An Electromagnetic Survey Method for Directionally Drilling a Relief Well Into a Blown Out Oil or Gas Well

This paper describes an electromagnetic method to facilitate drilling a well to intersect a target well casing. It has an important application in control of blown out oil and gas wells. By this method, a relief well was directionally drilled to intersect the casing of a blowout at 8,000 ft (2700 m). The relative distance and azimuthal direction to the target casing can be determined when the relief well is up to more than 100 ft (30 m) from the blowout.