Environmental group Greenpeace said Wednesday it intends to continue a protest aboard an oil drilling rig contracted to Chevron Corp. (CVX) in the U.K. for up to a month.

Two Greenpeace protesters attached themselves to the anchor chain of the Stena Carron drill ship Tuesday, and have since attached a "purpose built survival pod" to the chain that will allow them to stay in place for up to a month, Greenpeace said in a statement.

The Stena Carron is anchored offshore
Shetland , Scotland , as it prepares for a voyage to drill a well on Chevron's Lagavulin field.

Greenpeace protesters staged a similar protest by attaching themselves to the underside of a drilling rig under contract to Cairn Energy PLC (CNE.LN) in
Greenland earlier this month. They succeeded in halting operations on the rig for several days before being forced to abandon the protest due to severe weather.

Greenpeace says the drilling the rig will be performing is too environmentally risky following the BP PLC (BP) oil spill in the
Gulf of Mexico over the summer. Chevron said in a statement Tuesday that its drilling operations are safe and offered to meet with Greenpeace to address its concerns.