Renewable energy storage technologies are critical for transitioning to sustainable energy systems,with salt caverns playing a significant role in large-scale solutions.In water-soluble mining of low-grade salt format...Renewable energy storage technologies are critical for transitioning to sustainable energy systems,with salt caverns playing a significant role in large-scale solutions.In water-soluble mining of low-grade salt formations,insoluble impurities and interlayers detach during salt dissolution and accumulate as sediment at the cavern base,thereby reducing the storage capacity and economic viability of salt cavern gas storage(SCGS).This study investigates sediment formation mechanisms,void distribution,and voidage in the Huai'an low-grade salt mine,introducing a novel self-developed physical simulation device for two butted-well horizontal(TWH)caverns that replicates compressed air injection and brine discharge.Experiments comparing“one injection and one discharge”and“two injections and one discharge”modes revealed that(1)compressed air effectively displaces brine from sediment voids,(2)a 0.5 MPa injection pressure corresponds to a 10.3 MPa operational lower limit in practice,aligning with field data,and(3)sediment voidage is approximately 46%,validated via air-brine interface theory.The“two injections and one discharge”mode outperformed in both discharge volume and rate.Additionally,a mathematical model for brine displacement via compressed air was established.These results provide foundational insights for optimizing compressed air energy storage(CAES)in low-grade salt mines,advancing their role in renewable energy integration.展开更多
Evaluation and prediction of the long-term behavior of abandoned mines have to consider complex interactions of different physical processes.The hydro-mechanical coupling plays an important role for potential short-an...Evaluation and prediction of the long-term behavior of abandoned mines have to consider complex interactions of different physical processes.The hydro-mechanical coupling plays an important role for potential short-and long-term environmental risks(e.g.surface subsidence,pollution of the biosphere,damage of the geological barrier,damage of groundwater regime).This work addresses challenges and key mechanisms in respect to longterm predictions for abandoned salt and potash mines and provides a general simulation concept.Exemplary,this concept is applied to a generic salt mine model characterized by hydro-mechanical coupling and visco-elasto as well as elasto-plastic material behavior.The concept considers time-depending rock mass and backfill material behavior.Long-lasting and large-scale fluid flow within solution-filled and backfilled cavities as well as a cavern due to creep induced convergence is simulated.A new coupling scheme between the numerical codes FLAC3D and Ansys Fluent is developed and employed for this purpose giving plausible and accurate results by efficient simulation duration.The presented workflow provides a step-by-step overview for assessing long-term safety of abandoned mines,starting with indication of main aspects determining the geomechanical and hydraulic pro-cesses followed by the exemplary model set-up,the choice of constitutive models,the simplification of the modelled mining process,the model calibration and the interpretation of the numerical results.Different model scenarios in respect to initial fluid saturation are simulated considering a partially saturated mine and a fully saturated mine,which leads to free fluid surface evolution up to the generation of excess of fluid pressure.展开更多
Rock salt has excellent properties for its use as underground leak‐proof containers for the storage of renewable energy.Salt solution mining has long been used for salt mining,and can now be employed in the construct...Rock salt has excellent properties for its use as underground leak‐proof containers for the storage of renewable energy.Salt solution mining has long been used for salt mining,and can now be employed in the construction of underground salt caverns for the storage of hydrogen gas.This paper presents a wide range of methods to study the mineralogy,geochemistry,microstructure and geomechanical characteristics of rock salt,which are important in the engineering of safe underground storage rock salt caverns.The mineralogical composition of rock salt varies and is linked to its depositional environment and diagenetic alterations.The microstructure in rock salt is related to cataclastic deformation,diffusive mass transfer and intracrystalline plastic deformation,which can then be associated with the macrostructural geomechanical behavior.Compared to other types of rock,rock salt exhibits creep at lower temperatures.This behavior can be divided into three phases based on the changes in strain with time.However,at very low effective confining pressure and high deviatoric stress,rock salt can exhibit dilatant behavior,where brittle deformation could compromise the safety of underground gas storage in rock salt caverns.The proposed review presents the impact of purity,geochemistry and water content of rock salt on its geomechanical behavior,and thus,on the safety of the caverns.展开更多
