Proppants transport is an advanced technique to improve the hydraulic fracture phenomenon,in order to promote the versatility of gas/oil reservoirs.A numerical simulation of proppants transport at both hydraulic fract...Proppants transport is an advanced technique to improve the hydraulic fracture phenomenon,in order to promote the versatility of gas/oil reservoirs.A numerical simulation of proppants transport at both hydraulic fracture(HF)and natural fracture(NF)intersection is performed to provide a better understand-ing of key factors which cause,or contribute to proppants transport in HF-NF intersection.Computational fluid dynamics(CFD)in association with discrete element method(DEM)is used to model the complex interactions between proppant particles,host fluid medium and fractured walls.The effect of non-spherical geometry of particles is considered in this model,using the multi-sphere method.All interaction forces between fluid flow and particles are considered in the computational model.Moreover,the inter-actions of particle-particle and particle-wall are taken into account via Hertz-Mindlin model.The results of the CFD-DEM simulations are compared to the experimental data.It is found that the CFD-DEM sim-ulation is capable of predicting proppant transport and deposition quality at intersections which are in agreement with experimental data.The results indicate that the HF-NF intersection type,fluid velocity and NF aperture affect the quality of blockage occurrence,presenting a new index,called the blockage coefficient which indicates the severity of the blockage.展开更多
We investigate the effect of particle shape on the transportation mechanism in well-drilling using a three-dimensional model that couples computational fluid dynamics （CFD） with the discrete element method （DEM）. ...We investigate the effect of particle shape on the transportation mechanism in well-drilling using a three-dimensional model that couples computational fluid dynamics （CFD） with the discrete element method （DEM）. This numerical method allows us to incorporate the fluid-particle interactions （drag force, contact force, Saffman lift force, Magnus lift force, buoyancy force） using momentum exchange and the non-Newtonian behavior of the fluid. The interactions of particle-particle, particle-wall, and particle-drill pipe are taken into account with the Hertz-Mindlin model. We compare the transport of spheres with non-spherical particles （non-smooth sphere, disc, and cubic） constructed via the multi- sphere method for a range of fluid inlet velocities and drill pipe inclination angles. The simulations are carried out for laboratory-scale drilling configurations. Our results demonstrate good agreement with published experimental data. We evaluate the fluid-particle flow patterns, the particle velocities, and the particle concentration profiles. The results reveal that particle sphericity plays a major role in the fluid-solid interaction. The traditional assumption of an ideal spherical particle may cause inaccurate results.展开更多
文摘Proppants transport is an advanced technique to improve the hydraulic fracture phenomenon,in order to promote the versatility of gas/oil reservoirs.A numerical simulation of proppants transport at both hydraulic fracture(HF)and natural fracture(NF)intersection is performed to provide a better understand-ing of key factors which cause,or contribute to proppants transport in HF-NF intersection.Computational fluid dynamics(CFD)in association with discrete element method(DEM)is used to model the complex interactions between proppant particles,host fluid medium and fractured walls.The effect of non-spherical geometry of particles is considered in this model,using the multi-sphere method.All interaction forces between fluid flow and particles are considered in the computational model.Moreover,the inter-actions of particle-particle and particle-wall are taken into account via Hertz-Mindlin model.The results of the CFD-DEM simulations are compared to the experimental data.It is found that the CFD-DEM sim-ulation is capable of predicting proppant transport and deposition quality at intersections which are in agreement with experimental data.The results indicate that the HF-NF intersection type,fluid velocity and NF aperture affect the quality of blockage occurrence,presenting a new index,called the blockage coefficient which indicates the severity of the blockage.
文摘We investigate the effect of particle shape on the transportation mechanism in well-drilling using a three-dimensional model that couples computational fluid dynamics （CFD） with the discrete element method （DEM）. This numerical method allows us to incorporate the fluid-particle interactions （drag force, contact force, Saffman lift force, Magnus lift force, buoyancy force） using momentum exchange and the non-Newtonian behavior of the fluid. The interactions of particle-particle, particle-wall, and particle-drill pipe are taken into account with the Hertz-Mindlin model. We compare the transport of spheres with non-spherical particles （non-smooth sphere, disc, and cubic） constructed via the multi- sphere method for a range of fluid inlet velocities and drill pipe inclination angles. The simulations are carried out for laboratory-scale drilling configurations. Our results demonstrate good agreement with published experimental data. We evaluate the fluid-particle flow patterns, the particle velocities, and the particle concentration profiles. The results reveal that particle sphericity plays a major role in the fluid-solid interaction. The traditional assumption of an ideal spherical particle may cause inaccurate results.
