As a non-renewable rare industrial gas resource,the decreasing production of helium has stimulated the demand for large-scale storage.Dewar tanks,storage tanks and other liquid helium storage methods are difficult to ...As a non-renewable rare industrial gas resource,the decreasing production of helium has stimulated the demand for large-scale storage.Dewar tanks,storage tanks and other liquid helium storage methods are difficult to meet the needs of largescale and long-term storage.Salt caverns have been widely used in gas energy storage due to their low permeability,which has been proven by decades of stable operation of natural gas storage.However,helium has higher permeability under the same storage conditions,and the feasibility of using rock salt for helium storage has not yet been evaluated by mature theories and standards.In addition,an overlooked fact is that the permeability characteristics of rock salt and micro-permeable layers(MPL)are very different,and MPL can provide leakage channels for high-pressure helium.In this paper,a seepage movement model of small molecule gas in MPL is established.Its calculative accuracy and engineering applicability are verified by the seepage test results.The MPL has crystal structure,which makes the permeability change with different confining pressure and gas injection pressure.The change of permeability is caused by the residual brine in the crystal void.The compaction and the increase of flow velocity of salt rock crystal void increase the viscous resistance and decrease the flow velocity.The permeability of nitrogen and helium in the MPL is different,but the difference decreases at high confining pressure and high injection pressure.In deep salt formations with plateau potential stress,the difference of surrounding rock leakage characteristics between helium and natural gas is smaller,and the expected leakage amount of helium is lower.The paper proposes a numerical calculation model suitable for predicting leaks in salt cavern helium storage facilities with known faults and structural planes,completing the assessment of helium leakage in salt caverns considering the gas physical properties,injection and production conditions,operating pressure,and in-situ stress of surrounding rocks.The above achievements can provide technical references for early-stage leakage prediction and parameter optimization in helium storage salt cavern engineering.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.42072307,52404066)the Hubei Province Outstanding Youth Fund(Grant No.2021CFA095)+1 种基金the Natural Science Foundation of Wuhan(Grant Nos.2024040701010062,2024040801020255)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDC10020300)。
文摘As a non-renewable rare industrial gas resource,the decreasing production of helium has stimulated the demand for large-scale storage.Dewar tanks,storage tanks and other liquid helium storage methods are difficult to meet the needs of largescale and long-term storage.Salt caverns have been widely used in gas energy storage due to their low permeability,which has been proven by decades of stable operation of natural gas storage.However,helium has higher permeability under the same storage conditions,and the feasibility of using rock salt for helium storage has not yet been evaluated by mature theories and standards.In addition,an overlooked fact is that the permeability characteristics of rock salt and micro-permeable layers(MPL)are very different,and MPL can provide leakage channels for high-pressure helium.In this paper,a seepage movement model of small molecule gas in MPL is established.Its calculative accuracy and engineering applicability are verified by the seepage test results.The MPL has crystal structure,which makes the permeability change with different confining pressure and gas injection pressure.The change of permeability is caused by the residual brine in the crystal void.The compaction and the increase of flow velocity of salt rock crystal void increase the viscous resistance and decrease the flow velocity.The permeability of nitrogen and helium in the MPL is different,but the difference decreases at high confining pressure and high injection pressure.In deep salt formations with plateau potential stress,the difference of surrounding rock leakage characteristics between helium and natural gas is smaller,and the expected leakage amount of helium is lower.The paper proposes a numerical calculation model suitable for predicting leaks in salt cavern helium storage facilities with known faults and structural planes,completing the assessment of helium leakage in salt caverns considering the gas physical properties,injection and production conditions,operating pressure,and in-situ stress of surrounding rocks.The above achievements can provide technical references for early-stage leakage prediction and parameter optimization in helium storage salt cavern engineering.
