14 results about "Underground coal gasification" patented technology

This invention discloses an underground ignition tool and its operating method for underground coal gasification processes, comprising: a casing with a tool connector inside; an oxygen injection tool connected to the tool connector inside the casing, the oxygen injection tool having a water channel and an oxygen interface; a connector shell fixedly fitted onto the outer side of the tool connector; a hydraulic piston movably disposed within the inner cavity of the connector shell; a separation shell detachably connected to the bottom of the inner wall of the connector shell; and an oxygen pressure piston movably engaged within the inner cavity of the separation shell. This underground ignition tool and its operating method for underground coal gasification processes perfectly solve the technical problem of underground gasifiers being unable to operate continuously and requiring shutdown and closure, while also possessing significant advantages such as simple operation and convenient installation.

This application discloses an in-situ permeability testing system for underground coal gasification, including a core holder comprising a cylinder, a seepage ring, an axial pressure loading component, a gas pipeline, a sealing assembly, a confining pressure sleeve, a core heating element, a temperature and flow rate measurement assembly, an inlet gas pressure measurement assembly, an outlet gas pressure measurement assembly, and a permeability calculation assembly. The system can calculate the permeability of the core using the core holder outlet temperature, outlet flow rate, inlet gas pressure, and outlet gas pressure, combined with the core's dimensional parameters and the gas viscosity at the core holder outlet temperature. This system can simulate the high-temperature, high-pressure, and high-stress environment of deep underground coal gasification and directly perform in-situ core permeability testing, better ensuring the accuracy and reliability of the test results. This application also discloses an in-situ permeability testing method for underground coal gasification.

This invention discloses a simulation method for the automatic expansion of the combustion chamber in underground coal gasification, relating to the fields of coal mining and numerical simulation technology. The method first constructs an initial reference model and converts it into a steeply dipping strata model using parameter-driven coordinate mapping technology. Subsequently, a parameterized volumetric moving heat source model associated with the coordinate mapping is constructed, with its trajectory dynamically and adaptively positioned according to the dip angle. Further, an update algorithm for rock parameters with nonlinear temperature changes is established, and a heterogeneous field is introduced. Finally, a thermo-mechanical interleaved sequential coupling calculation is performed. In the heat conduction sub-loop, the mesh is dynamically reconstructed based on a temperature threshold to generate cavities, and a mechanical equilibrium sub-loop is triggered to perform stress redistribution calculations when the advance distance threshold is reached. This invention, by coordinating the time scale differences between thermo-mechanical calculations, achieves the simulation of the dynamic evolution of cavities and the asymmetric shear slip failure mechanism of steeply dipping overburden, balancing computational efficiency and result reliability.

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.

This invention discloses an adaptive upscaling method for multi-field coupled fracture evolution in thermal flow solidification, relating to the fields of unconventional oil and gas reservoir development and reservoir numerical simulation. The method includes: establishing fine-scale and coarse-scale models; establishing a simplified model and running it to obtain the temperature field; running the full physical coarse-scale model and correcting the predicted fine-scale temperature; iteratively calculating the fine-scale reaction rate and upscaling; adaptive dynamic correction of the reaction frequency factor of the coarse-scale model; coarse-scale multi-field coupled solution and thermally induced fracture identification; thermally induced fracture merging and evolution and updating of multi-field physical parameters; time stepping and simulation termination. The beneficial effects of this invention are that, while ensuring the accuracy of fine-scale calculations, it can significantly accelerate the simulation of multi-field coupled fracture dynamic evolution, and can be widely applied to field-scale numerical simulations of various underground energy engineering projects with solid-phase reactions as the main controlling mechanism, such as in-situ conversion of oil shale, underground coal gasification, and in-situ upgrading of oil sands.

The present application belongs to the technical field of underground coal gasification, and discloses a method and system for preparing rich-methane coal gas by deep underground coal gasification. After the underground coal gasification enters a normal gasification stage, under the conditions of relatively low temperature and high pressure, waste water containing catalyst is injected into the underground gasification furnace, and by adjusting the gas-water ratio and / or the position of the gas injection point, the volume percentage of methane in the coal gas is kept above 35%. The system for realizing the above method comprises an underground gasification furnace, a double-layer continuous pipe and its injection device, a variable-frequency water injection pump and a UCG control unit; the continuous pipe gas inlet is connected with a gasifying agent storage device, and the continuous pipe water inlet is connected with the variable-frequency water injection pump; the underground gasification furnace is connected with the UCG control unit; and the variable-frequency water injection pump is connected with a catalytic waste water pool. The present application forms a stable and necessary process control method and operation system for maintaining the production of rich-methane coal gas in the gasification coal seam, and the prepared coal gas has high methane content.

