Reservoir Modeling Presentation Notes

Introduction

• Presenter: Manchester Hustavi, Reservoir Geologist at Illinois State Geological Survey
• Topic: Concept of reservoir modeling, its goals, and fundamental principles.

Key Concepts in Reservoir Modeling

• Familiarity with Various Subjects:

  • Importance of knowledge in:
    • Sedimentology
    • Seismic interpretation
    • Petrophysics (water saturation, porosity, permeability)
    • Collaboration with reservoir engineers.

• Workflow:

  • Integrate data from different disciplines (geophysicists, petrophysicists, and engineers).
  • Update models based on findings from other specialists.

3D vs. 2D Reservoir Models

• Preference for 3D Models:
  • Historical context: 2D models were common 30-40 years ago.
  • Advantages of 3D models:
    • Better volume calculations
    • Improved visualization of spatial relationships (porosity, permeability, water saturation).
  • Software examples: Petrol, Rooks, Roxar.

Depositional Environments

• Importance of identifying:
  • Type of reservoir (carbonate vs. siliciclastic).
  • Depositional trends (e.g., turbidites, channels).
• Understanding sedimentary trends aids in modeling properties (e.g., porosity).

Zonation and Sequence Stratigraphy

• Zonation:
  • Historical vs. current methods; sequence stratigraphy offers a better framework.
  • Sequence stratigraphy connects surfaces based on timing of sediment deposition.
  • Concept of flow units in hydrocarbon movement.

Diagenesis

• Key processes affecting reservoir quality:
  • Processes:
    • Dissolution, compaction, cementation, dolomitization.
    • Impact on porosity and permeability.

Structural Mapping and Static Models

• Structural Maps:
  • Need structural maps from sedimentologists or geophysicists for static model creation.
  • Importance of well data (wellheads, surveys, logs).
  • Types of maps: Structural, thickness, and trend maps.

Creating 3D Models

• Steps to create a geocellular model:
  1. Stratigraphic framework creation.
  2. Structural framework adjustments (importing faults).
  3. Grid creation (defining dimensions and inserting properties).
  4. Property modeling (interpolating/extrapolating data).

Geostatistics and Modeling Properties

• Use of variograms in geostatistics:
  • Understanding similarity and dissimilarity in properties helps in modeling.
  • Different methods for distributing properties (deterministic vs. stochastic).

Summary and Closing

• Importance of collaboration between geologists, engineers, and petrophysicists for accurate models.
• Encouragement for ongoing education (upcoming course on static and dynamic modeling).

Questions and Answers

• Discussion on various topics related to reservoir modeling, including methods for porosity/permeability scaling and the impact of AI in modeling.