Abrégé

The present invention provides a methane synthetic method, used for synthesizing underground gasified crude gas into methane. The method comprises: step 1: gasifying an underground coal layer by using an underground gasification furnace to produce crude gas; step 2: removing impurities in the crude gas by using a crude gas pretreatment system; step 3: calculating a required removal quantity of CO2 in the crude gas and removing the corresponding quantity of CO2 by using a low-temperature methanol washing device according to the required removal quantity of CO2; and step 4: synthesizing the crude gas into methane by using a methanation device. According to the method for synthesizing crude gas into methanol and a methanol synthetic system in the present invention, carbon dioxide is absorbed by using a low-temperature methanol washing device, so that the content of carbon dioxide in the crude gas can be reduced, the composition of raw material gas for synthesizing the methanol is more stabilized, and the stable and safe methanol production using the methanation device can be ensured.

Classes IPC  ?

• C07C 1/04 - Préparation d'hydrocarbures à partir d'un ou plusieurs composés, aucun d'eux n'étant un hydrocarbure à partir d'oxydes de carbone à partir de monoxyde de carbone avec de l'hydrogène
• C07C 1/12 - Préparation d'hydrocarbures à partir d'un ou plusieurs composés, aucun d'eux n'étant un hydrocarbure à partir d'oxydes de carbone à partir d'anhydride carbonique avec de l'hydrogène
• C10L 3/08 - Production de gaz naturel de synthèse
• C01B 3/52 - Séparation de l'hydrogène ou des gaz contenant de l'hydrogène à partir de mélanges gazeux, p. ex. purification par contact avec des liquidesRégénération des liquides usés
• C07C 9/04 - Méthane

Abrégé

Disclosed is an an underground gasification well-cementing method. The method comprises the following steps: descending a cementing casing (3) into a well until the bottom end of the cementing casing (3) enters into a coal seam (1) by a set depth (H), and connecting the cementing casing (3) to a well wall of a well (2), wherein the cementing casing (3) at least comprises a telescopic flexible casing (31), the bottom end of the telescopic flexible casing (31) forms the bottom end of the cementing casing (3), and the upper end of the flexible casing (31) is located not lower than the maximum water diversion fissure zone (4) over the coal seam. In addition, a well structure is disclosed. The well structure comprises a well (2) which penetrates into a coal seam (1) from the ground and a cementing casing (3) connected to a well wall, wherein the cementing casing (3) comprises a telescopic flexible casing (31), the bottom end of the telescopic flexible casing (31) is located at a set depth (H) in the coal seam, and the upper end of the flexible casing (31) is located not lower than the maximum water diversion fissure zone (4) over the coal seam.

Classes IPC  ?

• E21B 17/20 - Tubes de forage flexibles ou articulés

Abrégé

Disclosed is a well head structure of an underground gasification furnace. The well head comprises a blowout preventing box (1), a sealing device, a middle-high pressure gas injection device (3) and a well pipe (4). The middle-high pressure gas injection device (3) comprises a first communication pipe (7) and a first gas injection pipe (8), and the first communication pipe (7) is in communication with the first gas injection pipe (8). The blowout preventing box (1), the sealing device, the first communication device (7) and the well pipe (4) are sequentially arranged and communicate with one another. A continuous oil pipe enters from the blowout preventing box (1) into the well pipe (4) sequentially through the sealing device and the first communication pipe (7). The first gas injection pipe (8) is in communication with an outer gasifying agent source via a middle-high pressure gasifying agent pipeline, and a middle-high pressure gasifying agent enters the first communication pipe (7) through the first gas injection pipe (8) and then enters the well pipe (4). The well head structure is reasonable in design and simple in structure, the descending operation of the continuous oil pipe can be achieved, and it is guaranteed that the whole operation process is simple, convenient and safe.

Classes IPC  ?

