Gas flooding such as CO2 flooding may be effectively applied to ultra-low permeability reservoirs, but gas channeling is inevitable due to low viscosity and high mobility of gas and formation heterogeneity. In order t...Gas flooding such as CO2 flooding may be effectively applied to ultra-low permeability reservoirs, but gas channeling is inevitable due to low viscosity and high mobility of gas and formation heterogeneity. In order to mitigate or prevent gas channeling, ethylenediamine is chosen for permeability profile control. The reaction mechanism of ethylenediamine with CO2, injection performance, swept volume, and enhanced oil recovery were systematically evaluated. The reaction product of ethylenediamine and CO2 was a white solid or a light yellow viscous liquid, which would mitigate or prevent gas channeling. Also, ethylenediamine could be easily injected into ultra-low permeability cores at high temperature with protective ethanol slugs. The core was swept by injection of 0.3 PV ethylenediamine. Oil displacement tests performed on heterogeneous models with closed fractures, oil recovery was significantly enhanced with injection of ethylenediamine. Experimental results showed that using ethylenediamine to plug high permeability layers would provide a new research idea for the gas injection in fractured, heterogeneous and ultra-low permeability reservoirs. This technology has the potential to be widely applied in oilfields.展开更多
The lipid profile remains an important laboratory assessment to prevent cardiovascular disease. Interpretation of the non-fasting lipid profile has significantly changed based on new information concerning the pathoge...The lipid profile remains an important laboratory assessment to prevent cardiovascular disease. Interpretation of the non-fasting lipid profile has significantly changed based on new information concerning the pathogenesis of atherosclerosis. In particular, the assessment of risk from cholesterol containing particles following triglyceride metabolism (termed remnant cholesterol) can now be done from a lipid profile. In addition, non-HDL cholesterol as calculated from the lipid profile will provide a complete assessment of total circulating cholesterol containing particles. Furthermore, the formula for measurement of LDL cholesterol from a lipid profile has now been revised so that triglyceride levels exert less interference. Finally, the old concept that the “higher the HDL-c, the better” is no longer tenable. New data indicate that the optimal high density lipoprotein level is below 100 mg/dl for both male and female patients. Correct interpretation of the lipid profile will optimize anti-atherosclerotic therapy and reduce the number one cause of death in the United States.展开更多
基金Financial support for this work from National Sciencetechnology Support Plan Projects (No. 2012BAC26B00)the Science Foundation of China University of Petroleum, Beijing (No.2462012KYJJ23)
文摘Gas flooding such as CO2 flooding may be effectively applied to ultra-low permeability reservoirs, but gas channeling is inevitable due to low viscosity and high mobility of gas and formation heterogeneity. In order to mitigate or prevent gas channeling, ethylenediamine is chosen for permeability profile control. The reaction mechanism of ethylenediamine with CO2, injection performance, swept volume, and enhanced oil recovery were systematically evaluated. The reaction product of ethylenediamine and CO2 was a white solid or a light yellow viscous liquid, which would mitigate or prevent gas channeling. Also, ethylenediamine could be easily injected into ultra-low permeability cores at high temperature with protective ethanol slugs. The core was swept by injection of 0.3 PV ethylenediamine. Oil displacement tests performed on heterogeneous models with closed fractures, oil recovery was significantly enhanced with injection of ethylenediamine. Experimental results showed that using ethylenediamine to plug high permeability layers would provide a new research idea for the gas injection in fractured, heterogeneous and ultra-low permeability reservoirs. This technology has the potential to be widely applied in oilfields.
文摘The lipid profile remains an important laboratory assessment to prevent cardiovascular disease. Interpretation of the non-fasting lipid profile has significantly changed based on new information concerning the pathogenesis of atherosclerosis. In particular, the assessment of risk from cholesterol containing particles following triglyceride metabolism (termed remnant cholesterol) can now be done from a lipid profile. In addition, non-HDL cholesterol as calculated from the lipid profile will provide a complete assessment of total circulating cholesterol containing particles. Furthermore, the formula for measurement of LDL cholesterol from a lipid profile has now been revised so that triglyceride levels exert less interference. Finally, the old concept that the “higher the HDL-c, the better” is no longer tenable. New data indicate that the optimal high density lipoprotein level is below 100 mg/dl for both male and female patients. Correct interpretation of the lipid profile will optimize anti-atherosclerotic therapy and reduce the number one cause of death in the United States.
