228 results about "Underground coal gasification" patented technology

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.

A passage formation method for underground coal gasification is provided. The method comprises the following steps of: (a) building a fire area in the bottom coal bed of a first bore hole; (b) performing mechanical and directional drilling operation in a neighbor coal bed close to the bottom of the first bore hole in the vicinity of the fire area through the lower end of a second bore hole which is another existing bore hole or a newly-drilled bore hole outside the fire area, so as to pre-penetrate the neighbor coal bed and thus to form a directional passage communicated with the fire area in the neighbor coal bed; and (c) delivering an oxygen-containing gas to the fire area through the second bore hole and the directional passage, and thermally processing the directional passage to enlarge the directional passage and thus to form a gasification passage used for a underground coal gasification furnace.

A coal gasification process of coal bed deep underneath includes a gasification furnace in the coal bed, a gas let in canal linking one end of the furnace to ground, a gas let out canal linking the other end of the furnace to ground. Gas generated by coal burning in the furnace is collected. A drain system links a drain outlet over 10 meters below the furnace to the ground.

The invention proposes a novel underground coal gasification furnace which is particularly suitable for the gasification of a coalbed containing water. An underground gasification furnace and a coalbed drainage passage integrated with each other are simultaneously constructed through a coalbed directional drilling process. The coalbed drainage passage can be effectively used for the coalbed drainage before gasification and the furnace body drainage during gasification, thereby ensuring the discharge of the water in the coalbed and consequently realizing the stable gasification of the coalbed containing water. The furnace has the advantages that the composite underground gasification furnace and the drainage passage are simultaneously constructed through the advanced coalbed directional drilling process, thereby bringing about easy execution and short construction period; as the drainage passage is positioned below the gasification passage, the drainage is smooth, and the problem of blockage does not easily happen; and the water in the drainage passage can be pumped out from a plurality of orientations, thereby bringing about rapid drainage. According to the requirements of furnace body drainage, the drainage holes of the gasification passage can be increased flexibly, thereby substantially solving the drainage problem of the coalbed containing water, and avoiding the impact of coalbed water inrush on coalbed gasification.

The invention discloses a poly-generation system of underground coal gasification (UCG) and a method thereof. .The system comprises a UCG subsystem, a thermal value and component regulation subsystem and a chemical production system; the UCG subsystem is used for injecting gasification agent into a gasification tunnel after gasification fire so that the gasification agent conducts gasification reaction with a coal bed in the gasification tunnel to generate synthesis gas; crude synthesis gas is led into the thermal value and component regulation subsystem; the thermal value and component regulation subsystem is used for reintegrating the component and thermal value of the synthesis gas and sending the reintegrated synthesis gas into the chemical production system as feed gas; the chemical production system is used for producing chemical products by utilizing the synthesis gas sent by the thermal value and component regulation subsystem. By adopting the method and system provided by the invention, coal gasification poly-generation process can be completed under the condition of energy saving and environmental protection.

An underground coal gasification method. The method comprises disposing multiple injection wells (3) and gas collection wells (4) in a gasification operation zone; adding a catalyst and a propping agent into injection wells and gas collection wells by means of a fluid medium; fracturing and reforming the coal layer using a fracturing device to form large areas of fissures and cracks; forming gasification paths in the form of directional wells between the injection wells and gas collection wells; adding a gasification agent, a catalyst, and water through the injection wells to cause coal layer combustions and chemical reactions; collecting at the gas collection wells the gas produced by means of collection devices. The fissure paths between the wells formed by reforming large fractures, and the metal mineral particles used as a propping agent for the paths between wells effectively enable the maintenance of the effective communication in the injection well network for long durations; the metal mineral particles also function as a catalyst and an aggregating agent during gasification, thereby substantially enhancing the coal gasification volume.

