Improving wellbore stability of shale by adjusting its wettability

After adding CTAB to the WBM or water, CTA+ is easy to adsorb on the surface of shale via an ionic bond (the red dotted line), forming a hydrophilic base toward the shale and a lipophilic base toward the WBM or water, thus, increasing the contact angle and decreasing the contact area with shale.201