Co2MnSi thin films are made by magnetron sputtering onto MgO （001） substrates. The crystalline quality is improved by increasing depositing temperature and/or annealing temperature. The sample deposited at 550℃ and...Co2MnSi thin films are made by magnetron sputtering onto MgO （001） substrates. The crystalline quality is improved by increasing depositing temperature and/or annealing temperature. The sample deposited at 550℃ and subsequently annealed at 550℃ （sample I） exhibits a pseudo-epitaxial growth with partially ordered L21 phase. Sample I shows a four-fold magnetic anisotropy, in addition to a relatively weak uniaxial anisotropy. The Gilbert damping factor of sample I is smaller than 0.001, much smaller than reported ones. The possible reasons responsible for the small Gilbert damping factor are discussed, including weak spin-orbit coupling, small density of states at Fermi level, and so on.展开更多
为揭示低渗气藏中注CO2提高气藏采收率和CO2埋存(carbon sequestration with enhanced gas recovery,CSEGR)技术的效果,以苏里格气田召10区块为例,开展了注CO2驱气的长岩心实验,并使用数值模拟的研究手段,分析了该区块采用CSEGR技术的...为揭示低渗气藏中注CO2提高气藏采收率和CO2埋存(carbon sequestration with enhanced gas recovery,CSEGR)技术的效果,以苏里格气田召10区块为例,开展了注CO2驱气的长岩心实验,并使用数值模拟的研究手段,分析了该区块采用CSEGR技术的可行性,并重点研究了扩散、吸附、天然裂缝、井型对于CO2突破时间、气藏采收率及CO2埋存的影响。模拟结果表明:采用面积为3.2km^2的平行四边形“二注七采”井网,在气藏衰竭开采至12MPa后注CO2,在CO2突破时能够提高采收率14.26%,共能实现3.8×10^6t的CO2埋存;在废弃压力3MPa时注入CO2采收率仅能增加2.2%,但CO2埋存量可提高至1.44倍;在低渗气藏中扩散和吸附对于CO2驱的影响不大;随着扩散系数增大,CO2突破越快,提高采收率效果越差;吸附滞后现象会略微降低提高采收率的效果;天然裂缝的存在会使气窜现象严重,突破时间大大提前,且裂缝渗透率越高,提高采收率效果越差,但依然可以实现CO2安全稳定埋存;与直井相比,采用水平井注气将使提高采收率效果降低6%~8%,但对埋存有利。展开更多
基金Supported by the National Basic Research Program of China under Grant No 2015CB921502the National Natural Science Foundation of China under Grant Nos 11474184 and 11174183+3 种基金the 111 Project under Grant No B13029the Natural Science Foundation of Shandong Province under Grant No JQ201201the Doctorate Foundation of Shandong Province under Grant No BS2013CL042the Young Scientists Fund of the National Natural Science Foundation of China under Grant No 11204164
文摘Co2MnSi thin films are made by magnetron sputtering onto MgO （001） substrates. The crystalline quality is improved by increasing depositing temperature and/or annealing temperature. The sample deposited at 550℃ and subsequently annealed at 550℃ （sample I） exhibits a pseudo-epitaxial growth with partially ordered L21 phase. Sample I shows a four-fold magnetic anisotropy, in addition to a relatively weak uniaxial anisotropy. The Gilbert damping factor of sample I is smaller than 0.001, much smaller than reported ones. The possible reasons responsible for the small Gilbert damping factor are discussed, including weak spin-orbit coupling, small density of states at Fermi level, and so on.
文摘为揭示低渗气藏中注CO2提高气藏采收率和CO2埋存(carbon sequestration with enhanced gas recovery,CSEGR)技术的效果,以苏里格气田召10区块为例,开展了注CO2驱气的长岩心实验,并使用数值模拟的研究手段,分析了该区块采用CSEGR技术的可行性,并重点研究了扩散、吸附、天然裂缝、井型对于CO2突破时间、气藏采收率及CO2埋存的影响。模拟结果表明:采用面积为3.2km^2的平行四边形“二注七采”井网,在气藏衰竭开采至12MPa后注CO2,在CO2突破时能够提高采收率14.26%,共能实现3.8×10^6t的CO2埋存;在废弃压力3MPa时注入CO2采收率仅能增加2.2%,但CO2埋存量可提高至1.44倍;在低渗气藏中扩散和吸附对于CO2驱的影响不大;随着扩散系数增大,CO2突破越快,提高采收率效果越差;吸附滞后现象会略微降低提高采收率的效果;天然裂缝的存在会使气窜现象严重,突破时间大大提前,且裂缝渗透率越高,提高采收率效果越差,但依然可以实现CO2安全稳定埋存;与直井相比,采用水平井注气将使提高采收率效果降低6%~8%,但对埋存有利。
