Green and Biodegradable Surfactant Based Shale Inhibitors for Water Based Fluids

In recent decades, many shale inhibitors have been developed to reduce clay swelling and improve dril-ling efficiency. Among these categories, biomolecules and biosurfactants have received much attention due to their high inhibition capacity, biodegradability, low toxicity, and compatibility with water -based drilling fluids. In this study, two green surfactants, Flaxseed Protein (FP) and Flaxseed Mucilage (FM) were extracted and analysed through a series of laboratory measurements to evaluate their effi-ciency as effective shale inhibitors. The results obtained indicated that both surfactants have good surviv-ability and functionality under different temperature conditions. They also possess the necessary functional groups to reduce interfacial tension, alter surface wettability and encapsulate clays to reduce hydration. It was also found that both surfactants are compatible with salt (KCl) and the presence of salts does not affect their functionalities. The results of the bentonite dispersion and shale inhibition tests also revealed that FM with its gelling properties forms a thin layer around the clay, while FP with its positive surface charge adsorbs on the clay surface where the affinity of the clay to interact with water decreases.(c) 2022 Elsevier B.V. All rights reserved.