Water invasion is a common phenomenon in gas reservoirs with active edge-and-bottom aquifers.Due to high reservoir heterogeneity and production parameters,carbonate gas reservoirs feature exploitation obstacles and lo...Water invasion is a common phenomenon in gas reservoirs with active edge-and-bottom aquifers.Due to high reservoir heterogeneity and production parameters,carbonate gas reservoirs feature exploitation obstacles and low recovery factors.In this study,combined core displacement and nuclear magnetic resonance(NMR)experiments explored the reservoir gas−water two-phase flow and remaining microscopic gas distribution during water invasion and gas injection.Consequently,for fracture core,the water-phase relative permeability is higher and the co-seepage interval is narrower than that of three pore cores during water invasion,whereas the water-drive recovery efficiency at different invasion rates is the lowest among all cores.Gas injection is beneficial for reducing water saturation and partially restoring the gas-phase relative permeability,especially for fracture core.The remaining gas distribution and the content are related to the core properties.Compared with pore cores,the water invasion rate strongly influences the residual gas distribution in fracture core.The results enhance the understanding of the water invasion mechanism,gas injection to resume production and the remaining gas distribution,so as to improve the recovery factors of carbonate gas reservoirs.展开更多
To investigate effect of metallic ion activation on different particle sizes of quartz in butyl xanthate solution,six common ions(Pb^(2+),Cu^(2+),Fe^(3+),Fe^(2+),Mg^(2+) and Ca^(2+)) were introduced as activators.The ...To investigate effect of metallic ion activation on different particle sizes of quartz in butyl xanthate solution,six common ions(Pb^(2+),Cu^(2+),Fe^(3+),Fe^(2+),Mg^(2+) and Ca^(2+)) were introduced as activators.The approaches of micro-flotation,adsorption test and zeta potential measurement were adopted to reveal the mechanism of ion activation.The results show that Pb^(2+),Cu^(2+) and Fe^(3+) are effective activators for the flotation of quartz in butyl xanthate solution because of their absorption on activated quartz surface.Average recoveries of fine particles(<37 μm) are greater than those of coarser particles(37-74 μm),suggesting that the former is easier to be activated and more likely to be floated and thus entrained in sulphide concentrate.From another perspective,addition of metallic ions(Pb^(2+),Cu^(2+) and Fe^(3+)) renders zeta potentials move positively,and addition of the same metallic ions and butyl xanthate makes zeta potential drop apparently,which support a mechanism where they adsorb onto quartz surface,resulting in an expected increase in butyl xanthate collector adsorption with a concomitant increase in the flotation recoveries.展开更多
基金Project(2016ZX05017)supported by the China National Science and Technology Major Project
文摘Water invasion is a common phenomenon in gas reservoirs with active edge-and-bottom aquifers.Due to high reservoir heterogeneity and production parameters,carbonate gas reservoirs feature exploitation obstacles and low recovery factors.In this study,combined core displacement and nuclear magnetic resonance(NMR)experiments explored the reservoir gas−water two-phase flow and remaining microscopic gas distribution during water invasion and gas injection.Consequently,for fracture core,the water-phase relative permeability is higher and the co-seepage interval is narrower than that of three pore cores during water invasion,whereas the water-drive recovery efficiency at different invasion rates is the lowest among all cores.Gas injection is beneficial for reducing water saturation and partially restoring the gas-phase relative permeability,especially for fracture core.The remaining gas distribution and the content are related to the core properties.Compared with pore cores,the water invasion rate strongly influences the residual gas distribution in fracture core.The results enhance the understanding of the water invasion mechanism,gas injection to resume production and the remaining gas distribution,so as to improve the recovery factors of carbonate gas reservoirs.
基金Project(51274255)supported by the National Natural Science Foundation of ChinaProject(2015CX005)supported by Innovation Driven Plan of Central South University,China+1 种基金Project(2016RS2016)supported by Hunan Provincial Science and Technology Leader(Innovation Team of Interface Chemistry of Efficient and Clean Utilization of Complex Mineral Resources),ChinaProject supported by the Postdoctoral Research Station of Central South University,China
文摘To investigate effect of metallic ion activation on different particle sizes of quartz in butyl xanthate solution,six common ions(Pb^(2+),Cu^(2+),Fe^(3+),Fe^(2+),Mg^(2+) and Ca^(2+)) were introduced as activators.The approaches of micro-flotation,adsorption test and zeta potential measurement were adopted to reveal the mechanism of ion activation.The results show that Pb^(2+),Cu^(2+) and Fe^(3+) are effective activators for the flotation of quartz in butyl xanthate solution because of their absorption on activated quartz surface.Average recoveries of fine particles(<37 μm) are greater than those of coarser particles(37-74 μm),suggesting that the former is easier to be activated and more likely to be floated and thus entrained in sulphide concentrate.From another perspective,addition of metallic ions(Pb^(2+),Cu^(2+) and Fe^(3+)) renders zeta potentials move positively,and addition of the same metallic ions and butyl xanthate makes zeta potential drop apparently,which support a mechanism where they adsorb onto quartz surface,resulting in an expected increase in butyl xanthate collector adsorption with a concomitant increase in the flotation recoveries.
