Widespread deep seismicity in the Delaware Basin, Texas, is mainly driven by shallow wastewater injection

Abstract

Industrial activity away from plate boundaries can induce earthquakes and has evolved into a global issue. Much of the induced seismicity in the United States' midcontinent is attributed to a direct pressure increase from deep wastewater disposal. This mechanism is not applicable where deep basement faults are hydraulically isolated from shallow injection aquifers, leading to a debate about the mechanisms for induced seismicity. Here, we compile industrial, seismic, geodetic, and geological data within the Delaware Basin, western Texas, and calculate stress and pressure changes at seismogenic depth using a coupled poroelastic model. We show that the widespread deep seismicity is mainly driven by shallow wastewater injection through the transmission of poroelastic stresses assuming that unfractured shales are hydraulic barriers over decadal time scales. A zone of seismic quiescence to the north, where injection-induced stress changes would promote seismicity, suggests a regional tectonic control on the occurrence of induced earthquakes. Comparing the poroelastic responses from injection and extraction operations, we find that the basement stress is most sensitive to shallow reservoir hydrogeological parameters, particularly hydraulic diffusivity. These results demonstrate that intraplate seismicity can be caused by shallow human activities that poroelastically perturb stresses at hydraulically isolated seismogenic depths, with impacts on seismicity that are preconditioned by regional tectonics.

On the Origin of Orphan Tremors and Intraplate Seismicity in Western Africa

“…In regions where elastic loading maintains a strong periodic signal, the same cyclic pattern is observed in seismic catalogs (Heki, 2003;Ader and Avouac, 2013). Furthermore, stress and pressure in the crust can be altered due to fluid injection and extraction, triggering earthquakes (Wang, 2001;Wang and Kümpel, 2003;Segall, 2010;Ellsworth, 2013;Segall and Lu, 2015;Shirzaei et al, 2016;Keranen and Weingarten, 2018;Kwiatek et al, 2019;Zhai et al, 2019;Zhai et al, 2021). The stress and pressure gain is a function of pumping and injection location, flux, and accumulated volume, while the rate of radial fluid migration is mainly controlled by crustal permeability (Wang, 2001;Segall and Lu, 2015).…”

Multivariate statistical appraisal of regional susceptibility to induced seismicity: application to the Permian Basin, SW United States

“…A LR approach is adopted because of the current number of factors that attributed to causing induced seismicity in the Permian Basin in published work so far (e.g. Dvory & Zoback, 2021;Savvaidis et al, 2020;Skoumal et al, 2020;Tung et al, 2020;Zhai et al, 2021). It can also be seen from Figure 3 that there is no obvious relationship between certain industrial operations and seismicity.…”

“…There is currently little evidence that seismicity is occurring in such shallow layers, although the hypocentral depth distribution of seismicity in the western Permian Basin remains debated. It has been recently suggested by Zhai et al (2021) that shallow wastewater injection may increase stress on near-basement faults through poroelastic stress transfer. Our LR result provides some additional evidence that shallow industrial activities may cause seismicity in the Delaware Basin area.…”

“…Although in Oklahoma near-basement injection clearly induces most seismicity, it remains highly debated as to whether earthquakes in the western Permian Basin are primarily influenced by deep SWD into the Ellenburger Group (Lemons et al, 2019;Skoumal et al, 2020;Tung et al, 2020), HF in the Wolfcamp Group (Savvaidis et al, 2020), shallow SWD into the Delaware Mountain Group (Deng et al, 2020;Zhai et al, 2021), or conventional production of fluids at shallow depth (Deng et al, 2020;Doser et al, 1991Doser et al, , 1992. Moreover, in much of the Permian Basin, there has been production of hydrocarbons from shallow formations, such as the Delaware Mountain Group and Bone Spring Group since the 1970s, which may affect the pre-existing state of stress (Dvory & Zoback, 2021).…”

“…Although there have been several recent studies on seismicity in the Delaware Basin (e.g. Skoumal et al, 2020Tung et al, 2020;Zhai et al, 2021), they have tended to focus on the individual clusters described above rather than taking a holistic view of seismicity across the whole area. Our focus in this paper is to use a statistical approach which can help to identify broad correlations that help to predict the spatial evolution of seismicity over the large area.…”