Nour Abdel Hadi

Topic

Surface Deformation as a Pressure Monitoring Proxy in CO₂ Injection Systems: A Poroelastic Analysis of Gorgon and West Hastings

School of Earth and Ocean Sciences

Date & location

• Tuesday, August 4, 2026
• 10:00 A.M.
• Clearihue Building, Room B017

Examining Committee

Supervisory Committee

• Dr. Yan Jiang, School of Earth and Ocean Sciences, University of Victoria (Co-Supervisor)
• Dr. Lucinda Leonard, School of Earth and Ocean Sciences, UVic (Co-Supervisor)
• Dr. Kelin Wang, School of Earth and Ocean Sciences, UVic (Member)

External Examiner

• Dr. Fanghui Deng, Department of Civil and Environmental Engineering, University of Houston

Chair of Oral Examination

• Dr. George Tzanetakis, Department of Computer Science, UVic

Abstract

Carbon dioxide injection alters subsurface pore pressure and effective stress, producing deformation that can be expressed at the ground surface. Surface deformation therefore offers a potential pressure monitoring proxy for CO₂ injection systems, but its interpretation is inherently non-unique, as similar displacement patterns can arise from different pressure distributions, mechanical layering, reservoir geometries, and structural controls. This thesis uses a consistent geodetic-poroelastic framework to interpret pressure driven reservoir response across two contrasting settings − the Gorgon carbon capture and storage project on Barrow Island, Western Australia, and the West Hastings CO₂−enhanced oil recovery field in Texas.

At Gorgon, Sentinel-1 InSAR time series show that injection clusters with comparable rates produce markedly different uplift, and that pressure continues migrating outward, surfacing as delayed uplift near a mapped fault well after local injection has declined. A calibrated layered poroelastic model, constrained by InSAR-derived deformation and available BHP data, reproduces the first-order near cluster response using cluster specific hydraulic diffusivities, but its failure to capture this delayed, spatially offset uplift points to unresolved structural compartmentalization. At the West Hastings CO₂-enhanced oil recovery field, the surface response is heavily complicated by competing injection and extraction cycles. Continuous 3D GNSS records demonstrate that while initial injection drove clear repressurization and uplift, subsequent extraction rendered vertical displacement weak and ambiguous. Crucially, horizontal GNSS components reversed direction prior to the vertical transition, successfully tracking lateral pressure redistribution and volumetric contraction within fault-bounded compartments.

Together, these case studies show that calibrated geodetic-poroelastic modelling can estimate pore pressure evolution from surface deformation while capturing the first-order deformation response. However, model data mismatches reveal behaviour not resolved by the simplified two-dimensional framework, including heterogeneity and structural compartmentalization. These mismatches indicate where more complex three-dimensional models may be required. The horizontal deformation components provide an especially important constraint, as they are sensitive to lateral pressure gradients that vertical displacement, near well pressure data, and operational records alone may not resolve.