Mining method selection is the first and the most critical problem in mine design and depends on some parameters such as geotechnical and geological features and economic and geographic factors. In this paper, the fac...Mining method selection is the first and the most critical problem in mine design and depends on some parameters such as geotechnical and geological features and economic and geographic factors. In this paper, the factors affecting mining method selection are determined. These factors include shape, thick- ness, depth, slope, RMR and RSS of the orebody, RMR and RSS of the hanging wall and footwall. Then, the priorities of these factors are calculated. In order to calculate the priorities of factors and select the best mining method for Qapiliq salt mine, Iran, based on these priorities, fuzzy analytical hierarchy process （AHP） technique is used. For this purpose, a questionnaire was prepared and was given to the associated experts. Finally, after a comparison carried out based on the effective factors, between the four mining methods including area mining, room and pillar, cut and fill and stope and pillar methods, the stope and nillar mining method was selected as the most suitable method to this mine.展开更多
According to information from on-the-spot investigations, the tectonics of salt mining areas and digital seismic records, we studied the activity of earthquakes induced by water pumping in and out of the salt mines in...According to information from on-the-spot investigations, the tectonics of salt mining areas and digital seismic records, we studied the activity of earthquakes induced by water pumping in and out of the salt mines in Shuanghe town, Changning county, Sichuan Province. The study found that the rates of water injection and extraction in the Shuanghe salt mining region were evenly matched before April 2006 and earthquake activity was stable. On the other hand, shallow small and moderate earthquake numbers increased sharply after the water injection rate became much larger than the water extraction rate. Large injection over a long time may causes the permeation of water through pre-existing small fractures and micro-cracks in the Changning anticlinal and accelerate the rupture of micro tectonic formations in nearby regions, inducing small earthquake swarm activity. The Q value calculated by using digital earthquake records indicates a relatively inhomogeneous medium in this area. The results of the accurate location of small earthquakes show that sources are relatively shallow and are concentrated at a depth of 2km to 3km. Focal mechanism solutions reveal a normal dip-slip character of shallow earthquakes. All of these show certain characteristics of earthquake activity induced by water injection.展开更多
Siwa Oasis,one of Egypts most remote settlements,is also a popular tourist destination thanks to the beautiful salt pools with water that people can float in.Salt is both a blessing and a curse in Siwa.Years ago,peopl...Siwa Oasis,one of Egypts most remote settlements,is also a popular tourist destination thanks to the beautiful salt pools with water that people can float in.Salt is both a blessing and a curse in Siwa.Years ago,people started realizing that there was money to be made in the salt trade,and salt mining operations created the salt lakes that the oasis is now famous for.展开更多
基金financial support from the National Key Research and Development Program of China(No.2024YFB4007100)the Basic ForwardLooking Project of the Sinopec Science and Technology Department,“Research on the Long-Term Sealing Mechanism of Multi-layer Salt Cavern Hydrogen Storage”(No.P24197-4)。
文摘Renewable energy storage technologies are critical for transitioning to sustainable energy systems,with salt caverns playing a significant role in large-scale solutions.In water-soluble mining of low-grade salt formations,insoluble impurities and interlayers detach during salt dissolution and accumulate as sediment at the cavern base,thereby reducing the storage capacity and economic viability of salt cavern gas storage(SCGS).This study investigates sediment formation mechanisms,void distribution,and voidage in the Huai'an low-grade salt mine,introducing a novel self-developed physical simulation device for two butted-well horizontal(TWH)caverns that replicates compressed air injection and brine discharge.Experiments comparing“one injection and one discharge”and“two injections and one discharge”modes revealed that(1)compressed air effectively displaces brine from sediment voids,(2)a 0.5 MPa injection pressure corresponds to a 10.3 MPa operational lower limit in practice,aligning with field data,and(3)sediment voidage is approximately 46%,validated via air-brine interface theory.The“two injections and one discharge”mode outperformed in both discharge volume and rate.Additionally,a mathematical model for brine displacement via compressed air was established.These results provide foundational insights for optimizing compressed air energy storage(CAES)in low-grade salt mines,advancing their role in renewable energy integration.
