Induced Seismicity in the Delaware Basin, Texas

Abstract

The seismicity rate in the Delaware Basin, located in western Texas and southeastern New Mexico, has increased by orders of magnitude within the past~5 years. While no seismicity was reported in the southern Delaware Basin during 1980-2014, 37 earthquakes with M > 3 occurred in this area during 2015-2018. We generated an improved catalog of~37,000 earthquakes in this region during 2009-2018 by applying multistation template matching at both regional and local stations using all earthquakes in the Advanced National Seismic System (ANSS) and TexNet catalogs. We found that the vast majority of the seismicity is most likely associated with wastewater disposal, while at least~5% of the seismicity was induced directly by hydraulic fracturing. We inferred far-field effects of wastewater disposal inducing earthquakes over distances >25 km. The spatial limits of seismicity correlate with geologic structures that include the Central Platform and Grisham Fault, suggesting hydrologic compartmentalization by low-permeability boundaries. Given that the seismicity rate increased throughout the duration of the study, if industry operations continue unaltered, it is likely that both the seismicity rate and number of M > 3 earthquakes may continue to increase in the future.

Hydraulic Fracturing‐Induced Seismicity

“…(c) Time series of earthquakes (circles) and times of HF stimulations (bars) that are shown in (b). Figure modified from Skoumal et al (2020).…”

“…No earthquakes greater than 3.0 M had been detected in this area prior to 2015; during 2015–2020, more than 67 earthquakes ( M > 3) occurred, with the largest event being a 5.0 Mw . The majority of the earthquakes have been suggested to be induced by wastewater disposal, with ~5% of seismicity (of 1,850 earthquakes) induced by HF (Skoumal et al, 2020), although another study has suggested HF as a primary factor for inducing many of these events (Lomax & Savvaidis, 2019). This discrepancy highlights potential difficulties of spatiotemporal association to HF stimulation, especially in areas with ongoing earthquakes.…”

“…This discrepancy highlights potential difficulties of spatiotemporal association to HF stimulation, especially in areas with ongoing earthquakes. The most apparent cases of HF‐induced seismicity is in the southwestern portion of the Basin (Lomax & Savvaidis, 2019; Skoumal et al, 2020), an area where limited wastewater disposal is occurring (Figures 13b and 13c). To date, the largest magnitude event (3.0 M ) associated with HF in the Delaware Basin occurred in May 2018 (Skoumal et al, 2020).…”

“…The most apparent cases of HF‐induced seismicity is in the southwestern portion of the Basin (Lomax & Savvaidis, 2019; Skoumal et al, 2020), an area where limited wastewater disposal is occurring (Figures 13b and 13c). To date, the largest magnitude event (3.0 M ) associated with HF in the Delaware Basin occurred in May 2018 (Skoumal et al, 2020). The true extent of HF‐induced seismicity may be much larger, but confident assessments are limited by high seismicity rates (associated with wastewater disposal and/or hydrocarbon production) and the absence of HF stimulation details in public records documenting stimulation activities.…”

“…The majority of HF‐induced earthquakes (with high‐precision hypocenters) tend to locate within a few wellbore dimensions from their causal HF pad (Skoumal et al, 2020). In lower‐resolution regional studies, nearly all of the clusters' error ellipsoids tend to encompass their causal pad location (Babaie Mahani et al, 2017; Lei et al, 2019; Schultz et al, 2017).…”