N281 Introduction to Seismic Interpretation for Exploration and Production

Course Facts

Course Code:
N281
Duration:
8 days
Type:
Classroom
CEU:
6.4 Continuing Education Units
PDH:
64 Professional Development Hours
Certificate:
Certificate Issued Upon Completion

Summary

For petrotechnical professionals seeking to gain a practical knowledge and understanding of the techniques and concepts used in the seismic interpretation process, this course provides a thorough introduction covering all aspects, from the fundamentals of the seismic method to mapping and the use of seismic attributes. This course is an expanded version of course N085 with additional exercise materials related to structural mapping, bid-round evaluations, direct hydrocarbon indicators, and reserve estimation. 

Duration and Training Method

This is an eight-day classroom course with exercise and lecture materials derived from "real-world" examples of producing fields and basins.

Participants will learn to:

  1. Explain fundamental aspects of seismic wave propagation, diffractions, and reflection criteria.
  2. Compare 2D and 3D seismic acquisition techniques; evaluate key survey requirements necessary to achieve project objectives.
  3. Assess the importance of key seismic data processing steps including datum and statics corrections, velocity analyses, migration and depth imaging.
  4. Contrast 2D and 3D seismic data benefits, recognize common imaging pitfalls.
  5. Explain how prospect risk factors can influence project objectives and interpretation workflows.
  6. Demonstrate practical interpretation skills; construct and use synthetic seismograms, perform well-seismic ties, 2D line correlation, horizon and fault identification, seismic picking and basic mapping.
  7. Compare seismic time-to-depth conversion techniques and recognize potential pitfalls.
  8. Determine factors affecting seismic resolution at the reservoir scale.
  9. Differentiate the various types of seismic attributes available and select appropriate attributes for a given project.
  10. Demonstrate the relationship between mapping exercises on paper and modern workstation practices.
  11. Employ understanding of structural styles, tectonic factors, stratigraphy and basic rock property assumptions in a comprehensive interpretation framework.
  12. Demonstrate the use of vertical profiles and time slices in 3D interpretation.
  13. Participate in a regional “bid round” evaluation to identify high-potential exploration blocks.
  14. Map the extent of a field using a DHI (Direct Hydrocarbon Indicator).
  15. Estimate recoverable reserves from a field discovery.

Seismic data, in particular 3D seismic data, is a mainstay of the petroleum industry. Seismic data are used by geophysicists, geologists and engineers alike to image subsurface structure and stratigraphy, identify hydrocarbons, and thereby generate drilling prospects and effectively drain oil and gas reservoirs. Achieving an understanding of all of the methods and concepts used during the interpretation process can be a daunting task. A partial list of disciplines incorporated into a complete interpretation includes rock physics, signal processing, wireline log analysis, computer visualization, structural geology, stratigraphy and petroleum engineering. Few, if any, new hires have mastered, or perhaps even been exposed to, all of these disciplines during their university education. Other, more experienced, petroleum professionals may have become specialists in one of these or other fields, and lack the “big-picture” view necessary for maximizing the value of a seismic interpretation.

The following 8 days of lectures, discussions, exercises and case histories are designed to provide broad exposure to the range of skills required of effective seismic interpreters:

Day 1:

  1. Prospect risk factors influencing interpretation workflows
  2. The seismic method
    a. Rock properties
    b. Wave propagation, reflectivity, impedance
    c. Data acquisition – Land and Marine
    d. Exercises; reflection coefficients, time/depth domains, mapping

Day 2:

  1. Seismic data processing overview
    a. Conventional pre-stack processing
    b. Post-stack processing
    c. Seismic migration
    d. Exercises; datum statics, migration
  2. Calibration methods (well-tie)
    a. Velocity surveys
    b. Sonic logs
    c. Synthetic Seismograms
    d. Exercise; Seismic well tie
  3. Vertical Seismic Profiles
    a. Exercise; VSP correlation to surface seismic

Day 3:

  1. Structural Interpretation
    a. Tectonic influences on structural   styles
    b. Fault interpretation
    c. Exercise - Fault plane     interpretation
    d. Horizon interpretation    techniques
    e. Horizon attributes
    f. Exercise – Structure mapping
    g. Validation methods
    h. Interpretation pitfalls
    i. Exercise – Compressional    tectonics

Day 4: 

  1. Exercise: 2D loop ties, mapping a compressional anticline
  2. Lithology and Fluids
    a. Acoustic impedance and inversion
    b. AVO and Elastic seismic response   
    c. Pore pressure effects on velocity
    d. Interpretation tools for Unconventional Reservoirs

Day 5: 

  1. Modeling and depth conversion tools
    a. Types of velocity information
    b. Depth conversion methods
    c. Exercise: Velocity model building
    d. Workflow: Depth conversion using 2-layer model
    e. Image ray map migration
    f. Pre-Stack depth migration
  2. Validation using 2D modeling, ray tracing, and full waveform modeling

Day 6:

  1. Project planning and Interpretation tools
    a. Interpretation techniques
    b. Workflow design to meet project objectives
  2. Stratigraphic Interpretation
    a. Sequence stratigraphy
    b. Seismic facies identification
    c. Exercise – Seismic stratigraphy, Scotia shelf
    d. Seismic tuning and isochron mapping
    e. Stratigraphic slices
    f. Spectral decomposition
    g. Visualization tools

Day 7:

  1. Regional play analysis and prospect definition workflow
    a. Play elements discussion and exercise
    b. Geologic overview: Gippsland Basin
    c. Exercise – Prospect identification using 2D grid
    d. Exercise – Synthesis of critical play elements, bidding for blocks
    e. Exercise – Detailed prospect mapping (2D)
    f. Exercise – Drill site selection
    g. Evaluation of exploration well, calibration to seismic

Day 8:

  1. 3D mapping techniques
    a. Exercise - Fault mapping using horizontal and vertical slices
    b. Exercise - Reservoir mapping using vertical profiles and time slices
    c. Exercise - Construction of a reservoir isochron map
    d. Exercise - Mapping environment of deposition using seismic facies
    e. Exercise - Using a hydrocarbon indicator to map reservoir size
    f. Exercise – Estimating recoverable reserves
  2. Course summary – Review of Learning outcomes

Who should attend

Geoscientists who are new to the petroleum industry and who require tools and techniques for the practical use and interpretation of seismic data; Geotechnical assistants who are involved in seismic interpretation projects; Petrophysicists, Engineers and Project Managers who would like to learn more about the utilization of seismic data in various project settings.

Prerequisites and linking courses

A general geological background and some familiarity with Oil and Gas industry terms and practice are assumed. N085 also provides the foundation necessary for other geophysics courses such as:

  •  N004: (The Essentials of Rock Physics for Seismic Amplitude Interpretation) 
  •  N040: (Interpretation of 3D Seismic Data)
  •  N049: (Seismic Attributes for Exploration and Reservoir Characterization)
  •  N282: (Introduction to Full Azimuth Imaging for Conventional and Resource Plays)
  •  N286: (Seismic Acquisition Principles and Practice)
  •  N206: (The Geophysics of Tight Gas and Shale Gas)

Click on a name to learn more about the instructor

John Randolph