Study title

The data in “Low salinity water flooding of North Sea reservoirs: Physical and chemical effects, 2013” were gathered by carrying out experiments by using a routine/1D-model of low salinity floods at a laboratory scale. The purpose of this was to establish descriptions of the main mechanisms in low salinity water flooding and to study the effects of adsorption and desorption of polar oil components, and ion-exchange (minerals and reservoir rock) on zeta potential and contact angle. A function describing the effect of salinity reduction on the flow saturation functions were included in the model. The model was validated by comparing the modelling results with core flooding experiments. Specially designed experiments were important in validation of the model. The chemical modelling included: Incorporation of surface chemistry in the existing chemical modelling software EQAlt (Cathles 2006), prediction of surface potential as a function of the aqueous chemistry, pressure and temperature, inclusion of oil rock interactions in the chemical model, guided by experiments performed and prediction of water flooding behaviour by the chemical model. In a larger scale the project enabled a simple extension to a water flood simulator to be used to translate laboratory results into field scale estimates of low salinity water flooding processes. Potential at larger scale will be evaluated using real or realistic sandstone reservoir models. A tool/best practice suitable for evaluation of potential for sandstone reservoirs was established.