The invention relates to an underground coal gasification system and a production process thereof. The system comprises an air course and a gas transmission course which are arranged in a coal seam, a plurality of gasification channels are arranged in the coal seam, the two mutually parallel ends of each gasification channel respectively communicate with the air course and the gas transmission course, and a water drainage closed wall is arranged in the gas transmission course; and the both ends of the air course are respectively connected with an intake airway and a return airway of a mine system. The gasification process comprises the following steps: igniting; judging whether the burning point is required to be moved forward; moving the burning point of the coal seam backwards; plugging a gas passage of a combustion-supporting gas injection branch pipe which is disabled, and filling a burning control area with paste. The coal underground gasification system and the production process have the advantages that the coal seam can be mined to the utmost extent; the leakage of the combustion-supporting gas to the burning control area can be thoroughly cut off when the secure retraction during the coal underground gasification process is realized; the problem that the gasification agent is short-circuited because a passage is formed due to the collapsing of the coal seam floors in the gasification channel and the earlier period gasification area can be solved in the later period of the underground coal gasification, the gas production is secure and reliable, and the gasification rate is high.

The invention discloses a test device and a test method for simulating in-situ underground coal gasification. The test device comprises a gasifying furnace body, a top cover, a furnace wall injection pipe, a furnace wall exhaust pipe, a gasifying agent preparing unit, an injection pipeline, an exhaust pipeline, a gas flow meter, a gas pressure meter, a gas temperature measuring thermocouple, a gas purifying unit, a gas dispersing unit, an inside-furnace temperature monitoring unit, a gas chromatograph, an igniter, a displacement meter, a filling unit and a computer, wherein the outer shape of the gasifying furnace is cylindrical; the wall of the gasifying furnace comprises a steel plate, a common brick layer, an insulation material, a water jacket layer and a refractory brick layer from outside to inside sequentially, The test device is reasonable in structure and multifunctional, and can utilize instruments to objectively and actually measure temperature fields in a coal seam and a roof rock stratum, gasifying agent ratio and gas production index parameters, overlaying rock movement and ground surface subsidence parameters, and gasifying furnace cavity-growth characteristic parameters, and facilitate research on furnace structure parameters and a gasifying process, so as to determine in-situ underground coal gasification process parameters and an in-situ underground coal gasification production scheme, which are suitable for on-site conditions.

The invention discloses a coal underground gasification combustion space area mapping system and a mapping method thereof and belongs to the technical field of mine surveying and mapping. According to the coal underground gasification combustion space area mapping system and the mapping method thereof, a driving device is utilized to push a 3D laser scanner, a dual camera sensor and an industrial endoscope into combustion space areas through vertical holes, the combustion space area near each vertical hole are scanned through laser, laser collection, data transmission of an industrial switch and imaging of a graphic workstation are performed through the dual camera sensor, so that the mapping of internal shapes of the combustion space areas is completed, actual shapes of the combustion space areas inside a coal seam are learnt about visually, various technical parameters of a well drilling type underground coal gasification technology are checked, and theoretical support is provided for stability and continuity in the underground coal gasification process.

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).

The invention relates to the field of underground coal gasification, in particular to a technique for monitoring the combustion state of an underground coal gasification furnace. The invention provides system, device and method for identifying the combustion state of an underground coal gasification furnace. The method comprises the following steps: arranging detection points in the ground surface exploration range of the underground coal gasification furnace; collecting radon gas at the detection points and carrying out temperature measurement at a certain number of determined underground detection points; determining an underground temperature field according to the collected radon gas and the measured temperature so as to identify the combustion state of the underground coal gasification furnace. Because the radon gas is collected at the ground surface of the underground coal gasification furnace, the underground temperature field is identified according to the radon gas collected at the detection points and the underground temperature of at least one detection point, and the underground temperature field directly reflects the combustion state of the underground coal gasification furnace, therefore, the invention is more accurate compared with the prior art which conjectures the combustion state of the underground coal gasification furnace by parameters of syngas.

Disclosed is a gasification furnace for the gasification pilot plant test of underground coal and the process thereof. The equipment of the process comprises a gas supply system, a gasification furnace, a temperature measuring pressure measuring and ingredient detecting system, a high temperature shooting system and a gas purifying system. The gasification furnace has a refractory material inner liner in the housing, has a grouting hole on the housing for performing seal to the coal bodies inside the furnace, and can perform gasification test in high temperature high pressure condition. The furnace body is formed with a gasifying agents and water-gas input/output hole, a grouting hole, a cooling water input/output hole, a temperature/pressure/ingredient measuring auxiliary hole, a high temperature shooting system viewing hole, a resistor method measuring hole and a manhole. The invention fully considers the pressurized condition in the underground coal gasification process, meets the requirement of gasification pressuring to coal in the pilot plant test, can investigate the technological experiment of normal/high pressure underground coal gasification and combustion point returning. The gasification furnace is equipped with a plurality of temperature measuring, pressure measuring and gas ingredient measuring systems and high temperature visual monitoring systems, can perform on-line monitoring and real time control to various parameters in the pilot plant test process.

