Comparison of Shale Inhibitors for Hydration, Dispersion, and Swelling Suppression

The properties of conventional shale hydration inhibitors were studied using samples of Longmaxi shale. The inhibition was evaluated by the rolling recovery test, linear swelling rate, and clay interlayer spacing. The results indicate that K₂SiO₃ inhibits clay hydration far better than other inorganic shale inhibitors while polyamine is superior to other organic shale inhibitors of clay hydration. Alkaline solution is more effective in suppressing shale dispersion. A neutral environment has little impact on this parameter. On the contrary, an acidic medium can even promote it. Most of the inhibitors are incapable of suppressing simultaneously clay dispersion and expansion. Therefore, they should be used in conjunction to suppress synergistically clay hydration, dispersion, and expansion.