Description
Function for imaging of the results of 2D ZO-MF search for multi line projects.
This procedure gives possibility to create zero offset (ZO) MultiFocusing stack, perform velocity constrain picking and export MF parameters in multi line project. Velocity constrain picking performed using spatial interpolation for all lines of the project. The navigation between lines by picking on the "Location map".
Output data – MF parameters;
Visual – Location map, Projections of the semblance cube, Output gathers.
Velocity Analysis– Unlike the CMP processing MF has multidimensional semblance cube that makes picking too complex. For this picking of velocity function in MF replaced by picking of velocity corridor (constrain), the optimal parameters of MF selected automatically. For stacking will be used only events located inside the velocity constrain. Between two locations the velocity constrain interpolated, interpolation of velocity corridor reduce possibility of error in contrast to velocity interpolation during CMP velocity analysis (Figure 2).
Input data
MF Storage Driver Collection
Collection of databases with calculated MF parameters, single file for each line
GMFPickingItem
Link to velocity constrain picking that can be taken from another procedure
Parameters
Polygon picking params
Gives possibility to change creation parameters in some areas. Usually used on the late stages of processing/interpretation
PolygonId
Polygon identification
Default:0;
MinVelocity
Minimum stacking velocity for polygon area
Default: 0;
MaxVelocity
Maximum stacking velocity for polygon area
Default: 0;
UseAngle
Use specified angle range
Default:false;
Clear Angle Inside Area
Do not take specified angle range during stacking
Default: false;
MinAngle
Minimum angle for polygon area
Default: 0;
MaxAngle
Maximum angle for polygon area
Default: 0;
UseGamma
MinGammae
MaxGamma
Current Line
Name of the selected line
Image creation parameters
Image creation is a stacking procedure of time-corrected events corresponds to the optimal MF parameters.The number of events to be preserved during the MF Search determined in Parametrization – MF engine → Wave values → Maximum number of directions. Each event stored in database has following properties:
•Semblance value
•Time
•And indexes corresponding to the MF parameter
During the stacking can be applied different criteria for selection: by angle range, by velocity range or by semblance distribution.
Directions
Maximum number of events to be stack.
•Default: 1
•Values: 1-Maximum Number of Directions preserved during the search
From angle
First value of angle range to stack.
•Default: -90
•Range: -90 - 0
To angle
Last value of angle range to stack.
•Default: 90
•Range: 0 - 90
SN Enhance
Turn ON/OFF normalization of data over semblance prior stacking.
Default: False
Correlation threshold
Threshold for event participation in the summation as a percentage ratio of the maximum value.
•Default: 10
•Range: 10 - 90
Min angle distance selection
Minimum distance in terms of semblance grid along angle axe, between events selected for summation. Parameter gives possibility to separate events with different correlation by angle (Figure 1).
•Default: 1
•Range: 1 - 100
Min radius distance selection
Minimum distance in terms of semblance grid along velocity axe, between events selected for summation. Parameter gives possibility to separate events with different correlation by velocity (Figure 1).
Default: 100
Range: 1 - 100
Testing
Use Trace headers
Max Distance To MF CMP
Interpolation Window Length
Stabilization Window Length
Shift Type
Visualization
Apply following filters on sections and velocity semblance, for visualization only
Datum
Value of final (flat) datum
Default: 0;
ShiftToDatum
Turn ON/OFF shift to final (flat) datum
Default: false;
VelocityAGC
Types
Types of MF parameters to be created during imaging, created both vista item for visualization and gather
Stack
Create zero offset MultiFocusing stack section
Default:true;
Correlation
Create MF correlation section
Default: false;
Angle
Create MF emergency angle section
Default: false;
Gamma
CRE
Create MF CRE section
Default: false;
CRE2
CRE Azimuth
CEE
Create MF CEE section
Default: false;
CEE2
CEE Azimuth
V Slow
V Fast
Dip
Azimuth Dip
VSlow / cos(Dip)
VFast / cos(Dip)
Fold
Create MFfold section
Default: false;
Export Params
Write mode
Default: direct;
Values: direct, append;
Convert To Feet
Convert output measurement system to feet
No Zero Values For Velocity
Fill samples with zero velocities with V 0
Zero padded
Fill traces with zero fold (non calculated) with zeros and write them to the output. Otherwise this traces are not written to output SEG-Y
Shift to datum
Shift exported results to final (flat) datum
Default: false;
Datum
Value of final (flat) datum
Default:0;
Band-pass
Use
Turn ON/OFF band pass filter
Default: false;
Frequency 1
Default:1
Frequency 2
Default:5
Frequency 3
Default:100
Frequency 4
Default:105