A Novel Ascorbic Acid Based Natural Deep Eutectic Solvent as a Drilling Mud Additive for Shale Stabilization

Abstract

During drilling, almost 70% of wellbore instability issues result from the encountering of shale formations. Various additives such as salts, silicates, and polymers are used in water-based mud to enhance its shale-inhibition capability; however, such additives have certain limitations. Lately, ionic liquids and deep eutectic solvents (DES) have been used by various research groups as shale inhibitors in drilling fluid due to their biodegradability and efficacy. However, their popularity faded when a natural derivative of DES, i.e., Natural Deep Eutectic solvent (NADES), came into the picture. This research utilizes the in-house-prepared Ascorbic acid and Glycerine (AA:Gly)-based NADES as a drilling fluid additive for shale inhibition and compares its efficacy with counterpart inhibitors such as KCl, imidazolium-based ionic liquid, and Choline Chloride-based DES. The results show that 3% NADES improved the overall Yield point to Plastic viscosity ratio, with a 39.69% decline in mud cake thickness and a 28% decline in the filtrate volume of drilling mud. Along with improved drilling fluid properties, 3% NADES resulted in 77.77% shale inhibition and 87% shale recovery. Surface tension, d-spacing, zeta potential, and FESEM have been conducted to justify and elucidate the inherent mechanism behind the working of NADES as a drilling fluid additive and clay stabilizer. Thus, Ascorbic acid-based NADES is recommended as a potential non-toxic and cheap drilling fluid additive to improve drilling fluid properties and clay stability.

Deep Eutectic Solvents: Comprehensive Review and Future Directions on Synthesis and Oilfield Applications

“…Rasool et al 2023 performed research using a DES-based on Ascorbic acid and Glycerine. The findings indicate that the addition of 3% DES resulted in an increase in the YP to AV ratio, accompanied by a significant decrease of 39.69% in mud cake thickness and a 28% reduction in the amount of filtrate in the drilling mud . Acidic DESs, on the other hand, can negatively affect drilling mud filtration .…”

“…The findings indicate that the addition of 3% DES resulted in an increase in the YP to AV ratio, accompanied by a significant decrease of 39.69% in mud cake thickness and a 28% reduction in the amount of filtrate in the drilling mud. 138 Acidic DESs, on the other hand, can negatively affect drilling mud filtration. 131 Viscoelastic DESs can also be viable alternatives for incorporation into drilling fluid formulations.…”

Reactivity of Basaltic Minerals for CO2 Sequestration via In Situ Mineralization: A Review

“…It enables scientists to evaluate the reactivity of basaltic minerals, assess the suitability of specific basalt formations for CO 2 storage, and predict the long-term behavior of stored CO 2 . Additionally, geochemical analysis assists in identifying potential risks associated with basalt storage, drilling through basalts with appropriate drilling methods and drilling fluids [98][99][100][101][102] and problems such as mineral alterations or the release of hazardous elements.…”

Epsom Salt-Based Natural Deep Eutectic Solvent as a Drilling Fluid Additive: A Game-Changer for Shale Swelling Inhibition

“…Misan et al studied the successful applications of NADESs in the agri-food sector [41]. Rasool et al (2023) tested the successful applications of ascorbic acid-based NADES as a shale swelling inhibitor [42]. This research will utilize Epsom salt as a hydrogen bond acceptor and glycerine as a hydrogen bond donor, selected based upon M.H.…”