636results about "Coal gasification" patented technology

A method of recovering hydrocarbons from hydrocarbonaceous materials can include forming a constructed permeability control infrastructure. This constructed infrastructure defines a substantially encapsulated volume. A comminuted hydrocarbonaceous material can be introduced into the control infrastructure to form a permeable body of hydrocarbonaceous material. The permeable body can be heated sufficient to remove hydrocarbons therefrom. During heating the hydrocarbonaceous material is substantially stationary as the constructed infrastructure is a fixed structure. Removed hydrocarbons can be collected for further processing, use in the process, and/or use as recovered.

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.

The invention discloses a method and device for exploiting aquo-complex through the combination of the pressure reducing technology and the hydraulic fracturing technology. Double pitshaft sleeve tubular columns are designed. An outer pitshaft tubular column is used for exploiting natural gas aquo-complex from storage layers in the mode of reducing pressure and pumping gas. Various sensors are arranged at the bottom of an inner pitshaft tubular column and are used for detecting and monitoring conditions of the storage layers. Meanwhile, fracturing liquid is injected into the storage layers according to actual requirements, and manual hydraulic fracturing operation is conducted, so that the permeability of the storage layers is improved, and fluid smoothly flowing through channels and smooth conduction of pressure reduction and gas exploitation are ensured. The method comprises the steps of constructing an exploiting well, and arranging the double pitshaft sleeve tubular columns and relevant exploiting and monitoring devices; reducing pressure of natural gas aquo-complex and decomposing the natural gas aquo-complex; monitoring storage layer information, and utilizing the hydraulic fracturing technology to ensure the permeability of the storage layers; collecting and outputting natural gas and water. The method and device integrate the advantages of the pressure reducing technology and the advantages of the hydraulic fracturing technology, can be used for exploiting natural gas aquo-complex resources and can grasp and feed back storage layer change information at the same time so as to achieve the purpose of economic, efficient and safe commercial exploitation of natural gas aquo-complex resources.

Methods for assessing a temperature in an opening in a subsurface formation are described herein. A method may include assessing one or more dielectric properties along a length of an insulated conductor located in the opening and assessing one or more temperatures along the length of the insulated conductor based on the one or more assessed dielectric properties.

The invention is a continuous process for producing methane from an underground coal bed or an above ground carbon-containing resource using hydrogen as a recycling working fluid. For an underground coal seam, the process includes injecting (220) hydrogen into the coal seam to form a reaction effluent of methane, hydrogen and carbon monoxide; extracting the reaction effluent (230) for processing above ground; cleaning the reaction effluent (120); cooling the cleaned reaction effluent (130) and processing it through a water gas shift reactor (140); separating (150) hydrogen, methane, and carbon dioxide into separate streams; producing the carbon dioxide stream (160) as a product gas; processing a first portion (170) of the methane stream in a steam reformer, water gas shift reactor and gas separator (180) to produce segregated flows of hydrogen and carbon dioxide, combining the segregated hydrogen flow with the separated hydrogen stream (190); heating and repressurizing (200) the combined hydrogen stream to the temperature and pressure of the hydrogen in the first step; producing a second portion (210) of said methane stream as a product gas; and injecting (220) the combined hydrogen stream into the underground coal bed to continue the process.

Disclosed are methods for solution mining of evaporite minerals, such as trona, comprising drilling an access well and at least two lateral boreholes; injecting a fluid; circulating the fluid through the lateral boreholes with a controlled fluid flow; and collecting a pregnant solution. Also disclosed are methods of solution mining that include injecting an aqueous solution into an underground trona cavity at a temperature sufficient to maintain at least a portion of the solution in the cavity in the Wegscheiderite solid phase region; removing aqueous solution from the cavity; and recovering alkaline values from the removed aqueous solution. Also disclosed are methods of solution mining that include injecting an aqueous solution into an underground trona cavity; removing aqueous solution from the cavity, wherein the temperature of the removed aqueous solution is at about the TWA point temperature; and recovering alkaline values from the removed aqueous solution.

