150results about "Coal gasification" patented technology

The invention relates to the technical field of underground coal gasification, in particular to a coal underground gasification process stability monitoring and evaluating method which comprises the following steps: determining a space mapping relation between a gasifier temperature field and an acoustic emission event according to the temperature gradient and the acoustic emission event of a gasifier; carrying out three-dimensional inversion on a combustion cavity of the gasification furnace, and determining attenuation trends of the coal seam under different temperature gradients; according to the attenuation trend of the coal seam under different temperature gradients, the propelling direction of the boundary of the combustion cavity is determined by utilizing the spatial distribution density and the relative position of each acoustic emission event; according to the propelling direction of the fuel cavity boundary, boundary moving paths are formed, and the propelling area proportion of each position in the propelling direction is calculated according to the distance difference of the boundary moving paths; and according to the propulsion area proportion of each position in the propulsion direction and the expansion rate of the combustion cavity, determining the space stability classification of each part of the combustion cavity. The accuracy and the efficiency of monitoring underground gasification of the coal seam are realized.

The invention relates to the technical field of coal underground gasification control, in particular to a stable control method for the gasification process of deep coal passing through dirt band. The gas pressure distribution data and the pore change characteristic data of the deep coal gasification area are collected in real time through the distributed sensor array, the gas dynamic correction permeability is generated, the gas injection pressure is adjusted and dynamically corrected according to the gas dynamic correction permeability, and the gas pressure is kept stable; screening a potential risk area through a main stress direction deviation angle and a stress concentration coefficient in the dirt band layer, analyzing a shear stress threshold value of the potential risk area based on a stress-strain coupling model, and judging a stability evaluation index of the potential risk area; and when the stability evaluation index is lower than a threshold value, a multi-stage emergency regulation and control mechanism is triggered, and a dirt band layer reinforcement intervention scheme is generated. By means of multi-source data fusion and a dynamic feedback mechanism, the limitation of a traditional method for lagging response of the instability risk of the dirt band layer is broken through, and full-closed-loop intelligent stable control over the gasification process is achieved.

The invention discloses a coal seam group occurrence three-area linkage gas extraction method. Firstly, a coal seam is divided into an underground coal gasification area, a pressure relief permeability increasing area and an original extraction area; in the initial stage of underground coal gasification, in the process that high-temperature combustible gas generated by underground coal gasification is injected into a ground drilling well, the high-temperature combustible gas and a coal body are subjected to heat transfer, so that the temperature of the coal body is increased, and gas desorption is enhanced; under the continuous coupling action of high temperature and high pressure of the high-temperature combustible gas, the permeability of the coal body is improved; in the process that high-temperature combustible gas is injected into the ground drilling well, gas extraction is continuously conducted on other adjacent drilling holes; under the condition that gas injection and gas extraction are sequentially and circularly performed in ground drilling, the coal body is circularly impacted by positive pressure-negative pressure alternating aerodynamic force, and further fracturing of the coal body is facilitated; under the triple effects of high-temperature coal body gas desorption strengthening, coal body permeability increasing and gas displacement, large-flow and high-quality extraction of deep coal seam gas is finally achieved.

The invention relates to the field of clean energy development and utilization, in particular to an underground coal gasification method with high-temperature steam as a gasifying agent and an experimental device. The method comprises the steps of exploration, well building, permeability increasing, gasification, coal gas utilization and waste treatment, the experimental device comprises a steam generator and a gasification furnace, the steam generator injects high-temperature steam into the gasification furnace, the high-temperature steam is used for coal gasification, in the gasification step, the high-temperature steam is injected into a coal seam, and the high-temperature steam is used for coal gasification. The high-temperature steam serving as a gasifying agent is subjected to a series of reactions with the coal, the high-temperature steam is gasified to generate coal gas through chemical reaction with the coal, and the high-temperature steam is also used for heating the coal to pyrolyze the coal to generate coal gas; according to the method, oxygen is not directly injected into the coal seam, the coal seam is not ignited, and combustion of coal is not involved, but high-temperature steam is injected into the coal seam, the underground coal gasification process is completed through the oxidation-reduction reaction and the distillation pyrolysis action of the high-temperature steam and the coal, and the raw gas is generated.

