Reservoir Geophysics for Geologists and Geophysicists

Course Title : Reservoir Geophysics for Geologists and Geophysicists

Course Duration : 5 days

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


Course Description

The course is aimed at imparting working knowledge in Seismic Reservoir Analysis for geologists,  geophysicists and reservoir engineers.  At the outset, the course introduces briefly necessary concepts on seismic wave propagation, ray theory, attenuation and other details associated with wave propagation,  field data acquisition, and processing  in land and marine environments.

The next section discusses seismic velocities (Vp, Vs), seismic resolution, fluid and rock properties, Direct Hydrocarbon Indicators (DHI), and Well Log analysis required for geophysical reservoir characterization,

The next section introduces the concept of Amplitude Variation with Offset (AVO) studies and how it can be applied for reservoir characterization using the intercept VS  gradient cross plotting and Fluid Factor approaches.

Next section discusses how Impedance (AI) inversion in the post-stack domain can be used to infer lithologic and reservoir fluid properties. In the pre-stack domain quantitative impedance attributes can be extracted that  can provide significant controls on reservoir properties for determining hydrocarbon content. Lamda, Mu, Rho (LMR) attributes provide significant information about the rock and fluid types in the reservoir.

Next section discusses application of seismic attributes to  derive information that  can provide  qualitative and quantitative constraints on  reservoir properties. Post-stack single trace seismic attributes tend to provide information about the reservoir at the trace location. Multi-trace seismic attributes tend to provide  information about reservoir geometry,  structural and stratigraphic features of reservoir, and hydrocarbon indications in some situations. Dip, azimuth, curvature, and coherence attributes provide excellent controls on structural details. Instantaneous amplitude, frequency, phase, and spectral decomposition, provide information about  reservoir  stratigraphy and hydrocarbon presence.  Seismic attributes can be computed for mapped horizons, and in between horizons, to analyze  interface and formation characteristics/properties.

Day 1

Necessary Concepts

Introduction

  • Exploration for Hydrocarbons – The Big Picture
    • Wave Propagation, Compressional, and Shear Wave
    • Refraction, Reflection,  and Diffraction
    • Reflection Time – Zero Offset, Non-Zero Offset
    • Reflection Strength from Interfaces
    • Reflection Polarity & Character
    • Partitioning of energy at an interface, Zoeppritz’s equations
  • Seismic Data Acquisition
    • Land  and Marine Data Acquisition
  • Concept of Common Depth Point Shooting, Multiplicity
  • Seismic Data Processing
  • Practical Seismic Data Processing: Pre-Stack and Post-Stack
  • Amplitude Preserving Processing for AVO – for Inversion
  • Deconvolution – For improving vertical resolution
  • Stacking Velocity Analysis – for better structure imaging
    • Statics and  Residual Statics –  for removing structural artifacts
    • Migration – for repositioning reflection energy
Day 2

Seismic Velocities, Rock Physics, DHI and Well Log Analysis

  • Seismic Velocities Factors Affecting P & S -Wave Velocity
  • Empirical Relationships
  • Fundamentals of well-log analysis – Gamma, SP, Sonic, Density and Neutron
  • Seismic to Well Tie – Synthetic Seismogram
  • VSP, check shot survey
  • Average velocity, Interval velocity and Depth Conversion
  • Seismic Resolution – Horizontal and Vertical
  • Fluids Properties
  • Rock Physics
  • Fluid replacement modeling
  • Rock Physics Templates
  • DHI analysis – flat-spot, bright-spot, dim-spot, polarity reversal, chimney effects
Day 3

Reservoir Characterization through AVO

Introduction to Amplitude Variation with Offset (AVO)

  • Zoeppritz equation
  • Approximations to Zoeppritz equation
  • AVO classification – Class I, II, III, IV Sands
  • AVO intercept/gradient crossplotting
  • AVO – Geostack and Fluid Factor
  • AVO in Carbonates
  • Anisotropic AVO
  • Discussion on the applicability and limitations of AVO
Day 4

Reservoir Characterization Using Seismic Inversion

  • Geophysical Inversion Principle
  • Convolutional trace model
  • Inversion Methods
  • Post Stack Inversion
  • Acoustic Impedance Inversion
    • Recursive Inversion
    • Sparse spike inversion
    • Model Based Inversion
    • Colored Inversion
  • Elastic Impedance Inversion
  • Pre Stack Inversion
  • LMR and Seismic Petrophysics
  • Discussion on the robustness of AI/EI/LMR methods
  • Application to Unconventional Reservoirs
Day 5

Reservoir Characterization Using Seismic Attributes

  • Introduction to Seismic attributes
  • Seismic Attributes
  • Instantaneous Attributes
  • Dip, Azimuth, and Curvature, Roughness
  • Coherence
  • Spectral Decomposition
  • Horizon and Formation attributes
  • Seismic Attributes expression of Structure and Stratigraphy
  • Integrating seismic attributes, AVO and AI/EI/LMR for reservoir characterization
  • 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.