Time Series Analysis of Surface Deformation Associated With Fluid Injection and Induced Seismicity in Timpson, Texas Using DInSAR Methods

In recent years, a rise in unconventional oil and gas production in North America has been linked to an increase in seismicity rate in these regions (Ellsworth, 2013). As fluid is pumped into deep formations, the state of stress within the subsurface changes, potentially reactivating pre-existing faults and/or causing subsidence or uplift of the surface. Therefore, hydraulic fracturing and/or fluid disposal injection can significantly increase the seismic hazard to communities and structures surrounding the injection sites (Barnhart et al., 2014). On 17th May 2012 an Mw4.8 earthquake occurred near Timpson, TX and has been linked with wastewater injection operations in the area (Shirzaei et al., 2016). This study aims to spatiotemporally relate, wastewater injection operations to seismicity near Timpson using differential interferometric synthetic aperture radar (DInSAR) analysis. Results are presented as a set of time series, produced using the Multidimensional Small Baseline Subset (MSBAS) InSAR technique, revealing two-dimensional surface deformation

Quantifying Oil and Gas Industry Related Geohazard Using Radar Interferometry and Hydro-geomechanical Modeling

The Permian Basin, containing a large amount of oil and gas, has been intensively developed for hydrocarbon production. However, the hazards related to the oil and gas industry including surface deformation and the underlying mechanisms in this region have not been well known. My PhD study aims to monitor the geohazards in the Permian Basin and better comprehend the subsurface mechanisms with the aid of high-resolution and high-accuracy Interferometric Synthetic Aperture Radar (InSAR) images. Generally, as the pore pressure is influenced by wastewater injection/hydrocarbon production, the pressure changes can propagate to other surrounding underground and overlying rock/soil layers, resulting in surface deformation. The distribution and temporal development of the surface deformation can be obtained from InSAR processing and analysis. To reveal the underground geo-mechanical process responsible for the development of the surface deformation, numerical modeling based on poroelasticity is then applied to estimate the effective parameters (i.e., parameters inferred from the simulation) including depth and volume. This method is applied to three cases in West Texas. At a site in Reeves county, InSAR detects surface uplift up to 17 cm near a wastewater disposal well from 2007 to 2011. Results from both elastic and poroelastic models indicate that the effective injection depth is much shallower than reported. The most reasonable explanation is that the well was experiencing leakage due to casing failures and/or sealing problem(s). At a site in Winkler county, surface uplift and the follow-on recovery detected by InSAR from 2015 to 2020 can be attributed to nearby wastewater disposal. Bayesian inversion with the poroelastic models provides estimates of the local hydro-geomechanical parameters. The posterior distribution of subsurface effective volumes reveals under-reported volumes in the well near the deformation center. We also investigate a case of aseismic slip related to oil and gas activities. The combination of InSAR observation and poroelastic finite element models in three cases shows the capability to investigate the ongoing geohazards related to fluid injection and hydrocarbon production in the Permian Basin. This kind of study will be helpful to the decision-making of federal/local authorities to avoid future geohazards related to oil and gas activities

Hazard Implications of the 2016 Mw 5.0 Cushing, OK Earthquake from a Joint Analysis of Damage and InSAR Data

The Cushing Hub in Oklahoma, one of the largest oil storage facilities in the world, is federally designated as critical national infrastructure. In 2014, the formerly aseismic city of Cushing experienced a Mw 4.0 and 4.3 induced earthquake sequence due to wastewater injection. Since then, an M4+ earthquake sequence has occurred annually (October 2014, September 2015, November 2016). Thus far, damage to critical infrastructure has been minimal; however, a larger earthquake could pose significant risk to the Cushing Hub. In addition to inducing earthquakes, wastewater injection also threatens the Cushing Hub through gradual surface uplift. To characterize the impact of wastewater injection on critical infrastructure, we use Differential Interferometric Synthetic Aperture Radar (DInSAR), a satellite radar technique, to observe ground surface displacement in Cushing before and during the induced Mw 5.0 event. Here, we process interferograms of Single Look Complex (SLC) radar data from the European Space Agency (ESA) Sentinel-1A satellite. The preearthquake interferograms are used to create a time series of cumulative surface displacement, while the coseismic interferograms are used to invert for earthquake source characteristics. The time series of surface displacement reveals 4⁻5.5 cm of uplift across Cushing over 17 months. The coseismic interferogram inversion suggests that the 2016 Mw 5.0 earthquake is shallower than estimated from seismic inversions alone. This shallower source depth should be taken into account in future hazard assessments for regional infrastructure. In addition, monitoring of surface deformation near wastewater injection wells can be used to characterize the subsurface dynamics and implement measures to mitigate damage to critical installations

