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HELP: Hingle and Pickett Plot |
The LAS (Log ASCII Standard) is rapidly becoming the accepted industry standard for electronic transmission of digital wireline logs. Earlier digital formats were commonly coded in binary (such as LIS) and so required specialized software to read them. The LAS standard was introduced by the Canadian Well Logging Society(1) in 1989 to standardize the organization of digital log curve information for personal computer users. It did this very successfully and the standard became popular worldwide. Version 1.2 was the first version and followed in September 1992 by version 2.0 to address some inconsistencies. A more versatile version LAS 3.0 was released in 1999 however at present LAS 2.0 remains the dominant product. LAS 3.0 clarifies several of the poorly defined specifications of LAS 2.0 and provides expanded data storage capabilities, but has seen limited implementation.
This program will read either a Log ASCII Standard (LAS) version 2.0 or 3.0 files and version 1.2 but the Well Information Section is backward in data definition.
The sections defined for the LAS 2.0 standard are as follows (see reference below for the complete document):
LAS 3.0 (see reference below for the complete document) will be used to save the PfEFFER Session since it can hold all the well data in one file. You can even think of LAS 2.0 as a subset of LAS 3.0 since the LAS 2.0 is only concerned with the LOG Data.
The ~Version and ~Well sections must appear in every LAS 3.0 file as the first and second sections respectively.
Other sections are grouped by data type. Each group consists of two or three sections; a Parameter Data section (optional for all but Log data), a Column Definition section, and a Column Data section, in that order.
For example, core analysis data would have the following three sections:
~Core_Parameter
~Core_Definition
~Core_Data.
At least one group or data type of either the defined LAS 3.0 data types or a user defined type must exist in every LAS 3.0 file.
The Column Definition and the Column Data sections for each data type are matched sets and must both appear in that order. The corresponding Parameter Data section is optional (except for Log data), but if used must appear before it's corresponding Column Definition Section.
LAS 3.0 defines six specific well related data types and their root Section Title names. They are:
~Ascii or ~Log
~Core
~Inclinometry
~Drilling
~Tops
~Test
Additional data types can be defined by the user and content rules discussed elsewhere in the document may define other section titles.
Stand alone user defined Parameter Data sections can be included. Care must be taken to use standalone Parameter Data sections only when the data contained does not fit into any of the other defined data types.
When used, the section order of each set of the three sections for each data type must be Parameter, Definition, then Data.
Blank lines and comment lines can appear within Column Data sections, but can only appear BEFORE the first Column Data line of that section, or after the LAST Column Data line of that section.
The names of each channel can optionally appear above each channel as a comment line immediately before, after or on the section title line of that section if space allows.
Note: Do not use the ~Other section recognized by LAS ver 2.0. It is no longer allowed in LAS 3.0. Any data that can be stored in such a section, must now be stored properly in a user defined Parameter Data or Column Data section.
The PfEFFER Sections are as follows where the ~IQ_FLOW contains the Flow unit parameters and data values, which will rebuild the data sheets for each flow unit selected, and ~IQ_Pfeffer contains the raw data in the spreadsheet.
~IQ_Flow_Parameter - Parameters section for the flow units
~IQ_Flow_Definition - Curve Definition section for the flow units
~IQ_Flow_Data | IQ_Flow_Definition - Data section for the flow units
~IQ_Pfeffer_Parameter - Parameters section for the PfEFFER spreadsheet
~IQ_Pfeffer_Definition - Curve Definition section for the PfEFFER spreadsheet
~IQ_Pfeffer_Data | IQ_Pfeffer_Definition - Data section for the PfEFFER spreadsheet
Download 12345a.las porosity log and 12345b.las resistivity log as examples logs for the Populating the Home Area Columns example. Click on each link and then "Sava As" to save to your PC, making sure you have the ".las" at the end of the filename, i.e. 12345a.las and 12345b.las respectively.
The files 12345a.las and 12345b.las are two ASCII files of logs coded in LAS format and will be used to demonstrate the OpenLAS function. These files are from the same well; 12345a.las is a record of a porosity log run, while 12345b.las records the resistivity logs made on a separate run. There are many instances where all the logs are merged on a single LAS file, but the use of two files in this demonstration will train the user to handle situations where there are either single or multiple LAS files from a single well.
There will be occasions when the user would like to inspect the contents of an LAS file. So, for example, the user may wish to find the identity of the well, the types of logs, depth range, well or log parameters. Alternatively, the user can suspect that the file is not coded correctly in LAS format if the Import LAS function fails, and so wishes to examine the file to troubleshoot the problem. The LAS file is an ASCII file and can be read by any text editor, i.e. Notepad, WordPad, TextPad, etc.
