Can someone provide some example motor-BHA’s you perform spudding with?
As recently as 6 months ago I spudded a well in the NCS with a 26x42 BHA no motor. Everything went perfectly well, I double checked the engineering on the rig and my main concerns in executing were planting the bit & HO straight, and then ensuring smooth, controllable drilling (by limiting WOB to ~5kips) to ensure balanced WOB across bit & HO. We didn’t wait for low tide, we bedded the bit at about 1 degree inclination and skidded over the rig by about 2ft (adjustment will vary depending on depth to sea bed etc - make a rough Pythagoras calculation). As an exploration well, if we’d had to we could have easily respudded but I know that won’t be the case in all circumstances.
To be honest I don’t really know where you would put the motor - above the HO?? If rathole length is not a concern then I guess I can see positives to the motor being below the HO. It will ensure that the bit drills off faster than the HO, stabilizing the WOB distribution. Hydraulics might be tricky, though nothing is likely to be running at full efficiency in this scenario. The smaller annulus may help transport the cuttings but on the other hand it leaves plenty of scope for packoff…
I think there is some conflation going on with the discussion about steering. How do you steer in a 200ft spud hole? As another poster mentioned, you might not even see the results as they’d remain ahead of the MWD. I guess in some cases you may drill a pilot hole to be opened afterwards. In that case then sure, run a steerable motor if you want. If running an 11” motor in a conductor BHA I would expect a straight housing, or zero bend setting. By the way if you do want to steer, you can actually scribe in easily enough up to, say, 1000ft. You are not looking for precision there, just ensuring you point the spoon in the right quadrant. If AC is a big concern, you need GWD if you want to maintain any pretence of having process safety.
Nonetheless, I dispute the belief that the big 3 OFS companies would always recommend a motor. 5 hours BRT is not going to impact their bottom line, especially as any revenue may need spent on servicing, reline etc. In my experience we look at local offsets for the first guidance. I can imagine perhaps recommending running the motor if it saves BHA time eg. to the 26” BHA after the 42x26, but this is less of a concern now with dual derrick rigs, pre-made-up BHA components etc.
A benefit of the motor is to add weight to the BHA, some drillers like this as it reduces stress on the top drive. I suppose the net effect depends on how far to sea bed and how hard is the formation. Maybe more of a concern on land.
Have you considered CWD as an alternative? This is a very common tophole approach in the Andaman Sea and Gulf of Thailand, although to be fair the formation is extremely soft there.