Questions about the LIE Single Fracture problem

Dear OGS developers,

I am new to OGS and really like its robust capabilities. I appreciate you all for making this code open source, thus benefiting the whole THMC community.

I am trying to develop a discrete fracture network model using OGS6. The purpose is to get some insight into field operations by simulating the coupled HM process in a fractured unconventional gas reservoir. I found the benchmark study - LIE 2D single fracture ( is a good example for me to begin with. But now I have a couple of questions, hopefully, you could help out.

  1. In the project file, i.e., “single_fracture.prj”, the mesh info is imported from “single_fracture.vtu”. I understand this .vtu file is converted by using the “GMSH2OGS.exe”. But could you share the file that was needed for this conversion? I tried to modify the mesh info and followed the instructions on OGS website, but my .vtu file was missing some info, comparing to this given “single_fracture.vtu”.

  2. How did you generate the “single_fracture.gml” file? I can build my work upon this .gml file, but would like to have some instructions on generating my own file. This is particularly helpful if I later want to develop my own model with complex geometries.

  3. Another question regarding the “single_fracture.gml” file. What does the following commands mean?

I appreciate your help in advance very much. For easier communication, I am attaching those files I referred to in this inquiry. (25.3 KB)

Wenfeng Li

Connecting to question 3: