8 results about "Coal matrix" patented technology

The invention relates to the field of coal seam anti-reflection, and particularly discloses a coal seam carbon dioxide and static expanding agent synergistic anti-reflection system and method. Slurry prepared by mixing a static expanding agent and water is injected into the expansion fracturing drill hole, in the process that the static expanding agent is subjected to hydration reaction and generates expansion stress, carbon dioxide gas is injected into the expansion fracturing drill hole through the carbon dioxide gas injection pipe, carbon dioxide and the hydration product of the static expanding agent are subjected to carbonization reaction to generate larger expansion stress, and the expansion fracturing drill hole is formed. Expanding the coal body fractures to form expansion fractures; the carbon dioxide is driven by differential pressure to seep into a coal matrix along expansion fractures, and adsorbed gas is driven to be desorbed into a free state through a competitive adsorption effect; and under the combined action of extraction negative pressure and carbon dioxide displacement, the free-state gas moves from the fracture channel to the extraction drill hole, and extraction is conducted through the gas extraction system. Carbon dioxide and the static expanding agent cooperate to improve permeability of the coal body, the displacement effect of carbon dioxide on gas is promoted, and the gas extraction effect is improved.

The application discloses an interface activity buffer additive and a pulverized coal deliming method, and a gradient proportioning composite acid system of nitric acid-hydrochloric acid-hydrofluoric acid is used in cooperation with an interface activity buffer additive (containing a specific zwitterionic betaine derivative and a citric acid buffer pair) to construct a H+ concentration gradient microenvironment on the surface of coal particles, target dissolution of ash minerals in a high concentration area, and protection of coal matrix in a low concentration area. The deliming rate is greater than 98%, acid consumption is reduced by 35%, and waste liquid is easy to handle up to the standard. The application solves the industry problems of poor selectivity, great coal damage and heavy secondary pollution of traditional pickling, and provides key technical support for efficient and clean utilization of high-ash coal.

The present application provides a kind of quantitative evaluation shale, coal matrix free gas conduction ability test method, for the limitation of existing coal matrix diffusion coefficient test method, this method uses raw coal as experimental object, by monitoring the dynamic deformation evolution characteristics of coal matrix system in gas injection process, combined with the coal matrix effective diffusion coefficient model based on dynamic strain constructed, the diffusion coefficient of different characteristic directions of coal matrix system is back calculated, so as to achieve the goal of quickly and accurately testing the anisotropy of coal matrix system free gas diffusion coefficient.This method can simultaneously achieve the goal of testing the anisotropy of raw coal sample free gas diffusion coefficient, so as to provide more accurate reservoir physical parameter for the free gas migration characteristics in coalbed methane, shale gas exploitation, and provide reference basis for later reservoir reconstruction and development.

The invention discloses a method and a device for fixed-point modification of a coal adsorption position based on infrared detection-pulsed nanoparticles, and relates to the technical field of coal mine safety engineering. According to the method, infrared is used for detecting the surface of a coal sample, an adsorption potential distribution diagram is drawn through emissivity data, and a high / low-density area is identified. The nanoparticles-containing foams are directionally delivered to a target area according to a modification target (enhancing or weakening adsorbability), and enrichment is guided by means of a magnetic field. Then, laser irradiation is adopted to enable the coal matrix to be heated in a transient state, and fixed-point transformation of the adsorption site is achieved. Finally, the effect change is verified through infrared scanning and methane adsorption testing. According to the method, fixed-point weakening and enhancement of the adsorption position can be achieved, and a new technical approach is provided for improving the coal bed gas exploitation efficiency and reducing the coal and gas outburst risk.

