Practical Depth Conversion with Petrel | RILS format (Remote Instructor-Led Series)

Day 1: Practical Depth Conversion with Petrel                                                          

Module 1:  Overview of Depth Conversion

* Learning Objectives and Importance:   

• Discuss goals for vertical time-to-depth conversion

* Topics:          

• Accuracies for relative structure, well prognoses, volumetric estimates, and reservoir models

Module 2:  Sources of Velocity

* Learning Objectives and Importance:   

• Review sources of velocity information

* Topics:          

• Sonic logs, check shots, and VSPs
• PSDM Tomography
• Full Waveform Inversion

Module 3:  Defining Velocity Types

* Learning Objectives and Importance:   

• Review definitions and characteristics of velocities for Petrel representation

* Topics:          

• Types of velocities and Petrel Templates
• Conversion of velocity types (e.g. RMS to Interval)
• Import and conversion of velocity text files

Module 4:  Functional Representation of Velocities

* Learning Objectives and Importance:   

• Define velocities fields using vertical functions

* Topics:          

• Velocity representation via Time-Depth functions
• Velocity as a function of time, V0+KT
• Velocity as a function of depth, V0+K(Z-Z0)
• Petrel Velocity Models with time and depth functions

Day 2: Practical Depth Conversion with Petrel 

Module 5:  Gridded Representation of Velocities

* Learning Objectives and Importance:   

• Define velocities fields using grids

* Topics:          

• Spatial velocity variations (lateral gradients)
• Creating an edited PSTM velocity model in Petrel

Module 6:  Vertical Time-to-Depth Conversion (Basic)

* Learning Objectives and Importance:   

·       Implement well-top calibrated depth conversion using T/Z functions and/or Petrel Velocity Models

* Topics:          

• Simple, intuitive depth conversion (no velocity model)
• T/Z Function Lookup Table plus Well Adjustment
• Basic Petrel Velocity Models
• V0+KT
• Seismic velocities
• V0+K(Z-Z0)
• Time-to-Depth QCs

Day 3: Practical Depth Conversion with Petrel                                      

Module 7:  Well and Seismic Data Integration

* Learning Objectives and Importance:   

• Understand methods for linking well and seismic information in Petrel

* Topics:          

• Establishing seismic data polarity and phase (the wavelet)
• Creating synthetic seismogram well-tie correlations
• Image volumes (“Wiggle trace”)
• Inversion volumes (P Impedance)

Module 8:  Database Validation

* Learning Objectives and Importance:   

• Appreciate the need to review and correct the database prior to  incorporating well control

* Topics:          

• Confirming database settings
• Using basic depth-conversion QCs to encounter database discrepancies
• Conditioning Surfaces for input to Models

Day 4: Practical Depth Conversion with Petrel                           

Module 9:  Vertical Time-to-Depth Conversion (Advanced)

* Learning Objectives and Importance:

• Explore advanced depth conversion with layer-based Petrel Velocity Models

* Topics:

• Geologic and data-driven modeling considerations
• Multi-layer Petrel Velocity Models
• V0 + KT
• V0 + K(Z-Z0)
• PSTM Velocities
• Pseudo Interval Velocities
• “Simple” thrust models (forming complex models in Petrel)

Module 10: Petrel Models and Uncertainty Analysis

* Learning Objectives and Importance:   

• Implement domain conversion and uncertainty analysis with Petrel Velocity and 3D Models

* Topics:          

• Evaluating depth uncertainty
• Mean and standard deviation workflow
• Impact of structural uncertainty on volumetrics in 3D Models

Day 5: Practical Depth Conversion with Petrel                           

Module 11:  Pitfalls of Vertical Depth Conversion

* Learning Objectives and Importance:   

• Understand accuracy of vertical (PSTM) time-to-depth methods and when they fail

* Topics:          

• QCs and validity of vertical depth conversion

Module 12:  Calibration of Depth Migration with Well Tops

* Learning Objectives and Importance:   

·       Learn approaches for stable integration of depth-domain seismic (PSDM) with well control

* Topics:          

• Working in the time domain
• Creating the calibrated time/velocity model (the anisotropic Vz model)
• Database QC
• Conversion of time data (seismic/surfaces/faults) to well-top calibrated depth
• Petrel Z-Z depth calibration (depth stretch only)
• Depth-uncertainty analysis