A method of storing hydrogen involves forming an excavation in the earth and constructing a storage tank therein comprised of integrated primary and secondary containment structures. The primary containment structure composed of a plurality of joinable cylindrical segments, or pre-fabricated sections joined to form a cylinder within the excavation. The secondary containment structure formed by pumping a curable, flowable composition into the cylinder, allowing it to flow out the bottom and up the second annulus to the earth's surface, and then hardening; thereby encasing the primary containment structure. The bottom of the cylinder is sealed with the bottom assembly. The top assembly is attached to the cylinder and tubing and packer are run into the cylinder creating a first annulus between the cylinder and tubing. Top assembly is sealed, fluids circulated out, and the tank dried. Thereafter, the tank is capable of safely storing hydrogen gas.

A method of storing hydrogen involves forming an excavation in the earth and constructing a storage tank therein comprised of integrated primary and secondary containment structures. The primary containment structure composed of a plurality of joinable cylindrical segments, or pre-fabricated sections joined to form a cylinder within the excavation. The secondary containment structure formed by pumping a curable, flowable composition into the cylinder, allowing it to flow out the bottom and up the second annulus to the earth's surface, and then hardening; thereby encasing the primary containment structure. The bottom of the cylinder is sealed with the bottom assembly. The top assembly is attached to the cylinder and tubing and packer are run into the cylinder creating a first annulus between the cylinder and tubing. Top assembly is sealed, fluids circulated out, and the tank dried. Thereafter, the tank is capable of safely storing hydrogen gas.

A method for geo-sequestration of a carbon dioxide includes selection of a target water-laden geological formation with low-permeability interbeds, providing an injection well into the formation and injecting supercritical carbon dioxide (SC-CO.sub.2) and water or bine into the injection well under conditions of temperature, pressure and density selected to cause the fluid to enter the formation and splinter and/or form immobilized ganglia within the formation.

A method for geo-sequestration of a carbon dioxide includes selection of a target water-laden geological formation with low-permeability interbeds, providing an injection well into the formation and injecting supercritical carbon dioxide (SC-CO.sub.2) and water or bine into the injection well under conditions of temperature, pressure and density selected to cause the fluid to enter the formation and splinter and/or form immobilized ganglia within the formation.

This disclosure relates to a method and a system for sequestering carbon-containing materials in underground wells. An example method includes: obtaining a material comprising a carbon-containing liquid; optionally testing the material for compatibility with an underground well; optionally adjusting a property of the material to improve the compatibility; and providing the material for injection into the underground well.

Provided herein is a method for constructing a pumping-injection well of a groundwater reservoir in a dump of an open-pit mine. The pumping-injection well includes a bottom pipe, intermediate pipes, and a top pipe in sequence from bottom to top connected from bottom to top. The method includes: arranging a rubble barrier around the pumping-injection well, and installing the bottom pipe of the pumping-injection well at a designed position of the pumping-injection well as a center of circle; continuing to install an intermediate pipe on the bottom pipe, and pile up a rubble pile; continuing to stack multiple intermediate pipes, and starting the construction of the groundwater reservoir; discarding discarded materials from the open-pit mine to form a dump; continuing to stack intermediate pipes to build an inverted trapezoidal surface sump around the pumping-injection well; and installing the top pipe and a well cover to form a complete pumping-injection well.

An arrangement for storing thermal energy, including a shaft (1) and at least one tunnel (2), the shaft (1) and the tunnel (2) being in fluid communication with each other. The tunnel (2) includes at least a first (2a), a second (2b), and a third (2c) tunnel section. The second tunnel section (2b) is arranged between and connected to the first (2a) and third (2c) tunnel sections. The second tunnel section (2b) is sealed off at an end (4) connected to the third tunnel section (2c), and the third tunnel section is further connected the shaft (1). The shaft (1) and first (2a) and third (2c) tunnel sections hold fluid for thermal storage. The second tunnel section (2b) is an expansion space should a volume of the fluid expand beyond a volume of the shaft (1) and the first (2a) and third (2c) tunnel sections.

An arrangement for storing thermal energy, including a shaft (1) and at least one tunnel (2), the shaft (1) and the tunnel (2) being in fluid communication with each other. The tunnel (2) includes at least a first (2a), a second (2b), and a third (2c) tunnel section. The second tunnel section (2b) is arranged between and connected to the first (2a) and third (2c) tunnel sections. The second tunnel section (2b) is sealed off at an end (4) connected to the third tunnel section (2c), and the third tunnel section is further connected the shaft (1). The shaft (1) and first (2a) and third (2c) tunnel sections hold fluid for thermal storage. The second tunnel section (2b) is an expansion space should a volume of the fluid expand beyond a volume of the shaft (1) and the first (2a) and third (2c) tunnel sections.

A method for operating a kerogen-rich unconventional gas reservoir characterized by there being multiple hydraulically-fractured wells drilled thereinto comprises: recovering a methane-containing gas from a first hydraulically-fractured well drilled into the gas reservoir, steam-methane reforming the recovered methane-containing gas to yield a hydrogen gas and an inorganic carbon-containing gas, injecting at least a portion of the hydrogen gas into a second hydraulically-fractured well drilled into the gas reservoir, and injecting at least a portion of the inorganic carbon-containing gas into a third hydraulically-fractured well drilled into the gas reservoir.

A method for operating a kerogen-rich unconventional gas reservoir characterized by there being multiple hydraulically-fractured wells drilled thereinto comprises: recovering a methane-containing gas from a first hydraulically-fractured well drilled into the gas reservoir, steam-methane reforming the recovered methane-containing gas to yield a hydrogen gas and an inorganic carbon-containing gas, injecting at least a portion of the hydrogen gas into a second hydraulically-fractured well drilled into the gas reservoir, and injecting at least a portion of the inorganic carbon-containing gas into a third hydraulically-fractured well drilled into the gas reservoir.