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 can interact with water by swelling, dispersing or fracturing. The reaction of these clays can slow drill rates, cause wellbore stability, and even cause stuck pipe.
Shale inhibition can range from small amounts of salt to more complex additives including encapsulating polymers and amines.
AES Drilling Fluids has the resources to evaluate formation material an determine the most cost effective shale inhibitor from its selection of additives or make a recommendation based upon local experience.
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.
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.
There are a number of shale inhibitor additives depending on the drilling scenario. Contact your AES Drilling Fluids Account Manager to review product details for your application.