I'm a geophysicist by experience and training. I see your company is heavily into steerable tools. I spent a bit of time with a blue company as an MWD engineer once. The whole signal formation and transmission environment presents a lot of challenges for successful decoding of the toolface info for BHA orientation and location. I always struggled to see how unschooled field engineers decoding toolfaces from deviated boreholes were allowed to serve as and to present downhole borehole orientation information to state agencies certifying those as accurate, effectively serving as surveyors but with no prior training to understand maps, boundaries - especially as it applied to mineral ownership issues, etc.
Knowing from experience the many things that can go wrong on a downhole survey leaves me wondering why the survey data from those past generation of tools was taken as acceptably accurate. It was not standard practice at the time to take a multishot to verify hole geometry and once it all went horizontal you had to trust the MWD/LWD. In many cases that was fine but in some situations that was dicey. Some of those MWDs were notoriously bad as engineers pushed them past the limits of signal decoding in order to avoid being charged for the trip to retrieve, especially the one I worked with.
That's how I remember it all anyway. Email is in profile if you want to chat. Good luck in your endeavors!