The invention discloses a coal underground gasification injection-production well pattern determination method, device and equipment and a medium. The method comprises the steps that an injection well site is determined according to a gasification control area of a target reservoir development body, and an injection well bore structure is determined according to injection conditions and coal seam parameters corresponding to the gasification control area; determining a migration path concentration area and an enrichment area of preset generated gas, and determining a production well site according to the migration path concentration area and the enrichment area of the preset generated gas; and according to the injection well site, the injection well body structure and the production well site, coal underground gasification injection-production well pattern distribution of the target reservoir development body is determined. According to the technical scheme, by selecting the proper injection well site, the injection well body structure and the production well site, coal underground gasification injection-production well pattern distribution is determined, coal underground gasification injection-production well pattern deployment is achieved, and the coal seam combustion rate and the preset generated gas recovery rate are increased.

A method for fracturing a subsurface rock formation for hydrogen production includes injecting a fluid comprising water into a subsurface rock formation under controlled conditions, generating fractures in the subsurface rock, and recovering hydrogen gas produced by subsurface rock after the generation of the fractures. The fluid is injected at a pressure below the breakdown pressure of the subsurface rock.

An in-situ large-area drilling and furnace construction method for coal gasification and co-mining of kerosene and / or coalbed methane is provided, which includes: constructing an injection well to the target coal seam and then constructing a horizontal well to divide the target coal seam into sections of coal; extracting coalbed methane; transforming the horizontal wells on both sides of the coal in the first section of coal into coal gasification production wells, and dividing them into intake and exhaust channels; constructing ventilation boreholes to form a “honeycomb shaped” gasifier, which ignites and gasifies to promote the production of combined gases from combustion; after the combustion of first section of coal is completed, continuing to construct the next section of coal and drill holes between adjacent horizontal wells to achieve continuous coal seam combustion and gasification. The method of the present disclosure can improve combustion efficiency and increase kerosene extraction efficiency.

A method of generating biogas is disclosed, including delivering a feedstock downhole to a coal reservoir, generating biogas within the coal reservoir, and harvesting the biogas. The method comprises delivering a feedstock downhole to a coal reservoir via an injection well, generating biogas within the coal reservoir through microbial action, creating a biogas that is isotopically differentiable from a background gas that is native to the coal reservoir, harvesting the biogas at the injection well and one or more offset wells of the coal reservoir, analyzing the biogas and coal bed methane from the coal reservoir at the injection well and at one or more offset wells within the same coal reservoir, detecting the biogas at the offset wells using isotopic differentiation, and mapping the migration of the biogas from the injection well to the offset wells using the biogas as an isotopic tracer.

A method for passively producing hydrogen from a geological formation includes drilling a plurality of lateral wellbores into an iron-rich geological formation from a mother wellbore extending from a surface location. Each of the plurality of lateral wellbores has an inclination along its length of less than 90 degrees. A biocide configured to inactivate hydrogen-consuming microbes is placed into the plurality of lateral wellbores and thereby into formation water that is flowed from the geological formation into the plurality of wellbores. Hydrogen gas effervesced from the formation water in the plurality of lateral wellbores is collected via the mother wellbore. The hydrogen gas is generated at least in part from a water reduction reaction of minerals of the geological formation with the formation water and risen through the plurality of lateral wellbores passively by buoyancy effects without pumping.

The application discloses a coal drilling type coal underground gasification furnace, a gasification furnace construction method and a coal seam gasification method. A gas outlet well is connected with a gas injection well through a horizontal section at the top of a coal seam to form a U-shaped gasification furnace structure. The coal seam is excavated at the joint of the gas injection well, so that the coal seam collapses, stress is redistributed, the cavity is enlarged, the coal seam below the pocket section of the gas injection well is ignited, the coal seam is positively advanced, and the effective synthesis gas is discharged to the ground through the gas outlet well. The application can well develop and utilize tectonic coal, and has the advantages of environmental protection, safety and good economic benefits.

The present invention belongs to, but is not limited to, the technical field of underground coal gasification, and discloses an underground coal gasification method and gas injection equipment; constructs a directional borehole and a gasification channel that penetrates an underground coal seam; lowers a gas injection pipe carrying a plasma torch into the gasification channel and injects a gasifying agent to implement in-situ gasification of the underground coal seam; and the generated coal gas is transported to the surface through the borehole for collection. The underground coal gasification method and gas injection equipment proposed by the present invention activate the gasifying agent through multiple plasma torches built into the directional channel at the end of the gas injection pipe and then directionally injects it into the coal seam. The gasifying agent contacts and gasifies the coal seam in a relatively short period of time, thereby achieving directional transportation of the plasma gasifying agent and improving the effective utilization rate of the plasma gasifying agent, thereby increasing the effective component content of the coal gas. At the same time, the combustion zone of the coal seam after gasification will expand in a fan-shaped manner longitudinally with the gasifying agent outlet of each plasma torch as the center. The expansion equivalent radius of the combustion zone is relatively large, and a single gasification channel can gasify a large amount of coal.

