In geosciences the discretization of complex 3D model volumes into finite elements can be a time-consuming task and often needs experience with a professional software. In particular, low angle outcropping or out-pinching geological units, i.e. geological layers that are represented in the model volume, pose serious challenges. Another example are changes in the geometry of a model, which can occur at one point of a project, when re-meshing is not an option anymore or would involve a significant amount of additional time to invest.

In order to speed up and automate the process of discretization, Apple PY (Automatic Portioning Preventing Lengthy manual Element assignment for PYthon) separates the process of mesh-generation and unit assignment. It requires an existing mesh together with separate information on the depths of the interfaces between geological units (herein called horizons). These two pieces of information are combined and used to assign the individual elements to different units. The uniform mesh is created with a standard meshing software and has to be available as an Abaqus input file. The information on the horizons depths and lateral variations in the depths is provided in a text file. Apple PY compares the element location and depth with that of the horizons in order to assign each element to a corresponding geological unit below or above a certain horizon.

Version HIstory

This ia a major release of APPLE PY, including a new version of the manual. Previous versions are accessible via https://doi.org/10.5880/wsm.2019.003 (Ziegler et al., 2019).

Changes to version 1.02 (5 December 2020):

• Apple PY v1.3 supports multiple files with horizon depths that may even have a different lateral spacing between the grid points.

• Instead of absolute horizon depths, a mean value and a standard deviation can be provided together with a type of distribution from which Apple PY estimates the horizon depth.

• Due to the end of the support for Python 2.x Apple PY has been updated to run with Python 3.x.

• Various small changes have been implemented in order to make the script more robust. The reading of the code has been facilitated by using more functions and additional comments.