• E21B 33/03 - Têtes de puitsLeur mise en place
• E21B 34/02 - Aménagements des vannes pour les trous de forage ou pour les puits dans les têtes de puits

Abrégé

A nozzle comprising a main body (10), said main body being a casing structure comprising a core pipe (11) and an external casing (12) each having an annular cross-section; the end of the core pipe and of the external casing have tapered cone-shaped structures which form a nozzle cap (13); the nozzle cap is provided with a gas injection port (14) in communication with the core pipe; and the sidewall of the external casing is provided with a plurality of spray holes (15, 16); during the gasification process, a gasification agent containing oxygen is supplied to the core pipe, water or an aqueous solution is supplied to the external casing, and the water or aqueous solution flows into a gasifier via the spray holes on the sidewall of the external casing and via the spray holes on the nozzle cap. The present invention allows for the integration of nozzle water-injection and cooling. This not only effectively provides the water necessary for a water gas reaction, but also effectively cools the nozzle. The extent to which the nozzle is overheating can be inferred from the change in water-injection pressure, and adjustments can thus be made during the gasification process. In injection method for the nozzle is also disclosed.

Classes IPC  ?

• E21B 43/295 - Gazéification de matières minérales, p. ex. pour produire des mélanges de gaz combustibles

Abrégé

A coal co-gasification method, comprising the following steps: 1, fuel and a first pressurised oxygen-containing gas are injected into a gasifier, and the fuel is ignited so as to increase the temperature inside the gasifier; 2, when the temperature increase reaches a temperature capable of igniting coal-water slurry to be injected, injection of the fuel and the first pressurised oxygen-containing gas is stopped, and the coal-water slurry and a second pressurised oxygen-containing gas are injected into the gasifier so as to perform coal-water slurry gasification; 3, once the coal-water slurry gasification has stabilised, a third pressurised oxygen-containing gas and carbon dioxide carrying powdered coal are injected into the gasifier to perform co-gasification. The method operates stably, and overcomes cumbersome and time-consuming adjustment steps in the prior art.

Classes IPC  ?

• C10J 3/46 - Gazéification des combustibles granuleux ou pulvérulents en suspension

Abrégé

A coal co-gasification method, comprising the following steps: 1, fuel and a first pressurised oxygen-containing gas are injected into a gasifier, and the fuel is ignited so as to increase the temperature inside the gasifier; 2, when the temperature increase reaches a temperature capable of igniting powdered coal to be injected, injection of the fuel is stopped, injection of the first pressurised oxygen-containing gas is continued, and a pressurised carbon dioxide gas carrying the powdered coal to be injected is injected into the gasifier so as to perform powdered coal gasification; 3, once the powdered coal gasification has stabilised, coal-water slurry and an oxygen-containing gas are injected into the gasifier to perform co-gasification. The method operates stably, and overcomes cumbersome and time-consuming adjustment steps in the prior art.

Classes IPC  ?

• C10J 3/46 - Gazéification des combustibles granuleux ou pulvérulents en suspension

Abrégé

An underground gasification ignition method comprises the following steps: making a directional drilling and a vertical well to construct an underground gasification furnace; using a cold fracturing method to pre-penetrate a coal seam; and igniting in the vertical well at an end of the directional drilling.

Classes IPC  ?

• E21B 43/295 - Gazéification de matières minérales, p. ex. pour produire des mélanges de gaz combustibles
• E21B 43/247 - Combustion sur place en association avec des procédés de fracturation

Abrégé

Disclosed is a nozzle comprising a housing (1), the housing comprising a first portion (8) and a second portion (9), the first portion (8) and the second portion (9) being in fluid communication via a front hole (10), and a side hole (6) being provided on a side wall of the second portion (9). The nozzle further comprises a sealing assembly (3) able to open and close the front hole (10) and the side hole (6) in a sliding manner in the housing, and a spring (2) provided between the housing and the sealing assembly. Furthermore, an underground coal gasification method using the nozzle is disclosed, which comprises the steps of adjusting the injection flow rate and injection pressure of a gasification agent and the pressure of a gas output channel port, and controlling the opening and closing of the front hole (10) and the side hole (6). The nozzle can optionally alternately or simultaneously open the front hole and the side hole without any manual operation. In the underground coal gasification process, opening the front hole of the nozzle can guide the movement of a gasification working face, opening the side hole can intensify gasification of a coal seam at two sides of a gasification channel, making the two sides of the gasification channel expand more uniformly, increasing the rate of recovery of coal resources.