The invention discloses coal underground gasification simulation experiment equipment and method.The equipment comprises a screening mechanism, the screening mechanism comprises a screening shell and screening assemblies, a plurality of sliding grooves are obliquely formed in the screening shell in the vertical direction, and the screening assemblies are slidably arranged in the sliding grooves; a feeding port is formed in the top of the screening shell, a first material guiding plate is obliquely and fixedly arranged at the feeding port, a plurality of material conveying plates are obliquely and fixedly arranged in the screening shell in the vertical direction, the screening assembly comprises two arc-shaped screening bases, a first screening net, a second screening net and a material pushing assembly, and the screening bases are arranged in the screening shell. Supporting plates are fixedly arranged on the screening bases in an inclined mode, a first screening net is fixedly arranged between the two supporting plates, an arc-shaped second screening net and an arc-shaped check ring are fixedly arranged between the two screening bases, two openings are formed between the arc-shaped check ring and the second screening net, and the material pushing assembly is rotationally arranged on the screening bases.

Injecting CO2 that is diluted within water, into a coal seam, which allows for the sequestering and control of downhole CO2 within connected fractures without damaging the subterranean formation.

The invention relates to the technical field of underground coal gasification gas purification, in particular to an efficient gas filtering device for an underground coal gasification curve type production well, which comprises a conveying channel, a gas inlet channel, a gas outlet channel and a gas outlet channel, the first bend is used for connecting the inlet channel and the connecting channel, and a plurality of first spiral ribs which are spirally arranged are arranged in the first bend; the second bend is used for connecting the connecting channel and the discharging channel, and a plurality of second spiral ribs which are spirally arranged are arranged in the second bend; according to the fine filtration unit, the separation efficiency can be improved by utilizing the characteristics of a curve flow field, large impurities are subjected to pre-separation treatment through centrifugal force generated by airflow steering, the service cycle and the service life of the fine filtration unit can be prolonged, the cleaning frequency can be reduced, and the blocking cycle can be prolonged.

The invention discloses a coal underground gasification strengthening method which comprises the following steps: step 1, drilling a U-shaped well of which the horizontal section is positioned in a coal seam at a target coal seam, respectively arranging an injection well and a production well at two ends of the U-shaped well, and putting a multi-channel continuous pipe into the horizontal section through the injection well; 2, oxygen, fuel and an ignition agent are injected into the horizontal section through the multi-channel continuous pipe to ignite the coal seam, then oxygen and a gasification agent are continuously injected through the multi-channel continuous pipe to enable the coal seam to be gasified to generate raw gas, and a gasification cavity is formed in the coal seam in the gasification process; 3, fuel and oxygen are injected into the newly-formed gasification cavity through the multi-channel continuous pipe, combustible gas cloud is formed at an outlet by the fuel and the oxygen, then the combustible gas cloud is ignited through an ignition agent sprayed out of the multi-channel continuous pipe for deflagration, and raw gas is produced; step 4; repeating the step 3 until the gasification of the cavity body of the gasification cavity is completed; and 5, the multi-channel continuous pipe is dragged to retreat, the steps 2-4 are repeated till gasification transformation of the whole coal seam is completed, and the gasification efficiency is high.

The invention discloses a simulation device for oil-rich coal in-situ negative pressure pyrolysis and oil gas collection, and aims to solve the problem that multi-condition synergistic effect is not considered in oil-rich coal pyrolysis in an existing laboratory. The system comprises a pyrolysis system, an environment and pressure supply system, a condensed oil gas extraction system, a gas extraction system and a tar quality analysis system, the pyrolysis system comprises a pyrolysis cabin, a heating system is arranged in the pyrolysis cabin, the environment and pressure supply system comprises an atmosphere environment supply system and an in-situ pressure supply system, the condensed oil gas extraction system comprises an oil gas collection assembly, the gas extraction system comprises a gas analyzer and a negative pressure extraction assembly, and the tar quality analysis system comprises a rotary evaporator. The heating system, the atmosphere environment supply system, the in-situ pressure supply system, the oil gas collection assembly, the gas analyzer and the rotary evaporator are all connected with the control terminal. The simulation of the pyrolysis process of the oil-rich coal under the multi-condition synergistic effect is realized by constructing multi-condition coupling oil-rich coal pyrolysis characteristic monitoring.

