Principles of Subsurface Mapping

Program Objectives

This course is designed to demonstrate the fundamental methodology and associated techniques to derive reasonable and valid maps and cross-sections through interpretation of subsurface data.. The objective is to teach correct structural and stratigraphic geologic principles and workflows for correlation of significant surfaces resulting in cross-sections and subsurface maps. The resulting interpretations can impact exploration, development, rejuvenation of mature fields and identification of overlooked areas. Emphasis is on techniques to display an accurate 3D geologic framework. A review of structural geology terminology and concepts is the first step. Mapping principles and contouring techniques will be discussed and contrasted. The importance of accurately integrating and correcting measured depth to true vertical subsea depth in directional wells, as well as its impact on interpretation and the financial bottom-line, will be covered. Correlation techniques and their application are integral parts of the course. Correlation of horizons and faults is the key to the generation of reasonable fault maps, structural maps, isochores and isochrons, cross sections, and seismic interpretations. The use of isochore and isopach maps in interpreting structural evolution and depositional trends will be examined and practiced. Well planning to test the validity of subsurface mapping will be addressed. Participants will generate volumetrics from maps and prepared data sets. Field development plans (FDP’s) are discussed in relation to the subsurface interpretation incorporating structure, net pay maps as well as hydrocarbon contacts and potential barriers from faults and pinchouts of reservoir.
Course Outline
Day 1
  • Structural Geology 
    • Extensional, Compressional, Strike-Slip
    • Fault Terminology
  • Subsurface Mapping Principles 
    • Data requirements and issues
    • Correlation, Grids, Horizons 
  • Contouring 
    • 3D Perspective and Rules
    • Mechanics of Manual Contouring 
    • Gridding and Kriging 
    • Computer Contouring 
Day 2
  • Directional Wells and Directional Surveys 
    • Directional well types
    • Measurement Tools and Well Plots 
    • Survey calculations and uncertainties 
  • Geophysical Data 
    • Subsurface interpretation 
    • Well ties 
  • Log Correlation
    • Procedures, Guidelines, Type Log 
    • Vertical, Directional, Horizontal wells 
    • Computer-based correlations 
    • Handling complexities 
    • Documentation

Day 3
  • Cross Sections
    • Types, Planning and Design 
    • Vertical Exaggeration 
    • Well projection 
    • Computer-generated sections 
    • Faults 
  • Fault Maps 
    • Fault patterns 
    • Seismic integration 
    • Growth faults 
    • Directional wells 
    • Correction factors 
Day 4
  • Structure Maps
    • Contouring guidelines 
    • Using log and seismic data 
    • Integrating fault traces and gaps 
    • Other mapping techniques 
  • Seismic Mapping 
    • Planning and documenting 
    • Fault and horizon interpretation 
    • Structure mapping 
    • Horizon and fault integration
  • Isochores and Isopach Maps 
    • Sand-shale distribution 
    • Bottom and edge water reservoirs 
    • Wedge and fluid contact methods 
    • Vertical thickness correction factors 
  • Volumetrics 
  • Well Planning 
  • Pitfalls and Quick Look Techniques 
Day 5
  • Integrated Exercises 
  • Final Exam