Numerical simulation of reactive flow in hot aquifers : SHEMAT and processing SHEMAT

1 Introduction.- 2 Numerical Simulation of Reactive Flow using SHEMAT.- 2.1 General.- 2.2 Governing Equations.- 2.2.1 General.- 2.2.1 Ground Water Flow.- 2.2.2 Heat Transport.- 2.2.3 Species Transport.- 2.2.4 Physical Properties.- 2.2.5 Chemical Reactions.- 2.3 Numerical Techniques.- 2.3.1 Finite Difference Method.- 2.3.2 Flow Discretization.- 2.3.3 Discretization Schemes for Transport of Heat and Dissolved Species.- 2.3.4 Equation Solver.- 2.3.5 Time Step Control.- 2.3.6 Process Coupling.- 2.4 Input / Output.- 2.4.1 General Overview.- 2.4.2 Control File.- 2.4.3 Input File.- 2.4.4 Output File.- 2.4.5 Plot Files.- 2.4.6 Output Grid.- 2.4.7 Monitoring Files.- 2.4.8 Run-time Information.- 2.5 Practical Modeling: Remarks, Explanations and Instructions.- 2.5.1 Problem Size.- 2.5.2 Remarks on Flow Input Parameters.- 2.5.3 Boundary Conditions and Wells.- 2.5.4 Time.- 2.5.5 Convergence.- 2.6 Code Verification.- 2.6.1 Theis Problem.- 2.6.2 Rotating Cone Test.- 2.6.3 Henry's Problem.- 2.6.4 Elder's problem.- 3 Pre- and Post-Processing with "Processing SHEMAT".- 3.1 What is Processing SHEMAT?.- 3.1.1 Professional Graphical Data Input Features.- 3.1.2 Sophisticated Modeling Tools.- 3.2 Modeling Environment.- 3.2.1 Units.- 3.2.2 Toolbar.- 3.2.3 Grid Editor.- 3.2.4 Data Editor.- 3.2.5 Value.- 3.2.6 Options.- 3.3 Menu System.- 3.3.1 File.- 3.3.2 Grid.- 3.3.3 Type.- 3.3.4 Time.- 3.3.5 Flow.- 3.3.6 Heat.- 3.3.7 Transport.- 3.3.8 Reaction.- 3.3.9 Models.- 3.3.10 Tools.- 3.3.11 Help.- 4 Advanced Features.- 4.1 Chemical Equilibrium Speciation for Brines at High Temperatures and Ionic Strength.- 4.1.1 Activity calculations.- 4.1.2 Comparison of the Pitzer and Debye-Huckel Models.- 4.1.3 Chemical Module based on Pitzer's Equations.- 4.1.4 Specification of the Chemical Module.- 4.2 Fractal Relation Between Porosity and Permeability: Theory and Verification.- 4.2.1 Introduction.- 4.2.2 Permeability Derived from Pore Space Models.- 4.2.3 Exponents in the Relationship between Porosity and Permeability Implemented in SHEMAT.- 5 Tutorial for "Processing SHEMAT".- 5.1 Introduction.- 5.1.1 General Information.- 5.1.2 How to use this Tutorial.- 5.1.3 Description of the Example Problem.- 5.2 Creating a Fluid Flow, Heat Transfer, and Solute Transport Model.- 5.2.1 Generating a New Model.- 5.2.2 Defining the Flow Parameters.- 5.2.3 Defining the Heat Parameters.- 5.2.4 Defining the Transport Parameters.- 5.2.5 Running Models and Visualizing Results.- 5.3 Using the Geochemical Reaction Module.- 5.3.1 General Information.- 5.3.2 Refining the Model Grid.- 5.3.3 Defining the Reaction Parameters.- 5.3.4 Running Geochemical Reaction Models and Visualizing Results.- 5.4 Expanding the Model to Three Dimensions.- 5.4.2 Defining the additional Model Parameters.- 5.4.3 Running 3-D Models and Visualizing Results.- 6 Applications.- 6.1 Development of a Preferential Flow Path in an Anhydrite Cemented Sandstone: Numerical Simulation of a Core Flooding Experiment.- 6.1.1 Problem description.- 6.1.2 Laboratory core flooding experiment.- 6.1.3 Concept and conditions for preferential flow path development.- 6.1.4 Model description and assumptions.- 6.1.5 Results and Discussion.- 6.1.6 Conclusion.- 6.2 Modeling Flooding of a Sandstone Core with Reactive Transport and Subsequent Changes in Porosity and Permeability.- 6.2.1 Problem description and experimental data.- 6.2.2 Model Description and Assumptions.- 6.2.4 Results and Discussion.- 6.3 Injection Well with Reaction Kinetics.- 6.3.1 Problem description.- 6.3.2 Model description and assumptions.- 6.3.3 Results and Discussion.- 6.3.4 Conclusion.- 6.4 Magmatic Intrusions in Long Valley Caldera.- 6.4.1 Long Valley Caldera: introduction and regional setting.- 6.4.2 Model description and assumptions.- 6.4.3 Steady-state Conductive Models.- 6.4.4 Transient Models of Heating and Cooling.- 6.4.5 Discussion.- 6.5 Rhine Graben Cross Section.- 6.5.1 Rhine Graben: Introduction and regional setting.- 6.5.2 Temperature Data Across the Upper Rhine Graben.- 6.5.3 Model description and assumptions.- 6.5.4 Results and Discussion.- 6.5.5 Discussion.- 6.6 Thermal Transect of Continental Lithosphere in Canada.- 6.6.1 Problem description.- 6.6.2 Temperature in the lithosphere: a matter of uncertainty.- 6.6.3 Model description.- 6.6.4 Results and discussion.- 6.7 Waiwera Coastal Geothermal System.- 6.7.1 Problem description.- 6.7.2 Observations.- 6.7.3 Model description and assumptions.- 6.7.4 Results and Discussion.- 6.7.5 Conclusions.- References.