Chemical flooding is one of the effective technologies to increase oil recovery of petroleum reservoirs after water flooding.Above the scale of representative elementary volume(REV), phenomenological modeling and nume...Chemical flooding is one of the effective technologies to increase oil recovery of petroleum reservoirs after water flooding.Above the scale of representative elementary volume(REV), phenomenological modeling and numerical simulations of chemical flooding have been reported in literatures,but the studies alike are rarely conducted at the pore-scale,at which the effects of physicochemical hydrodynamics are hardly resolved either by experimental observations or by traditional continuum-based simulations.In this paper,dissipative particle dynamics(DPD),one of mesoscopic fluid particle methods,is introduced to simulate the pore-scale flow in chemical flooding processes.The theoretical background,mathematical formulation and numerical approach of DPD are presented.The plane Poiseuille flow is used to illustrate the accuracy of the DPD simulation,and then the processes of polymer flooding through an oil-wet throat and a water-wet throat are studies, respectively.The selected parameters of those simulations are given in details.These preliminary results show the potential of this novel method for modeling the physicochemical hydrodynamics at the pore scale in the area of chemical enhanced oil recovery.展开更多
Chemical flooding has been widely used in the oil industry since the 1980s for enhanced oil recovery(EOR)process.Previous studies have shown that the effectiveness of calcium carbonate scale inhibitors is affected by ...Chemical flooding has been widely used in the oil industry since the 1980s for enhanced oil recovery(EOR)process.Previous studies have shown that the effectiveness of calcium carbonate scale inhibitors is affected by many factors,such as water composition,system pressure,temperature,production rates,pH etc.The breakthrough of the EOR chemicals in the production well could also affect scale formation process and interfere with the scale treatment program as well.However,the studies on the impacts of injected EOR chemicals to scale inhibitor performances are very limited.This paper presents the comprehensive laboratory study on the impacts of the EOR chemicals on CaCO3 scale formation and prevention using static bottle and dynamic tube blocking methods.The EOR chemicals used in this study are a combination of surfactants and polymers.Three different types of inhibitors were evaluated:triphosphonate,penta-phosphonate,and polyacrylate based chemicals.Inhibition(%)from the bottle test and minimum effective dose(MED)based on the tube blocking method were determined for each inhibitor at 160F.Scale precipitates from the bottle tests were also characterized for morphology and polymorphs using environmental scanning electron(ESEM)and X-ray diffraction(XRD)techniques.Results suggest that the performance of scale inhibitors could be substantially affected by the EOR chemicals.In dynamic tube blocking tests,the MED values of inhibitors were increased roughly 10 times with the EOR chemicals.The static bottle tests showed considerable changes under the test conditions.The impact of EOR chemicals were also demonstrated by the remarkable ranges of crystal morphologies,changing from simple aragonite columns to nanorod,distorted spheroid,and flower-like superstructure in the presence of EOR chemicals and inhibitors.展开更多
基金supported by the National Basic Research Program of China(2005CB221307 & 2005CB221304)China Postdoctoral Science Foundation(20090460391 & 201003138)PetroChina RIPED Innovations Foundation.
文摘Chemical flooding is one of the effective technologies to increase oil recovery of petroleum reservoirs after water flooding.Above the scale of representative elementary volume(REV), phenomenological modeling and numerical simulations of chemical flooding have been reported in literatures,but the studies alike are rarely conducted at the pore-scale,at which the effects of physicochemical hydrodynamics are hardly resolved either by experimental observations or by traditional continuum-based simulations.In this paper,dissipative particle dynamics(DPD),one of mesoscopic fluid particle methods,is introduced to simulate the pore-scale flow in chemical flooding processes.The theoretical background,mathematical formulation and numerical approach of DPD are presented.The plane Poiseuille flow is used to illustrate the accuracy of the DPD simulation,and then the processes of polymer flooding through an oil-wet throat and a water-wet throat are studies, respectively.The selected parameters of those simulations are given in details.These preliminary results show the potential of this novel method for modeling the physicochemical hydrodynamics at the pore scale in the area of chemical enhanced oil recovery.
文摘Chemical flooding has been widely used in the oil industry since the 1980s for enhanced oil recovery(EOR)process.Previous studies have shown that the effectiveness of calcium carbonate scale inhibitors is affected by many factors,such as water composition,system pressure,temperature,production rates,pH etc.The breakthrough of the EOR chemicals in the production well could also affect scale formation process and interfere with the scale treatment program as well.However,the studies on the impacts of injected EOR chemicals to scale inhibitor performances are very limited.This paper presents the comprehensive laboratory study on the impacts of the EOR chemicals on CaCO3 scale formation and prevention using static bottle and dynamic tube blocking methods.The EOR chemicals used in this study are a combination of surfactants and polymers.Three different types of inhibitors were evaluated:triphosphonate,penta-phosphonate,and polyacrylate based chemicals.Inhibition(%)from the bottle test and minimum effective dose(MED)based on the tube blocking method were determined for each inhibitor at 160F.Scale precipitates from the bottle tests were also characterized for morphology and polymorphs using environmental scanning electron(ESEM)and X-ray diffraction(XRD)techniques.Results suggest that the performance of scale inhibitors could be substantially affected by the EOR chemicals.In dynamic tube blocking tests,the MED values of inhibitors were increased roughly 10 times with the EOR chemicals.The static bottle tests showed considerable changes under the test conditions.The impact of EOR chemicals were also demonstrated by the remarkable ranges of crystal morphologies,changing from simple aragonite columns to nanorod,distorted spheroid,and flower-like superstructure in the presence of EOR chemicals and inhibitors.
