CN-122014158-A - CO2Mineralization sealing and geological hydrogen synergistic enhanced exploitation method and simulation experiment method

Abstract

The invention discloses a method for CO 2 mineralization and sequestration and geological hydrogen synergistic enhancement exploitation and a simulation experiment method, which are applied to geological hydrogen reservoirs containing super bedrock, and the method comprises the following steps of screening the super bedrock reservoirs rich in mafic minerals, and arranging a bottom injection well and a top recovery well; injecting supercritical CO 2 into the bottom injection well, fracturing to form a fracture network, establishing a migration channel for CO 2 sinking-H 2 floating, extracting geological hydrogen, regulating and controlling a recovery pressure difference to limit CO 2 from channeling, monitoring the components and the yield of the extracted gas, mineralizing and storing CO 2 and replenishing artificial geological hydrogen, and improving the recovery ratio of the geological hydrogen in a multi-cycle and gradually completing mineralizing and storing CO 2 . Aiming at the characteristic of low pore and low permeability of an ultra-basic rock reservoir and the seepage control characteristic of cracks, the method provides a supercritical CO 2 fracturing technology and CO 2 displacement to improve the permeability and reaction contact area of the reservoir, can synchronously improve the geological hydrogen recovery rate and the efficiency and economy of CO 2 sealing and realize the cyclic synergistic enhancement of hydrogen energy development and CO 2 mineralization sealing.

Inventors

• LIU QUANSHENG
• TANG XUHAI
• HUANG LIZHI
• Qiao Jiangmei
• LIU YIWEI
• LI MENGYI
• TONG YUWEN

Assignees

• 武汉大学

Dates

Publication Date

20260512

Application Date

20260126

Claims (10)

