Ebraheam:

This link may provide you with some insights:

http://www.ux.uis.no/~s-skj/ipt/Proceedings/SCA.1987-2004/1-SCA1994-08.pdf

Best

Syed

Thank you very much for your help

The best way would be using any surfactant. You can use any surfactant which has charge opposite to the rock sample. However, you have to check experimentally which sample will give you desired result. 

The change in wettability will be dependent upon surfactant type and rock mineralogy. Depending upon the rock type and surfactant use, surfactant may make them more water wet or oil wet.  

You may go through the following for more details: 

http://pubs.acs.org/doi/abs/10.1021/ef1001716

http://pubs.acs.org/doi/abs/10.1021/la802464u

In any interface there exists an unequal distribution of electric charge, in the interface between the mineral (limestone) and the surfactant. The limestone acquires a negative charge such that the cations present in the solution tend to neutralize the charge of the rock and the excess in these ions gives place to the formation of an electric potential through the interface denominated “Stern double electric layer”.

In seawater the absence or very low concentration of divalent cations in solution causes interaction of the surfactant on the rock by ionic interactions among the cationic surfactant and the surface with a negative charge tendency. For the connate water, the presence of the electrolytes (Ca2+, Mg2+) causes the mineral surface to have a positive charge tendency, so the interaction with the surfactant takes place by the anionic group.

By the same way the electrical double layer theory implies that the divalent cations like Ca2+ are located in the double layer preferably than the monovalent cations like Na+, because divalent ions have less solvation area (Ca2+ 145 Å2) than the monovalent cations (Na+ 196 Å2). In this case the exchange capacity of the cations is bigger due to the high amount of Ca2+ in solution, giving place to a higher concentration of species on the mineral. Thereby the surfactant interaction depended on the predominant cations in the aqueous médium.

Thank you very much, David, for your clarification