To access Hingle & Pickett PLot Applet go to http://www.kgs.ku.edu/software/Pf/.
At the top of the web page there is a menu "Main Page|Description|Applet|Help|Copyright & Disclaimer|"
Select the "Applet" menu option a "Warning - Security" Dialog will appear. Since the program has to be able to read and write to your PC and access the Kansas Geological Survey (KGS) Database and File Server requires this dialog. The program does not save your files to KGS, but allows you to access the KGS for well information that may be missing in your Kansas logs. The program does not use Cookies or any hidden software it only reads the LAS and CSV files for the Hingle & Pickett Plot Session.
Select the "Hingle & Pickett Plot Icon" Button, which will show the "Load Data" Dialog.
The above image is an example of a previous PfEFFER Session LAS 3.0 File imported into the program. You will notice that there are a number icon buttons on this dialog, which is designed to assist the user in importing data into the Hingle & Pickett Plot program. This program primarily requires the Log ASCII Standard (LAS) files to run, but the user can also download formation top picks from the KGS as well as measured core data. The program can also read CSV ASCII Files for formation tops as well as Measured Core Data, the user only needs to map the file columns to the program variables. A help file is created to help the user download data from KGS and your PC Load Existing Source Data.
This help will focus on loading two LAS files from the user's PC only at this time. This program will allow the user to import up to 3 LAS files for a single well.
Select the LAS File Icon Button in the PC (ASCII Data Files) Panel.
The "Select LAS File form your PC" Dialog will appear.
Select the 12345a.las file and then select the "Open" Button to import the 1st LAS file into the program.
NOTE: The program assumes that you are reading a LAS file type so the extension should be ".las",
but the program does not care if there is an extension, only that the file is a valid LAS file type.
The "LAS File Curve Selection" displays all the contents of the data sections in the Log ASCII Standard (LAS) version 3.0 file. A LAS version 2.0 file only has "~Log Definition" section displayed. The "X" column identifies which curve will be plotted on the Profile Plot. The user only needs to check or uncheck the box to include or not include in the log data. The program will not allow you to select the same curve type more than once. The "MNEM" column represents the curve mnemonics for the LAS file, there are 31 "KGS" Standard Tool Types the user can select from, but if a "?" is present the program does not recognize the mnemonic in the LAS File. The user can select the button with the "?" to select a "KGS" Standard Curve from the KGS Standard Mnemonics Table to represent the mnemonic that was in the LAS File. The colored boxes around the check boxes are a visual aid, i.e. orange is resistivity curves, blue is porosity curves, green is density, dark green is sonic, radioactive curve types are red, etc. Since all the curves selected are acceptable, select the "Continue" Button.
Notice that in the "Data Loaded" Panel under the "Log ASCII Standard (LAS) Files:" Section, the 1st LAS 12345a.las is entered. Also notice in the Data Type Section that a "YES" is entered below the "LAS" Column in the "Log Data" Row. In the Log Curves, the program recognizes the Neutron Porosity, Bulk Density, the Gamma Ray and Photoelectric Factor Log Curves by placing a "YES" under the "LAS" Column. Notice that the Resistivity Row has a red "NO" and the Porosity Row has a green "YES". The primary curves that must be present at a minimum to run PfEFFER is a Resistivity Curve and a Porosity Curve. Since only the Porosity Curve is green we must get the Resistivity Curve from the second LAS File.
Select the LAS File Icon Button in the PC (ASCII Data Files) Panel, as above.
Select the 12345b.las file and then select the "Open" Button to import the 1st LAS file into the program.
Notice that there are really two log types in the "LAS File Curve Selection" Dialog. The Spectral Gamma Ray Logs and the Resistivity Logs. We will uncheck the Spectral Gamma Ray logs since they are not necessary for this excercise and since the Gamma Ray log that is check has problems it will not interfere with the Gamma Ray curve data that has already be imported.
Notice that in the "Data Loaded" Panel under the "Log ASCII Standard (LAS) Files:" Section, the 2nd LAS 12345b.las is entered. In the Log Curves, the program recognizes all the log curves. Notice that the Resistivity Row has a green "YES" and the Porosity Row has a green "YES". Both Curve types are represented so the Plot session will run. Select the "Continue" Button to display the Hingle & Pickett Plots and Plot Control Dialog.
Now select the "Continue" Button.
REFERENCE:
(1) Canadian Well Logging Society, LAS - Log ASCII Standard http://www.cwls.org/las_info.php