Title
3-D mechanical analysis of complex reservoirs: A novel mesh-free approach
Author
van Wees, J.D.
Pluymaekers, M.
Osinga, S.
Fokker, P.
van Thienen-Visser, K.
Orlic, B.
Wassing, B.
Hegen, D.
Candela, T.
Publication year
2019
Abstract
Building geomechanical models for induced seismicity in complex reservoirs poses a major challenge, in particular if many faults need to be included. We developed a novel way of calculating induced stress changes and associated seismic moment response for structurally complex reservoirs with tens to hundreds of faults. Our specific target was to improve the predictive capability of stress evolution along multiple faults, and to use the calculations to enhance physics-based understanding of the reservoir seismicity. Our methodology deploys a mesh-free numerical and analytical approach for both the stress calculation and the seismic moment calculation.We introduce a high-performance computational method for high-resolution induced Coulomb stress changes along faults, based on a Green?s function for the stress response to a nucleus of strain. One key ingredient is the deployment of an octree representation and calculation scheme for the nuclei of strain, based on the topology and spatial variability of the mesh of the reservoir flow model. Once the induced stress changes are evaluated along multiple faults, we calculate potential seismic moment release in a fault system supposing an initial stress field. The capability of the approach, dubbed as MACRIS (Mechanical Analysis of Complex Reservoirs for Induced Seismicity) is proven through comparisons with finite element models. Computational performance and suitability for probabilistic assessment of seismic hazards are demonstrated though the use of the complex, heavily faulted Gullfaks field. © 2019 The Author(s). Published by Oxford University Press on behalf of The Royal Astronomical Society.
Subject
Dynamics and mechanics of faulting
Geomechanics
Induced seismicity
Geomechanics
Mesh generation
Numerical methods
Stresses
Topology
Geological Survey Netherlands
2015 Energy
To reference this document use:
http://resolver.tudelft.nl/uuid:96a68790-4b30-494b-97f3-1b0f5574903a
DOI
https://doi.org/10.1093/gji/ggz352
TNO identifier
869721
Publisher
Oxford University Press
ISSN
0956-540X
Source
Geophysical Journal International, 219 (219), 1118-1130
Document type
article