Functionalized Layered Nanomaterials: A Next-Generation Shale Inhibitor

Detrimental formation damage can occur while drilling unconventional shales, owing to hydration and subsequent swelling of the clays. Therefore, clay stabilization is an essential component for efficient wellbore construction and treatments involving water-based reservoir fluids. Several different types of clay stabilization additives are available commercially, whereas, it is important to compare their cost, effectiveness, durability, and environmental impact while making a decision. We have developed organic-inorganic layered material (MSil-N) where the organic functionalities have been covalently linked on the surface of the inorganic nanometer-thick platelets. Analytical techniques such as powder X-ray diffraction and spectroscopy were used to characterize this novel, next-generation shale inhibitor. Clay stabilization efficacy of MSil-N is studied and compared with conventional clay inhibitors through clay swelling tests using a capillary suction timer. Pierre II shale was also used to determine swelling and hydration characteristics using the dispersion method. We have also demonstrated the formation of the coating on the surface of shales using electron microscopy. Conventional clay stabilization compounds are solely organic molecules, however, MSil-N is a hybrid of organic and inorganic components. The presence of inorganic entities in MSil-N provides excellent coating strength compared to a solely organic film on the clay, effectively shielding from the hydration of clays. Since the ionic MSil-N have inorganic moieties, it shows exceptional thermal stability unlike organic inhibitors.