Export logs

File tab

The file tab contains the file name and export format options. Use the "Browse" button to display the Window's file dialog box.

Output File Name -Sets the name and location of the exported file.  Select the Browse button to navigate to the desired directory and to select the file name.

• Export Format
  • LAS - Most common industry standard log ASCII format.  This format is almost universally recognized by most oil and gas applications.  
  • LIS - An older binary log format, and cannot be viewed in a text editor.  LIS files can contain curves from multiple wells in a single data file.
  • Tabular - Generic ASCII text file containing log values as data columns.  Petra creates *.DAT files by default, but these can be easily be renamed to *.TXT.
  • MORE - This option creates files specifically formatted for the MORE simulator.
  • ·RC2 - RC2's ResPrep ASCII file format.

Logs tab

Selects the log curves that will be included in the export file. Click on the filter icon to create more sophisticated search results .

Log curves available for export are dependent on the well source selected:

• Single well file formats: Only log curves available for the selected well are available for export.
• Multiple wells output:  All log curves available for the current well list can be selected for export.

Depths tab

The depths tab sets the depth interval for the exported file. Depths can be selected based on measured depths, TV depths, or using formation tops. A "Sample Decimation Rate"  of 2, for example, would export every other depth sample. The depths tab is also where the additional depth values are selected. Check the TVD, Subsea Depths, and/or Subsea TVD options to include these depths as log curves.

• Set Depth Range
• Sample Decimation Rate - Decimates the data to only export every N’th sample.  Setting this value to 5, for instance, would only export every 5th sample.  By default, this option is set at 1 to export every datapoint in the curves.
• Include TVD Depths - Uses the well's directional survey points to create a curve that lists the TVD for every MD.  
• Include Subsea Depths - Uses the well's active datum to create a curve that lists the SS for every MD.
• Include Subsea TVD Depths - Uses the well's active datum and directional survey points to create a curve that lists the SSTVD for every MD.  
• Include XY Location as a Curve - Adds two columns for the X and Y position of the wellbore for every MD.  This option is really only useful for deviated and directional wells.
• Correct Dir Survey to Grid North -Applies the convergence angle correction to the directional survey azimuth values.  This option should only be used where the the survey azimuth values are oriented towards true north, rather than grid north.

Options tab

Sets additional options for LAS and tabular formats, including null values, column width, and decimal places.  

• ASCII File Null Value - This option specifies the value exported for null log values.  The null value for LAS files is -999.25.
• Column Width - This option specifies the total width of the columns.
• Number of Decimal Places - This option sets the number of decimal places to the right of the decimal point.
• Drop Null Records from Ascii File - This option removes curves with only null values from the export.  Curves containing a mixture of null and non-null values will still be exported to the file.
• Substitute Well Label for UWI in Ascii File - When exporting the log, Petra adds a small header to the top of the file.  This option swaps out the UWI for the entry in the well label.

LAS tab

The LAS tab adds zone data items to the LAS header, sets up batch LAS exports,  format allows one of more zone data items to be placed in the file header.

• Zone Header Data - Values you want written in the ~Parameters section for the LAS file.
  • Include Zone Data in LAS Headers - Toggles adding the additional zone data items and tops to the LAS file.  Toggling this option saves any changes made on the "Select Zone Item List" tool, but will not include the items in the exported LAS file.
  • Select Zone Data For Headers... -Opens the Select Zone Item List.  To add data items and tops to the LAS file, select the relevant zone and item.  
  • Write Tops to Special "~tops" Section - By default, Petra exports all data items and tops into the "~Parameter Block" in the exported LAS file.  This option instead saves tops to a new "~tops" section of the LAS file.
• Export Multiple Wells (One Well per File) - Each LAS file can only contain a single wells' curves.  This option creates the Wells tab;  for the  multiple LAS files.
• File Names Derived from - This option controls how Petra names the multiple LAS files.  
  • Well Seq Nu
  • API Series Num
  • Full API or UW
  • Well Label
• Truncate Curve Names to 4 Chars
• Do Not "Wrap" Curve Data - Forces Petra to write every depth onto a single line, instead of wrapping onto a different line.
• Write API into "WELL" Keyword - Writes the well UWI/API into the LAS file's "WELL" keyword, instead of the default well name entry
• Substitute Label for UWI - Writes the well label into the LAS file's "UWI" keyword, instead of the default UWI entry.
• Output Alias Name Instead of Raw Curve Name - Attempts to rename the selected curves in the exported file based on the project's log aliases.  By default, Petra exports aliased curves using the actual or "raw" curve name associated with the exported well.  
• Export Only those Curves with a Sample Rate of - Only export curves with the specified sample rate.  Curves with a different sample rate will not be exported to the file.
• Use Top Aliases - Uses top aliases for the export.  In practice, this option will attempt to replace the missing top with one of the other "equivalent" tops on the alias list.  

Dates tab

Restricts the export of logs to only curves modified within a date range.

LIS tab

Header Remark - This option simply adds a remark in the file header.   LIS export format allows a comment to be placed in the file header.

MORE tab

Contains options used to export logs to the MORE simulator.

Write Well ID From -Determines the well identifier written to the output file.  Options include UWI, well name, well number, well label, or WSN.

RC2 tab

The RC2 tab contains options used when exporting logs in the RC2 ResPrep format.  The *.ASC files created can include directional survey data, formation tops, and log curves.

• Export Deviation Survey - Option includes directional surveys in the RC2 File.
• Export Tops - Opens the Select Zone Item List.  Note that this list only includes tops in the FMTOPS zone.  To add tops to the RC2 file, select the relevant top on the Zone Item list.  
• Generate Well ID From - Determines the well identifier written to the output file.  Options include UWI, well name, well number, well label, or WSN.
• Output File Names Derived From -Option controls how Petra names and stores the RC2 files.  Multiple wells are exported with each well written to a different disk file.  
  • Well Seq Num - Names RC2 files based on the WSN in Petra.
  • API Series Num - Names RC2 files based on the UWI code in Petra.
  • Prefix - Adds a prefix to the beginning of the filename.