State of stress in the Permian Basin, Texas and New Mexico: Implications for induced seismicity

Abstract

Since the 1960s, the Permian Basin of west Texas and southeast New Mexico has experienced earthquakes that were possibly triggered by oil and gas activities. In recent years, seismicity has been concentrated near Pecos, Texas; around the Dagger Draw Field, New Mexico; and near the Cogdell Field, Snyder, Texas. We have collected hundreds of measurements of stress orientation and relative magnitude to identify potentially active normal, normal/strike-slip, or strike-slip faults that might be susceptible to earthquake triggering in this region. In the Midland Basin and Central Basin Platform, the faulting regime is consistently normal/strike slip, and the direction of the maximum horizontal compressive stress (SHmax) is approximately east–west, although modest rotations of the SHmax direction are seen in some areas. Within the Delaware Basin, however, a large-magnitude clockwise rotation (∼150°) of SHmax occurs progressively from being nearly north–south in the north to east-southeast–west-northwest in the south, including the western Val Verde Basin. A normal faulting stress field is observed throughout the Delaware Basin. We use these stress data to estimate the potential for slip on mapped faults across the Permian Basin in response to injection-related pressure changes at depth that might be associated with future oil and gas development activities in the region.

Induced Seismicity in the Delaware Basin, Texas

“…On the contrary, if the earthquake hypocentral depths are predominately below the interbedded shales and no such conduits exist, poroelastic effects due to production could explain why earthquakes occurred even without a direct hydraulic connection, albeit promoting failure on predominately normal or reverse faults (Chang & Segall, 2016). More than one third of the focal mechanisms from TexNet are reported as strike-slip, and while many mechanisms have large azimuthal gaps, these mechanisms are generally consistent with the normal and strike-slip faulting environment suggested by stress measurements (Snee & Zoback, 2018). If strikeslip mechanisms are prevalent in the Delaware Basin, hydrocarbon production is unlikely to be the primary cause of these earthquakes.…”

“…As the Central Basin Platform is a tectonically uplifted basement block (Figure 10c), horizontal fluid migration would likely be inhibited. Strong, systematic changes in the S Hmax direction are observed across the Grisham fault (Forand et al, 2017;Snee & Zoback, 2018; Figure 10d), which suggests that perhaps the magnitude of crustal stresses impacts the occurrence of seismicity. Absolute stress measurements and better constraints on the stress rotation in the vicinity of the Grisham fault would aid our understanding of the induced earthquakes.…”

Physics-Driven Optimization of Drained Rock Volume for Multistage Fracturing: Field Example from the Wolfcamp Formation, Midland Basin

“…That is why A φ should not only vary with depth but also with lithology. This depth dependency may be an explanation of the higher anisotropy predicted by Snee and Zoback (2018 , Table A4). Another explanation may be in a limited number of observations (18 data points) for the whole Permian Basin region.…”

“…In our fracture propagation model, we use the S Hmax direction and horizontal stress anisotropy estimated by Agharazi (2016) from microseismic focal mechanism solutions: the azimuth of the maximum horizontal stress is N 103 0 E, and the stress anisotropy is 8% (equivalent to ΔS ~ 600 psi for TVD=9,400 ft). Snee and Zoback (2018) proposed that the stress regime is depth-independent and thus assumed a 2D stress map ( Fig. 4).…”

Scales of Stress Heterogeneity Near Active Faults in the Santa Barbara Channel, Southern California

“…In this study, we adhere to the common assumption that one of the principal stresses is vertical, and the other two principal stresses (S Hmax and the minimum horizontal principal stress, S hmin ) therefore lie in the orthogonal horizontal plane (Bell, 1996;Peška & Zoback, 1995;Snee & Zoback, 2018;Zoback, 1992;Zoback et al, 2003). We, however, note that in structurally complex areas such as the western Transverse Ranges where oblique-slip faulting, inclined-axis fault-block rotations, and fault Sankur et al (1990) showing the NW-trending Sockeye anticline structure, which is cut by NW-striking thrust faults that extend from at least 1.5-2 km depth towards the surface.…”