1. A method of co 2 mineralization sequestration and geological hydrogen synergistic enhanced recovery, characterized in that the method is applied to geological hydrogen reservoirs containing super bedrock, the method comprising the steps of: Screening a super-bedrock reservoir rich in magnesium-iron minerals, and arranging at least one bottom injection well and at least one top recovery well in the super-bedrock reservoir, wherein the perforation section of the bottom injection well is positioned at the bottom of the super-bedrock reservoir, and the perforation section of the top recovery well is positioned at the top of the super-bedrock reservoir; Injecting supercritical CO 2 into the bottom injection well, and forming a fracture network in the super-basic rock reservoir through supercritical CO 2 fracturing by controlling injection pressure and injection rate, so that CO 2 fills the lower space of the super-basic rock reservoir preferentially; CO 2 migrates downwards in the super-bedrock reservoir and forms a lower gas cushion layer, geological hydrogen is enriched towards the upper part of the super-bedrock reservoir under the displacement and buoyancy actions of the lower gas cushion layer, and a migration channel for CO 2 sinking-H 2 floating upwards is established; Geological hydrogen enriched at the upper part of the super-basic rock reservoir is produced through the top recovery well, the recovery pressure difference is regulated so as to limit CO 2 from channeling upwards, and the produced gas components and the yield are monitored; Judging whether a well closing triggering condition is met, if not, continuing the previous step, if so, entering a well closing stage, wherein in the well closing stage, based on a CO 2 -super-basic rock-water reaction process, CO 2 is mineralized and stored in situ by utilizing a carbonate mineral formation effect, hydrogen is produced by utilizing a serpentine effect, and CO 2 mineralization and storage and artificial geological hydrogen supply are realized; and after the well closing time reaches the criterion, restarting the bottom injection well, repeating the steps, improving the geological hydrogen recovery ratio in a plurality of cycles, and gradually completing CO 2 mineralization sealing.
2. 2. The method of CO 2 mineralization sequestration and geological hydrogen synergistic enhanced mining according to claim 1, wherein in screening the super bedrock reservoirs, the reservoir is evaluated for ground temperature, burial depth, original permeability, pore structure, geological hydrogen sequestration characteristics and mineral composition, and the basalt comprising olivine, pyroxene, serpentine, or magnesium iron minerals rich in basalt is selected as the rock mass for providing reactants for CO 2 mineralization sequestration and serpentine hydrogen production.
3. 3. The method of CO 2 mineralization sequestration and geological hydrogen synergistic enhanced recovery according to claim 1, wherein the perforation section of the bottom injection well is arranged in the lower 1/6-1/2 section of the target super-bedrock reservoir thickness, and the perforation Duan Bu of the top recovery well is placed in the upper 1/6-1/2 section of the super-bedrock reservoir thickness to form a stable CO 2 bedding and H 2 enriched zone in the vertical direction, inhibiting CO 2 from channeling up to the top recovery well.
4. 4. The method for CO 2 mineralization sequestration and geological hydrogen synergistic enhanced mining according to claim 1, wherein supercritical CO 2 injection pressure is higher than the super bedrock reservoir fracture initiation pressure, and multi-stage fracture channels are formed by continuous injection, staged injection, stepped pressurization and/or pulse injection.
5. 5. The method of CO 2 mineralization sequestration and geological hydrogen synergistic enhanced recovery according to claim 1, wherein prior to injecting supercritical CO 2 into the bottom injection well, water or a solution containing a pro-reactive agent is injected into the bottom injection well, followed by CO 2 and water alternate injection to expand the contact interface of CO 2 with minerals of the super-bedrock reservoir and enhance mineralization sequestration and displacement effects.
6. 6. The method of CO 2 mineralization sequestration and geological hydrogen synergistic enhanced recovery according to claim 1, wherein the well-tie trigger conditions include at least one of: (1) Geological hydrogen production continuously decreases with time; (2) The hydrogen recovery amount in unit time is lower than a recovery preset threshold value; (3) And the concentration of CO 2 in the produced gas of the top recovery well is increased to be above a concentration preset threshold.
7. 7. The method of CO 2 mineralization sequestration and geological hydrogen synergistic enhanced mining according to claim 1, wherein the carbonate mineral generated by the CO 2 -super bedrock-water reaction comprises at least magnesium carbonate and calcareous carbonate, fills in part of the fissures and pores of the fissure network, and sequesters CO 2 in mineral form for a long period of time.
8. 8. The method of CO 2 mineralization sequestration and geological hydrogen synergistic enhanced recovery according to claim 1, wherein the well-packing time is determined according to one or a combination of the following: (1) The change rate of bottom hole pressure is reduced to a pressure preset threshold value during well closing and is kept stable for a preset time; (2) The change rate of the geochemical parameter of the formation fluid at the bottom of the well monitored during well closing is reduced to a change preset threshold value and kept stable for a preset time; (3) The well closing time reaches the minimum effective reaction time determined according to the reaction dynamics and does not exceed the preset maximum well closing time.
9. 9. The method of CO 2 mineralization sequestration and geological hydrogen CO-enhanced recovery according to claim 8, wherein the chemical parameters include at least Mg 2+ 、Ca 2+ and HCO 3 - concentrations, as well as pH and conductivity.
10. 10. A simulated experiment method for CO 2 mineralization sequestration and geological hydrogen synergic enhanced exploitation for verifying the method for CO 2 mineralization sequestration and geological hydrogen synergic enhanced exploitation according to any one of claims 1-9, characterized in that the simulated experiment method at least comprises: Selecting basalt, carrying out a CO 2 -rock-water reaction experiment with the duration not less than 90 days in a 20-25 ℃ environment, mixing a powder sample prepared from basalt with CO 2 saturated water, and continuously reacting for 90 days; Selecting the olivine, carrying out a CO 2 -rock-water reaction experiment for 1 day at50 ℃, mixing a powdery sample prepared from the olivine with CO 2 saturated water for continuous reaction, and detecting the hydrogen yield, the difference of ferrous ion content and the content of CO 2 before and after the reaction in the experiment.

