Oxidizing agent injection equipment for underground coal gasification process and application thereof

Abstract

This invention provides an oxidant injection device for an underground coal gasification process. The oxidant injection device includes an oxidant pathway which includes a swivel joint, coiled tubing, and a mechanical shear-off device which are in gas tight connection with each other in that sequence. Attached to the mechanical shear-off device is an oxidant nozzle, wherein the shear-off device is adapted to shear the oxidant nozzle to allow retraction of the coiled tubing when necessary, and wherein the swivel joint causes the surface oxidant source to be in gas tight connection with the coiled tubing reel centre shaft, thereby allowing continuous oxidant injection during the process of moving the oxidant nozzle via the movement of the coiled tubing when rotating the coiled tubing reel. In addition, the invention also provides the application of the oxidant injection device in the underground coal gasification process, whereby the oxidant injection device can specifically be used for the ignition and normal operation process.

Dependencies are inferred from the claim text.