Spatial Analysis of Membrane Distillation Powered by Waste Heat from Natural Gas Compressor Stations for Unconventional Oil and Gas Wastewater Treatment in Weld County, Colorado

The effective treatment of unconventional oil and gas (UOG) wastewater is a promising and potentially necessary strategy of wastewater management in the UOG industry. While tremendous efforts have been focused on the development of treatment technologies, logistical considerations such as wastewater transportation have been rarely studied in the literature. In this study, we applied spatial analysis tools based on geographic information systems to quantitatively investigate the effects of transportation distance and cost on centralized wastewater treatment (CWT) and deep-well injection (DWI) in Weld County of Colorado, a major UOG-producing state in the United States. CWT using membrane distillation technology powered by waste heat from natural gas compressor stations (NGCSs) was used as the model wastewater treatment approach in our analysis. By analyzing 7583 active UOG production wells, we demonstrate that the distance and cost of wastewater transportation for CWT are comparable to those for DWI in Weld County and that the comparison between CWT and DWI is dependent on the scale of analysis. We also correlated the waste heat availability with the potential UOG wastewater treatment demand at 35 NGCSs. Our analysis shows that the abundance of available waste heat does not always match wastewater treatment demand at NGCSs, requiring a diversion of wastewater that further increases the transportation distance and cost. Our work indicates the importance of logistical considerations in evaluating the viability of CWT for UOG wastewater management. The spatial analysis framework demonstrated in this study is a critical component complementary to the current efforts of treatment technology development, in order to better evaluate the viability and facilitate wide adoption of UOG wastewater treatment via a systems engineering approach.