Experiential investigations for shale–fluid interaction and identification of novel chemical additives as efficient shale swelling inhibitor

The shale instability is a great challenge for both conventional and unconventional hydrocarbon exploitation. Although numerous chemical inhibitor additives have been used to reduce shale swelling, the efficacy of each additive may vary in field conditions due to the heterogeneous nature of the shales, in terms of mineralogy, chemistry, microstructure, etc. Therefore, a special study for in-field inhibitor implementation is essential. The traditional additives including potassium chloride, polyamine, partially hydrolyzed polyacrylamide, and formulated novel chemical swelling inhibitors were used to carry out extensive laboratory investigations on shale inhibition. The formulated polyamine and xantham gum-based inhibiors acted as the most effective inhibitor to control the swelling up to 40%. The X-ray diffraction studies reveal the shale types, microstructures, chemistry, and their control on inhibition behavior. The montmorillonite-rich shales are significantly hydratable and expansive, while organic matter shows a negative correlation with shale swelling.

The roles of different chemical inhibitors are investigated for different types of shales.

The use of chemical additives in shale drilling fluids raises concerns about the environmental impact of extraction processes, emphasizing the need for sustainable alternatives and eco-friendly practices in the energy industry. The identification of novel chemical additives prompts discussions on the role of governmental policies and regulations in ensuring the responsible use of these substances, addressing potential environmental and health risks associated with shale exploration and drilling. Controversies may arise regarding the economic feasibility and long-term sustainability of adopting new shale swelling inhibitors, requiring a delicate balance between economic interests, technological advancements, and environmental responsibility within the energy sector.