Course Title: Structural Geology Discipline: Geology Level: Basic-Intermediate Duration: 5 Days Instructor: Prof. Charles Kluth About the course: This course covers the basic ideas of structural geometry and kinematics, providing structural geology nomenclature, modern concepts, tools and techniques used in the petroleum industry today with emphasis on applications to hydrocarbon exploration and production. This includes faults (normal, reverse, thrust and strike-slip), folds, dipmeter analysis, structural inversion, structural restoration and synorogenic sedimentation. It also includes joints and fractured reservoirs, smallscale structures and fault seals. The course includes exercises on well and seismic data to illustrate the points made in lectures, as well as exercises on interpretation of seismic data in complex structural areas. The strategy of this course is to cover some basic material in each section, for those who do not necessarily have a strong background in structural geology and then progress in a logical way to more advanced topics and tools. One of the goals of the course is to give those participants who are not specifically structural geologists, the ability to participate in structural conversations and to recognize when they have structural geology problems. A second goal is to give those working as structural geologists new ideas and tools to attack structural geology problems. A third goal is to give both groups, specialists and non-specialists, ideas and approaches of how to evaluate uncertainty and therefore trap risk. Examples and exercises from around the world will illustrate and support the rapid assimilation of the ideas presented. The whole course is set up in a way that will accelerate participants experience, regardless of present level of understanding. Audience: Geologists and Geophysicists Agenda:
Day 1 1. INTRODUCTION Purpose of this Class How We Will Proceed in This Class -Nomenclature--the language of structural geology -Concepts--foundation on which we build interpretations -Tools and techniques--how do we interpret our data Guard Against the Hidden Assumption- Uncertainty and Risk and the Role of Geologists Brief Introduction to Stress and Strain Brief Introduction to Rock Mechanics Principles Why it's Important to Know Something about These Topics Introduction to Fractures, Faults and Faulting 2. CONCEPTS OF SHORTENED TERRANES Reverse and Thrust Faults and Fault Growth -Definition, separation and slip -Concept of regional elevation -Significance--crustal shortening, uplift Thrust Fault Geometry -Ramps and flats -Nomenclature -Geometry of the fault, hanging wall and footwall -Frontal ramps -Triangle zones -Lateral ramps -Sequence of thrusting -Critical taper -Basement involvement -Determining the age of thrusting -Hydrocarbon systems in thrust belts -Field examples, maps and sections -Seismic examples, lines and time slices--exercises for recognition -Tools for analysis Displacement diagrams exercise Consistency of displacement in sections and maps--exercises
Stratigraphic separation diagrams Reverse Fault Geometry -Basement involved structures -Dual fault zone Day 2 3. FOLDS AND FOLDING Fold Geometry Basic Concepts -Axis--trend and plunge -Axial surface -Crestal culminations Folds and Folding Mechanisms -Parallel folds -Similar folds -Flow folds -Importance of recognizing fold type and folding mechanisms -Seismic and field examples exercises Fold Geometries and Kinematics -Fault bend folds -Fault propagation folds -Detachment folds -Trishear model of folds -Seismic and field examples -Seismic interpretation exercises Other Classifications of Folds Limb Dips Folds in Map View and Implications at Depth -Curving axial traces -Axial bypass -Depth to detachment-exercise Growth Strata Record of Fold Growth -Accommodation space -Thickness record of fold growth -Possible control on sedimentary facies -Growth strata exercise 4. CONCEPTS OF EXTENDED TERRANES
Recognition of Normal Faults -Field and seismic examples Implication of Extensional Faults -Crustal extension -Subsidence Curved Faults -Recognition -Relationship of the shape of the fault to the shape of the hanging wall Planar Faults -Recognition -Amounts of extension -Field and seismic examples Normal Fault Systems and Fault Growth -Recognition -Scale of observations -Relays and fault interaction -Influence on sedimentary architecture and reservoir facies -Strike offset diagrams Day 3 5. STRIKE-SLIP AND STRUCTURAL INVERSION Types of Strike-Slip Faults -Recognition of strike-slip faults and structures - en echelon patterns -Determining the sense of slip -Crustal scale transforms -Transfer zones -Tear faults -Compartmental faults -Restraining and releasing bends Pop-ups Pull-aparts Characteristics and implications -Strike-slip fault terminations
-Transfer and transform faults -Transtension and transpression -Strain partitioning Inversion Structure -Types of inversion -Recognition of inversion structures Concepts Field and seismic examples -Implications of inversion -Three dimensional inversion Day 4 6. FRACTURES AND FRACTURED RESERVOIRS Stress and Strain and Types of Fractures -Recognizing modern-day in situ stress -Measurements -Bore hole breakouts Recognition of Fractured Reservoirs -Heterogeneity Methods of Analysis -Trends -Spacing -Bed contained or not bed contained -Swarms -Ages of joint systems -Volume drained -Optimum drilling angle 7. SMALL SCALE STRUCTURES AND SUB-SEISMIC FAULTS Illustration of Why They are Important Fractals How to Determine the Fractal Dimension How to Predict the Number of Small Faults Literature Example Small-scale Faults and Shear Angle in the Hanging Wall of Alistric Normal Fault
8. FAULT SEALS Capillary Entry Pressure Top Seals Juxtaposition Seals Fault Zone Processes -Dip seal and cross seal -Dip leak and cross leak -Shale smear -Cataclastic deformation -Authogenic overprint -Fault seals in shortening and in carbonates - grain size analysis in fault zones -Recognition of seals and leaks -Risking fault seals and leaks Day 5 9. DIPMETER ANALYSIS What a Dipmeter is Image Logs and Dip Tadpole Plots SCAT Analysis of Dipmeters -Types of plots -Determining trend and plunge of the axis of a fold -Cross section view Transverse sections Longitudinal sections -Identifying faults 10. SEISMIC INTERPRETATION EXERCISES--PICK A LOCATION Thrust Belt Extension 11. SUMMARY AND WRAP UP