BP begins drilling the first of two relief wells that may later be used to inject mud and cement into the existing well.

BP begins process to establish two relief wells.

He further claimed that the relief wells will not stop the oil spill.

BP is drilling two relief wells into the original well to enable them to block it.

The relief wells are expected to begin operating in August 2010 at a cost of about $100 million per well.

The authorities in charge of the dam had been forced to sink relief wells to ventilate the reservoir.

Two relief wells were drilled to relieve pressure from the well to allow response personnel to cap it.

These so-called relief wells can take a month or more to drill.

Drill relief wells into the producing zone to redirect some of the oil and make the fire smaller.

The first relief wells were drilled in Texas in the mid 1930s.