Gas and water migration through the hydrate-bearing sediment are characteristic features in marine gas hydrate reservoirs worldwide.However,there are few experimental investigations on the effect of water-gas flow on ...Gas and water migration through the hydrate-bearing sediment are characteristic features in marine gas hydrate reservoirs worldwide.However,there are few experimental investigations on the effect of water-gas flow on the gas hydrate reservoir.In this study,gas-water migration in gas hydrate stability zone(GHSZ)was investigated visually employing a high-resolution magnetic resonance imaging(MRI)apparatus,and the formation of hydrate seal was experimentally investigated.Results revealed that normal flow of gas-water at the low flow rate of 1–0.25 mL/min will induce the hydrate reformation.Conversely,higher gas-water flow rates(at 2–0.5 and 4–1 mL/min)need higher reservoir pressure to induce the hydrate reformation.In addition,the hydrate reformation during the gas-water flow process produced the hydrate seal,which can withstand an over 9.0 MPa overpressure.This high overpressure provides the development condition for the underlying gas and/or water reservoir.A composite MRI image of the whole hydrate seal was obtained through the MRI.The pore difference between hydrate zone and coexistence zone produces a capillary sealing effect for hydrate seal.The hydrate saturation of hydrate seal was more than 51.6%,and the water saturation was more than 19.3%.However,the hydrate seal can be broken through when the overpressure exceeded the capillary pressure of the hydrate seal,which induced the sudden drop of reservoir pressure.This study provides a scientific explanation for the existence of high-pressure underlying gas below the hydrate layer and is significant for the safe exploitation of these common typical marine hydrate reservoirs.展开更多
AIM:To evaluate the correlation between Demodex infestation and keratitis,and to assess demodicosis using a simple approach.METHODS:A modified slit lamp illumination(at 40×magnification)was used to observe Demode...AIM:To evaluate the correlation between Demodex infestation and keratitis,and to assess demodicosis using a simple approach.METHODS:A modified slit lamp illumination(at 40×magnification)was used to observe Demodex tails in 40patients with refractory keratitis and 80 healthy controls.Bacterial smear and culture of the conjunctival sac and corneal lesion were performed to identify the pathogen.Tea tree oil ointment(TTOO)was added as a Demodex killing agent for lid scrubs to the treatment when Demodex infestation was confirmed.RESULTS:Demodex tails were found in all patients compared to 42/80 of the controls(P<0.01).Seventeen patients presented blepharitis,while 23 were free of scales and inflammation at the lid margin.The demodicosis was mild,moderate,and severe in 8,19,and 13 patients,respectively,compared to mild in 42 controls(P<0.01).The keratitis was mild,moderate,and severe in 13,19,and 8patients,respectively.The severity of Demodex infestation was not correlated to the severity of keratitis(P=0.126).The growth of Staphylococcus was revealed in nine patients who did not react to antibiotic eye drops prior to the TTOO treatment.Patients’signs and symptoms got resolved after the lid scrub with TTOO.CONCLUSION:Ocular Demodex needs to be checked and treated in refractory keratitis patients with or without blepharitis.A slit-lamp illumination under high magnification favors the judgment of the severity of Demodex infestation.展开更多
基金supported by the National Key Research and Development Plan of China(2021YFC2800902)the National Natural Science Foundation of China(52206076,U19B2005)+1 种基金the Fundamental Research Funds for the Central Universities of China(DUT21ZD103)the Opening Fund of MOE Key Laboratory of Ocean Energy Utilization and Energy Conservation(LOEC-202204).
文摘Gas and water migration through the hydrate-bearing sediment are characteristic features in marine gas hydrate reservoirs worldwide.However,there are few experimental investigations on the effect of water-gas flow on the gas hydrate reservoir.In this study,gas-water migration in gas hydrate stability zone(GHSZ)was investigated visually employing a high-resolution magnetic resonance imaging(MRI)apparatus,and the formation of hydrate seal was experimentally investigated.Results revealed that normal flow of gas-water at the low flow rate of 1–0.25 mL/min will induce the hydrate reformation.Conversely,higher gas-water flow rates(at 2–0.5 and 4–1 mL/min)need higher reservoir pressure to induce the hydrate reformation.In addition,the hydrate reformation during the gas-water flow process produced the hydrate seal,which can withstand an over 9.0 MPa overpressure.This high overpressure provides the development condition for the underlying gas and/or water reservoir.A composite MRI image of the whole hydrate seal was obtained through the MRI.The pore difference between hydrate zone and coexistence zone produces a capillary sealing effect for hydrate seal.The hydrate saturation of hydrate seal was more than 51.6%,and the water saturation was more than 19.3%.However,the hydrate seal can be broken through when the overpressure exceeded the capillary pressure of the hydrate seal,which induced the sudden drop of reservoir pressure.This study provides a scientific explanation for the existence of high-pressure underlying gas below the hydrate layer and is significant for the safe exploitation of these common typical marine hydrate reservoirs.
基金Supported by the National Natural Science Foundation of China(No.82271052,No.82271058,No.U20A20386)the Taishan Scholar Program(No.tspd20150215,No.tsqn201909188)。
文摘AIM:To evaluate the correlation between Demodex infestation and keratitis,and to assess demodicosis using a simple approach.METHODS:A modified slit lamp illumination(at 40×magnification)was used to observe Demodex tails in 40patients with refractory keratitis and 80 healthy controls.Bacterial smear and culture of the conjunctival sac and corneal lesion were performed to identify the pathogen.Tea tree oil ointment(TTOO)was added as a Demodex killing agent for lid scrubs to the treatment when Demodex infestation was confirmed.RESULTS:Demodex tails were found in all patients compared to 42/80 of the controls(P<0.01).Seventeen patients presented blepharitis,while 23 were free of scales and inflammation at the lid margin.The demodicosis was mild,moderate,and severe in 8,19,and 13 patients,respectively,compared to mild in 42 controls(P<0.01).The keratitis was mild,moderate,and severe in 13,19,and 8patients,respectively.The severity of Demodex infestation was not correlated to the severity of keratitis(P=0.126).The growth of Staphylococcus was revealed in nine patients who did not react to antibiotic eye drops prior to the TTOO treatment.Patients’signs and symptoms got resolved after the lid scrub with TTOO.CONCLUSION:Ocular Demodex needs to be checked and treated in refractory keratitis patients with or without blepharitis.A slit-lamp illumination under high magnification favors the judgment of the severity of Demodex infestation.
