This paper presents a three-dimensional fully hydro-mechanical coupled distinct element study on fault reactivation and induced seismicity due to hydraulic fracturing injection and subsequent backflow process,based on...This paper presents a three-dimensional fully hydro-mechanical coupled distinct element study on fault reactivation and induced seismicity due to hydraulic fracturing injection and subsequent backflow process,based on the geological data in Horn River Basin,Northeast British Columbia,Canada.The modeling results indicate that the maximum magnitude of seismic events appears at the fracturing stage.The increment of fluid volume in the fault determines the cumulative moment and maximum fault slippage,both of which are essentially proportional to the fluid volume.After backflow starts,the fluid near the joint intersection keeps flowing into the critically stressed fault,rather than backflows to the wellbore.Although fault slippage is affected by the changes of both pore pressure and ambient rock stress,their contributions are different at fracturing and backflow stages.At fracturing stage,pore pressure change shows a dominant effect on induced fault slippage.While at backflow stage,because the fault plane is under a critical stress state,any minor disturbance would trigger a fault slippage.The energy analysis indicates that aseismic deformation takes up a majority of the total deformation energy during hydraulic fracturing.A common regularity is found in both fracturing-and backflow-induced seismicity that the cumulative moment and maximum fault slippage are nearly proportional to the injected fluid volume.This study shows some novel insights into interpreting fracturing-and backflowinduced seismicity,and provides useful information for controlling and mitigating seismic hazards due to hydraulic fracturing.展开更多
This paper presents an improved three-dimensional non-equilibrium mixing pool model.It is a simplified form of the original model and is more practical for applications.The simulation re-sults show that the industrial...This paper presents an improved three-dimensional non-equilibrium mixing pool model.It is a simplified form of the original model and is more practical for applications.The simulation re-sults show that the industrial scale distillation tray columns can be described closely by the improvedmodel.The effects of model parameters,such as the number of mixing pools,the point efficiencyand flow pattern,on separation are analyzed quantitatively.展开更多
为了能够将脉冲等离子体推力器成功地运用于空间,需对其羽流进行研究。将一维MHD双温放电模型的计算结果作为入口条件,运用DSMC(Direct Simulation Monte-Carlo)/PIC(Particle in Cell)流体混合算法一体化模拟实验室PPT羽流。验证计算...为了能够将脉冲等离子体推力器成功地运用于空间,需对其羽流进行研究。将一维MHD双温放电模型的计算结果作为入口条件,运用DSMC(Direct Simulation Monte-Carlo)/PIC(Particle in Cell)流体混合算法一体化模拟实验室PPT羽流。验证计算显示该模型具有一体化模拟脉冲等离子体推力器羽流的能力。对不同初始放电能量下的羽流场进行模拟,给出了离子、中性粒子、电子温度、轴线上质量流率和出口平面返流质量流率的变化情况。计算结果显示高放电能量下返流量更大,同时中性粒子在返流中所占比例也越大。展开更多
基金supported by the Key Innovation Team Program of Innovation Talents Promotion Plan by Ministry of Science and Technology of China(Grant No.2016RA4059)National Natural Science Foundation of China(Grant Nos.41672268 and 41772286)。
文摘This paper presents a three-dimensional fully hydro-mechanical coupled distinct element study on fault reactivation and induced seismicity due to hydraulic fracturing injection and subsequent backflow process,based on the geological data in Horn River Basin,Northeast British Columbia,Canada.The modeling results indicate that the maximum magnitude of seismic events appears at the fracturing stage.The increment of fluid volume in the fault determines the cumulative moment and maximum fault slippage,both of which are essentially proportional to the fluid volume.After backflow starts,the fluid near the joint intersection keeps flowing into the critically stressed fault,rather than backflows to the wellbore.Although fault slippage is affected by the changes of both pore pressure and ambient rock stress,their contributions are different at fracturing and backflow stages.At fracturing stage,pore pressure change shows a dominant effect on induced fault slippage.While at backflow stage,because the fault plane is under a critical stress state,any minor disturbance would trigger a fault slippage.The energy analysis indicates that aseismic deformation takes up a majority of the total deformation energy during hydraulic fracturing.A common regularity is found in both fracturing-and backflow-induced seismicity that the cumulative moment and maximum fault slippage are nearly proportional to the injected fluid volume.This study shows some novel insights into interpreting fracturing-and backflowinduced seismicity,and provides useful information for controlling and mitigating seismic hazards due to hydraulic fracturing.
基金Supported by the National Natural Science Foundation of China.
文摘This paper presents an improved three-dimensional non-equilibrium mixing pool model.It is a simplified form of the original model and is more practical for applications.The simulation re-sults show that the industrial scale distillation tray columns can be described closely by the improvedmodel.The effects of model parameters,such as the number of mixing pools,the point efficiencyand flow pattern,on separation are analyzed quantitatively.
文摘为了能够将脉冲等离子体推力器成功地运用于空间,需对其羽流进行研究。将一维MHD双温放电模型的计算结果作为入口条件,运用DSMC(Direct Simulation Monte-Carlo)/PIC(Particle in Cell)流体混合算法一体化模拟实验室PPT羽流。验证计算显示该模型具有一体化模拟脉冲等离子体推力器羽流的能力。对不同初始放电能量下的羽流场进行模拟,给出了离子、中性粒子、电子温度、轴线上质量流率和出口平面返流质量流率的变化情况。计算结果显示高放电能量下返流量更大,同时中性粒子在返流中所占比例也越大。
