We present an oscillation-based method to measure absolute adsorption,or total gas,contained in porous rocks without and with excess adsorption.Experiments conducted with a macroporous Berea sandstone sample in nitrog...We present an oscillation-based method to measure absolute adsorption,or total gas,contained in porous rocks without and with excess adsorption.Experiments conducted with a macroporous Berea sandstone sample in nitrogen where excess adsorption is negligible show that absolute adsorption can be obtained after the added mass of co-accelerated gas outside the sample is subtracted.In experiments conducted in propane with a crushed Niobrara shale sample with micro-and mesopores,absolute adsorption included significant excess adsorption.After subtracting both the added mass outside the sample and the gas that would be in the sample assuming no excess adsorption existed,estimated excess adsorption of propane is in good agreement with that projected based on capillary condensation of propane in the volume of mesopores.展开更多
Coreflood,interfacial tension(IFT),contact angle,and phase behavior measurements were performed to investigate the viability of a hybrid of low-salinity water,surfactant,and CO_(2) flood enhanced oil recovery(EOR)proc...Coreflood,interfacial tension(IFT),contact angle,and phase behavior measurements were performed to investigate the viability of a hybrid of low-salinity water,surfactant,and CO_(2) flood enhanced oil recovery(EOR)process.Low-permeability carbonate reservoir cores were aged for eight weeks at reservoir temperature and pressure.Coreflood and contact angle between oil droplets and core surface measurements were performed.Additional contact angle measurements on sandstone and shale cores were also performed.The coreflood sequences were seawater flood,followed by low-salinity water flood,followed by surfactant floods until residual oil saturations to each flooding sequences and finally CO_(2) injection.Coreflood in low-permeability carbonate cores show that the hybrid EOR process produces incremental oil up to twenty-five percent beyond seawater flooding.Contact angle measurements on carbonate,sandstone and shale cores indicate that wettability alteration and IFT decrease are the main oil-mobilizing mechanisms in the hybrid EOR process.The hybrid EOR process mobilizes part of the residual oil because:(i)low-salinity brine improves wettability towards hydrophilic condition favorable for surfactant flooding;(ii)surfactant in lowsalinity water solubilizes some of the remaining oil as Winsor type IImicroemulsion and lowers IFT between oil and water;and(iii)CO_(2) will follow surfactant to mobilize more of the remaining oil in the wettability-improved condition.展开更多
基金support from the Colorado School of Mines Undergraduate Research Fellowship,the Unconventional Natural Gas and Oil Institute(UNGI)the Unconventional Reservoir Engineering Project(UREP)consortia at the Colorado School of Mines,and the Chevron International Fellowship。
文摘We present an oscillation-based method to measure absolute adsorption,or total gas,contained in porous rocks without and with excess adsorption.Experiments conducted with a macroporous Berea sandstone sample in nitrogen where excess adsorption is negligible show that absolute adsorption can be obtained after the added mass of co-accelerated gas outside the sample is subtracted.In experiments conducted in propane with a crushed Niobrara shale sample with micro-and mesopores,absolute adsorption included significant excess adsorption.After subtracting both the added mass outside the sample and the gas that would be in the sample assuming no excess adsorption existed,estimated excess adsorption of propane is in good agreement with that projected based on capillary condensation of propane in the volume of mesopores.
基金The authors are grateful to Abu Dhabi National Oil Company(ADNOC)and the Petroleum Institute(PI)at Abu DhabiMarathon Center of Excellence for Reservoir Studies(MCERS)and Center for Earth Materials,Mechanics,Characterization(CEMMC)at Colorado School of Mines(CSM)for their support of this study.
文摘Coreflood,interfacial tension(IFT),contact angle,and phase behavior measurements were performed to investigate the viability of a hybrid of low-salinity water,surfactant,and CO_(2) flood enhanced oil recovery(EOR)process.Low-permeability carbonate reservoir cores were aged for eight weeks at reservoir temperature and pressure.Coreflood and contact angle between oil droplets and core surface measurements were performed.Additional contact angle measurements on sandstone and shale cores were also performed.The coreflood sequences were seawater flood,followed by low-salinity water flood,followed by surfactant floods until residual oil saturations to each flooding sequences and finally CO_(2) injection.Coreflood in low-permeability carbonate cores show that the hybrid EOR process produces incremental oil up to twenty-five percent beyond seawater flooding.Contact angle measurements on carbonate,sandstone and shale cores indicate that wettability alteration and IFT decrease are the main oil-mobilizing mechanisms in the hybrid EOR process.The hybrid EOR process mobilizes part of the residual oil because:(i)low-salinity brine improves wettability towards hydrophilic condition favorable for surfactant flooding;(ii)surfactant in lowsalinity water solubilizes some of the remaining oil as Winsor type IImicroemulsion and lowers IFT between oil and water;and(iii)CO_(2) will follow surfactant to mobilize more of the remaining oil in the wettability-improved condition.
