International Journal of Rock Mechanics Mining Sciences 39

Outline Introduction FLAC 3 D TOUGH 2 Coupling module Examples Results Conclusion 2

Introduction Coupled thermal–hydrologic–mechanical processes under multiphase flow conditions are prevalent in geoscientific applications. A

Introduction However, there is no single computer code that handles general coupled thermal–hydrologic– mechanical

FLAC 3 D FALC (Fast Lagrangian Analysis of Continua ), the finite difference code

3 D FLAC Motion equations Cauchy’s fomula 7

TOUGH 2 TOUGH(Transport of Unsaturanted Groundwater and Heat) developed in the Earth Sciences Division

Conclusion We have linked two codes—TOUGH 2 and FLAC 3 D—for analysis of coupled

Conclusion In both these examples, the hydromechanical changes are relatively slow, which is most

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International Journal of Rock Mechanics & Mining Sciences 39 (2002) 429 -442 A MODELING APPROACH FOR ANALYSIS OF COUPLED MULTIPHASE FLUID FLOW , HEAT TRANSFER, AND DEFORMATION IN FRACTURED POROUS ROCK J. Rutqvist , Y. -S. Wu , C. -F Tsang , G. Bodvarsson 指導教授: 陳瑞昇、董家鈞老師學生: 楊慶中日期: 99. 12. 30 1

Outline Introduction FLAC 3 D TOUGH 2 Coupling module Examples Results Conclusion 2

Introduction Coupled thermal–hydrologic–mechanical processes under multiphase flow conditions are prevalent in geoscientific applications. A few of the most important include nuclear waste disposal in geological media, deep underground injection of hazardous waste and underground storage of carbon dioxide into permeable aquifers. 3

Introduction However, there is no single computer code that handles general coupled thermal–hydrologic– mechanical processes. The two codes—TOUGH 2 and FLAC 3 D are linked using sequential execution and data transfer through nonlinear coupling functions. 4

FLAC 3 D 5

FLAC 3 D FALC (Fast Lagrangian Analysis of Continua ), the finite difference code is developed by the United States Itasca Consulting Group Inc in 1986 , and FLAC 3 D developed in 1994. Code is developed for rock and soil mechanics and can also handle thermomechanical and hydromechanical problem for single-phase fluid flow. 6

3 D FLAC Motion equations Cauchy’s fomula 7

FLAC 3 D 8

TOUGH 2 9

TOUGH 2 TOUGH(Transport of Unsaturanted Groundwater and Heat) developed in the Earth Sciences Division of Lawrence Berkeley National Laboratory in 1987. TOUGH 2 is a simulator for multiphase, multicomponent , non-isothermal flows in fracturedporous media. 10

TOUGH 2 Governing equations 11

Coupling module 12

Coupling module 14

Coupling module 15

Examples Results 17

Examples Results 18

Examples Results 19

Examples Results 20

Examples Results 21

Examples Results 22

Examples Results 23

Examples Results 24

Examples Results 25

Conclusion 26

Conclusion We have linked two codes—TOUGH 2 and FLAC 3 D—for analysis of coupled thermalhydrologic-mechanical processes. The coupling modules contain nonlinear stress versus permeability functions. 27

Conclusion In both these examples, the hydromechanical changes are relatively slow, which is most suitable for the sequentially explicit solution. Problems with higher strain rates relative to fluid mobility may require the sequential implicit approach or ultimately a fully implicit coupled approach.

Thank for your attention 29