Description

Method for CO 2 mineralization and sequestration and geological hydrogen synergistic enhancement exploitation and simulation experiment method Technical Field The invention relates to the technical field of underground energy development and carbon emission reduction, in particular to a method for mineralizing and sealing CO 2 and synergistically enhancing geological hydrogen exploitation and a simulation experiment method, which are suitable for an underground geological system containing super-bedrock. Background The hydrogen energy is an important clean secondary energy source and plays an important role in constructing a low-carbon energy system. In addition to industrial hydrogen production, geological hydrogen naturally generated and existing underground has the advantages of zero carbon emission, large potential of resource amount and the like in recent years. Natural geological hydrogen is mainly endowed in special geological environments such as superbasic rock, serpentine rock mass and the like. However, natural geological hydrogen has a low natural generation rate, and is mostly applied to cracks, so that the overall permeability is low, and efficient recovery is difficult to realize by simply relying on natural seepage. The existing natural geological hydrogen exploitation has many limitations that on one hand, natural geological hydrogen has low natural generation rate and is mostly distributed in cracks, the state is dispersed and the permeability is limited, high-efficiency recovery is difficult to realize by relying on natural seepage alone, and on the other hand, the super-bedrock reservoir matrix has low permeability and insufficient connectivity, and seepage conditions need to be improved by means of measures such as fracturing and seepage increasing. Meanwhile, from the perspective of continuous hydrogen supply, the reaction of superbase rock-water is slow, a sustainable supply and enhancement mechanism is lacking, compared with the reaction rate of superbase rock-CO 2 -water is faster, the method is not only favorable for carbon fixation of CO 2 minerals under the condition of proper temperature and pressure, but also is expected to provide continuous supply for geological hydrogen, and the related coupling development technology is still immature. Carbon capture, utilization and sequestration (CCUS) have been used in salty water, hydrocarbon reservoirs, etc. as an important technological path for reducing greenhouse gas emissions. However, the traditional CCUS projects mostly aim at single CO 2 for sealing, the engineering investment is large, the economic benefit mainly depends on policy incentives, and the overall economy is limited. The prior public researches and patents focus on geological sequestration of CO 2 or development of natural geological hydrogen respectively, and a technical route for coupling the CO 2 carbon sequestration process with natural geological hydrogen enhanced exploitation in the same system does not form a mature system yet. Thus, there is a need for a new method that can simultaneously increase geological hydrogen recovery efficiency and achieve stable sequestration of CO 2 in a subterranean system. Disclosure of Invention The invention aims at solving the problems existing in the prior art and provides a method for CO 2 mineralization and sequestration and geological hydrogen synergistic enhancement exploitation and a simulation experiment method. In order to achieve the above purpose, the invention adopts the following technical scheme: A method of CO 2 mineralization sequestration and geological hydrogen CO-enhanced recovery for application to geological hydrogen reservoirs containing hypersaline rock, the method comprising the steps of: Screening a super-bedrock reservoir rich in magnesium-iron minerals, and arranging at least one bottom injection well and at least one top recovery well in the super-bedrock reservoir, wherein the perforation section of the bottom injection well is positioned at the bottom of the super-bedrock reservoir, and the perforation section of the top recovery well is positioned at the top of the super-bedrock reservoir; Injecting supercritical CO 2 into the bottom injection well, and forming a fracture network in the super-basic rock reservoir through supercritical CO 2 fracturing by controlling injection pressure and injection rate, so that CO 2 fills the lower space of the super-basic rock reservoir preferentially; CO 2 migrates downwards in the super-bedrock reservoir and forms a lower gas cushion layer, geological hydrogen is enriched towards the upper part of the super-bedrock reservoir under the displacement and buoyancy actions of the lower gas cushion layer, and a migration channel for CO 2 sinking-H 2 floating upwards is established; Geological hydrogen enriched at the upper part of the super-basic rock reservoir is produced through the top recovery well, the recovery pressure difference is regulated so as to limit CO