文摘Evaluation and prediction of the long-term behavior of abandoned mines have to consider complex interactions of different physical processes.The hydro-mechanical coupling plays an important role for potential short-and long-term environmental risks(e.g.surface subsidence,pollution of the biosphere,damage of the geological barrier,damage of groundwater regime).This work addresses challenges and key mechanisms in respect to longterm predictions for abandoned salt and potash mines and provides a general simulation concept.Exemplary,this concept is applied to a generic salt mine model characterized by hydro-mechanical coupling and visco-elasto as well as elasto-plastic material behavior.The concept considers time-depending rock mass and backfill material behavior.Long-lasting and large-scale fluid flow within solution-filled and backfilled cavities as well as a cavern due to creep induced convergence is simulated.A new coupling scheme between the numerical codes FLAC3D and Ansys Fluent is developed and employed for this purpose giving plausible and accurate results by efficient simulation duration.The presented workflow provides a step-by-step overview for assessing long-term safety of abandoned mines,starting with indication of main aspects determining the geomechanical and hydraulic pro-cesses followed by the exemplary model set-up,the choice of constitutive models,the simplification of the modelled mining process,the model calibration and the interpretation of the numerical results.Different model scenarios in respect to initial fluid saturation are simulated considering a partially saturated mine and a fully saturated mine,which leads to free fluid surface evolution up to the generation of excess of fluid pressure.
文摘Rock salt has excellent properties for its use as underground leak‐proof containers for the storage of renewable energy.Salt solution mining has long been used for salt mining,and can now be employed in the construction of underground salt caverns for the storage of hydrogen gas.This paper presents a wide range of methods to study the mineralogy,geochemistry,microstructure and geomechanical characteristics of rock salt,which are important in the engineering of safe underground storage rock salt caverns.The mineralogical composition of rock salt varies and is linked to its depositional environment and diagenetic alterations.The microstructure in rock salt is related to cataclastic deformation,diffusive mass transfer and intracrystalline plastic deformation,which can then be associated with the macrostructural geomechanical behavior.Compared to other types of rock,rock salt exhibits creep at lower temperatures.This behavior can be divided into three phases based on the changes in strain with time.However,at very low effective confining pressure and high deviatoric stress,rock salt can exhibit dilatant behavior,where brittle deformation could compromise the safety of underground gas storage in rock salt caverns.The proposed review presents the impact of purity,geochemistry and water content of rock salt on its geomechanical behavior,and thus,on the safety of the caverns.
文摘Mining method selection is the first and the most critical problem in mine design and depends on some parameters such as geotechnical and geological features and economic and geographic factors. In this paper, the factors affecting mining method selection are determined. These factors include shape, thick- ness, depth, slope, RMR and RSS of the orebody, RMR and RSS of the hanging wall and footwall. Then, the priorities of these factors are calculated. In order to calculate the priorities of factors and select the best mining method for Qapiliq salt mine, Iran, based on these priorities, fuzzy analytical hierarchy process （AHP） technique is used. For this purpose, a questionnaire was prepared and was given to the associated experts. Finally, after a comparison carried out based on the effective factors, between the four mining methods including area mining, room and pillar, cut and fill and stope and pillar methods, the stope and nillar mining method was selected as the most suitable method to this mine.
基金Key Project in the National Science and Technology Pillar Program in the Eleventh"Five-year Plan" Period (2006BA01B02-01-01)Project in the National Science and Technology Pillar Program(2006BAC01B04),China
文摘According to information from on-the-spot investigations, the tectonics of salt mining areas and digital seismic records, we studied the activity of earthquakes induced by water pumping in and out of the salt mines in Shuanghe town, Changning county, Sichuan Province. The study found that the rates of water injection and extraction in the Shuanghe salt mining region were evenly matched before April 2006 and earthquake activity was stable. On the other hand, shallow small and moderate earthquake numbers increased sharply after the water injection rate became much larger than the water extraction rate. Large injection over a long time may causes the permeation of water through pre-existing small fractures and micro-cracks in the Changning anticlinal and accelerate the rupture of micro tectonic formations in nearby regions, inducing small earthquake swarm activity. The Q value calculated by using digital earthquake records indicates a relatively inhomogeneous medium in this area. The results of the accurate location of small earthquakes show that sources are relatively shallow and are concentrated at a depth of 2km to 3km. Focal mechanism solutions reveal a normal dip-slip character of shallow earthquakes. All of these show certain characteristics of earthquake activity induced by water injection.
文摘Siwa Oasis,one of Egypts most remote settlements,is also a popular tourist destination thanks to the beautiful salt pools with water that people can float in.Salt is both a blessing and a curse in Siwa.Years ago,people started realizing that there was money to be made in the salt trade,and salt mining operations created the salt lakes that the oasis is now famous for.
