Question

When two immiscible fluid phases are placed in contact with a solid surface, one phase usually is attracted to solid more strongly than the other phase. The more strongly attracted phase is called the 'wetting phase'. The inter-molecular interaction of the non-wetting phase with the solid is \(\underline{\hspace{2cm}}\)I\(\underline{\hspace{2cm}}\) than its intra-molecular interaction. Due to this, the non-wetting phase tends to occupy the \(\underline{\hspace{2cm}}\)II\(\underline{\hspace{2cm}}\) of the reservoir.

• A. I = stronger, II = smaller pores
• B. I = stronger, II = larger pores
• C. I = weaker, II = smaller pores
• D. I = weaker, II = larger pores

Hint:

The non-wetting phase tends to occupy larger pores in porous media due to its weaker attraction to the solid surface.

Answer 1

The Correct Option is D

In the context of immiscible fluids in porous media (such as oil and water), the wetting phase is the phase that is attracted to the solid surface more strongly than the other phase. The non-wetting phase, on the other hand, interacts less strongly with the solid. This interaction governs how the fluids behave in the reservoir. - Stronger vs weaker interaction: The non-wetting phase experiences a weaker inter-molecular interaction with the solid compared to its intra-molecular interaction. This weaker interaction allows the non-wetting phase to flow more freely through the reservoir, occupying larger pores. - Pore size: Due to this weaker interaction, the non-wetting phase tends to accumulate in larger pores, as these provide more space for movement and accumulation. The wetting phase, being more strongly attracted to the solid, tends to occupy smaller pores near the solid surface. Thus, the correct relationship is I = weaker, II = larger pores. Therefore, option (D) is correct.