Fault Seal Analysis

Course Duration: 3-5 days, including lecture-based modules and hands-on exercises

Who Should Attend: Geologists, Geophysicists, Petrophysicists, Reservoir Engineers, and Exploration/Production Managers, and technical personnel

Course Summary: Understanding and mitigating risk factors of fault sealing character is a critical issue in many exploration regimes and during field development. Typical seismic interpretation of a fault as an individual and continuous fault is often flawed in that many faults are rather comprised of multiple segments/splays which may or may not be connected. Mechanical stratigraphy plays a fundamental role, whereby some layers may be displaced yet others may be only flexed, especially at reservoir-scale levels. A fault may be sealing in places but leaky in elsewhere allowing along-fault migration and/or cross-fault migration. Sealing character may change with time during production as pressure differentials are created across fault systems. This course addresses the fundamental concepts of understanding faults systems in risking exploration projects and during exploitation in development programs, from understanding the origin, nature, and geometry of faults systems in various tectonic environments; determination of sealing/non-sealing character of fault systems during their evolution within a mechanical stratigraphic assemblage; potential reservoir compartmentalization and reservoir navigation and/or development; subseismic fault prediction; deterministic and probabilistic (stochastic) modeling; and risk analysis and limitations of fault seal analysis. Numerous case studies and hands-on exercises include seismic attribute analysis of fault interpretation (getting the details of fault character as opposed to standard click-click-click techniques), fault plane mapping and fault juxtaposition diagrams, fault gouge and clay smear analysis, prediction/validation using mechanical stratigraphy concepts, simulated reservoir navigation exercise, and so forth.

Learning Outcomes:

• Understand the origin and development of faults and fault systems
• Be able to characterize and map key fault components from well and seismic data
• Understand properties controlling fault seal from exploratory investigation through potential changes with development
• Be able to assess risk elements associated with fault seal

Course Content:

• Fundamentals of Fault Systems—Examining the fundamental nature of faults, including their development in various tectonic/non-tectonic regimes; types of and interrelationships of faults; fault nucleation, growth, development, and seal.
• Fault Mapping Techniques—Well log-based fault plane maps and fault juxtaposition diagrams; seismic interpretation techniques, including standard approaches and seismic attribute analysis approaches for refining interpretations and manual versus automated techniques.
• Mechanical Stratigraphy and Seal Analysis—Understanding the response of the stratigraphic system to faulting, including rock mechanics and determination of rock properties from well logs, core tests, and seismic data; gouge and clay smear calculation techniques and integration with fault juxtaposition diagrams.
• Fault Prediction, Modeling, and Risk Assessment—Subseismic faults and their prediction, including fractal analyses, seismic attribute analysis, including shear wave birefringence; deterministic and probabilistic/stochastic techniques of fault seal prediction and reservoir character; risk assessment.
• Reservoir Dynamics and Fault Seal/Non-Seal Relations—Understanding fault relations at the reservoir level, including potential for reservoir compartmentalization (or lack thereof): changing sealing character due to pressure differentials created during production; reservoir navigation in faulted reservoirs.
• Case Studies and Hands-On Exercises—Multiple case studies and hands-on exercises related directly to lecture/discussion topics, including specific discussion of fault and seal risk in Indian frontier basins.