Sum Raster Pay Within Zone

The Sum Raster Pay Within Zone tool adds pay intervals within a zone together, and stores the value in a zone data item.  This can be useful for net pay mapping.

To open the Sum Raster Pay Within Zone tool, selectCompute>From Logs>Sum Raster Pay Within Zonefrom the menu bar at the top of the Main Module

Zones tab

Select Zones For Depth Interval

This list displays all the zones in the project.  Selecting a zone will set the location of the data items calculated (the computed value and the pay count) as well as set the upper and lower limits of the calculation.  By default, this tool searches for pa intervals within the top and base set by the the selected zone's interval definition.  To ignore the zone's interval definition, make sure to select the "Use Bounds Depths Even if Zone Depths are Undefined" option on the Depths tab.

Select Type of Pay Value To Compute

Total Pay Thickness - This calculation returns the summation of all pay intervals in the zone.

Average Pay Thickness of Each Pay Interval - This calculation returns the average thickness of all pay intervals in the zone.

Maximum Thickness of Any Pay Interval - This calculation returns the thickness of the thickest pay interval in the zone.

Minimum Thickness of Any Pay Interval - This calculation returns the thickness of the thinnest pay interval in the zone.

Zone Item To Store Computed - This entry sets the data item that will store the computed value.  Petra automatically attempts to create a data item name based on the type of pay value computed.  Note that this data item will be located inside the zone selected on the "Select ZONES For Depth Interval" list.

Zone Item To Store Pay Count - This tool can also calculate the number of pay intervals in the zone for each well.  This entry sets the name of the data item that stores this count.  Leaving this entry blank will disable the count.

Zone Item Source Code - This entry adds an additional source code to the calculation.

 
Substitute TD if Bottom of Zone Is Missing - Petra uses the selected zone's interval definition to establish the depth window for the raster pay calculation.  By default, if the lower boundary is missing, Petra will return a null value.  This option instead substitutes the TD of the well for wells missing the base of the zone.

Apply TVD Correction  - This option attempts to correct for deviated and horizontal wells by converting raster pay intervals picked in MD into TVD footage.

Store NULL Instead of Zero When No Pay is Picked - By default, Petra stores a 0 when no raster pay exists within the interval.  This option instead stores a null value.  

Do Not Overwrite Zeros With Nulls - Generally, Petra overwrites the selected data item whenever this calculation is run.  With this option selected, Petra will not overwrite wells with a 0 value in the data item with nulls.

 
Pay tab

Select Pay Interval To Sum - This list displays all the raster pay names in the project.  Here, select one or more pay names for the calculation.

Source - This dropdown limits the pay names to only those with a selected source code.  This can be useful for filtering out extraneous or irrelevant pay names.

Filter tab

Depth Bounds

Limit Depths within a Zone to the Interval Below - This option enables additional depth bounds for the raster pay summation.

Const Depths - The upper and lower entries set bounds on the summation by a simple MD or SS depth range.

Fm Tops - The upper and lower boundaries within the zone are set by two formation tops.

Use Tops Aliases - This option allows Petra to use log curve aliases.

Use Bounds Depths Even if Zone Depths are Undefined - This option ignores the selected zone's interval definition,  and only uses the depth bounds set on the Filter tab.