A process includes identifying a hydrocarbon-bearing reservoir containing a hydrocarbon fluid and a brine having a sufficient salinity level to prevent or inhibit one or more of methanogenesis and sulphate-reduction activity, and responsive to a concentration of hydrogen being below 1000 parts per million in a sample collected from the hydrocarbon-bearing reservoir, introducing at least one non-native or indigenous hydrogen producing microorganism or stimulating the activity of at least one indigenous bacteria capable of stimulating a microbial consortium to increase a production rate of hydrogen in the hydrocarbon-bearing reservoir.

The invention provides a spontaneous heating composite synergist as well as a preparation method and application thereof. The spontaneous heating composite synergist is prepared from the following components in parts by weight: 20 to 40 parts of a component A, 20 to 40 parts of a component B and 30 to 40 parts of a component C, wherein the component A comprises an alkali metal salt inner core and a first silane coupling agent and aluminate coupling agent composite shell layer which coats the outer surface of the alkali metal salt inner core through chemical bonds; the component B comprises an alkaline earth metal oxide core and a second silane coupling agent shell layer which coats the outer surface of the alkaline earth metal oxide core through a chemical bond; and the component C comprises an active metal core and a third silane coupling agent shell layer coated on the outer surface of the active metal core through a chemical bond. The self-heating composite synergist is subsequently applied to in-situ gasification, in-situ dry distillation, superheated steam gasification and supercritical water gasification of deep coal and has a relatively good heat-increasing synergistic effect.

The utility model relates to a combustion head assembly and a coiled tubing, the combustion head assembly comprises a combustion head, the combustion head is provided with a combustion-supporting channel used for conveying combustion-supporting gas, the combustion head is provided with an oxygen channel used for conveying oxygen, and the combustion head is provided with an electric ignition device; the protective cover comprises a cover body, the cover body is arranged at the end, provided with the electric ignition device, of the combustion head, the cover body is provided with a containing space used for containing the electric ignition device, and the cover body is provided with a first hole communicated with the containing space. The protective cover can prevent the electric ignition device of the combustion head from being damaged by the impact force of the sleeve, the first hole is formed in the cover body, it can be ensured that combustion-supporting gas is released to an underground gasification reaction area through the first hole, meanwhile, the gas can be prevented from being ignited in a sealed environment to cause explosion, and the safety of the combustion process is improved.

The application discloses a V-shaped tunnel underground in-situ gasification coupled power generation system, and relates to the technical field of coal underground gasification, in-situ combustion and clean energy power generation. The system is composed of an oxygen-enriched air separation unit, a vertical injection unit, a capillary pore network and a V-shaped tunnel gasification power generation unit, adopts a V-shaped shield tunnel with a concrete tile and an S32001 stainless steel composite lining to build an underground gasification area; high-pressure water and oxygen-enriched air are deeply injected into the capillary pores at a spacing of 50-200 meters through a branch pipe for multi-point injection, and synthesis gas is generated by underground high-temperature self-gasification; the synthesis gas drives a steam turbine to generate power, the gasification waste heat is recycled to increase efficiency, and slag is pumped under negative pressure to prevent blockage. The application realizes the integration of underground gasification and power generation, is stable and efficient, does not need large ground equipment, has a high coal utilization rate, is suitable for large-scale clean power generation of low-rank coal, and has industrial popularization value.

The application discloses a kind of close distance thin coal seam fluidized mining protective layer pressure relief and penetration enhancement method, it is related to coal mining technical field, including the following steps: arrangement and support structure installation;Thin coal seam coal body is ignited by ignition circuit with protection tube;Through oxygen inlet pipe input oxygen and pass through oxygen concentration sensor control air intake, promote coal body to generate carbon monoxide and hydrogen by oxidation-reduction reaction;Using air extraction pipe, air extraction control valve and generated gas detection end extract and monitor combustible gas;The cavity formed after thin coal seam reaction provides pressure relief and penetration enhancement space for lower thick coal seam.The application uses the above-mentioned close distance thin coal seam fluidized mining protective layer pressure relief and penetration enhancement method, with operation safety controllable, resource utilization rate is high, pressure relief effect is remarkable and the like advantage, it is applicable to the efficient utilization of close distance thin coal seam and the pretreatment before thick coal seam mining.

