Drivers of low salinity effect in sandstone reservoirs

Wettability of oil/brine/rock system is a fundamental petro-physical parameter, governing the subsurface multiphase flow behaviour, thus affecting hydrocarbon recovery. However, understanding the controlling factor(s) which drives the process is incomplete. Therefore, a detailed examination and characterization of reservoir surface forces as well as pore-surface chemistry are of vital importance. We combined contact angle, zeta potential and surface complexation modelling to demonstrate that DLVO theory and surface complexation modelling predict the same wettability trends. Moreover, we introduced Z* parameter (Z* = vertical bar Z(oil/brine) + Z(brine/rock)vertical bar) to manage low salinity water flooding, thus mitigate the uncertainty of low salinity effect. (C) 2017 Elsevier B.V. All rights reserved.