Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Study of seismic diffractions caused by a fracture zone at In Salah carbon dioxide storage project

Journal Article · · International Journal of Greenhouse Gas Control
 [1];  [2];  [2]
  1. University of Louisiana, Lafayette, LA (United States); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
  2. Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)

The In Salah CO2 storage project in Algeria has injected over 3 million tonnes of carbon dioxide into a water filled tight sand formation. Interferometric Synthetic Aperture Radar (InSAR) range change data revealed a double lobbed pattern of deformation that has been modeled as the opening of a sub-vertical fracture, or damage, zone. The location and geometry of the linear feature were subsequently verified using a seismic reflection survey. The elastic properties of the fracture zone, including anisotropic Poisson ratio (ν), Young's (E) and shear (G) moduli, were estimated from coupled geomechanical and hydrological modeling of surface deformation and pressure variations in the injection well. The elastic moduli reflect the fracture properties after CO2 flow through the fracture zone. Thus, the seismic signature of the fracture zone could be used for monitoring the CO2 plume. Using the estimated fracture model, we built two and three dimensional models consisting of an anisotropic fracture zone embedded within an isotropic background. Finite-difference modeling of seismic shot gathers allows us to estimate the effects of scattering from the fracture zone, potentially further constraining the geomechanical model. From the seismic modeling results, we find diffracted waves, induced by the fracture zone, which behave similar to point source diffractions. This modeling is intended to guide a search for diffraction events in the 3D surface seismic field data. The modeling results indicate that using the moduli estimated from geomechanical modeling, fracture scattered events would be 100 times lower amplitude than the interface reflections, and thus would be hard to detect. While diffracted waves are observed in the field data, which may imply the need for revision of the fracture model, including shape and elastic moduli, we are not able to match the field observation with our modeled events. This article presents a frontier study on the integration of geomechanical and geophysical methods at the In Salah site as a means to test the estimate of the subsurface CO2 flooded fracture properties.

Research Organization:
Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
Sponsoring Organization:
USDOE Office of Fossil Energy (FE), Clean Coal and Carbon Management
Grant/Contract Number:
AC02-05CH11231
OSTI ID:
1474893
Alternate ID(s):
OSTI ID: 1251660
Journal Information:
International Journal of Greenhouse Gas Control, Journal Name: International Journal of Greenhouse Gas Control Journal Issue: C Vol. 42; ISSN 1750-5836
Publisher:
ElsevierCopyright Statement
Country of Publication:
United States
Language:
English

References (28)

Convolution PML (CPML): An efficient FDTD implementation of the CFS-PML for arbitrary media journal January 2000
A study of caprock hydromechanical changes associated with CO2-injection into a brine formation journal March 2002
The Geomechanics of CO2 Storage in Deep Sedimentary Formations journal January 2012
Satellite imaging to monitor CO2 movement at Krechba, Algeria journal February 2009
Coupled reservoir-geomechanical analysis of CO2 injection and ground deformations at In Salah, Algeria journal March 2010
Modeling of deep fracture zone opening and transient ground surface uplift at KB-502 CO2 injection well, In Salah, Algeria journal January 2013
Satellite-based measurements of surface deformation reveal fluid flow associated with the geological storage of carbon dioxide: FLUID FLOW ASSOCIATED WITH THE STORAGE OF CO journal February 2010
Surface deformation associated with a dipping hydrofracture journal July 1983
Monitoring the geologic storage of carbon dioxide using multicomponent SAR interferometry journal January 2013
Time-lapse pre-stack seismic data registration and inversion for CO 2 sequestration study at Cranfield: Time-lapse, registration, pre-stack AVO inversion journal April 2014
An unsplit convolutional perfectly matched layer technique improved at grazing incidence for the viscoelastic wave equation journal October 2009
A Method for Detection of Diffracted Waves on Common-Offset Sections* journal May 1987
Diffraction imaging in depth journal September 2008
P-SV wave propagation in heterogeneous media: Velocity‐stress finite‐difference method journal April 1986
Imaging discontinuities on seismic sections journal March 1988
Finite‐difference modeling of faults and fractures journal September 1995
Seismic monitoring of diffraction images for detection of local heterogeneities journal May 1998
Fractured reservoirs: An analysis of coupled elastodynamic and permeability changes from pore-pressure variation journal September 2006
An unsplit convolutional perfectly matched layer improved at grazing incidence for the seismic wave equation journal September 2007
An unsplit convolutional perfectly matched layer improved at grazing incidence for seismic wave propagation in poroelastic media journal July 2008
Estimating permeability from quasi-static deformation: Temporal variations and arrival-time inversion journal November 2008
Diffraction imaging by multifocusing journal November 2009
Full-azimuth subsurface angle domain wavefield decomposition and imaging Part I: Directional and reflection image gathers journal January 2011
Characterization of a fracture zone using seismic attributes at the In Salah CO2 storage project journal May 2015
Common-reflection-surface-based workflow for diffraction imaging journal September 2011
Time-lapse seismic data registration and inversion for CO2 sequestration study at Cranfield journal November 2013
Dynamics of an expanding circular fault journal June 1976
Dynamic faulting studied by a finite difference method journal April 1982