jas1/lastools

‘lastools’ is an R package for reading and writing version 1.2 and version 2.0 Log ASCII Standard (LAS) and for performing common functions on LAS

About lastools

‘lastools’ is an R package for reading and writing version 1.2 and version 2.0 Log ASCII Standard (LAS) files (Canadian Well Logging Society (1990), Canadian Well Logging Society (2017d)) and for performing common functions on LAS files including:

• version conversion

• depth conversion

• merging

• visualizing/plotting

• re-sampling/filtering

• bulk loading to R data.table

While the Canadian Well Logging Society provides free software called LasApps (Canadian Well Logging Society (2017c)) and a Python package called lasio (Inverarity (2017)) exists to perform similar functions; at time of writing no R package existed for reading and manipulating LAS files.

The aim of lastools is to provide functionality for reading and manipulating LAS files in the R environment and to provide additional unique functionality not found in existing alternative packages/libraries/software.

Installation

lastools can be installed from github repository using devtools:

devtools::install_github("Gitmaxwell/lastools")

LAS Data

Las file

A LAS file is a standardized, structured ASCII file containing header information and log curve data derived from the continuous collection of (usually geophysical) measurements from a borehole or well (Firth (n.d.)). They are often termed wireline log LAS files and have the file extension “.las”. They are distinct from ‘lidar’ LAS files which are ’industry-standard binary format files for storing airborne lidar data.

The LAS standard was introduced by the Canadian Well Logging Society in 1989 and to date consists of 3 Versions (version 1.2 (1989), 2.0 (1992) & 3.0 (1999)) (Canadian Well Logging Society (2017a)). Version 2.0 replaced inconsistencies in version 1.2 while version 3.0 clarified some of the poorly defined specifications of LAS 2.0 and provides expanded data storage capabilities (Canadian Well Logging Society (1990), Canadian Well Logging Society (2017d), Canadian Well Logging Society (2017b)). Despite version 3.0 being the ‘latest’ version, its implementation and usage has been extremely limited (Canadian Well Logging Society (2017a)). Following this, the package lastools only provides support for LAS file versions 1.2 & 2.0.

The exact standards and structure/s for each LAS file type can be accessed via the below links (and/or from the embedded hyperlinks elsewhere):

Las Standard 1.2

Las Standard 2.0

Las Standard 3.0

References

Canadian Well Logging Society. 1990. “LAS 1.2 a Floppy Disk Standard for Log Data.” Connecticut, USA: Canadian Well Logging Society. 1990. http://www.cwls.org/wp-content/uploads/2014/09/LAS12_Standards.txt.

———. 2017a. “HELP: Load - Log Ascii Standard (Las) File, Versions 2.0 & 3.0.” Connecticut, USA: Canadian Well Logging Society. 2017. http://www.kgs.ku.edu/software/SS/HELP/las/index.html.

———. 2017b. “Las 3.0 Log Ascii Standard.” Connecticut, USA: Canadian Well Logging Society. 2017. http://www.cwls.org/wp-content/uploads/2014/09/LAS_3_File_Structure.pdf.

———. 2017c. “LAS (Log Ascii Standard).” Connecticut, USA: Canadian Well Logging Society. 2017. http://www.cwls.org/las/.

———. 2017d. “LAS Version 2.0: A Digital Standard for Logs.” http://www.cwls.org/wp-content/uploads/2017/02/Las2_Update_Feb2017.pdf.

Firth, David. n.d. “Log Analysis for Mining Applications.”

Inverarity, Kent. 2017. “Lasio - Log Ascii Standard (Las) Files in Python.” Kent Inverarity. 2017. http://pythonhosted.org/lasio/.