Q:

Is there QGIS plugin to allow 3d visualisation of geological borehole data similar to functionality of Target for ArcGIS?

I'm very new to QGIS, I have started using it as my new company is not willing to pay for ArcGIS and Target at this stage so I'm hoping QGIS can substitute not just in the interim but for good.
What I am looking for is a way to load in my borehole database and create 3d visualizations of the data, make cross sections and if possible model seams. Is there any capability within the QGIS world to undertake this kind of work?

A:

Yes, it is possible but using a Python script in the console 
see For geologists: 3D geological boreholes 

I presented the scripts in visualizing 3D data (Z values) or data with z attribute: a solution 
or QGIS, représentation 3D des couches vectorielles (shapefiles dits 3D ou shapefiles avec attributs z) avec les modules Python Matplotlib ou Visvis à partir de la console Python in French and QGIS, visualización 3D de capas vectoriales con Python  in Spanish.
More generally I use GRASS GIS to do, see Automatic 3D geological boreholes representation (automate v.extrude from a table ?): my solution in Python  and 3D geological volume modeling (raster 3D): is it really possible ?
 boreholes
 layer one
 layer two
with interpolated surfaces and cross sections:
 
or