Classes IPC  ?

• E21B 43/295 - Gazéification de matières minérales, p. ex. pour produire des mélanges de gaz combustibles

Abrégé

An underground coal gasification furnace comprises an ignition system and a gas injection system. The ignition system is provided with a first vertical drilling well (1) and a first horizontal directional drilling well (a) in communication with the first vertical drilling well. The gas injection system is provided with a second drilling well introduced into a coal seam. At least one second horizontal directional drilling well (b, c, d, e, f) of a horizontal section in the coal seam serves as the second drilling well. Also provided is an underground coal gasification method. The method comprises: enabling a flaming fire region of a first horizontal directional drilling well (a) to withdraw in a second horizontal directional drilling well (b, c, d, e, f) until withdraw to near a coal feeding point. The underground coal gasification furnace eliminates the defects of low cut-through speed and unstable structure in a gasification production stage in the prior art.

Classes IPC  ?

• E21B 43/295 - Gazéification de matières minérales, p. ex. pour produire des mélanges de gaz combustibles

Abrégé

A gas injection apparatus with a controllable gas injection point, a gas injection process, and a gasification method. The gas injection apparatus comprises a directional well channel (6), where a continuous oil pipe (3) is provided in the directional well channel (6). The continuous oil pipe (3) is connected to an oxygen/oxygen-rich gas pipeline. An annular gap between the continuous oil pipe (3) and the directional well channel (6) is connected to an auxiliary gasification agent pipeline and a vapor pipeline. A gas injection wellhead (2) is provided at the start end of the continuous oil pipe (3), and a nozzle (4) is provided at the tail end. In the present invention, based on directional drilling and continuous oil pipe technologies, the movement of a gas injection point is implemented by using a manner of combining directional drilling and a continuous oil pipe; meanwhile, by using a principle of controlling reverse combustion by adjusting a gasification agent injection parameter, the movement of a working surface position and a combustion speed of a flame are regulated, so as to achieve the objectives of ignition and gasification for reverse combustion of an underground coal layer.

Classes IPC  ?

• E21B 43/295 - Gazéification de matières minérales, p. ex. pour produire des mélanges de gaz combustibles

Abrégé

Provided is a method for fracture communication, passage processing, and underground gasification of an underground carbon-containing organic mineral reservoir, where a mixture of CO2 and O2 is used as a medium for a fracture communication step, a passage processing step, and/or a gasification step. The method uses the mixture of CO2 and O2 to extract and utilize the energy in the underground carbon-containing organic mineral reservoir, greatly increases energy utilization efficiency compared with conventional utilization schemes, and, compared with conventional underground gasification technologies, increases the calorific value of a combustible gas, increases and adjusts effective gas compositions, suppresses CO2 generation, and reduces raw material gas production costs, while at the same time implements the capturing of CO2 and utilization of same as a resource.

Classes IPC  ?

• E21B 43/26 - Procédés pour activer la production par formation de crevasses ou de fractures

Abrégé

Provided is a method for joint-mining of coalbed gas and coal. The method comprises: a well-drilling step; a fracturing and penetration step; a coalbed gas extraction step; an ignition step, and an underground gasification step. The method combines an underground coal gasification technology and a coalbed gas extraction technology, not only allows for utilization of the high temperature of underground gasification to heat a coalbed, thus increasing the permeability of a coal seam, and increasing the recovery rate of the coalbed gas, but also allows for utilization of the coalbed gas to perform the drilling and the fracturing and penetration processes, thus increasing the efficiency of underground coal gasification for mining.

Classes IPC  ?

