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Python library for working with the well log formats Digital Log Interchange Standard (DLIS V1) and Log Information Standard (LIS79)


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dlisio is an LGPL licensed library for reading well logs in Digital Log Interchange Standard (DLIS V1), also known as RP66 V1, and Log Information Standard 79 (LIS79).

dlisio is designed as a general purpose library for reading well logs in a simple and easy-to-use manner. Its main focus is making all the data and metadata accessible while putting few assumptions on how the data is to be used. This makes it suitable as a building block for higher level applications as well as for being used directly.

dlisio focuses above all on correctness, performance and robustness. Its core, which does all the heavy lifting, is implemented in C++. Both the C++ core and the python wrappers are backed by an extensive test-suite. It strives to be robust against files that do not strictly adhere to the specifications, which is a widespread issue with both DLIS and LIS files. dlisio tries to account for many of the known specification violations out there, but only when it can do so without compromising correctness. It will not do any guess work on your behalf when such violations pose any ambiguity.


dlisio supplies pre-built python wheels for a variety of platforms and architectures. The wheels are hosted through the Python Package Index (PyPI) and can be installed with:

pip install dlisio
macOS Intel macOS ARM Windows 64bit Windows 32bit manylinux x86_64 manylinux aarch64 manylinux i686 musllinux x86_64
CPython 3.7 - -
CPython 3.8 - -
CPython 3.9
CPython 3.10
CPython 3.11
CPython 3.12

See Build dlisio for building dlisio from source.

Getting started

dlisio's documentation is hosted on readthedocs. Please refer there for proper introduction to dlisio and the file-formats DLIS and LIS. Here is a motivating example showcasing how to read the curve-data from a DLIS-file:

from dlisio import dlis

with dlis.load('myfile.dlis') as files:
    for f in files:
        for frame in f.frames:
            curves = frame.curves()
            # Do something with the curves

and from a LIS-file:

from dlisio import lis

with lis.load('myfile.lis') as files:
    for f in files:
        for format_spec in f.data_format_specs():
            curves = lis.curves(f, format_spec)
            # Do something with the curves

In both cases the curves are returned as structured numpy.ndarray with the curve mnemonics as field names (column names).

Build dlisio

To develop dlisio, or to build a particular revision from source, you need:

If you do not have pybind11 installed on your system, the easiest way to get a working copy is to pip3 install pybind11 (NP! pybind11, not pybind)

layered-file-protocols has to be installed from source if you don't already have it on your system:

git clone
mkdir layered-file-protocols/build
cd layered-file-protocols/build
make install

To then build and install dlisio:

mkdir dlisio/build
cd dlisio/build

dlisio follows common cmake rules and conventions, e.g. to set install prefix use -DCMAKE_INSTALL_PREFIX. To build the python library it is usually a good idea to build shared libraries. To disable python, pass -DBUILD_PYTHON=OFF. By default, the python library is built.


We welcome all kinds of contributions, including bug reports, issues, feature requests and documentation. The preferred way of submitting a contribution is to make an issue on github.