A seepage-geomechanical coupled embedded fracture flow model has been established for multi-field coupled simulation in tight oil reservoirs,revealing the patterns of change in pressure field,seepage field,and stress ...A seepage-geomechanical coupled embedded fracture flow model has been established for multi-field coupled simulation in tight oil reservoirs,revealing the patterns of change in pressure field,seepage field,and stress field after long-term water injection in tight oil reservoirs.Based on this,a technique for enhanced oil recovery(EOR)combining multi-field reconstruction and combination of displacement and imbibition in tight oil reservoirs has been proposed.The study shows that after long-term water flooding for tight oil development,the pressure diffusion range is limited,making it difficult to establish an effective displacement system.The variation in geostress exhibits diversity,with the change in horizontal minimum principal stress being greater than that in horizontal maximum principal stress,and the variation around the injection wells being more significant than that around the production wells.The deflection of geostress direction around injection wells is also large.The technology for EOR through multi-field reconstruction and combination of displacement and imbibition employs water injection wells converted to production and large-scale fracturing techniques to restructure the artificial fracture network system.Through a full lifecycle energy replenishment method of pre-fracturing energy supplementation,energy increase during fracturing,well soaking for energy storage,and combination of displacement and imbibition,it effectively addresses the issue of easy channeling of the injection medium and difficult energy replenishment after large-scale fracturing.By intensifying the imbibition effect through the coordination of multiple wells,it reconstructs the combined system of displacement and imbibition under a complex fracture network,transitioning from avoiding fractures to utilizing them,thereby improving microscopic sweep and oil displacement efficiencies.Field application in Block Yuan 284 of the Huaqing Oilfield in the Ordos Basin has demonstrated that this technology increases the recovery factor by 12 percentage points,enabling large scale and efficient development of tight oil.展开更多
正在新疆奇台建设的110 m全向可动射电望远镜是一个可以接受微弱射电信号的天文设备,台址周围较大范围内存在着数量众多的干扰源会影响其观测精度与效率.本文提出了一种基于抛物方程和时域物理光学法(Parabolic Equation and Time Domai...正在新疆奇台建设的110 m全向可动射电望远镜是一个可以接受微弱射电信号的天文设备,台址周围较大范围内存在着数量众多的干扰源会影响其观测精度与效率.本文提出了一种基于抛物方程和时域物理光学法(Parabolic Equation and Time Domain Physical Optics, PE-TDPO)的混合计算方法,以110 m全向可动射电望远镜为研究对象,对台址附近大区域内干扰源信号的传播过程进行建模.在较大地理尺度上对干扰信号从台址远场至近场的电磁耦合特性进行了综合评估,为大型射电望远镜电磁干扰问题处理提供理论依据.本文以通信基站作为典型干扰源,基于数字地图建立射电望远镜台址周围的高精度地形模型,采用抛物方程对干扰信号的远场电波传播进行分析,得到从干扰源处至射电望远镜处的信号传播的路径损耗和传播因子;其次将PE方法计算得出的远场电场值代入TDPO的积分中,得到干扰信号在射电望远镜焦点处的近场耦合特性;最后讨论了远场干扰源特性对射电望远镜的远-近场耦合的影响.展开更多
基金Supported by the Joint Fund Project of the National Natural Science Foundation of China(U22B2075).
文摘A seepage-geomechanical coupled embedded fracture flow model has been established for multi-field coupled simulation in tight oil reservoirs,revealing the patterns of change in pressure field,seepage field,and stress field after long-term water injection in tight oil reservoirs.Based on this,a technique for enhanced oil recovery(EOR)combining multi-field reconstruction and combination of displacement and imbibition in tight oil reservoirs has been proposed.The study shows that after long-term water flooding for tight oil development,the pressure diffusion range is limited,making it difficult to establish an effective displacement system.The variation in geostress exhibits diversity,with the change in horizontal minimum principal stress being greater than that in horizontal maximum principal stress,and the variation around the injection wells being more significant than that around the production wells.The deflection of geostress direction around injection wells is also large.The technology for EOR through multi-field reconstruction and combination of displacement and imbibition employs water injection wells converted to production and large-scale fracturing techniques to restructure the artificial fracture network system.Through a full lifecycle energy replenishment method of pre-fracturing energy supplementation,energy increase during fracturing,well soaking for energy storage,and combination of displacement and imbibition,it effectively addresses the issue of easy channeling of the injection medium and difficult energy replenishment after large-scale fracturing.By intensifying the imbibition effect through the coordination of multiple wells,it reconstructs the combined system of displacement and imbibition under a complex fracture network,transitioning from avoiding fractures to utilizing them,thereby improving microscopic sweep and oil displacement efficiencies.Field application in Block Yuan 284 of the Huaqing Oilfield in the Ordos Basin has demonstrated that this technology increases the recovery factor by 12 percentage points,enabling large scale and efficient development of tight oil.
文摘正在新疆奇台建设的110 m全向可动射电望远镜是一个可以接受微弱射电信号的天文设备,台址周围较大范围内存在着数量众多的干扰源会影响其观测精度与效率.本文提出了一种基于抛物方程和时域物理光学法(Parabolic Equation and Time Domain Physical Optics, PE-TDPO)的混合计算方法,以110 m全向可动射电望远镜为研究对象,对台址附近大区域内干扰源信号的传播过程进行建模.在较大地理尺度上对干扰信号从台址远场至近场的电磁耦合特性进行了综合评估,为大型射电望远镜电磁干扰问题处理提供理论依据.本文以通信基站作为典型干扰源,基于数字地图建立射电望远镜台址周围的高精度地形模型,采用抛物方程对干扰信号的远场电波传播进行分析,得到从干扰源处至射电望远镜处的信号传播的路径损耗和传播因子;其次将PE方法计算得出的远场电场值代入TDPO的积分中,得到干扰信号在射电望远镜焦点处的近场耦合特性;最后讨论了远场干扰源特性对射电望远镜的远-近场耦合的影响.
