Petrel官方地震解释培训M7_Depth_Conversion.ppt

Stacking Velocities (Point data)
Velocity Model 1
Velocity Model 2* Active (selected) Velocity Model
*Optional exercises, see Attachments
Domain Conversion of objects
3. Define output (e.g. velocity cubes, V0 and k for Q.C. purposes)
• Domain convert via 1. Right click on object (uses currently ”active” velocity model) 2. General Depth Conversion Process for Multiple objects 3. 3D Grid Conversion 4. Within a workflow in Process manager
Seismic – Domain Conversion
Objectives
• Quality control time/depth relationships for wells • Define velocity model intervals • Create an uncorrected velocity model using well data • Create a final corrected velocity model using well data • Create a velocity model with uncertainty • Depth convert a 3D Grid • General depth conversion
C: Velocity SEGY (average) D: 3D Velocity Property (average)
1. Seg-Y 2. Velocity Surfaces 3. Well Data Points 4. T & V logs 5. Residual Points 6. Output Sheet
The Process
ZONES
Corrections
Velocity Output Advanced
Datum
1. Constant
2. Surface
3. Horizon*
Datum
Vo Vo + k(z-z0)
Datum
Vo
Vo + k(z-z0)
Vo + kz
Vo + kz
Additional Settings ++
(Gridding & SegY settings)
1. Constant 2. Surface 3. Horizon* 4. Well Tops
Or none
A: Auto 1. Correction (Vo) 2. TDR (Vo & k) B: User 1. Constant 2. Surface
1. Well trace Md inc 2. Depth & Time tolerance 3. Velocity & k clipping
Saved in Model tab
The exercise examples
Time/Depth relationship in wells
Velocity Cube (SEG-Y)
Velocity Model 3*
Define intervals
1. In the Process pane, open the Geophysics folder and double-click on the Make Velocity Model 2. Click the ”Append item in the table” icon as many times as available input objects 3. Change Bottom Interval to desired type 4. Select the levels to model, from Input or Models tab, click on its name and drop it into the dialog
• Define velocity model
1. Define velocity intervals (usually between time interpretation surfaces)
2. Define velocity functions (automatically calculated or userdefined)
objects • Define the velocity model by:
- Surfaces/constants - Well Time/Depth Relation - Velocity Cubes - 3D grids
• Convert both ways with the same model • Convert objects independent of the 3D grid • Perform conversions in the process manager
Optional: • Create a velocity model using a seismic velocity cube • Create velocity model using stacking velocities (xytv point-data)
Overview
• ‘Velocity Modeling’ is separate from ‘Domain Conversion’ • Interactively switch between time and depth for converted
百度文库
Velocity model – bridges the gap between time and depth domain
Time domain
Velocity model
Time -> depth conversion Depth -> time conversion
Depth domain
The Workflow