The invention discloses a porous coal surface in-situ growth amine modified copper oxide composite material as well as preparation and application thereof. The composite material takes coal as a raw material and comprises the following steps: firstly, converting pulverized coal into a porous coal matrix through a high-temperature activation process; then jointly adding the porous coal and copper salt into a mixed solvent of water and ethanol, and stirring to realize full dispersion; sequentially adding sodium hydroxide and an amine compound into the system, and continuously stirring to complete precursor regulation and control; then raising the temperature of the reaction system to 60-90 DEG C, keeping the temperature and stirring for 2-4 hours to promote complete reaction, and finally performing centrifugal separation, washing purification and drying treatment to obtain the target amine modified copper oxide / coal-based composite material. According to the prepared coal-based composite material, the surface of the coal matrix is uniformly covered with a large number of amine modified copper oxide active components, and the structure can provide rich active sites for a carbon dioxide reduction reaction. Based on the characteristics, the composite material shows excellent performance in a reaction for preparing ethylene through electrocatalytic reduction of carbon dioxide, the maximum Faraday efficiency of ethylene can reach 70.4%, the maximum current density can reach 342.3 mA / cm < 2 >, and the overall electrochemical performance is remarkably superior to that of a traditional material.

The invention discloses a coal seam gas control method based on hydrothermal activation type adsorption capsules, and belongs to the technical field of coal mine gas control and coal seam gas extraction. Comprising the following steps: preparing a hydrothermal activation type adsorption capsule from a double-layer capsule outer membrane and an adsorbent complex, and designing the shell wall thickness of a capsule inner membrane according to target activation time and the dissolution rate of a shell material; the adsorption capsule is delivered to the target coal seam hole section in a delivery mode; underground water in a target coal seam permeates and dissolves the capsule outer membrane and the capsule inner membrane, so that a large number of water molecules and CaO particles are subjected to a violent exothermic reaction to release heat, and a large number of methane molecules in an adsorption state are driven to be desorbed from a coal matrix; desorbed high-concentration methane molecules are rapidly captured and fixed through active carbon particles. According to the method, accurate targeted treatment of the gas is achieved by accurately feeding the adsorption capsules, the desorption rate and the total amount of the gas are remarkably increased through a CaO particle exothermic reaction, and passive adsorption is changed into active displacement-adsorption.

The invention belongs to the technical field of oil-gas field development and unconventional natural gas extraction, and discloses a deep coal seam in-situ pore wettability characterization method based on molecular simulation. The method comprises the following steps: screening a coal macromolecular structure model, and constructing a deep coal seam coal matrix model by adopting a coal molecular structure unit; constructing a layered interface model for calculating different interfacial tensions, performing molecular dynamics simulation on the layered model, and recording a pressure tensor track; pressure tensor data in the dynamic simulation process is extracted, layered statistics is conducted in the Z direction, the interfacial tension is calculated based on a pressure tensor method, and then the contact angle is calculated to represent the wettability of the reservoir. The convergence condition of the pressure difference along with the displacement can be automatically monitored, and the real boundary of the volume phase and the interface phase is judged, so that the calculation error generated by the simulation box boundary effect is eliminated, and the interface tension calculation reliability is improved; the micromechanism of low efficiency at the initial stage of deep coal bed gas drainage and production is explained through the layered interface model, and the method has extremely high industrial application value.

The invention discloses a gas-containing coal moisture invasion and microscopic damage visual measurement system and method, and belongs to the technical field of gas-containing coal body tests. Comprising a visual triaxial coal sample holder, an environment control system, a fluid injection system, a desorption system and a coal sample microscopic damage evolution collaborative characterization unit, loading shaft confining pressure on the coal sample and then simulating a gas pressurization adsorption process on the coal sample; methane desorption is simulated through a desorption system, and the permeability of the coal sample is measured by adopting a transient method; coal matrix strain is analyzed by using a DIC technology, and micro-fracture evolution is monitored by using an acoustic emission technology; according to the invention, the response mechanism and the moisture penetration process of the coal seam after moisture intrusion in a real stratum environment can be truly simulated, and full-scale visual analysis from microscopic damage to macroscopic response is completed, so that theoretical support is better provided for a coal seam anti-reflection technology and gas outburst.