Effects of Invasion of Water with and without Surfactant on the Oil Production and Flowback through an Oil Wet Matrix—A Microfluidic Chip Based Study

Abstract

The invasion of hydraulic fracturing fluids into the matrix through a relatively conductive fracture network causes capillary entrapment of the fluids that lead to the reduction of relative permeability of oil during production. Such a formation damage could be alleviated by the use of surfactants, however, their use does not always guarantee an efficient oil recovery. Through a microfluidic-chip based experimental study, the present work highlights the factors that control the later oil productivity and flowback especially through an oil-wetting matrix. The results from this study indicate that for an oil-wet formation, at shallow invasions, a water-based fracture fluid gives higher later oil production rates than a moderate IFT-reducing surfactant, and at deep invasions, the latter fluid gives better later oil production rates than the former. These results are very useful to the oil industry in making well informed decisions for selecting appropriate fracture fluids to stimulate oil-wet formations.