This invention discloses a multi-field coupled numerical simulation method for underground coal gasification, relating to the field of energy development technology. The invention first constructs a multi-field coupled physicochemical control model, a porosity dynamic evolution model, a permeability dynamic evolution model, and a non-ideal gas thermodynamic model to realistically recreate the underground coal gasification process. Based on these models, a fully autonomous and controllable numerical simulation framework is built from the ground up. The finite volume method is used to spatially discretize the governing equations, and a fully implicit nonlinear solver is developed to perform fully coupled iterative solutions for all physical fields within the same time step. Using the structural parameters and internal medium parameters of the actual coal seam, the spatiotemporal evolution laws of the temperature field, pressure field, component concentration field, and porosity / permeability parameters during the underground coal gasification process are obtained using the constructed underground coal gasification numerical solver. By combining dynamic property evolution with accurate thermodynamic simulation, a precise simulation of the underground coal gasification process is achieved.

Methods and systems for quenching an underground carbonaceous formation with carbon and / or sequestering carbon within an underground carbonaceous formation are disclosed herein. In some embodiments, a representative coal gasification system can comprise (i) an injection conduit extending from a ground surface to an underground coal gasification (UCG) reaction region of a coal seam, (ii) a production conduit extending from a first underground region toward the ground surface, and (iii) an injection well fluidically coupled to a source of process fluid and extending toward a second underground region. The second underground region is laterally spaced apart from the first underground region by an adjacent formation having a hydraulic resistance higher than that of a first hydraulic resistance and a second hydraulic resistance.

This utility model relates to the fields of oil and gas industry and clean coal technology, and discloses a gasifying agent injection tool for underground coal gasification. This device is used in underground coal gasification where oxygen / air and water are injected as gasifying agents into the coal seam in the combustion zone through a continuous tubing, injection tool body, check valve, extension pipe, and guide nozzle for gasification and combustion reaction. It mainly includes a continuous tubing connector, injection tool body, check valve, front nozzle, extension pipe, and guide nozzle. This utility model's gasifying agent injection tool can achieve safe unlocking, separation, and overload protection through controllable shearing, ensuring that other upstream equipment can be quickly pulled back, maintained, and replaced in a timely manner, thereby reducing equipment wear in the underground coal gasification process to a certain extent.

This invention relates to a method for detecting the underground gasification process of deep coal, comprising: drilling an injection well, an underground furnace, and a production well into a deep coal seam; connecting a temperature-measuring fiber optic cable to a drill bit and drilling a first temperature-measuring well and a second temperature-measuring well on both sides of the production well; lowering the drill bit down the production well to the lower part of the well, and then drilling a third temperature-measuring well above the furnace, with the tail ends of the three temperature-measuring wells extending to the corresponding furnace head ends; connecting a coiled tubing to a drill bit and drilling a first monitoring well and a second monitoring well on both sides of the injection well, with the tail ends of the two monitoring wells extending to the corresponding furnace tail ends; and then placing a detection device into the monitoring well along the coiled tubing for installing a microseismic probe inside the monitoring well.

2022271406 15 Nov 2022 3 / 3 FIGURE 3- Syngas predictive algorithm flowchart CONTROLLER Input Desired SynGas Quality START Request for Prediction Model Calculation of Predicted Value For Operational Parameters Display Predicted Values Vary Operational Parameters Based on Predicted Value 20 22 27 14 06 1 5 N ov 2 02 22022271406 15 Nov 2022 Predicted Values on Predicted Value

This invention relates to the field of underground coal gasification control technology, specifically a method for monitoring the propagation and expansion of combustion zones in underground coal gasification. The method includes: acquiring temperature, acoustic emission waveforms, and gas composition data for gasification combustion based on the three-dimensional location of the target coal seam, generating a monitoring area characterizing gasification expansion; constructing a moving boundary and regional configuration conditions for gasification combustion based on the acquired temperature values ​​and acoustic emission waveforms, generating characteristics of the gasification combustion propagation process; performing trend analysis on the propagation process characteristics, and identifying the main propagation direction of gasification combustion by combining the gasification stages corresponding to the gas composition; determining the combustion activity level before and after each cycle based on the discrimination period corresponding to the main propagation direction, and determining the target propagation position corresponding to the main propagation direction; and determining the parameter control target for each gas injection based on the relative distance between the target propagation position and the moving boundary. This method achieves both accuracy and efficiency in monitoring gasification combustion.

This invention discloses a two-stage, high-enthalpy-drop, 200-600MW ultra-high-power flue gas turbine power generation device, belonging to the field of waste heat turbine power generation equipment technology. Addressing the industry pain points of traditional flue gas turbines—such as a single unit power limit of only 33MW, the need for multi-stage thin-blade structures, the requirement for multiple units in parallel for ultra-high power, and low energy efficiency and high failure rates—this invention leverages the stable high-temperature flue gas conditions of underground coal gasification with ultra-high flow rates and constant temperature and pressure. It innovatively adopts a minimalist structure with only two-stage bladed disks, a short, rigid, integrally forged rotor, and wide, thickened, high-strength blades. Through precise load distribution between the two stages, it achieves concentrated work with a large enthalpy drop, breaking with traditional technical understanding and avoiding the risks of airflow shock waves and excessive stress in two-stage structures. The bearing conditions and shaft system stability are superior to multi-stage structures, enabling stable power generation across a wide power range of 200-600MW per unit. With its simple structure, high reliability, excellent energy efficiency, and minimal footprint, it fills the technological gap in ultra-high-power flue gas turbines, possessing high innovation, practicality, and industrial value.