Rise in core
[2][3] One study used the water advancing contact angle to estimate the wettability of fifty-five oil reservoirs.
De-oxygenated synthetic formation brine and dead anaerobic crude was tested on quartz and calcite crystals at reservoir temperature.
Another study described two initial conditions as reference and non-reference for calculating cut-off values by using advancing and receding contact angles and spontaneous imbibition data.
Rise in core uses a combination of Chilingar et al. and Morrow wettability cut-off criteria.
RIC wettability characterization technique is based on a modified form of Washburn's equation (1921).
The technique enables relatively quick and accurate measurements of wettability in terms of contact angle while requiring no complex equipment.
Thus, a mass change of a core sample due to water imbibition is equal to a mass change of a core sample due to oil imbibition, because water or oil penetration of the porous media at any time is a function of a balance between gravity and capillary forces.
Schematic view and experimental setups of the RIC wettability testing method is described in Figure 1.
A computer connected to a balance continuously monitors the core sample mass change over time.
Dodecane is an alkane that has low surface energy, very strongly wetting the rock sample in the presence of air, with contact angle θ equal to zero.
Constant ∁ is determined by the contact angle value for dodecane/air/rock system, determining physical properties of n-dodecane (ρ,μ,γ) and rearranging equation 1; The second step of the RIC experimental process is to saturate the neighboring core sample with crude oil and subjected the sample to water imbibition.
, fluid properties of oil/brine system (ρ,μ,γ) and the ∁ value are determined from the neighboring core sample into Eq.
