LAUSR

Abstract This work addresses three significant issues associated with hydraulic fracturing in US shale fields: flaring/venting of excess natural gas, disposal of flowback water and freshwater procurement. Flaring/venting of excess gas is a significant contributor to global emissions. This work presents a novel utilization concept, wherein excess gas is used onsite to power reverse osmosis (RO)-based treatment of flowback water to supply freshwater for oilfield operations. This study details technical and techno-economic analyses of the above concept. An analytical model is extended and improved to quantify RO-based freshwater production for flowback water of different salinities. The technical performance of RO systems is analyzed and compared with two competing gas utilization technologies (thermal desalination, atmospheric water harvesting). The use of these technologies in the top eight US shale fields is analyzed, and a techno-economic analysis of RO-based water treatment is conducted. Results indicate that this concept will significantly benefit the Eagle Ford and Niobrara shales. It can meet 200% of water requirements and reduce wastewater disposal by 60% in the Eagle Ford. Furthermore, such RO-based projects can have favorable payback periods of as low as one year. Importantly, this waste-to-value concept has worldwide relevance since the underlying issues are present globally.