Estimating permeability from quasi-static deformation: Temporal variations and arrival-time inversion

Abstract

Transient pressure variations within a reservoir can be treated as a propagating front and analyzed using an asymptotic formulation. From this perspective one can define a pressure 'arrival time' and formulate solutions along trajectories, in the manner of ray theory. We combine this methodology and a technique for mapping overburden deformation into reservoir volume change as a means to estimate reservoir flow properties, such as permeability. Given the entire 'travel time' or phase field, obtained from the deformation data, we can construct the trajectories directly, there-by linearizing the inverse problem. A numerical study indicates that, using this approach, we can infer large-scale variations in flow properties. In an application to Interferometric Synthetic Aperture (InSAR) observations associated with a CO 2 injection at the Krechba field, Algeria, we image pressure propagation to the northwest. An inversion for flow properties indicates a linear trend of high permeability.

Coupled reservoir-geomechanical analysis of CO2 injection and ground deformations at In Salah, Algeria

“…Because the reservoir initially is water filled, the injection of CO 2 into the water column induces multiphase flow. The CO 2 behaves supercritically at reservoir pressures, with a viscosity and density only moderately different from water (Vasco et al, 2008a). Figure 2a shows the average vertical uplift of about 5 mm per year above each of the three injection wells.…”

Geomechanical response to seasonal gas storage in depleted reservoirs: A case study in the Po River basin, Italy

“…PS density can be extremely high (even exceeding 1,000 per km 2 ) in urban and desert areas [Teatini et al, 2007;Bell et al, 2008], however it drops to zero in heavily vegetated zones, sometimes preventing the application of this advanced DInSAR technology in those areas. DInSAR, and in particular PSInSAR, measurements of the ground heave due to subsurface fluid injection have been successfully used to verify the efficiency of enhanced oil recovery (EOR) projects [Stancliffe and van der Kooij, 2001], detect the permeability of oil/gas fields [Vasco et al, 2008], and follow the CO 2 fate in geologic sequestration programs [Mathieson et al, 2009]. For a comprehensive description of the PSInSAR algorithms to measure progressive and seasonal ground displacements, see Colesanti et al [2003b].…”

Satellite‐based measurements of surface deformation reveal fluid flow associated with the geological storage of carbon dioxide

“…The injected carbon dioxide is associated with the In Salah CO 2 storage project located in Algeria [Vasco et al, 2008;Ringrose et al, 2009], one of only two existing large-scale sequestration efforts, the other being the Sleipner field under the North Sea [Arts et al, 2004]. In addition, there are projects in which carbon dioxide is injected into partially depleted oil reservoirs as a means of sequestration as well as enhancing oil recovery, as in the Weyburn project in Canada [White et al, 2004].…”

“…Then we estimate changes in the distance between a reference point in space and the scatterers located on the Earth's surface [Ferretti et al, 2001], the range change. The individual radar images are spaced roughly one to three months apart in time and provide a time series of the range changes associated with the CO 2 injection [Vasco et al, 2008]. For example, Figure 1 is an image of the range velocities of the 300,000 identified permanent scatterers.…”

“…[5] Following the initiation of injection at In Salah, TeleRilevamento Europa (TRE) and Lawrence Berkeley National Laboratory acquired, processed, and analyzed satellite radar images from the European Space Agency's (ESA) Envisat archive [Vasco et al, 2008] [Vasco et al, 2008]. The data associated with each satellite pass consist of a Frame, a dense grid of 20 m by 20 m pixels, covering an area of 100 km by 100 km.…”