Snap-off and trapping

[@hamzaalyaseri6047]

Dear proffessor Will there be residual non-wetting fluid in the throat due to snap-off phenomena, or is it only traped in the pore? or its depend on the radius of the throught. thank you in advance

[@BoffyBlunt]

No - if there is snap-off in a throat, the throat is completely filled with the wetting phase, and the residual saturation will be found in adjacent pores.

[@hamzaalyaseri6047]

Dear Professor, i might have misconception In terms of pressure, any fluid will flow directly towards the lowest pressure, which in this case is the wider thoughts. In another context, fluids tend to follow the path of least resistance. I understand that there are preferences and wetting properties that influence fluid flow through smaller throughts, but I'm struggling to grasp how these two principles work together. Is the high cohesive force in the small thoughts attracting the water, and because this high cohisive force we need a high pressure to overcome this attraction force and displace oil ? Thank you for your guidance.

[@BoffyBlunt]

The capillary pressure is determined by wettability - the cohesive force, as you say, for the fluid to the solid. In this case the water pressure is lowest in the small throats, as here the capillary pressure is highest.