Fundamentals of Seismic Exploration

Course Title : Fundamentals of Seismic Exploration

Course Duration : 5 days

  • Contact training@dallasgeophysics.com to schedule these courses at your institution.

Course Description

The course is aimed at teaching the physical concepts involved in the application of seismic methods to petroleum exploration. At the outset, the course introduces briefly the basics of hydrocarbon exploration in a regional setup including gravity, magnetic and refraction surveying. The next stage of the course focuses on seismic wave propagation, ray theory, attenuation and other propagation mechanisms associated with wave propagation. These principles are employed in the next section for developing an understanding of field data acquisition and processing in land and marine environments. The subsequent section on seismic interpretation is focused on introducing the method of translating the observed seismic sections to geological information critical to hydrocarbon exploration. The next stage of the course focuses on prestack data analysis for AVO studies. Prestack and poststack inversion are discussed in the next unit to derive quantitative information relating to the reservoir. Application of seismic attribute analysis for structure/stratigraphic mapping and reservoir characterization are discussed in the next unit along with Spectral Decomposition methods for thin bed mapping .

Recommended Participant Level: Entry Level Geologist, Geophysicist, Reservoir engineer, Petroleum Engineer. Those who have introduction to basic geology with college physics and math background, and with some experience in geoscience field in industry.

Day 1

Unit 1

  • Introduction
    • Exploration for Hydrocarbons – The Big Picture
    • Reconnaissance Survey for Regional mapping – Refraction, Gravity, Magnetic
    • Gravity & Magnetic Method for Basement Mapping
    • Regional Seismic Reflection Survey
    • Exploration Objectives

Unit 2

  • Seismic Method: Physical Principles
    • Elementary Wave propagation Concepts – Snell, Huygens, Fermat and Fresnel
    • Stress, Strain, Particle Velocity and Wave Velocity
    • Simple Wave Equation – Relation to elastic properties
    • Wave Propagation, Compressional, and Shear Wave
    • Surface Waves – Raleigh Wave, Love Wave
    • Refraction, Reflection, Diffraction and Multiple reflection

Unit 3

  • Travel-time plots x-t, x2-t2
  • Reflection from Multiple Interfaces
  • Reflection Time – Zero Offset, Non-Zero Offset
  • Velocity and Density vs Elastic Properties

Unit 4

  • Impedance and Impedance Contrast
  • Reflection Strength, Reflection Polarity & Character
  • Effects of medium on wave propagation – attenuation, absorption, spherical spreading,
  • Partitioning of energy at an interface, Zoeppritz’s equations
  • Distinction between zero-offset and non-zero offset reflections
Day 2

Unit 1

  • Seismic Signal
    • Waveform – Amplitude, Power, Energy
    • Amplitude Spectra, Phase Spectra
    • Wavelet Phase: Minimum Phase, Maximum Phase, Zero Phase
    • Auto-correlation, Cross-correlation, and Convolution
    • Signal Sampling: Nyquist Frequency

Unit 2

  • Seismic Data Acquisition
    • Seismic Source Characteristics
    • Land Data Acquisition
    • Marine Data Acquisition
  • Concept of Common Depth Point Shooting, Multiplicity
  • Horizontal Reflector, Normal Move Out
  • Ground Roll Suppression and Geophone Arrays
  • Seismic Resolution: Horizontal and Vertical

Unit 3

  • Seismic Data Processing
    • Practical Seismic Data Processing: Pre-Stack and Post-Stack
  • Pre Processing
    • Geometry, Quality Control
    • Amplitude Correction – Spherical spreading
    • Editing Muting, Sorting

Unit 4

  • Prestack Processing
    • Filtering: Band Pass, FK Filtering
    • Deconvolution, Spiking and Predictive Deconvolution,
    • Stacking Velocity Analysis, Residual Statics
    • Stacking
  • Post Stack Processing : Deconvolution, Filtering, Migration
DAY 3

Seismic Data Interpretation

Unit 1

  • Generation of hydrocarbons and migration; Types of traps
  • Seismic Measurements and Geology
  • Sonic and Density Logs
  • Synthetic Seismogram, Well tie
  • Seismic Velocities
  • Density, Compressional and Shear Wave Velocity and Geology

Unit 2

  • Fundamental Geophysical Assumptions
  • Collecting and examining data
  • 3D Seismic Data Interpretation
  • Picking Reflections, Mapping reflection horizons
  • Integrating Well data into interpretation

Unit 3

  • Seismic signatures:
  • Clays and silts; clastics, carbonates, salt, basement
  • Reflections associated with hydrocarbon and diagentic effects
  • Seismic Expression of Structural Features
  • Faults, Folds, Reefs, Unconformities, Channels
  • Seismic Expression of Stratigraphic Traps

Unit 4

  • Contouring and Mapping – Principles and Method
  • Computer contouring – isochron, isopach and depth maps
  • Contouring Pitfalls
Day 4

Quantitative Seismic Interpretation

Unit 1

  • Zero offset and non-zero offset
  • Pre-stack and post-stack seismic data amplitude distinction
  • True amplitudes in seismic processing
  • Amplitude Variation With Offset (AVO) – Bortfeld study
  • Zoeppritz, Shuey, Fatti & Smith formulation

Unit 2

  • Rock Physics – Lithology & Fluids
  • AVO intercept and gradient
  • AVO Cross Plotting
  • Rp-Rs, Fluid Factor
  • AVO Modeling

Seismic Inversion

Unit 3

  • Seismic Inversion
  • Prestack and Poststack inversions
  • Model Based Inversion
  • Pre-stack inversion
  • Elastic Impedance Inversion

Unit 4

  • Travel-time Inversion
  • Case studies – Post-stack, Pre-stack, and Elastic inversions
Day 5

Unit 1

  • Seismic Attributes
  • Spectral Decomposition
  • Coherency – mapping structure and stratigraphy

Unit 2

  • Dip, Azimuth, Roughness, Curvature – Structure Attributes
  • Seismic Attributes – Mapping Structure

Unit 3

  • Seismic Attributes – Mapping Stratigraphy
  • Seismic Attributes and Reservoir Characterization

Unit 4

  • 4-D Seismics, Reservoir Monitoring
  • 3C survey
  • Course Summary

  • Faculty:
    • Teaching faculty  hold Ph.D  with three  decades of  combined experience in academia and oil industry.
    • They teach professional courses all over the globe  for oil and mineral industry.
    • Contact training@dallasgeophysics.com to schedule these courses at your institution.

    Keywords: Petroleum, Gas, Oil, Hydrocarbon, Rock, Geology, Geophysics, Geoscience, Geologist, Geophysicist, Manager, Gravity, Magnetic, Seismic, Well logging, Welllog, Seismic attributes, Mechanical properties, Conventional resources , Unconventional resources, Shale oil, Shale gas