Fault Seal Analysis in Exploration and Development: Theory and Application

The objective of this course is to introduce concepts and methods in trap and seal analysis particularly as related to fault characterization including fault mapping and fault seal to geoscientists (geologists and geophysicists) and petroleum engineers so that they can apply these principles in their exploration and development projects. The lecture introduces fundamentals and advanced concepts for faulting and flow for the prediction of fault behaviour in subsurface traps. The concepts discussed in the lecture course are applied in simple exercises and related to the capabilities in the PETREL structural and fault analysis module to reinforce the technology.

• Agenda
• Topics
• Audience
• Prerequisites

• Agenda

  Day 1

  • Introduction to fault seal and trap analysis.

  • Trap and fault geometry concepts and estimating closures and initial seal risk.

  Exercise: Trap geometry and controls on hydrocarbon contacts.

  • Methods and concepts on correctly characterizing faults and throw distributions. Theory and methods for evaluating correct fault linkages.

  Exercise: Creating fault throw and separation maps.

  • Fault zone architecture, mechanical stratigraphy and the influence on fault flow resistance.

  • Fault population statistics.

  Exercise: Plotting and deciphering fault population statistics.

  Day 2

  • Review of fault rock types based on the undeformed host rock lithology.

  • Basic principles of flow through porous media including permeability and threshold pressure.

  Exercise: Estimating hydrocarbon gradients, capillary pressure and threshold pressure for reservoir and fault rock.

  • Introduction to fault mapping.

  Exercise: Generating juxtaposition Allan diagrams.

  Day 3

  • Discussion on estimating sealing capacity from the threshold pressure for a range of fault rock types.

  Exercise: Hydrocarbon column height exercise.

  • Discussion of relative permeability impact on flow resistance across faults.

  Exercise: Relative permeability exercise.

  • Review of methods for estimating the clay distribution across a fault surface including clay smear factor, shale gouge ratio and effective shale gouge ratio.

  • Discussion of techniques for calibrating relationships between fault rocks.

  Exercise: Estimating the clay smear factor and shale gouge ratio along faults.

  Day 4

  • Triangle diagrams for estimating fault seal.

  Exercise: Triangle diagram

  • Introduction to geomechanics for fault development and controls on slip.

  Exercise: Critical stress Mohr-Coulomb exercise.

  Day 5

  • Introduction to reservoir flow simulation and modeling fault flow resistance in development.

  Exercise: Estimating flow resistance and transmissibility multipliers.

  • Risking and uncertainty.

  • Validation of methods and summary of course concepts

• Topics

  Fault Geometry and fault zone architecture

  • Fault throw distributions and linkages.
  • Fault geometry characteristics and dimensions.
  • Development of fault zones and fault rocks.
  • Interpretation Techniques and pitfalls

  Flow basics

  • Permeability and Darcy’s Law.
  • Capillarity.
  1. Threshold pressure.
  2. Interfacial tension.
  3. Wettability
  4. Buoyancy force/capillary pressure.
  • Relative permeability.
  • Hydrodynamic seal.

  Fault rock and properties.

  • Description and deformation mechanisms.
  • Flow properties of faults.

  Fault mapping methods.

  • Juxtaposition seal.
  • Fault rock seal.
  • Shale Gouge Ratio.
  • Clay Smear.
  • Effective shale gouge ratio.

  Geomechanics as applied to fault seal.

  Reservoir flow simulation with faults.

  Applications of fault seal analysis in exploration and production.

  • Predicting seal capacity.
  • Risk and uncertainty.

• Audience

  The course is offered to geologists, geophysicists and petroleum engineers.

• Prerequisites

  Although no prerequisites are required for this course, the concepts are more suited to geoscientists with experience in mapping and evaluating exploration and development projects.

• Prerequisites