The invention discloses a movable ignition system for UCG (underground coal gasification), which comprises a movable ignition device, an overground gas supply system and a gas feeding pipe, wherein the movable ignition device is arranged on underground coal; the overground gas supply system is connected with the ignition device through a gas pipeline, and is used for supplying ignition gas for the ignition device from the ground through the gas pipeline; and the gas feeding pipe passes through a coal bed and communicates the underground coal with the overground coal, and is used for providing ignition air or oxygen for the underground coal from the ground. The ignition system disclosed by the invention can overcome a defect that a traditional igniter can not carry out secondary ignition quickly when a flameout phenomenon occurs in the process of gasification, and can move arbitrarily according to the needs of ignition in the process of gasification, thereby guaranteeing the continuity and timeliness of an ignition process, and saving time and labor; the movable ignition system can enlarge the scale of a gasification furnace, reduce the number of drilled wells, lower the production cost, and improve the production progress; especially for the underground gasification of deep and ultra-deep coal, the ignition system can significantly lower the operation cost; and due to a single gas pipeline design, the ignition process is safer, and the explosion hazard is reduced.

The invention belongs to the field of carbon dioxide emission reduction and carbon dioxide conversion, and relates to a method for converting greenhouse gases into high value-added CH4 and CO. The invention is characterized in that media block electric discharge to activate CO2 and H2 molecules and form uniformly distributed nonequilibrium plasmas, hydrogenation is carried out on activated species on a catalyst arranged in a plasma reactor, and CH4, CO, CH4 and CO mixtures are selectively generated; and the proportion of reaction gases of CO2 and H2 is not fixed. The method can convert the greenhouse gas CO2 into high value-added CH4 and CO. The method does not have special requirements or limits on the source and composition of the gas, thereby having universality on CO2 and H2 gases with various components. The technical method can be applied to the hydro-conversion of CO2 with high concentration, and can also be used for the hydro-conversion of CO2 in industrial gasses with low concentration and underground coal gasified gas.

The invention provides an underground coal gasification system and a gasification method. The underground coal gasification system comprises a first channel located in a coal bed, and a second channel, wherein the two ends of the first channel are communicated with a gas outlet hole and a via hole respectively; the two ends of the second channel are communicated with the via hole and a directional hole respectively; a combustion improver is supplied by the directional hole; the second channel forms a reverse penetration area; a gasification agent is supplied by the via hole; and the first channel forms a forward gasification area. The invention aims at providing the underground coal gasification system and the gasification method which can synchronize a reverse penetration process and a forward gasification process.

The invention belongs to the technical field of underground coal gasification, and particularly relates to a method for underground coal gasification for gasifier channel establishment. A main injection hole, an auxiliary injection hole, a main air outlet, an auxiliary air outlet, a water discharging hole, a crushing zone, horizontal holes, a hole packer and a temperature and pressure monitoring instrument are involved in the method. The ground coal mine face serves as a base point, the injection holes and the air outlets are arranged in a line, and the alignment direction of the injection holes and the air outlets is identical to that of the underground horizontal holes. A gasifier channel is formed through the method that underground drilled holes are in butt joint with the coal bed sections of the ground injection holes. The method has the advantages of being low in cost, high in success rate of butt joint, and particularly suitable for abandoned mines without economic exploitation value.

