Inhibitive properties comparison of different polyetheramines in water-based drilling fluid

Polyetheramines as shale hydration inhibitors in water-based drilling fluids have attracted great interests in recent years. In this paper, in order to clarify the relationship between inhibitive properties and molecular structures of polyetheramines, several inhibitive experimental methods including bentonite inhibition test, shale cuttings hot-rolling dispersion test, sedimentation volume measurement, and API filtration measurement were adopted to evaluate the inhibition variation of different polyetheramines. Furthermore, a series of analytical methods such as surface tension determination, zeta potential measurement, XRD, contact angle measurement, and water adsorption test were performed to identify the relationship between the inhibitive performance and molecular structures. The factors including molecular weight, number of amine group, and molecular chain affecting the interaction between polyetheramines and clay particles were analyzed. Polyetheramine with molecular weight of 230 and oxypropylene segment can reduce the interlayer spacing of the hydrated clay to the minimum and exhibit the best performance in comparison with others. The coordination of electrostatic adsorption with monolayer arrangement, hydrogen bonding, and hydrophobic shielding effect contributed to the top level of inhibition. (C) 2015 Elsevier B.V. All rights reserved.