BP has resumed drilling at a well off eastern Canada where it suffered an 855-barrel spill of drilling mud last month.

The UK supermajor has started the drilling operations again at the Aspy-D11 wildcat off Nova Scotia with the semi-submersible West Aquarius after being given the go-ahead from the Canada-Nova Scotia Offshore Petroleum Board (CNSOPB).

An ROV discovered a leak on 22 June about 30 meters below the water surface, leading to a halt on drilling.

Repairs have now been completed, with BP concluding that the cause of the spill was a loose connection of the booster line on the riser.

“BP has immediately implemented improved inspection procedures to prevent any future occurrences,” the company said.

“During the course of repair operations, there have been no spills, injuries or accidents. BP takes this incident very seriously and is fully cooperating with the ongoing incident investigation.

“On July 11, as a precautionary measure, BP disconnected and moved the West Aquarius drilling unit away from the exploratory well location during a hurricane which passed in the vicinity.

“Once the weather conditions improved, the West Aquarius moved back to the well location.”

The spill was of synthetic-based drilling mud at the well, which is being drilled in 2771 metres of water.