Interferometric SAR modelling of near surface data to improve geological model in the Surat Basin, Australia

• Published in: Journal of applied geophysics Vol. 194; p. 104444
• Main Authors: Fouladi Moghaddam, Negin, Nourollah, Hadi, Vasco, Donald W., Samsonov, Sergey V., Rüdiger, Christoph
• Format: Journal Article
• Language: English
• Published: United States Elsevier B.V 01.11.2021; Elsevier
• Subjects: Geophysical inverse modelling; GEOSCIENCES; Ground surface deformation; InSAR; Seismic acquisitions; Subsurface structures; Unconventional hydrocarbon; InSAR; Geophysical inverse modelling; Seismic acquisitions; Unconventional hydrocarbon; Subsurface structures; Ground surface deformation
• ISSN: 0926-9851; 1879-1859; 1879-1859
• DOI: 10.1016/j.jappgeo.2021.104444

This paper presents a study on geophysical inverse modelling for subsurface structural properties of an unconventional hydrocarbon site that was monitored previously by Interferometric Synthetic Aperture Radar (InSAR) technology for surface deformation. A static three-dimensional geomodel along with extracted property maps replicates the depth of each underlying stratigraphic unit and structural feature with the density of each geological layer. We examine the hypothesis that integration of elastic properties of each formation layer with InSAR observations in a stratified elastic medium will lead to a viscoelastic geophysical inverse problem that can be solved to estimate fractional volume change at the reservoir level. Moreover, we examine synthetic scenarios in which the elastic properties of the formations are perturbed before determining the resulting impact on the rate of surface deformation. The results show that although the slope of underlying formations, their density and depth can define the extent and pattern of a deformation signal, their properties have a marginal impact on volumetric change compared to the dense network of shallow depth Coal Seam Gas (CSG) mining wells. Besides, it is also demonstrated that the inversion of InSAR deformation maps can resolve the uncertainties associated with low-resolution seismic interpretation as well as filling the data gaps within seismic acquisitions. A significant contribution of this investigation to the geological basin modelling involves a) introducing a remote and non-invasive technology such as InSAR to improve geophysical mapping of subsurface structures such as faults in areas with sparse or no reflective seismic information, and b) applying a multi-layer viscoelastic geophysical source model for an unconventional hydrocarbon reservoir such as CSG. •A prominent Coal Seam Gas (CSG) site has been assessed using InSAR observations.•Non-invasive and remote InSAR technology is used to improve geophysical mapping.•A multi-layer viscoelastic geophysical source model is applied to a CSG reservoir.•Synthetic scenarios of elastic properties at the reservoir level are examined.•Controlling factors on the rate of surface deformation are determined.