lasio - Log ASCII Standard (LAS) files in Python


Read and write Log ASCII Standard files with Python.

This is a Python 3.5+ package to read and write Log ASCII Standard (LAS) files, used for borehole data such as geophysical, geological, or petrophysical logs. It’s compatible with versions 1.2 and 2.0 of the LAS file specification, published by the Canadian Well Logging Society. Support for LAS 3 is being worked on.

lasio is primarily for reading and writing data and metadata to and from LAS files. It is designed to read as many LAS files as possible, including those containing common errors and non-compliant formatting. It can be used directly, but you may want to consider using some other packages, depending on your priorities:

  • welly is a Python package that uses lasio for I/O but provides a lot more functionality aimed at working with curves, wells, and projects. I would recommend starting there in most cases, to avoid re-inventing the wheel!
  • lascheck is focused on checking whether your LAS file meets the specifications.
  • lasr is an R package which is designed to read large amounts of data quickly from LAS files; this is a great thing to check out if speed is a priority for you, as lasio is not particularly fast.
  • LiDAR surveys are also called “LAS files”, but they are quite different and lasio will not help you – check out laspy instead.

lasio stopped supporting Python 2.7 in August 2020. The final version of lasio with Python 2.7 support is version 0.26.