6. Seismic View Dialog

A seismic viewing utility is available from within the Stack Ghost Suppression (SGS) application. It is accessed by pressing the button on the tools menu bar. This allows both the currently selected seismic volume and the result of applying the convolution operator to be viewed. The convolved data is updated in real time using the currently derived operator. This allows the user to accurately access the results of their operator on a single line, before undertaking the more time consuming operation of applying it to a whole volume.

Figure 4.33. Seismic view

Seismic view


When the seismic view is first displayed, it contains three panels within the seismic display area. The first panel shows an example inline from the seismic volume that is currently selected as input for the application. Initially an inline from the central region of the volume is shown. The second and third panels are for displaying the result of applying the deghosting operator to the same inline, respectively. Initially these two panels are blank, which is normal. Once you have loaded some seismic trace data the deghosting operator will be automatically generated and applied to the current inline. The second updated displaying the results of the deghosting. The third panel displays an auto-correlation. You are then free to optimise your operators, using the Design Operator Controls, viewing the results of any changes in real time.

6.1. Toolbars

The top section of the seismic viewing window shows two toolbars allowing selection of inline/crossline, cross hair toggling, zoom in/out controls, colour palette selection, fit item, and fit row controls. The toolbars can be positioned at various locations by simple drag and drop using mouse left-button.

6.1.1. Inline/Crossline Selector

The inline/crossline selection tool allows the currently selected inline or crossline to be changed. The choice of whether this control is affecting inline or crossline position is made by either selecting a panel in the seismic display area of the viewer or by selecting 'Inline' or 'Crossline' from the 'Elements' display. When the inline or crossline is changed, the selected seismic (and convoluted) panels in the main display area will update immediately to show data for the selected inline/crossline.

6.1.2. Tools

IconDescription.
Cross HairToggles the cursor between a simple arrow, and a cross-hair.
Zoom InIncreases the size of all the seismic panels in the seismic display area.
Zoom OutDecreases the size of the seismic panels in the seismic display area.
Colour PaletteStarts a tool that allows the colour palette of the currently selected seismic data in the 'elements' selection view to be changed.
Default FitSets the default size to the seismic panels within the display window.
Fit itemForces the currently selected seismic panel to fit the whole of the display window.
Fit rowWhen multiple seismic panels are being displayed they will scaled so that a row of two seismic panels will fit within the display window.
Area of InterestThe seismic displayed within Seismic View will be now displayed based on the 3D survey area, the Seismic time-gate range selections done as part of the Select Input Data" dialog.

6.2. Elements tree view

The Elements selection panel allows the user to choose which seismic data is available to view in the main display area of the seismic viewer. Although the elements panel has already been configured for optimal usage, it can still be used to add additional seismic data to the main seismic display area as seen from the figure below.

Figure 4.34. Selecting Seismic Data

Selecting Seismic Data


Add a new inline/crossline: At its top level, the Elements control contains a list of inlines and crosslines that are available for display. To add an additional inline or crossline, right-click the word 'inline' (or 'crossline') and select 'Add Seismic Panel'. At this point a dialog will appear allowing the user to select a trace range and time range for the new display panel. It is suggested that unless otherwise required, the default extents are accepted. The extents can be adjusted either by using the spin boxes for min/max traces and min/max time samples or by grabbing the edges or corners of the blue box and dragging. Additionally, by grabbing within the blue box you can move it to a different region for the selected inline or crossline. A new entry will appear in the inline or crossline list in the elements view, labeled by the number of it's inline/crossline. By default the inline or crossline is through the centre of the survey area.

Add a Volume: Each numbered inline/crossline in the elements list can in turn have one of two volumes associated with it. These are the current volume that has been selected by the application and the volume produced by applying the current operator. To add a volume to a given inline/crossline, right-click on the desired inline/crossline number within the Elements display. Choose 'Add Seismic Data' and select the requested volume from a list that will appear. The named volume will then appear as an entry under the selected inline/crossline.

Display a volume: Seismic volumes at given inline/crossline positions can be displayed or hidden by clicking on their associated checkboxes within the Elements panel.

The elements selection panel can be closed or moved to other sections of the screen by clicking on its title bar and dragging with mouse left-button.

6.3. Property Viewer

The Property selection panel allows the user to view and optionally alter values of the currently selected item. When a panel is clicked on in the main window, or an item selected in the elements view, properties describing the selected item are displayed (e.g. 'Top Annotation' or 'Left Annotation'). Changing these values will alter the way in which seismic data is displayed in the main viewing window. The list of properties that can be altered depends on the selected item in the 'Elements' controller.

This panel can be closed or moved to other sections of the screen by clicking on it's title bar and dragging with mouse left-button.

6.3.1. Seismic Volume Properties

The figure below shows a seismic volume displayed as Variable Intensity with wiggle traces overlayed. A number of of the wiggle trace parameters have been changed from their default settings in the Property Editor. Here, the wiggle Left Fill has been turned on and the Left Fill Color changed to red. The Gain has been increased from 1 to 5 and the Wiggle Trace Step has been increased from 1 to 4 to improve clarity:

Figure 4.35. Seismic Volume Properties

Seismic Volume Properties


PropertyDescription
Variable Intensity

Toggles the display of the seismic data as a variable intensity image

Palette

Select the colour palette to use for the variable intensity display. Typical values are red-white-blue, or white-black.

Wiggle Traces

Toggles the display of wiggle traces.

Wiggle Right/Left fill

Choose whether to display the off center parts of a wiggle trace in a specified colour.

Gain

Increases the displayed amplitude of wiggle traces.

Wiggle Trace Step

Specifies the number of traces to skip between successive wiggle traces. With large amplitudes, wiggles can appear to merge into each other unless suitable trace step is chosen.

6.4. Seismic Display Area

The seismic display area shows the seismic data that has been selected by the 'Elements' controller. This is a highly flexible and interactive viewing area allowing the user to focus attention on areas of particular interest within the seismic volume. The seismic display area can contain one or more seismic panels. Within an individual seismic panel, a number of operations are available to change the extent of displayed data:

Desired actionDescription
Scaling:

Click on a panel to select, then with the 'Control' key pressed rotate the mouse wheel to zoom in/out on the selected seismic data. The data will zoom in/out around the current cursor location.

Horizontal scaling:

With the 'Control' and 'Alt' keys pressed, rotate the mouse wheel to zoom in/out on the selected seismic data in the horizontal direction.

Vertical scaling:

With the 'Control' and 'Shift' keys pressed, rotate the mouse wheel to zoom in/out on the selected seismic data in the vertical direction.

Moving data:

When the cursor is positioned over a seismic panel, press mouse button one. The cursor will change to a hand shape allowing data to be grabbed and moved.

Vertical scrolling:

When data in a seismic panel is zoomed in, the data can be scrolled vertically using the mouse wheel.

Horizontal scrolling:

When data in a seismic panel is zoomed in, the data can be scrolled horizontally. This is achieved by pressing the 'Alt' key and rotating the mouse wheel.

Change display data range:

At the top left corner of each seismic panel is a blue box. This shows the extent of the displayed seismic data compared to the extent of the available seismic data. Click mouse left-button on the blue box to display a 'Select trace/z range for display' dialog allowing you to adjust the extents either by using the spin boxes for min/max traces and min/max time samples or by grabbing the edges or corners of the blue box and dragging.

Remove seismic panel:

With the mouse over a seismic panel, right click and select "Remove" on the pop-up menu item. This will immediately remove the panel and all volumes displayed within that seismic panel.