(484d) Cellulose Nanocrystals As Shale Hydration Inhibitors for Water-Based Drilling Fluids

Water-based drilling fluids (WDFs) are used in oil well drilling operations to lubricate and cool down equipment, carry rock cuttings to the surface and prevent excessive uptake of water by the clay minerals in the reservoir. Shale hydration issues lead to reservoir instability and wellbore damage, causing important economic losses (>$500M/year) during drilling operations. As a result, the development of effective and environmentally friendly hydration inhibitors for WDFs is a very important issue in the petroleum field [1]. Recent studies suggest that biodegradable cellulose nanocrystals (CNCs) can be used as additives to WDFs to inhibit clay hydration and enhance filtration and rheology properties [2-4]. Here we report classical molecular dynamics simulation studies using all-atoms models, with the objective of fundamentally understanding the mechanisms by which CNCs inhibit clay hydration. Potential of mean force results between the surfaces of the CNCs and the clays as mediated by water molecules will be presented and discussed, shedding light on the interfacial adhesion forces between the CNCs and the clays.

1. Anderson, R. L.; Ratcliffe, I.; Greenwell, H. C.; Williams, P. A.; Cliffe, S.; Coveney, P. V. Clay swelling — A challenge in the oilfield. Earth-Science Reviews 2010, 98, 201-216.
2. Li, M.-C.; Wu, Q.; Song, K.; De Hoop, C. F.; Lee, S.; Qing, Y.; Wu, Y. Cellulose Nanocrystals and Polyanionic Cellulose as Additives in Bentonite Water-Based Drilling Fluids: Rheological Modeling and Filtration Mechanisms. Industrial & Engineering Chemistry Research 2016, 55, 133-143.
3. Song, K.; Wu, Q.; Li, M.-C.; Wojtanowicz, A. K.; Dong, L.; Zhang, X.; Ren, S.; Lei, T. Performance of low solid bentonite drilling fluids modified by cellulose nanoparticles. Journal of Natural Gas Science and Engineering 2016, 34, 1403-1411.
4. Song, K.; Wu, Q.; Li, M.; Ren, S.; Dong, L.; Zhang, X.; Lei, T.; Kojima, Y. Water-based bentonite drilling fluids modified by novel biopolymer for minimizing fluid loss and formation damage. Colloids and Surfaces A: Physicochemical and Engineering Aspects 2016, 507, 58-66.