The invention belongs to the field of coal-bed gas exploration and development, and in particular relates to a coal-bed gas thermal cavity completion method, which comprises the following steps of: (1) performing high temperature resistant cement casing cementation on the top of a coal bed; (2) drilling to a position 50 to 80 meters lower than the coal bed, and performing hole enlargement completion on a coal bed section; (3) removing coal dust from a shaft; (4) descending a thermal completion combination stem to the middle of a cavity; (5) injecting silane and oxygen, beginning combusting on the cavity part, and heating the coal bed; (6) when the temperature is higher than 600DEG C, determining whether to stop supplying the silane according to a component detection result of flow-back gas; and (7) when the temperature is raised to 1,500DEG C, stopping supplying the oxygen. By the method, the cavity completion is performed under the thermal condition, the coal bed around the shaft is stable and difficult to collapse, the ignition is simple and easy to control, and the method can be used for blind hole type underground coal gasification.

The invention discloses a method for increasing coalbed methane by waste heat in underground coal gasification process. The method comprises the following steps that S1, a gas injection well and a gasproduction well are driven to a target coal seam of underground coal gasification from the ground, so that a U-shaped well is formed; S2, a horizontal well section of a coalbed methane well and the space of a gasification channel of underground coal gasification form an X-shape intersection; S3, an auxiliary device of underground coal gasification is installed at the tail end of the gas injectionwell; S4, nearby coal can be heated by the high temperature produced by the combustion of the coal; S5, an air pumping device is installed at the ground end of the gas production well; S6, the heat is transferred to a coalbed gas production coal seam for heating by high-temperature airflow in a radiation and heat conduction mode, and the desorption rate of the coalbed gas is improved; and S7, thecoalbed gas is discharged from the coalbed gas well. According to the using method, heat generated in the underground coal gasification process can be reasonably utilized, and a large amount of energy consumption in the coalbed gas heat injection development process is reduced.

The invention discloses a method, a device and a system for determining internal combustion mined-out areas of an underground coal gasification furnace. The method includes acquiring a preset temperature equivalent line of the underground coal gasification furnace at a current moment according to acquired real-time concentration of earth-surface radioactive substances above the underground coal gasification furnace; acquiring a quantity of preset gas outputted by the underground coal gasification furnace; determining the internal combustion mined-out areas in preset states in the underground coal gasification furnace at the current moment according to the acquired preset temperature equivalent line and the acquired quantity of the preset gas. The quantity of the preset gas refers to the quantity of the preset gas outputted by the underground coal gasification furnace in a period from an initial moment to the current moment, the initial moment is a moment when the requirement of a preset temperature is met, and the preset gas is gas generated by the internal combustion mined-out areas in the preset states in the underground coal gasification furnace. The method, the device and the system have the advantage that the ranges and propagation rules of the internal combustion mined-out areas of the underground coal gasification furnace can be monitored in real time.

The invention relates to a cement composition, which comprises oil well cement, a heat stabilizer and a lightening agent. Taking the amount of the oil well cement as 100 weight portions, the content of the heat stabilizer is 10-50 weight portions, and the content of the lightening agent is 10-30 weight portions. Based on the total weight of the heat stabilizer, the heat stabilizer comprises 40-60 percent of 100-160-mesh quartz sand by weight and 40-60 percent of 180-250-mesh quartz sand by weight. The invention also relates to an application of the composition in production of an underground coal gasification furnace. The cement stone prepared with the cement composition has good resistance against high temperature. Moreover, the underground coal gasification furnace produced with the cement composition has long service life.

The invention relates to a detecting and controlling method for coal underground gasification indicating gas that belongs to underground coal developing. The invention supplies an enforceable controlling method for coal underground gasification producing. And a new aspect is supplied for the developing of coal industry.

The invention discloses a method for guiding the layout of gasification furnaces for underground coal gasification and determining the directions of main fractures in underground coal beds. The method comprises the following steps: drilling a central hole above the reserving area of an underground coal bed; drilling a plurality of surrounding holes on a circular layout line centering on the central hole; inputting pressurized air from the central hole to the underground coal bed so as to carry out high-pressure air fracturing; monitoring and determining the flow and components of gas discharged from each surrounding hole; carrying out comparison on the determined flow of each discharged gas, determining the position of a first surrounding hole with the largest flow of discharged gas, and determining the position of a second surrounding hole with the second-largest flow of discharged gas; and according to a formula provided by the invention, carrying out calculation on the angles of the main fractures. The practical and economical method provided by the invention can be used for shortening the breakthrough time for underground coal-bed gasification, and reducing the breakthrough difficulty of underground coal-bed gasification.