Multi-Temporal SAR Interferometry for Vertical Displacement Monitoring from Space of Tengiz Oil Reservoir Using SENTINEL-1 and COSMO-SKYMED Satellite Missions

This study focused on the quantitative assessment of the vertical displacement velocities retrieved using Sentinel-1 and Cosmo-SkyMed synthetic aperture radar images for the Tengiz oilfield. Tengiz oilfield was selected as a study area because of its historically reported continuous subsidence and limited up-to-date studies during recent years. The small baseline subset time-series technique was used for the interferometric processing of radar images acquired for the period of 2018–2020. The geospatial and statistical analyses allowed to determine the existing hotspots of the subsidence processes induced by oil extraction in the study area. Ground deformation measurements derived from the Sentinel-1 and COSMO-SkyMed satellite missions showed that the Tengiz oilfield continuously subsided during 2018–2020 with the maximum annual vertical displacement velocity around −77.4 mm/y and −71.5 mm/y, respectively. The vertical displacement velocities derived from the Sentinel-1 and the COSMO-SkyMed images showed a good statistical relationship with R 2≥0.73 and RMSE ≤3.68 mm. The cumulative vertical displacement derived from both satellites for the most subsiding location also showed a good statistical relationship with R 2 equal to 0.97 and RMSE = ± 4.69. The observed relative differences of measurements by both satellites were acceptable to determine the ongoing vertical surface displacement processes in the study area. These studies demonstrated a practical novelty for the petroleum industry in terms of the comparative assessment of surface displacement measurements using time-series of medium-resolution Sentinel-1 and high-resolution COSMO-SkyMed radar images

Influence of geological factors on surface deformation due to hydrocarbon exploitation using time-series InSAR: A case study of Karamay Oilfield, China

Surface deformation due to hydrocarbon extraction from buried reservoirs may gradually evolve to geological hazards, which can undermine the safety of infrastructure facilities. Monitoring the surface deformation and studying on the influencing factors of surface deformation have great significance to ensure the stability of oilfield development, and prevent geological hazards. In this study, Sentinel-1 interferometric synthetic aperture radar (InSAR) data of Karamay Oilfield acquired between January 2018 to December 2020 was used to map how the land surface has deformed in response to hydrocarbon exploitation. Based on the monitoring results of time series InSAR, geological data, and oilfield data, the correlations between the different factors and the surface deformation were analyzed. The results show that the reservoir buried depth, porosity and permeability have an impact on the surface deformation, and the influence on surface uplift is obviously greater than that on surface subsidence. Surface uplift decreases with the increasing buried depth and the decreasing porosity and permeability, and the correlation between porosity and surface uplift is the best. However, the impact is limited in the area with shallow reservoir depth, high porosity, and high permeability, such as the heavy oil blocks in the study area

Surface Deformation and Seismicity Linked to Fluid Injection in the Raton Basin

It is suggested that deep fluid injection may cause surface uplift and subsidence in oil and gas producing regions in addition to seismicity. This study uses the Raton Basin as an example to investigate the hydromechanical processes of surface uplift and subsidence following fluid injection and relate them to the region's seismic history. The Raton Basin, in southern central Colorado and northern central New Mexico, has experienced wastewater injection related to coalbed methane and gas production starting in 1994 and increased seismicity since 2001. In this study, we estimate the extent and magnitude of total vertical deformation in the Raton Basin from 1994 to 2020, and short-term deformation between the years 2017 to 2020 following a sharp decline in injection rates. Most modeled uplift between 1994 and 2020 occurred near the southern wells, where the greatest cumulative volume of wastewater was injected. However, modeled subsidence occurred around the southern and eastern wells between 2017 and 2020, after the rate of injection decreased. This shows that while the magnitude of uplift corresponds to cumulative injection volume and maximum rate in the long-term, short-term incremental deformation (uplift or subsidence) is controlled by changes in the rate of injection. The increased number of yearly earthquake events follow periods of modeled rapid uplifting throughout the basin, suggesting that surface deformation is caused by the same injection induced pore pressure perturbations that initiate seismicity.</p

