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LAS (Log ASCII Standard)

This LAS information site provides links to the File Specifications of the various versions of LAS, plus links to LAS Software. LAS versions 1.2 and 2.0 were written and maintained by the CWLS as public domain well log data formats. LAS version 3.0 was written and is maintained in the public domain by the LAS 3 Committee. You are free to use and distribute these data format Specifications and related Software provided you recognize the ownership of LAS 1.2 and LAS 2.0 Specifications and Software belong to CWLS, and ownership of LAS 3.0 Specifications and Software belong to the LAS 3 Committee.

The following links are presented in two groups: LAS Specifications, and LAS Software & Examples. Select a link from the first group to download the file format Specifications for the corresponding version of LAS. Use the second group of links if you want to download LAS 2.0 or LAS 3.0 examples or Software.

The LAS Version 2.0 link in the second group will initiate the download of an Adobe Acrobat ‘pdf’ file containing the LAS Version 2.0 Specifications updated in July 2009.The documentation includes a number of LAS 2.0 examples.

The LAS Applications Software was designed to perform routine operations on LAS 2.0 files such as correcting LAS files for common errors, conversion from version 1.2 to 2.0, re-sampling, wrapping, un-wrapping, depth conversion, converting text to LAS 2.0, a Certify routine, merging, changing curve mnemonics etc. It was designed for processing large volumes of LAS 2.0 files. The application uses Microsoft “.NET” software and is compatible with Windows XP, Vista and Windows 7.

LAS Version 3.0 Certify is the only LAS Version 3.0 Software available here. This MS Windows compatible application handles LAS Version 3.0 and earlier data files.

The LAS 3 Committee chose to not create an LAS 3.0 version of Reformat, preferring to leave that for commercial software developers.

LAS Specifications

Txt Icon LAS 1.2 Specifications (Text File)

LAS 3.0 Information:

PDF Icon LAS Version 3.0 (Adobe Acrobat File)

Zip Icon LAS Version 3.0 Example (ZIP File)

Zip Icon LAS Version 3.0 Certify Software (Windows based LAS certification program Nov-2000)
Also handles LAS Version 1.2 and 2.0 data files.)


If you have any questions please contact:

Ken Heslop, P.Eng.
Oakrock Ltd.
P.O. Box 92, Irricana, AB, CANADA T0M 1B0
1 (403) 935-4641

Chairman, CWLS LAS Committee
Chairman, LAS 3 Committee