TY - JOUR
T1 - Debunking the impact of salinity on crude oil/water interfacial tension
AU - Mehraban, Mohammad Fattahi
AU - Farzaneh, Seyed Amir
AU - Sohrabi, Mehran
N1 - Funding Information:
This work was performed as a part of the LSWI Joint Industry Project (JIP) in the Centre for EOR and CO Solutions at Heriot-Watt University, Edinburgh, Scotland, UK. The project is equally funded by ADNOC, BP, the UK Oil and Gas Authority, Total E&P, Wintershall Dea GmbH, Woodside Energy, and ConocoPhillips, which is gratefully acknowledged. 2
Publisher Copyright:
© 2021 American Chemical Society.
PY - 2021/3/4
Y1 - 2021/3/4
N2 - The salt content and composition of the water that is either produced with the oil or injected in an oil reservoir can change the composition of the oil at the oil/water interface. Having identified these compositional changes is key to designing the most optimized water ionic recipe to be used in waterflooding of an oil reservoir. Hence, there is a need to better understand the physicochemical interactions at the oil/water interface because of salinity effects. This study elucidates the effect of salinity on the interfacial interactions through pendant drop measurements of crude oil/water interfacial tension, surface charge evaluation by zeta potential, water content measurements by Karl Fischer titration, Fourier transform infrared (FT-IR), and ultraviolet− visible spectroscopy analyses. The interfacial tension results indicate that the interfacial tension increases with reduction in water salinity, which is shown for the first time by FT-IR and water content measurements to be proportional to the spontaneous formation of water microdispersion as the main mechanism of low salinity water injection. Formation of microdispersions and partitioning of surface-active materials by conjugated acidic compounds and/or acidic asphaltenes and low-molecular weight acidic compounds, respectively, are the main parameters controlling the crude oil/water interactions. Asphaltenes and acidic materials are shown to be the underlying compounds in the crude oil phase promoting the microdispersion formation.
AB - The salt content and composition of the water that is either produced with the oil or injected in an oil reservoir can change the composition of the oil at the oil/water interface. Having identified these compositional changes is key to designing the most optimized water ionic recipe to be used in waterflooding of an oil reservoir. Hence, there is a need to better understand the physicochemical interactions at the oil/water interface because of salinity effects. This study elucidates the effect of salinity on the interfacial interactions through pendant drop measurements of crude oil/water interfacial tension, surface charge evaluation by zeta potential, water content measurements by Karl Fischer titration, Fourier transform infrared (FT-IR), and ultraviolet− visible spectroscopy analyses. The interfacial tension results indicate that the interfacial tension increases with reduction in water salinity, which is shown for the first time by FT-IR and water content measurements to be proportional to the spontaneous formation of water microdispersion as the main mechanism of low salinity water injection. Formation of microdispersions and partitioning of surface-active materials by conjugated acidic compounds and/or acidic asphaltenes and low-molecular weight acidic compounds, respectively, are the main parameters controlling the crude oil/water interactions. Asphaltenes and acidic materials are shown to be the underlying compounds in the crude oil phase promoting the microdispersion formation.
UR - http://www.scopus.com/inward/record.url?scp=85102037538&partnerID=8YFLogxK
U2 - 10.1021/acs.energyfuels.0c03411
DO - 10.1021/acs.energyfuels.0c03411
M3 - Article
AN - SCOPUS:85102037538
SN - 0887-0624
VL - 35
SP - 3766
EP - 3779
JO - Energy and Fuels
JF - Energy and Fuels
IS - 5
ER -