Displaying Digital Logs Workflow

In the Profile View, there are a number of tracks in which digital logs can be displayed:

Side Track (on the left side of the window) 5 sub-tracks for digital log data

Bottom Track 5 sub-tracks for digital log data

Along wellbores (either vertical or horizontal) 1 track on each side of each wellbore

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To open the Log Display Options Dialog, from the Profile View, click the Digital Logs and Tracks Dialog button on the icon bar, or in the menu bar, choose Logs > Select Logs and Tracks:

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Log Display Options Dialog

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1 Side Track Preview

2 Grouping, Filtering, and Well Name Display options

3 Wells and Logs

4 Selected Log Statistics

5 Bottom Track Preview

6 Settings for selected digital log

7 Side and Bottom Track Settings

When the Log Display Options dialog opens, it will automatically display all wells selected in the Profile view and the digital logs loaded into the Petra database for those wells.

In the top bar (#2 in the image above), you can select various grouping and filtering options to quickly locate the wells and logs of interest to you:

Group by Well:

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Group by Log:

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Apply Filter:

Apply Filter opens the filtering dialog. In this dialog you can create filters to only show the logs of interest:

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To create a filter:

1.	At the bottom of the dialog, enter the condition you would like to filter on, for example Log Contains GR, and press the Add button.

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2.	Multiple conditions can be added, and filtering can be performed on Depths and Well Names in addition to Log names. Multiple conditions are applied using the and operator.

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3.	To view the filtered logs in the main dialog, press Ok:

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4.	To remove the filter, simply uncheck the Apply Filter checkbox.

Track Settings

To change the widths of the tracks, use the lower right portion of the dialog. There are 5 tracks available in the side track and bottom track.

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To activate a track, click its Active checkbox. You can also adjust the width (in inches).

Changes to the number and widths of tracks activated will be shown in the track previews:

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Changing Digital Log Settings

To activate a digital log, click the checkbox next to its row in the table.

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The blue highlight on the row selected indicates that you are working with that log curve in the settings panel on the right. To change the style and track settings of a different curve, simply click on its row to move the blue highlight color.

To change the style and track settings of multiple curves at the same time, simply control-click or shift-click on multiple rows. Settings will apply to all selected wells when you press Apply.

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To uncheck all digital logs that have been enabled, press the Clear All button.

Log Curve Settings

In the settings panel on the top right, the following tabs are available. Again, these settings all apply only to the well or wells highlighted in blue in the well and curve list.

The Scale tab is primarily used to select the log track and log scale limits. Scaling options apply to the highlighted log name in the wells and logs portion of the dialog (blue highlight).

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-	Active checkbox: Activates/deactivates the selected log. This has the same functionality as the checkbox discussed above.

-	Label: Change the logs label.

-	Disabled: Check this option to temporarily hide a log trace from the display but retain its settings.

-	Draw Along the Borepath: Draws the log along the borepath of the well.

o	Draw on Side of Borepath: Specify which side of the borepath the log should be drawn upon.

o	Borepath Track Width: Set the width, in inches, of the track along the borepath.

-	Use Alias Logs: Check this option if you want aliased curves to be plotted whenever the selected curve is absent.

-	Logarithmic Scale: Check this option to plot a log using log 10 value. The left and right scales should be entered as powers of 10 when using this option and the scale min/max must be >0.

-	Scale: Left/Right scale for selected log curve.

-	Side Track / Bot Track drop down: Select whether you would like this curve to appear in the Side Track or Bottom Track, and if so, in which sub-track.

The Style tab defines the appearance of each log trace. Color, line width, line style and shading options are provided. Color and style options apply to the highlighted log name in the wells and logs portion of the dialog (blue highlight).

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-	Shading Method: The display style for a log is controlled by the selected shading method.

o	No Shading: Displays a log using a single color selected from the "Line Color" palette provided.

o	Shade Using Cutoff: Displays the log in 2 colors and allows the log trace to be shaded based on a user-defined cutoff value. Proceed to the "Cutoff tab" to set the cutoff shading options.

o	GeoColumn Shading: Shades the selected log trace using values from another log curve. This option can be used to plot a litho-column type display. Proceed to the "GeoColumn tab" to set the GeoColumn shading options.

-	Line Style: Choose the line pattern for drawing the log trace.

-	Line Width: Choose the line width for drawing the log trace.

The Cutoff tab provides options relating to how a log is shaded based on a user-defined cutoff value. Two colors are used to plot the log trace - one for values below the cutoff and another for values above the cutoff. Shading can occur below or above the cutoff value.

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Shade:

o	Less than Cutoff: Draws the log curve using the two color scheme according to the cutoff value and shades values less than (below) the cutoff.

o	Greater Than Cutoff: Draws the log curve using the two color scheme according to the cutoff value and shades values greater than (above) the cutoff.

Cutoff:

o	Constant Cutoff: Enter the log value which defines the boundary at which color change and shading is to occur.

o	Statistical Cutoff: Provides a variable cutoff based on the average or mean log value and standard deviation. The cutoff value is entered as the number of standard deviations above the mean. The equation used is:

CUTOFF = MEAN + (SD x USERVALUE)

-	Shading Color: Choose the color to use when the log trace is less than the cutoff value. Check the associated color palette to change the color box.

-	Curve Line Color: Choose the color to use for the curve line.

-	Suppress Curve Outline: Suppresses the curve line

Use Discriminator: A discriminator curve is a "flag" curve containing 1's and 0's. When a discriminator curve is used, the GeoColumn shading will occur only where the discriminator curve is equal to 1. When this option is selected, the Discrim tab will appear where the discriminator curve can be selected:

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The GeoColumn tab provides options for displaying a curve using "GeoColumn" shading. The GeoColumn feature shades a curve with multiple colors based on curve values.

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-	Shading Direction: Specify which side of the curve should be shaded.

-	Log Used for Shading: The values from the curve selected here are used to define the color "cutoff" ranges. This curve can be the same curve as being shaded or can be any other curve.

-	GeoColumn Base Line Value: Shading occurs from the curve traces back to either the track edge or a specified curve value.

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-	Suppress Curve Outline: The curve trace is not drawn. Only the shading will be drawn.

-	Transparent When Background Color: When the shading color matches the screen background color, shading will not occur.

The Misc tab provides options for configuring the header for each curve in the track.

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Pressing the Apply button will update the Profile View with all of the changes you have made. You may need to move the dialog to the side to see the Profile View. The changes are not permanent until the OK button is pressed, which closes the dialog.

Advanced Options for Digital Log Curves

Traditionally, when drawing digital logs along a horizontal borepath, the logs may loop back onto themselves when the borepath has a high degree of curvature:

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Petra uses advanced functionality to ensure the digital log curve maintains a useful appearance by drawing a tangent line along the borepath and using that line as the track edge for the log curve:

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The settings for this advanced functionality can be found in the Track settings Advanced tab.

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