third of the initial estimate of 200,000 cubic metres per day made in the first days of the Elgin gas leak, the French oil and gas major said in a statement.
On Wednesday Total started work to drill a relief well 4,400 metres below the seabed after Britain's energy ministry gave the green light for the procedure which is expected to take around six month.
A second drilling rig, which was used on the nearby West Franklin field before the leak started, will be deployed from early May to support the relief well work, Total said in its statement.
Scottish authorities also said on Wednesday the leak had not directly contaminated the marine environment as no traces of oil or gas pollution were found in samples taken on the edge of a two-mile exclusion zone around the platform located 240 kilometres east off the coast of Aberdeen.
Total and the British government are also pursuing their preferred option of a so-called well kill, which is cheaper and faster but also more risky and which involves pumping heavy mud into the well from the platform.
The gas leak, which started on March 25, is costing Total $2.5 million per day, the company said.
Britain could be facing as much as a 6 percent cut to gas supplies this summer due to the closure of the Elgin and two neighbouring gas fields, National Grid
(Reporting by Karolin Schaps; Editing by Hans-Juergen Peters)