A method of producing hydrocarbon fluids from a subsurface organic-rich rock formation, for example an oil shale formation, in which the oil shale formation contains water-soluble minerals, for example nahcolite, is provided. In one embodiment, the method includes the step of heating the organic-rich rock formation in situ. Optionally, this heating step may be performed prior to any substantial removal of water-soluble minerals from the organic-rich rock formation. In accordance with the method, the heating of the organic-rich rock formation both pyrolyzes at least a portion of the formation hydrocarbons, for example kerogen, to create hydrocarbon fluids, and converts at least a portion of the water-soluble minerals, for example, converts nahcolite to soda ash. Thereafter, the hydrocarbon fluids are produced from the formation.

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 discloses a method for forcedly draining gas from underground gas and liquid alternate phase-drive fracture coal of a coal mine. The method includes constructing a fracture drilled hole and a water guide hole in a local coal seam or across seams and performing high-pressure-resistance sealing on the two drilled holes; connecting fracture equipment with the fracture drilled hole, injecting pressure water under the pressure not higher than 3MPa into the fracture drilled hole, performing hydraulic fracture on the fracture drilled hole for 10 minutes, then shutting off a water pump and stopping hydraulic fracture; starting a gas booster to perform gas-phase fracture on the fracture drilled hole, shutting off the gas booster when the pressure reaches 3MPa and stopping gas-phase fracture; repeating the same procedure by multiple times, stopping hydraulic fracture when water flows out of the water guide hole distanced from one side of the fracture drilled hole, continuing gas-phase fracture and finishing gas-phase fracture when water stops flowing out of the water guide hole or gas flows out; connecting the fracture drilled hole and the water guide hole into a gas drainage pipe network and draining the gas. The method has the advantages that the problem that water remains after single hydraulic fracture and prevents gas from being released and desorbed can be effectively solved, internal fracture of the coal can be developed sufficiently, and the gas permeability of the coal seams and a gas drainage effect can be improved.

The invention discloses a gas injection point retreating type coal underground gasification system and process. The gas injection point retreating type coal underground gasification system comprises an airway arranged in a coal layer and multiple coal underground gasification units, wherein the airway is connected to the multiple coal underground gasification units; and the technical steps are sequentially as follows: a step of cold-state testing, a step of ignition on a gasification working surface, a step of debugging of the gasification working surface and a step of gasification normal production process. According to the invention, mud can be prevented from blocking the gas injection point efficiently, and the coal layer can be exploited to the maximum extent, so that possibility of thoroughly cutting off the leakage of a gasification agent to a combustion space area is realized while safe retreating in the coal underground gasification process is realized, filling of the combustion space area is realized, collapse of the ground surface caused by the gasification is removed, stability of the gasification channel structure is guaranteed, problem of the short circuit of the gasification agent caused by a channel which is resulted from collapse of a coal layer plate in the gasification area in the early stage and the gasification channel at the later stage of the underground gasification is solved, the quality of the coal gas is improved, and safe and reliable coal gas production and high gasification rate are achieved.

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.

In-situ solution mining method of an ore bed, particularly containing trona, which comprises exposing to a solvent an ore region inside a borehole drilled in the ore, and dissolving a desired solute within the exposed region to provide a liquor and create a voided ‘undercut’, such undercutting making the ore susceptible to gravitational loading and crushing. Unexposed ore falls into the undercut by gravity without breaking the ore roof resulting in exposure of fresh ore to the solvent and in preventing solvent exposure to contaminating material near the roof. The desired solute is eventually dissolved away in the entire bed from its floor up to its roof. Solvent injection may be delivered through a conduit positioned inside the borehole, and may be moved by retracting or perforating the conduit. The method may employ an advancing undercut initiated up-dip and traveling down-dip, or a retreating undercut initiated down-dip and traveling up-dip.

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.