The present invention discloses a deep coal supercritical water forward gasification method, comprising the following steps: injecting fracturing fluid from an injection well and creating a negative pressure in a production well, so that under the guidance of the negative pressure of the production well, the fracturing fluid fractures the coal seam to form a communication fracture network between the output section of the injection well and the input section of the production well; injecting supercritical water from the injection well into the coal seam to heat up a portion of the coal body of the coal seam; injecting oxygen from the injection well into the coal seam to cause an oxidation reaction between a portion of the coal body of the coal seam and the oxygen, thereby heating the portion of the coal body of the coal seam and the oxygen, and then a redox reaction occurs between a portion of the coal body of the coal seam and the supercritical water and oxygen to form a reaction zone of the coal seam and generate gas; the gas enters the production well through the communication fracture network and is produced through the production well; and alternately injecting supercritical water and oxygen until the reaction zone of the coal seam is gradually advanced from the output section of the injection well through the communication fracture network to the input section of the production well. The present invention can improve the gas capture efficiency, the total gas production volume, and the resource utilization rate of the coal seam.

This invention relates to a method for deep underground coal gasification, comprising: drilling a plurality of gasification wells within a block, the wells being arranged in three rows from the edge of the block to fracturing the bottommost coal seam; the first gasification well being an injection well and the second gasification well being a production well, gasifying the bottommost coal seam between the first row and the second gasification well; when the high-temperature gasification zone of the gasified coal seam extends to the front of the gas cooling zone, the second gasification well is shut down, and the third gasification well is used as a production well to continue gasifying the coal seam; simultaneously, a fourth gasification well is drilled; after the coal seam is completely gasified, the bottommost coal seam between the second row and the third gasification well is gasified again, and so on, gasifying the bottommost coal seam between each gasification well; simultaneously, cement slurry is injected into the first gasification well to fill the gasified goaf; and so on, filling the goaf between each gasification well; and then, following the above method, each coal seam is gasified and filled sequentially from bottom to top.

The invention discloses a method and system for increasing yield of hydrogen through coal underground gasification development, and relates to the technical field of coal underground gasification development. The method comprises the following steps that a water injection well, an oxidizing agent injection well and a production well are formed in an area with a coal layer; the underground coal layer is ignited through the oxidizing agent injection well, and a cavity is formed in the coal layer; injecting water vapor into the cavity through the water injection well; and monitoring the content of hydrogen produced by the production well, and when the daily hydrogen production has an obvious decreasing trend, controlling the end, located in the cavity, of the water injection well to move upwards and backwards, so that the end, located in the cavity, of the water injection well moves to the outer boundary area of the cavity. When the hydrogen production rate is detected to be reduced, the water injection retraction operation is performed, so that the water injection point is aligned with the boundary of the current underground coal layer, the gasification reaction with water is recovered, and the yield of H2 is increased.

The present application relates to the technical field of coal mining, in particular to a coal mine intelligent collaborative mining system and method based on plasma technology. The system comprises an intelligent master control hub, a shared support module, a plasma rock breaking and tunneling device, a gas extraction and permeability improvement assembly, a non-pillar mining-high energy ion gasification assembly, and a global safety protection system. The present application builds an integrated collaborative architecture of "intelligent master control hub + shared support module + three major functional execution systems", fundamentally overcoming the fundamental defects of traditional technology and existing plasma research "single-point breakthrough, difficult to collaborate", realizing the transition from "equipment integration" to "system intelligence", and through multi-dimensional monitoring network, the physical field, gas concentration and structural stress are monitored at millisecond level, breaking through the limitations of each link of traditional coal mining, realizing a safe, efficient and green mining mode, the method is safer, more uniform and more durable, and has a wide application prospect.

The application discloses a multi-working mode coordinated exploitation well pattern and an exploitation method thereof, and belongs to the technical field of coal bed gas exploitation. The exploitation well pattern comprises a first horizontal well and a second horizontal well, the first horizontal well and the second horizontal well form a communication channel in a target coal bed, and the communication channel is used for selectively accelerating extraction of coal bed gas or serving as a reaction channel for underground coal gasification; and the exploitation well pattern further comprises a multifunctional well, which is communicated with the communication channel. The application constructs a multi-working mode coordinated exploitation well pattern of "double horizontal wells + multifunctional well", realizes the collection of monitoring production parameters, gas production and extraction, injection of carbon dioxide reaction slurry and solidifying fluid in the multifunctional well, realizes the cooperation of CO2 filling, reinforcement, sealing and storage, and solves the problems of lack of special carbon storage channels and difficulty in multi-technology cooperation in the prior art.

