Seismic Data Interpretation

Seismic data interpretation projects are implemented with the help of DV-1 Discovery, DV-SeisGeo and INPRES software systems that are based on proprietary developments and dynamic visualization technology.

With its powerful science and technology facilities, CGE is able to achieve optimal solutions to detecting and mapping hydrocarbon traps, to determining reservoir properties and fluid saturation of formations.

Major procedures involved in seismic data interpretation are as follows:

  1. Validation for tying reflectors to stratigraphy:
    • VSP data interpretation
    • 1D/2D seismic modeling
    • assess similarity between real and synthetic traces
    • analyze contribution made by boundaries to reflections
    • assess signal phase characteristics
    • assess amplitude characteristics of a layer in the wavefield
    • use seismic stratigraphy to identify reflectors
    • compute seismic markers from VSP data and acoustic logs
  2. Detailed correlation of reflectors:
    • 2D/3D auto correlation
    • update correlation in zones of poor reflection continuity by analyzing correlative amplitude vs. effective thickness
    • check correlations for accuracy in poor reflection continuity zones
    • assess how permafrost effects are accounted for by examining:
      • eflector depth (well data) vs. reflector time plots
      • gas-water contact time surface for a massive gas pool
      • time vs. depth plots for all reflectors
  3. Fault identification and tracking by jointly examining:
    • seismic section
    • seismic attribute maps
    • maps showing first and second derivative surfaces
    • strike curvature maps and outline maps
    • form index maps
  4. Construction of isochron maps:
    • map smooth
    • map edit
    • analysis of maps and map sets in 3D view
  5. Validated selection of a velocity model, and velocity-model-based structural imaging:
    • compute vertical spectra of velocities
    • compute horizontal spectra of velocities
    • examine created velocity-depth model for accuracy
    • compute interval velocities and average velocities for all target horizons
  6. Construction and analysis of structure maps showing stratigraphic surfaces for target strata and key horizons. Assessment of structural imaging confidence:
    • by estimating structural imaging errors through comparing with drilling data from wells not involved in the structure map construction (validation method)
    • by using key boundaries
    • on the basis of math models of tectonic development history for stratigraphic intervals
  7. Seismic inversion;
    • compute acoustic impedance sections
    • employ simulated annealing method to recover effective model of medium
    • run elastic AVO-inversion by stacking the data at different dip angles (prediction of Vp, Vs and P sections)
  8. Generation of seismic attribute sections:
    • convert seismic sections to sections of instantaneous amplitudes, instantaneous frequencies, instantaneous phases and sections of seismic trace derivative integrals
  9. Computation of reflection strength maps, heterogeneity maps and other maps
  10. Construction and edit of seismic attribute maps, with the stratum sedimentation model honored
  11. Seismic facies analysis:
    • compute sedimentation sections
    • compute seismic facies sections
    • identify seismic facies as a result of integrated interpretation of seismic, sedimentation and seismic facies sections, etc.
    • run seismic facies analysis on attribute sections
    • identify paleo-deltas, paleo-channels, paleo-bars and barrier islands, etc.
    • analyze and compare seismic and logged facies
    • run joint interpretation of data obtained from seismic facies analysis and paleo-tectonics analysis for restoration of sedimentation environments for sand body reservoirs, and for determination of genesis and facial environments for such sand body reservoirs
    • establish correlative relationships between amplitudes (and other attributes) and effective thicknesses and average porosity
    • evaluate prospectivity of identified sedimentation bodies based on saturation determinations from well tests and logs
    • provide recommendations on new exploration well locations
    • classify identified seismic facies
  12. Analysis of tectonic and paleo-structural development of a study area:
    • compute sections showing paleo-history of how horizons were formed
    • run analysis of paleo-history vertical cross-sections along arbitrary lines
    • generate paleo-tectonics sections
    • analyze paleo-tectonics sections
    • generate and analyze paleo-structural plan-views of horizons
    • bring paleo-tectonics and seismic facies analysis data to consistency
  13. Generation of a reservoir model:
    • create a sedimentation model based on paleo-tectonics and facies analyses
  14. Geostatistical analysis of correlative relationships between seismic attributes and estimation parameters, e.g. effective (net) thickness and reservoir’s open porosity coefficients:
    • assess correlative relationships between seismic attributes and reservoir thickness during 1D modeling
    • seek relationships between AVO-attributes and parameters being computed
    • establish relationships individually between different sedimentation environments
    • run multi-attribute analysis using multiple regression method
    • use neural networks for reservoir characterization
    • compute parameter prediction maps
    • compare parameter prediction maps with sand body distribution maps
    • assess prediction veracity of estimation parameters
  15. Identification, delineation and making ready of structural and non-structural prospects for drilling
  16. Issuance of recommendations on drilling new exploration (or production) wells