Forward osmosis desalination in upstream oil and gas: Impacts of produced water exposure on membrane physiochemical properties and contaminant transport

An emerging membrane technology that can treat impaired water for industrial reuse in the oil and gas industry is forward osmosis (FO). In FO, a highly concentrated draw solution imparts an osmotic pressure difference across a semipermeable membrane to extract water from impaired feed solutions. The use of FO has already shown many advantages in the treatment of a variety of complex industrial wastewaters. The main advantages include low hydraulic pressure operation, reduced fouling propensity compared to pressure-driven membrane processes, and high rejection of emerging contaminants and dissolved solids. While field and pilot-scale testing of FO at the industrial level have proved promising, there is still much to learn about the performance and sustainability of the FO process when treating oil and gas exploration and production wastewaters. In this study, which is part of a five year evaluation funded by the United States Department of Energy (DOE), we discuss the impacts of produced water exposure on the transport and active layer surface properties of cellulose triacetate and polyamide thin-film composite FO membranes. Results from recent bench-scale evaluations will be summarized and supported by findings from on-going pilot-scale experiments.