• E21B 43/00 - Procédés ou dispositifs pour l'extraction de pétrole, de gaz, d'eau ou de matériaux solubles ou fusibles ou d'une suspension de matières minérales à partir de puits

Abrégé

The present invention relates to a bioavailability method for a product gas from underground coal gasification. The method comprises: a raw material gas preparation stage, acquiring a crude coal gas from an underground coal gasification process, acquiring a raw material gas by purifying and adjusting the crude coal gas, the acidic sulfide content in terms of sulfur of the raw material gas is less than 2 vol% and the initial molar ratio of (CO and/or CO2):H2 is at least approximately 1:3; and a microbial fermentation stage, at a pressure between 0.1 MPa and 0.4 MPa and room temperature, the raw material gas is utilized for a microbial fermentation process in a fermentation apparatus with the presence of a microbial strain, thus biosynthesizing ethanol and/or ethanoic acid, and giving off a methane-rich tail gas as a byproduct.

Classes IPC  ?

• E21B 43/295 - Gazéification de matières minérales, p. ex. pour produire des mélanges de gaz combustibles
• C12P 7/06 - Éthanol en tant que produit chimique et non en tant que boisson alcoolique
• C12P 7/54 - Acide acétique

Abrégé

An oil shale exploitation method comprises: forming a gas inlet pipeline (1) and a gas outlet pipeline (3) in an oil shale; forming a gasification channel (5) that connects the gas inlet pipeline and the gas outlet pipeline in the oil shale; feeding a combustible gas and oxygen into the well through different gas inlet pipelines, and then igniting, in an aerobic environment, the combustible gas fed into the well at the lower opening of the pipeline for conveying the combustible gas, so as to heat the oil shale; and recycling through the gas outlet pipeline an oil-gas mixed product formed after thermal decomposition of kerogen in the oil shale. The method has simple process and low energy consumption, and is capable of heating kerogen in the shale bed, thereby exploiting an oil shale mineral layer to obtain oil and gas products more economically and reasonably.

Classes IPC  ?

• E21B 43/243 - Combustion sur place
• E21B 36/00 - Aménagements pour le chauffage, le refroidissement ou l'isolation dans les trous de forage ou dans les puits, p. ex. pour être utilisés dans les zones de permagel

Abrégé

Disclosed is an oil shale exploitation method, comprising: forming a first channel reaching the ground surface in the oil shale; forming a second channel reaching the ground surface from a coal layer located under the oil shale and a third channel that communicates with the second channel and reaches the ground surface from the coal layer; performing underground gasification on the coal layer to form a combustion cavity; and collecting oil and gas. Further provided is an oil shale exploitation device, the coal layer being located under the oil shale. The device comprises: a first channel disposed in the oil shale and reaching the ground surface from the oil shale; a second channel disposed in the coal layer and reaching the ground surface from the coal layer, the first channel being located above the second channel; and a third channel that communicates with the second channel and reaches the ground surface from the coal layer. According to the present invention, not only the energy utilization is increased, but also an artificial heat source is not required to implement gas preparation through in-situ dry distillation of oil shale.

Classes IPC  ?

• E21B 43/295 - Gazéification de matières minérales, p. ex. pour produire des mélanges de gaz combustibles
• E21B 43/00 - Procédés ou dispositifs pour l'extraction de pétrole, de gaz, d'eau ou de matériaux solubles ou fusibles ou d'une suspension de matières minérales à partir de puits

Abrégé

An underground coal gasification and linkage method comprises the following steps: a) establishing a fire region (4; 21) in a bottom coal layer of a first drill hole (1; 11; 22); b) taking another existing drill hole outside the fire region or a newly drilled drill hole as a second drill hole (2; 13, 14, 15; 23, 24, 25), and mechanically and directionally drilling a nearby coal layer near the bottom of the first drill hole near the fire region through the lower end of the second drill hole, so as to link the nearby coal layer, thereby forming, in the nearby coal layer, a directional passage (5; 17; 27) communicating with the fire region; and c) conveying oxygen-containing gas to the fire region through the second drill hole and the directional passage, and performing hot working on the directional passage, so as to expand the directional passage, thereby forming a gasification passage used for an underground coal gasification furnace.

Classes IPC  ?

• E21B 43/295 - Gazéification de matières minérales, p. ex. pour produire des mélanges de gaz combustibles