Inert gas injection to help control or extinguish coal fires

Abstract

A method of locating and controlling subsurface coal fires is provided that includes mapping a subsurface coal bed fire using a magnetometer, where the mapping includes locating a combustion zone and an air inlet to the combustion zone of the coal bed fire, drilling an injection port from the earth surface to a previously burned zone of the combustion zone, where the injection port is disposed between the air inlet and the combustion zone, inserting a tube in the injection port, where the tube has an exterior tube seal disposed around the tube, and the exterior tube seal isolates the earth surface from the combustion zone along an exterior of the tube. The method further includes injecting an inert gas through the tube to the combustion zone, where the inert gas controls the combustion zone of the coal bed fire.

Dependencies are inferred from the claim text.