Performance Evaluation of a Novel Amin-Based Shale Stabilizer in Water-Based Drilling Fluids

Wellbore instability during the drilling of shale formation is the most troublesome and the costly issue facing drilling engineers. Early attempts to control these instabilities are the usage of appropriate additives in water based drilling fluids. This study aims to introduce a new water-based drilling fluid amine-based additive called tallow amine ethoxylate in order to hydration decrease and stability increase of shale formation. Shale hydration Inhibition performance of tallow amine ethoxylate was investigated through different experiments under various experimental conditions. The results showed that bentonite particles are not capable of being hydrated or dispersed in the mediums containing tallow amine ethoxylate, and also tallow amine ethoxylate had comparable and competitive inhibition performance with potassium chloride as a common shale stabilizer in drilling industry. Tallow amine ethoxylate is also compatible with other common drilling fluid additives. Some functional groups exist in tallow amine ethoxylate which are capable of forming hydrogen bonding with surfaces of bentonite particles, leading to decrease of water adsorption on bentonite particles’ surfaces which results in bentonite swelling reduction.