A combustible ice mining automatic anti-blocking ball valve with an optical fiber sensing and intelligent alcohol injection system comprises a valve body provided with a medium channel and a valve cavity, and a ball body and a valve seat which are located in the valve cavity. The optical fiber sensing network is embedded in the inner wall of the valve body; the alcohol injection actuating mechanism comprises a plurality of groups of independent and controllable alcohol injection nozzles arranged in the valve body, and the alcohol injection nozzles respectively point to the upstream and the downstream of the valve seat; the intelligent control terminal is electrically connected with the optical fiber sensing network and the alcohol injection executing mechanism respectively; the intelligent control terminal comprises a data reconstruction module, a state identification module and a strategy execution module; the data reconstruction module is used for demodulating optical signals fed back by the optical fiber sensing network and mapping the optical signals into a real-time three-dimensional temperature field cloud picture and a local strain distribution picture in the valve cavity; and the state identification module is used for outputting a state instruction for representing the generation position and the growth stage of the hydrate based on the coupling relationship between the spatial and temporal change characteristics of the three-dimensional temperature field cloud picture and the local strain distribution diagram.

The utility model relates to the technical field of treatment systems for the content of CO and H2 in coal gasification gas, in particular to a post-treatment system for improving the content of CO and H2 in coal gasification gas. According to the technical scheme, the post-treatment system for increasing the content of CO and H2 in the coal gasification gas comprises a high-temperature pure oxygen non-catalytic partial oxidation reaction module, according to the utility model, the non-catalytic partial oxidation reaction equipment and the heat recovery equipment are arranged, so that the process flow of purifying the underground coal gasification product gas is greatly simplified, and the product gas can be subjected to primary purification and heat recovery; the technical process of the product gas purification treatment device matched with the underground coal gasification device is more economical and reasonable, the advantages of reliability and low cost of the underground coal gasification technology are fully played, the problems existing in the existing underground coal gasification technology are solved, CH4 in coal gas is cracked, CO and H2 are generated, and the product gas purification treatment device is more environmentally friendly. And the content of effective components in the coal gas is increased.

The invention belongs to the technical field of coal mining, and discloses a coal underground gasification filling method. After gasification is started, a set filling signal is judged according to the total volume content of effective components of gas at a gas outlet hole, the yield in unit time or a cavity volume expected value of a combustion space area; filling slurry is injected into the combustion space area through the gasifying agent injection hole, the gasifying mode is switched into the filling mode in real time or step by step, and gas production of the gas outlet hole is kept; whether an expected filling target is achieved or not is judged by monitoring the temperature, the effective component content or the gas production rate of gas produced by a gas outlet hole in real time or monitoring whether the maximum filling amount of single filling is achieved or not in real time; after the expected filling target is achieved, the filling mode is switched into the gasification mode in real time or step by step; and repeating the steps until the gasification coal seam is completely mined. According to the method, gasification and filling are combined, the coal recovery rate is increased, the combustion space area is filled in time, and geological environment damage possibly existing in the large combustion space area or occurring in the future is eliminated.

The invention provides an underground coal gasification device and an underground coal gasification method, and relates to the technical field of underground coal gasification production. The underground coal gasification device comprises a sleeve and a return operation mechanism. The horizontal section of the well body is located on a coal seam. The well body has an injection end and a production end. The retreating operation mechanism comprises a perforator and a dry distiller which can retreat in the first direction and move synchronously. The perforator is located in the casing pipe and comprises perforating bullets capable of being emitted outwards in the radial direction of the casing pipe so that through holes can be formed in the casing pipe. The dry distiller is located on the side, facing the production end, of the perforator, the dry distiller is provided with a first position located in the coal seam open hole and a second position located in the casing pipe, when the dry distiller is located at the first position, the dry distiller conducts dry distillation modification on the coal seam open hole, and when the dry distiller is located at the second position, the dry distiller corresponds to the through hole. The underground coal gasification device can solve the problems that ignition is difficult due to coal seam water vapor, coal is easy to extinguish during combustion, and the conversion efficiency of raw gas is low.