Estimation of Reservoir Uplift, Seismicity and Failure Likelihood during CO₂ Injection through Coupled Reservoir Simulation

Abstract

CO2 sequestration and injection projects are being intensively studied and conducted throughout the world. The CO2 has to be trapped below a caprock and the trap itself occurs in a complex geological setting which creates a complex geometrical model. Increased pore pressure may result in uplift of the formation and generation of new fractures or reactivation of existing structures that will generate preferred fluid flow pathways along which dissolved CO2 which may escape into the atmosphere or freshwater zones above, or result in seismicity in the region. To assess and mitigate these geomechanical risks, a thorough simulation coupling fluid flow through porous media and geomechanics of a realistic representation of the reservoir as well as the overburden is required. The shared earth model of a candidate shallow CO2 sequestration site in the state of Missouri was separately discretized before coupled simulation in the finite element software and reservoir simulator predicted fracture formations. A coupling module was developed which uses the relative spatial position of finite element nodes compared to finite difference grid blocks to relate the two simulation grids. Results of this study are used for predicting the best CO2 injection location and injection rates to provide maximum storage capacity and injection rates for safe sequestration.This knowledge is then used for determining type, time and amount of sealant to inject for mitigation of flow through caprock fractures so that storage of CO2 at required injection rate is maintained.

Meeting Name

Canadian Unconventional Resources Conference 2011, CURC 2011 (2011: Nov. 15-17, Calgary, Alberta, Canada)

Department(s)

Geosciences and Geological and Petroleum Engineering

Sponsor(s)

Schlumberger
Calfrac Well Services Corp (CWS)
Talisman Energy Inc.
Nexen
Shell

Keywords and Phrases

Basin structures; Caprock; Coupled simulation; Coupling fluids; Discretizations; Existing structure; Finite difference grids; Finite Element; Finite element simulation model; Finite element software; Flowthrough; Fluid saturations; Fluid-flow pathways; Fluid-flow properties; Geological setting; Geometrical models; Horizontal layers; Injection rates; Missouris; Modeling studies; Pseudo-compressibility; Reservoir models; Reservoir pressures; Reservoir simulation; Reservoir simulator; Shared earth models; Shear fracture; Simulation Grid; Spatial positions; State of stress; Storage capacity; Computer software; Flow of fluids; Fracture; Geomechanics; Maximum likelihood estimation; Petroleum reservoir evaluation; Petroleum reservoirs; Pore pressure; Resource valuation; Water injection; Carbon dioxide

International Standard Book Number (ISBN)

978-1618394217

Document Type

Article - Conference proceedings

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2011 Elsevier B.V., All rights reserved.

Publication Date

01 Nov 2011

Link to Full Text

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