The present invention discloses an I-shaped water-retaining dam for an underground reservoir in a coal mine. The I-shaped water-retaining dam is located between coal pillar dams to isolate an underground reservoir from a corresponding coal roadway. The I-shaped water-retaining dam includes an upper flange plate, a web plate, and a lower flange plate from top to bottom, where a vertical face of a dam body is of an I shape; the upper flange plate extends into a roadway roof; two ends of the web plate are embedded into the coal pillar dams; and the lower flange plate extends into a floor. The I-shaped water-retaining dam is located in an underground coal roadway, and bears complex surrounding rock stress. The present invention effectively overcomes water seepage of a weak part at an upper part of a conventional I-shaped water-retaining dam.

A fluidized coal mining method for implementing CO.sub.2 underground storage, includes mining area division, tunneling mining, filling and supporting, roof and bottom plate sealing, and boundary surrounding rock sealing. A goaf formed by a mining device after tunneling and mining along a mining strip is filled and supported, and filling and supporting can form a high-strength supporting wall body, which not only provides an effective supporting effect for roof and bottom plate rocks, but also forms a filled and supported wall body; a space for underground storage of CO.sub.2 is formed between adjacent filled and supported wall bodies; at the same time, the mining device further seals the roof and a bottom plate of the goaf, and seals boundary surrounding rocks of a mine field, so that the entire mine field forms a whole closed space for the underground storage of CO.sub.2 after mining is completed.

An apparatus of salt cavern gas storage without cushion gas includes: a salt cavern; sediments; a drainage assembly; a gas injection and production pipe; a debrining string, one end of which is connected to the drainage assembly, and the other end of which protrudes from the ground to be connected to a water source assembly; a communicating assembly, which is used to make the gas injection and production pipe be in communication with the debrining string on the ground. A closed loop is formed by making the gas injection and production pipe and the debrining string be in communication with each other on the ground through the communicating assembly, thus the non-cushion gas injection-production operation of sediment particles in the salt cavern is realized.

The present invention discloses a multi-energy complementary system for a co-associated abandoned mine and a use method. The multi-energy complementary system for a co-associated abandoned mine includes a mining mechanism, a grouting mechanism and an energy mechanism. In the present invention, the mining of coal and uranium resources is realized through the mining mechanism, the subsidence and seepage reduction of the stratum is realized through the grouting mechanism, and the effective utilization of waste resources is realized through the energy mechanism. Finally, with the efficient cooperation of the three mechanisms, safe and efficient development and utilization of co-associated resources in the full life cycle are realized, and the purposes of green and efficient mining of coal and uranium resources and secondary development of a coal seam goaf are achieved, thereby facilitating the realization of dual-carbon goals and the development of low-carbon green energy.

A system and method of creating, operating and maintaining a hydrocarbon storage facility in a salt cavern within an underground salt deposit. The system is portable and can be transported to areas near different well heads. The portability also enables adjacent well heads to be worked in succession to create a large storage cavern by interlinking a series of smaller caverns. This formation processes ensures that a storage cavern can be isolated within the confines of a salt deposit. Using the same portable equipment, the system can be configured to form a salt cavern, displace stored material out of a salt cavern, and repair or maintain a salt cavern well.

A method for forming and maintaining a fundamentally impervious boundary to very high purity hydrogen stored in a salt cavern is provided. The cavern includes a salt cavern wall. The method includes introducing a compressed very high purity hydrogen gas into a salt cavern, thereby producing a stored very high purity hydrogen gas; forming a fundamentally impervious boundary to the very high purity hydrogen along at least a part of the perimeter of the salt cavern, and maintaining the fundamentally impervious boundary to the stored very high purity hydrogen gas at a pressure greater than 1.0 psi per linear foot of height within the cavern, and less than 4.0 psi per linear foot of height within the cavern and thereby retaining within the salt cavern over 95% of the stored very high purity hydrogen over a period of time of at least 72 hours.

A method for forming and maintaining a fundamentally impervious boundary to very high purity hydrogen stored in a salt cavern is provided. The cavern includes a salt cavern wall. The method includes introducing a compressed very high purity hydrogen gas into a salt cavern, thereby producing a stored very high purity hydrogen gas; forming a fundamentally impervious boundary to the very high purity hydrogen along at least a part of the perimeter of the salt cavern, and maintaining the fundamentally impervious boundary to the stored very high purity hydrogen gas at a pressure greater than 1.0 psi per linear foot of height within the cavern, and less than 4.0 psi per linear foot of height within the cavern and thereby retaining within the salt cavern over 95% of the stored very high purity hydrogen over a period of time of at least 72 hours.

A system for forming and/or maintaining a fundamentally impervious boundary within a salt cavern for storing very high purity hydrogen is provided. The system includes a salt cavern comprising a salt cavern wall; a conduit configured to introduce a compressed very high purity hydrogen gas into a salt cavern, thereby producing a stored very high purity hydrogen gas; the conduit also configured to remove the compressed very high purity hydrogen gas from the salt cavern, wherein the stored very high purity hydrogen gas is maintained at a pressure greater than about 1.0 psi per linear foot of height within the cavern, and less than about 4.0 psi per linear foot of height within the cavern.

A system for forming and/or maintaining a fundamentally impervious boundary within a salt cavern for storing very high purity hydrogen is provided. The system includes a salt cavern comprising a salt cavern wall; a conduit configured to introduce a compressed very high purity hydrogen gas into a salt cavern, thereby producing a stored very high purity hydrogen gas; the conduit also configured to remove the compressed very high purity hydrogen gas from the salt cavern, wherein the stored very high purity hydrogen gas is maintained at a pressure greater than about 1.0 psi per linear foot of height within the cavern, and less than about 4.0 psi per linear foot of height within the cavern.

Disclosed is a method for backfilling and reconstructing a carbon storage space in an abandoned main roadway and storing CO.sub.2. A surrounding rock of the main roadway is surveyed through geophysical exploration technology, and an anchor bolts (anchor cables) are used to reinforce and support an area which has unstable confining pressure bearing. According to a width and a height of the roadway section of the main roadway, a support formwork is forged in advance, and after the support formwork is placed in the main roadway, backfilling slurry is injected to the periphery of the support formwork. Meanwhile, supercritical carbon dioxide is injected into the backfilling slurry and the roadway, respectively.