Lecture on Reservoir Simulation and Modeling Fundamentals

Introduction

• Presenter: Mr. Abdullah and Professor Suresh Kumar
• Company: Reservoir Solutions
• Focus: Technical studies, courses for oil and gas professionals
• Services Offered:
  • Technical reservoir studies and field development planning
  • Reservoir static and dynamic modeling
  • Economic feasibility studies
  • Technical support for academic research
  • Petroleum courses and mentorship programs
• Recent Studies:
  • Reservoir modeling for oil companies in the Philippines
  • Gas condensate field development for Turkish company
  • Economic feasibility study in Turkey and Saudi America

Courses Offered

• Practical Reservoir Static and Dynamic Modeling
• PVT and Equation of State Tuning
• Dynamic Modeling using Software
• Special Core Analysis and Reservoir Engineering Applications
• Integrated Reservoir Management
• Upcoming Courses:
  • PVT and Equation of State Modeling starting November 5
  • Production Optimization in December
  • Workshop on Well Integrity Management

Introduction to Dr. Suresh Kumar

• Position: Professor of Reservoir Simulation, IIT Madras
• Experience: 14+ years in reservoir aspects
• Academic Background: PhD in flow through fractured reservoirs
• Publications: Books and 131 articles

Key Concepts Covered in Lecture

Basics of Reservoir Simulation

• Importance: Standard in solving reservoir engineering problems
• Types:
  • 1D, 2D, 3D Simulators
  • Radial and Cartesian coordinates
  • Different fluid types (renewable gases, black oils, gas condensates)
• Simulation Uses: Planning field development, minimizing decisions
• Historical Context:
  • Early methods (pre-1960s): Analytical methods, material balance
  • Evolution in 1960s: Development of complex computer programs
  • 1970s: Shift from general models to specific EOR process models
• Challenges:
  • Simulation errors possible due to inadequate data and assumptions
  • Importance of understanding geology, reservoir engineering, and numerical methods

Conceptual Modeling

• Importance: Visualizing 3D reservoir structure
• Key Elements: Solid grains and pore spaces
• Fluid Pathways: Hydraulically connected pores, dead ends
• Driving Forces: Pressure gradient, gravity, capillary forces
• Miscibility: Importance of understanding partial miscibility
• Flow Direction: Horizontal, vertical, inclined
• Porosity and Permeability: Distribution and variability
• Phase Equilibrium: Isothermal retrograde condensation and isobaric retrograde vaporization
• Overall Process: Listing and analyzing dominant physical, chemical, and biological processes

Mathematical Modeling

• Objective: Translate conceptual model into mathematical equations
• Types of Equations: Partial differential equations (PDEs)
  • Elliptic, Parabolic, Hyperbolic PDEs
• Conservation Laws: Mass and momentum conservation
• Challenges: Deducing well-posed problems, handling coefficients
• Representative Elementary Volume (REV): Ensuring accurate continuum description
• Importance of Accurate Data: Porosity, permeability, phase pressures

Numerical Modeling

• Objective: Solve PDEs using numerical methods
• Numerical Methods: Finite Difference, Finite Element, Finite Volume
  • Finite Difference: Simplicity but lacks control over variables between nodes
  • Finite Element: Introduces elements for better control but can struggle in small areas
  • Finite Volume: Conserves system properties better, more reliable
• Grid Selection: Based on geology, fluid displacement, numerical accuracy, etc.
• Challenges: Numerical dispersion, stability issues, history matching
• Verification and Validation: Ensuring results match field data and experimental results

Practical Considerations and Challenges

• Importance of Multidisciplinary Knowledge: Geology, engineering, thermodynamics
• Errors and Assumptions: Impact of incorrect data, missing physical/chemical processes
• Machine Learning and AI: Potential but requires deep understanding of reservoir physics
• History Matching: Iterative process to match simulation with actual data

Conclusion

• Q&A: Addressed questions on numerical dispersion, machine learning, boundary conditions
• Final Thoughts: Emphasis on understanding basics before using software packages
• Future Directions: Continued importance of oil and gas, need for fundamental research

Next Steps

• Certificates and Course Registration: Instructions provided to attendees
• Recording Availability: Lecture will be uploaded on Reservoir Solutions' YouTube channel