This work presents experimental data on volumetric swelling of Estonian kukersite oil shale kerogen in 11 different binary mixtures, prepared using nine different solvents. Variations in equilibrium swelling ratios have been studied as a function of mixture composition. The results confirm the important role of specific interactions in determining the swelling behavior of this kerogen. Swelling of kukersite kerogen in mixtures with high electron donor number solvents ( such as pyridine, propylamine, and NMP) show the highest values of equilibrium swelling ratios over the very broad solubility parameter range. In terms of maximizing swelling of this kerogen, binary solvent mixtures do not offer particular advantage relative to pure, strong electron donor solvents. (C) 2012 Elsevier Ltd. All rights reserved.