ArcGIS Server 11.5 on Linux does not include the Python GDAL package libraries. They were included in previous versions of ArcGIS Server.

Solución alternativa

If there is access to an ArcGIS Server 11.5 Windows environment the extracted conda package can be copy and pasted from there into  /install directory/bin/python/envs/arcgispro-py3/lib/site-packages directly. Place the osgeo and osgeo_utils folders directly into the ArcGIS Server 11.5 Linux environments lib/site-packages/directory. 

Pasos para reproducir