GPS-based monitoring of surface deformation associated with CO2 injection at an enhanced oil recovery site

Abstract

High precision GPS measurements have been used to measure surface deformation associated with CO2 injection at an Enhanced Oil Recovery (EOR) field in South Texas.We describe a filtering procedure to reduce noise associated with seasonal hydrologic effects, achieving post-filter precisions of better than 2 mm and 3 mm in horizontal and © 2015. This manuscript version is made available under the Elsevier user license http://www.elsevier.com/open-access/userlicense/1.0/ 2 vertical components respectively. A model assuming uniform pressurization of a thin horizontal disc-shaped pressure source in an elastic half-space fits the surface deformation data quite well. The model predicts a location of the pressurized source consistent with injection locations, and suggests minimal horizontal migration of the CO2 fluid during the test period. Our results suggest that a sparse network of dual frequency GPS receivers can be used to augment sub-surface data for Monitoring, Verification and Accounting (MVA) activities associated with Carbon Capture, Utilization and Storage, deriving independent constraints on pressure changes in the reservoir at depth as well as CO2 plume migration.

InSAR monitoring of ground deformation due to CO2 injection at an enhanced oil recovery site, West Texas

“…However, the best-fit Young's moduli derived from the low and medium pressure conditions (6 GPa and 10 GPa) are quite small compared to the best-fit Young's modulus derived from the high-pressure condition (18 GPa), and are on the low side of plausible crustal values. A similar deformation study in south Texas (Karegar et al, 2015) where pressure data were available for calibration gave a best estimate of average Young's modulus of 55 GPa +80/−20 GPa; at 95% confidence, the minimum estimate obtained in that study was 15 GPa, similar to our high estimate. We therefore take the estimate of 18 GPa as the most plausible value for Young's modulus and the corresponding estimate of the high-pressure buildup condition (up to 10 MPa) as the best pressure change estimate.…”

“…If the pressure change is large enough, the surface deformation may be measurable. In principle, the measured surface deformation can be inverted to estimate pressure changes at depth and track the CO 2 plume (e.g., Vasco et al, 2008Vasco et al, , 2010Rinaldi and Rutqvist, 2013;White et al, 2014;Karegar et al, 2015). Over long periods (decades or centuries), chemical reactions that result in formation of mineral phases will cause pressure and volume reduction and subsidence, and could not be distinguished from migration or leakage with this technique alone.…”

Sizing a geodetic network for risk-oriented monitoring of surface deformations induced by CO 2 injection: Experience feedback with InSAR data collected at In-Salah, Algeria

“…Other techniques include optical-instrument leveling, tiltmeter-based measurements and Global positioning system (GPS) (e.g. Karegar et al, 2015). Each technique has pros and cons and can be combined with each other for a more comprehensive characterization of the surface deformations (e.g.…”

A New Hybrid Method for Estimating Hydrologically Induced Vertical Deformation From GRACE and a Hydrological Model: An Example From Central North America

“…For larger areas, the amplitude and phase of the vertical and horizontal components of the deformation are better explained with a spherical nonrotating elastic layered Earth model (Chanard et al, ). In addition, if the spatial extent of the load is large, the Young's modulus may have to be unrealistically increased to include more distant loads in the computation (e.g., Chanard et al, ; Fu & Freymueller, ; Karegar et al, ).…”

“…Among the various types of geophysical fluid loads (atmosphere, ocean, and cryosphere), hydrological loading often represents the dominant signal in the vertical component, especially at multiannual and shorter periods (e.g., Fritsche et al, ; Jiang et al, ). Accurate modeling of these effects in position time series is therefore beneficial for reliable long‐term surface velocity estimates (Klos et al, ; Santamaría‐Gómez & Mémin, ) and noise analysis (Bogusz & Klos, ; Davis et al, 2012; Santamaría‐Gómez et al, ), as well as studies of tectonic processes (Bennett, 2008; Blewitt & Lavallée, ; Bos et al, ; Vergnolle et al, ), volcanic processes (Henderson & Pritchard, ), geodynamics (Chanard et al, ; Clarke, ), sea level rise (Santamaría‐Gómez et al, ), geomechanics (Karegar et al, ), and reference frame definition (Collilieux et al, ; Krásná et al, ).…”