Potential for Using Energy from Flared Gas for On-Site Hydraulic Fracturing Wastewater Treatment in Texas

Abstract

Hydraulic fracturing faces several environmental challenges: the process is highly water-intensive, generates significant volumes of wastewater, and is associated with widespread flaring of coproduced natural gas. One possible solution to simultaneously mitigate these challenges is to use energy from flared natural gas for on-site wastewater treatment, thereby reducing flared gas, volumes of wastewater, and volumes of freshwater necessary for subsequent shale production as treated wastewater could be reused. This study builds an analytical framework for understanding the feasibility of this approach. We concluded that the thermal energy required to treat wastewater from the first 10 days after well completion is 148000–865000 MJ (140–820 MMBTU) and would generate 750–6800 m3 of treated water. Additionally, using the volume of flared natural gas in Texas in 2012, the theoretical maximal volume of treated water that could be generated was calculated to be 180–540 million m3, representing approximately 3–9% of the state’s annual water demand for municipal purposes or 1–2.4% of total statewide water demand for all purposes (Water for Texas: 2012 State Water Plan; Texas Water Development Board: Austin, TX, 2012).