Introduction to Depth Imaging with Omega and Petrel

At the end of this class students will be have the skills needed to be a contributing member of a depth imaging production processing team. These skills will cover the most common workflows involved in processing a marine 3D dataset through a depth imaging sequence.

• Agenda
• Topics
• Audience
• Prerequisites

• Agenda

  Day 1

  Building an Initial Model

  • Methods for building initial models
  • Preparation of initial velocity model (clipping and smoothing)
  • Initial model QC

  At the end of this session the student will be able to build an initial depth imaging model from provided inputs using the SVM model building software. They will be able to QC the initial model with SVM and execute a migration sequence using initial model.                

  Day 2

  Isotropic Tomographic Updating (Part 1)

  • Kirchhoff Depth Migration
  • Data conditioning for CIP picking process
  • CIP Picking
  • CIP Diff
  • ZTOMO

  At the end of this session the student will be able to execute an isometric tomography sequence. They will be able to explain the key components of the tomography software and the tomographic sequence.

  Day 3

  Isotropic Tomographic Updating (Part 2)

  • RMO QC and RMO QC tool (Volumetric QC and PSI)
  • Tomographic QC and update (Tomographic QC tool)
  • Key assumptions and limitations of the tomographic process  

  At the end of this session the student will be able to QC an isometric tomography sequence. They will be able to QC and perform an isotropic tomographic update of an initial model and migrate the updated model and QC the results.                

  Day 4

  Understanding Anisotropy (Part 1)

  • Review concept of anisotropy
  • Anisotropy and symmetry classes
  • Building a TTI anisotropic depth model    

  At the end of this session the student will be able to explain the concept of anisotropy and the impact of anisotropy on the depth imaging process.                

  Day 5

  Understanding Anisotropy (Part 2)

  • Conversion of initial model to anisotropic TTI model
  • Methods for determining anisotropic property fields
  • Use of the Seiscal tool    

  At the end of this session the student will be able to build and QC an anisotropic TTI depth imaging model. They will be able to explain the basic methods used to derive anisotropic property fields and use the Seiscal tool. They will be able to build and QC an initial anisotropic TTI model, migrate it and QC the results.

  Day 6

  Conventional Smoothing Filters versus Steering Filters in Anisotropic Tomography Round 1 (Part 1)

  • Steering filters in tomography
  • Anisotropic tomographic updating

  At the end of this session the student will be able to explain the role of smoothing filters both conventional and steering in tomography and how to QC them. They will be able to execute the anisotropic tomography sequence, CIP pick, RMO QC, dip estimation and QC, and derive the tomography equations.

  Day 7

  Anisotropic Tomography Round 1 (Part 2)

  • Well constrained tomography
  • Anisotropic tomographic updating

  At the end of this session the student will be able to complete the first round of anisotropic tomographic update and QC. They will be able to update the initial TTI anisotropic model, QC results and migrate the data.

  Day 8

  Anisotropic Tomography Round 2 (Part 1)

  • Understanding migration algorithms
  • Anisotropic tomographic updating

  At the end of this session the student will be able to carry out the second round of the anisotropic tomography sequence, CIP pick, RMO QC, dip estimation and QC and derivation of tomography equations. They will be able to explain the merits of the different migration algorithms.

  Day 9

  Anisotropic Tomography Round 2 (Part 2), Well Section Window and Seiscal

  • Understanding multi azimuth tomography
  • Anisotropic tomographic updating
  • Well Section Window – velocity model and pre-stack data QC
  • SeisCal – 1D anisotropic model calibration

  At the end of the session the student will be able to complete the second round anisotropic tomographic update, QC it and migrate the data. They will be able to explain the basics of multi azimuth tomography.

  Day 10

  Review and Presentation of Final Results

  • Presentation of final results      

  In this closing session we will review and present the final results. Students present their own results and learn the appropriate process for presenting final results for a depth imaging project.                

• Topics

  • Build, modify, and QC velocity models in SVM (including anisotropy)
  • Run and QC tomographic updates of these models
  • Prepare data and models for Kirchhoff pre-stack migration
  • Run, test, and parameterize Kirchhoff pre-stack migration using these models
  • (Optional) Relate the above to a basic understanding of seismic imaging

• Audience

  The class is suitable either for less experienced geophysicists wanting to learn the basics of depth imaging, or for experienced depth imagers wishing to secure the functional capabilities necessary to perform depth imaging.

• Prerequisites

  Competency in Omega is mandatory. Petrel experience is advantageous. An understanding of the concepts underlying time seismic data processing and common depth processing challenges is required. This class needs to be taken in conjunction with the Seismic Velocity Modeling class in order to understand how to derive viable models suitable for depth processing in Omega and Petrel.

• Prerequisites