The sweet spot of forward osmosis: Treatment of produced water, drilling wastewater, and other complex and difficult liquid streams

• Highly impaired liquid streams can be sustainably treated by forward osmosis. • Forward osmosis treatment of drilling mud and produced water was evaluated. • Water recovery N 70% was achieved in pilot and demonstration scales.

Forward osmosis is a suitable and effective process for treatment of difficult waste streams, and it was demonstrated at all scales of research and development, including bench scale, pilot scale, and commercial demonstration. Specifically in O&G exploration and production, FO is a promising technology that enables exploration companies to utilize effective wastewater treatment and promote beneficial water reuse in decentralized and remote locations. Currently, there are several different approaches and methods for implementing the technology; however, it is unclear which approach is most suitable, leaving significant room for more research. Ultimately, O&G exploration companies will choose the water management option that (a) is physically practical for on-site operation with their waste stream, (b) accepted by state and federal regulators, and (c) sustainable over extended periods of operation. Compared to traditional disposal methods, both the HTI Green Machine and the Oasys Water Membrane Brine Concentrator FO systems demonstrated net cost advantages of more than 45% and 60%, respectively, in recent demonstration scale tests; however, a direct cost comparison between these two FO technologies is difficult to conduct at this time. The Green Machine is suitable for treating O&G waste streams Table 2 Overview of draw solutes/solution used in FO investigations and their recovery methods. Adapted from [25,28]. Year Draw solute/solution Recovery method Research group NH3 and CO2 Volatile solutes (e.g. SO2) Neff [97] Batchelder