Shale inhibition requirements vary by the properties of the formation. Mixed clay layers can respond to water in different ways. AES Drilling Fluids has the tools to evaluate and recommend the most cost-effect solution. From encapsulating polymers like our ENERPLUS to highly inhibitive amine products like our AES CLAY SHIELD, we have the additives to provide the right level of inhibition.
AES CLAY SHIELD amine-based inhibitor
Shale Inhibition Mechanisms
Shale inhibitors limit the interaction of water with clay particles. When water enters a clay, it causes the layers to fan out (swell) or break apart (disperse). The exact details of the process can be somewhat complex, but generally speaking it’s possible to offer a basic overview.
A shale inhibitor can limit water entry through two primary mechanisms. One is when the cation present is exchanged for one that can increase the attraction between clay platelets, limiting entry of water. Typically this method includes adding salt, such as potassium chloride, to the base fluid.
Inhibition concept
Another mechanism, commonly referred to as encapsulation, is when a material adsorbs onto the edges of the clay platelets to limit hydration. Encapsulators include partially hydrolyzed polyacrylamide (PHPA) products such as ENERPLUS and PXL BLUE. Amines such as AES CLAY SHIELD perform in a similar function, but do not contribute to excess viscosity.
