Abstract: An injection device, which comprises a nozzle and which is used for an underground coal gasification process; the nozzle and the injection device are used for continuously injecting a high-concentration oxidant into an underground coal layer during the underground coal gasification process, in which case the high-concentration oxidant may be used safely and steadily to obtain a high-quality and stable product gas, while a retraction cycle and/or a retraction distance of a retraction method in the existing technology may be greatly shortened, thus achieving the continuous and steady operation of the underground coal gasification process. Also disclosed is a method for operating the injection device.

Abstract: An ignition device for an underground coal gasification process, and an underground coal gasification method for carrying out ignition. The ignition device comprises a conveying device, a cut-off device (7), an ignition detonator (6) and one or more fuel packs (5), sequentially connected. The fuel packs are serially connected with each other. The conveying device is a coiled tubing/conjugation tube (12), or an integrated signal cable (21). The ignition detonator runs through one or more fuel packs and ignites the one or more fuel packs starting from the top of the device in a delayed manner. The cut-off device breaks off after the ignition detonator is started, so that ignition device components comprising the conveying device are at least withdrawn to a safe position. Each fuel pack comprises thermite and is used for igniting an underground coal seam (1) after the fuel pack is ignited.

Abstract: A production well apparatus for underground coal gasification and an underground coal gasification method using same. The production well apparatus comprises a well head apparatus, a sleeve (8), a product pipe (1), a coolant pipe (3), and a monitoring meter system (7). Coolant is injected, during underground coal gasification, to be in contact and mixed with product gas, and the product gas is discharged after cooled, such that the operation is safer and more controllable. Moreover, most of the components of the production well apparatus can be completely or partially recycled and reused after the gasification is completed.

Abstract: An oxidant injection device for an underground coal gasification process 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 center 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.

Abstract: An injection device, which comprises a nozzle and which is used for an underground coal gasification process; the nozzle and the injection device are used for continuously injecting a high-concentration oxidant into an underground coal layer during the underground coal gasification process, in which case the high-concentration oxidant may be used safely and steadily to obtain a high-quality and stable product gas, while a retraction cycle and/or a retraction distance of a retraction method in the existing technology may be greatly shortened, thus achieving the continuous and steady operation of the underground coal gasification process. Also disclosed is a method for operating the injection device.

Abstract: An ignition device for an underground coal gasification process, and an underground coal gasification method for carrying out ignition by using the same. The ignition device comprises a conveying device, a cut-off device (7), an ignition detonator (6) and one or more fuel packs (5), all of which are sequentially connected. The multiple fuel packs are serially connected with each other. The conveying device is a coiled tubing/conjugation tube (12), or an integrated signal cable (21). The ignition detonator runs through one or more fuel packs and ignites the one or more fuel packs starting from the top of the device in a delayed manner. The cut-off device breaks off after the ignition detonator is started, so that ignition device components comprising the conveying device are at least withdrawn to a safe position. Each fuel pack comprises thermit and is used for igniting an underground coal seam (1) after the fuel pack is ignited.

Abstract: A production well apparatus for underground coal gasification and an underground coal gasification method using same. The production well apparatus comprises a well head apparatus, a sleeve (8), a product pipe (1), a coolant pipe (3), and a monitoring meter system (7). Coolant is injected, during underground coal gasification, to be in contact and mixed with product gas, and the product gas is discharged after cooled, such that the operation is safer and more controllable. Moreover, most of the components of the production well apparatus can be completely or partially recycled and reused after the gasification is completed.

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.

Abstract: The invention provides methods for mobilizing and recovering petroleum from subterranean formations by in situ combustion.

Abstract: The invention provides methods for mobilising and recovering petroleum from subterranean formations by in situ combustion.

Abstract: The invention relates to compositions and method for construction of an underground coal gasification (UCG) well liner assembly. In particular, a well liner segment for use in the construction of a UCG well liner assembly for conveying product gas to a production well is disclosed. Also disclosed are a system and method for UCG product gas production.

Abstract: The invention relates to compositions and method for construction of an underground coal gasification (UCG) well liner assembly. In particular, a well liner segment for use in the construction of a UCG well liner assembly for conveying product gas to a production well is disclosed. Also disclosed are a system and method for UCG product gas production.

Abstract: An ignition apparatus (150) configured to ignite an underground coal seam (151). The ignition apparatus (150) comprising an ignition system, a positioning system, a sensor (170) and a controller (165). The ignition system comprises ignition means and an ignition tool (155) for igniting the underground coal seam (151) from within the well channel (154) or well liner encasing the well channel (154). The positioning system comprises coiled tubing (156) connected to the ignition tool (155) and extendible through a well head (153) within the well channel (154) to position the ignition tool (155) at a desired location within the well channel (154). The positioning system further comprises a spool (157) for transporting and dispensing the coiled tubing (156).