Title
GHGT-10: Assessing the integrity of fault- and top seals at CO2 storage sites
Author
Orlic, B.
ter Heege, J.H.
Wassing, B.
Contributor
Orlic, B. (editor)
ter Heege, J.H. (editor)
Publication year
2011
Abstract
Induced stress changes due to CO2 injection into geological reservoirs can mechanically damage bounding fault- and top seals creating preferential pathways for CO2 migration from the containment or trigger existing faults causing seismic activity at storage sites. In this paper we present geomechanical simulations of the poro-mechanical effects, thermal and chemical effects of CO2 injection on the integrity of fault- and top seals. Simulation work was performed as part of recent feasibility studies for geological CO2 storage in a depleted gas field and a saline aquifer in the Netherlands. Poro-mechanical and thermal effects were investigated using site-specific finite element and finite difference models as well as (semi-)analytical methods. Long term chemical effects were investigated using generic discrete element models of a representative anhydrite caprock sample. The analysis show that (1) geomechanical numerical models can be used to define clear criteria for maximum admissible pressure build-up during CO2 injection to prevent caprock fracturing, shearing of pre-existing fractures and fault reactivation, (2) combined poro-elastic and thermal effects of CO2 injection may induce fracturing in the near-well area, (3) long term chemical reactions of anhydrite caprock with CO2-rich fluids may cause significant reduction in failure strength at timescales of ~50000 years.
Subject
Earth / Environmental
SGE - Sustainable Geo Energy PG - Petroleum Geosciences
ELSS - Earth, Life and Social Sciences
Geological Survey Netherlands
Geosciences
Energy / Geological Survey Netherlands
CO2 storage
Seal integrity
Fault integrity
Fault reactivation
Reservoir geomechanics
To reference this document use:
http://resolver.tudelft.nl/uuid:ebbb1bd7-f951-4dc0-a8aa-22bd9193a448
TNO identifier
503686
Publisher
CATO-2
Source
CATO-2 Deliverable WP3.03-D10 : Reservoir-caprock-overburden deformation and effects on caprock integrity : Final Report, 2011, 6-16
Bibliographical note
Paper presented at the 10th Int. Conf. on Greenhouse Gas Control Technologies
Document type
conference paper