Geomechanics of subsurface water withdrawal and injection

Land subsidence and uplift, ground ruptures, and induced seismicity are the principal geomechanic effects of groundwater withdrawal and injection. The major environmental consequence of groundwater pumping is anthropogenic land subsidence. The first observation concerning land settlement linked to subsurface processes was made in 1926 by the American geologists Pratt and Johnson, who wrote that \u2018\u2018the cause of subsidence is to be found in the extensive extraction of fluid from beneath the affected area.\u2019\u2019 Since then, impressive progress has been made in terms of: (a) recognizing the basic hydrologic and geomechanic principles underlying the occurrence; (b) measuring aquifer compaction and ground displacements, both vertical and horizontal; (c) modeling and predicting the past and future event; and (d) mitigating environmental impact through aquifer recharge and/or surface water injection. The first milestone in the theory of pumped aquifer consolidation was reached in 1923 by Terzaghi, who introduced the principle of \u2018\u2018effective intergranular stress.\u2019\u2019 In the early 1970s, the emerging computer technology facilitated development of the first mathematical model of the subsidence of Venice, made by Gambolati and Freeze. Since then, the comprehension, measuring, and simulation of the occurrence have improved dramatically. More challenging today are the issues of ground ruptures and induced/triggered seismicity, which call for a shift from the classical continuum approach to discontinuous mechanics. Although well known for decades, anthropogenic land subsidence is still threatening large urban centers and deltaic areas worldwide, such as Bangkok, Jakarta, and Mexico City, at rates in the order of 10 cm/yr

Mechanisms and Mitigation of Injection-Induced Earthquakes

Injection-induced seismicity caused by wastewater injection is a continuing problem for the central and eastern United States. Mitigation of induced earthquakes often focuses on operational parameters like injection rate. While pore pressure increase has been the main mechanism invoked in injection-induced seismicity, other mechanisms like Coulomb static stress transfer may play a role. In this dissertation, I examine the mechanisms of injection –induced earthquakes in relation to mitigation.I investigate the role of aggregate injection rate, the combined injection rate of multiple wells, by modeling pore pressure increase caused by 22 wastewater disposal wells injecting into the same disposal zone within 30 km of seismicity in Greeley, Colorado. I find that the wells 15 – 30 km from the seismicity contribute approximately 44% of pore pressure increase at the location of the earthquakes. Therefore, aggregate injection rate and well spacing is important when planning mitigation strategies. I also derive a simple relation between pore pressure change and surface deformation that can be used to constrain hydraulic parameters of confined aquifers to a first-order. This relation can estimate expected surface deformation associated with pore pressure model results, which can then be compared to observed surface deformation using geodetic techniques. I validate this relation by constraining the storativity of an aquifer in Texas that experienced uplift associated with wastewater disposal.Finally, I investigate the role of small magnitude earthquakes in induced seismicity. I use generic models to test if small magnitude earthquakes can cumulatively transfer, through earthquake interactions, stress of a magnitude comparable to pore pressure increase from wastewater injection. I find that the stress caused by earthquake interactions (Coulomb static stress transfer) is comparable in magnitude to pore pressure increase. However, the area influenced by the increased stress is much smaller than in pore pressure diffusion. This means that earthquake interactions may induce more earthquakes though over a smaller area than pore pressure increase. If earthquake interactions induce additional events, reduction in injection rate or even shutting down a well may not mitigate seismicity. Therefore, earthquake interactions should be taken into account when planning mitigation, especially the timing of mitigation measures

ALOS-2/PALSAR-2 Calibration, Validation, Science and Applications

Twelve edited original papers on the latest and state-of-art results of topics ranging from calibration, validation, and science to a wide range of applications using ALOS-2/PALSAR-2. We hope you will find them useful for your future research