The MS-Q Force Field for Clay Minerals:  Application to Oil Production

Abstract

A Morse-charge equilibration force field (MS-Q FF), originally developed for the bulk oxides SiO 2 and Al 2 O 3 , has been used to model kaolinite and pyrophyllite clay minerals and their interactions with representative organic molecules. The MS-Q FF reproduces the structural parameters for these clay minerals and gives accurate enthalpies of immersions in water, organic solvents, and hydrocarbons. To form a basis for improving squeeze corrosion treatment strategies, we calculate the adsorption energy of oleic imidazoline, a corrosion inhibitor oil production chemical.

Effects of solid surfaces on hydrate kinetics and stability

“…Both experimental results and simulations agree that the (1014) surface is the most stable one under both dry and wet conditions (corresponds to the lowest surface energy). Our results for pure water and calcite and calcite in vacuum showed a good qualitative agreement with (wildly varying) results of previous numerical treatment of other authors, as well a good quantitative agreement with the work of Hwang et al (2001). The best agreement was with Hwang et al (2001) due to their model used and their approach was followed, though with modifications (cross-interactions).…”

“…Our results for pure water and calcite and calcite in vacuum showed a good qualitative agreement with (wildly varying) results of previous numerical treatment of other authors, as well a good quantitative agreement with the work of Hwang et al (2001). The best agreement was with Hwang et al (2001) due to their model used and their approach was followed, though with modifications (cross-interactions). The differences between wet and dry surface energies were also consistent.…”

“…Both models were adopted from Hwang et al (2001). The z, R 0 , D 0 exp-6 parameters were fitted (Mayo et al 1990) to yield accurate lattice parameters.…”

The energetics of nanophase calcite

“…These values vary, depending on the modeled crystal face, the surface terminating groups, and the details of the calculation. The {1 0 1 4} face is the lowest energy face, with relaxed hydrous surface energies ranging from 0.14 to 0.387 J/m 2 Titloye et al, 1998;Hwang et al, 2001;Kerisit et al, 2003;Duffy and Harding, 2004;Kvamme et al, 2009). Several other higher energy faces have also been modeled with hydrous surface energies ranging from 0.43 to 0.77 J/m 2 Titloye et al, 1998;Hwang et al, 2001;Braybrook et al, 2002;Kerisit et al, 2003;Duffy and Harding, 2004;Bruno et al, 2008;Massaro et al, 2008;Kvamme et al, 2009).…”

Structure and stability of kaolinite/TiO2 nanocomposite: DFT and MM computations

“…Considering that Ti 4+ is present in our models, we could not use any of following force fields: consistent-valence force field [28], Teppen force field [29,30], CLAY force field [31], Morse charge equilibration force field [32], or the Dreiding force field [33].…”