Center for Injection and Seismicity Research, The University of Texas at Austin
Over the past decade, the Permian Basin region has served as a natural laboratory for understanding the reservoir dynamics and impacts of fluid injection at the basin scale. The ongoing need to dispose of tens of millions of barrels of produced water daily in the region has driven the evolution of injection practices across a range of geologic and operational settings. Injection in the Permian Basin occurs across distinct geologic systems: in shallow and deep reservoirs in the Midland and Delaware Basins, and in the Central Basin Platform. Deep injection targeting carbonate units overlying crystalline basement is comparable to injection settings in the Fort Worth Basin and midcontinent regions such as Oklahoma and Kansas, and is associated with historically high rates of seismicity on faults extending from basement into the injection strata. Operational changes including reductions in deep injection volumes have coincided with a ~50% decrease in M ≥ 3.0 earthquakes over the past year. Shallow injection is associated with seismicity to a lesser degree, but increasing reliance on these strata is causing surface uplift, up to tens of centimeters in places, well control issues in overpressured intervals, and localized surface flows from legacy vertical wellbores.
This lecture draws on integrated data and models spanning surface to basement, to examine how large-scale injection drives changes in pressure and stress, resulting in geomechanical challenges. We will explore the geologic controls on injection-induced hazards, highlight the importance of monitoring and data integration, and offer lessons for safely managing large-scale injections in other basins globally.