Bayesian Monte Carlo Inversion of InSAR Time Series Deformation Induced by Wastewater Injection: A Case Study in West Texas

Wastewater disposal can induce detectable surface uplift, which may cause ground instability and threaten infrastructure. The distributions of local hydro-geomechanical parameters, especially Young's modulus and hydraulic conductivity, play an essential role in these geohazards. To constrain these parameters, we have inverted spatio-temporal deformation measured by Interferometric Synthetic Aperture Radar (InSAR) and injection information using a Bayesian Monte Carlo approach with a poroelastic finite element model. Sentinel-1A/B imagery from 2014 to 2020 is processed to track the spatio-temporal deformation in Winkler county, West Texas, USA. The posterior distribution of subsurface effective volumes reveals under-reported volumes in the well near the deformation center. In addition, the inversion results provide better constraints for the parameters than those solely obtained based on the cumulative spatial deformation or temporal development of the deformation center. Plain Language Summary Wastewater disposal into injection wells is the most common way to manage the produced water in the oil and gas industry. It can cause surface uplift and influence ground stability. The surface deformation is mainly controlled by the local properties of the rocks and injection volumes. We measured the time-series deformation in West Texas using satellite radar images and then inverted for the properties of rocks with numerical methods. In addition to estimating the local properties of rocks, our results show under-reported volumes at the dominant well.