In mineral exploration there might on average be one hole drilled a DECADE that is 2000 meters long. In oil drilling most holes these days are that long (e.g. Bakken Oil play in Saskatchewan) and in the range of 5,000-10,000 meters in the deep sea drilling off Brazil.

The big difference in oil drilling vs hard rock drilling is that mineral drilling focuses on recovering "drill core" all the way down the hole and oil drilling focuses on getting to the target depth of the oil bearing zone. Hard rock drilling uses an open core bit and oil drilling uses a solid bit that produces rick chips.

So when it comes to deep 'core' drilling there isn't a lot of experience. I'm guessing here but I expect that there isn't 10 hard rock geologist in the world that have sat on such a hole. Most geologists don't even have direct knowledge about drilling one.

If you are looking for some rough guideline see below. Understand variations in rock conditions (hardness, changes from one rock type to another, shearing, faults, voids, alteration) plus bit/hole size, plus depth, plus crew performance, plus weather, plus drill performance, etc, all affect drilling rates.

Short holes 50- 100m about a day depending on overburden depth and set up time.

Short/medium holes 100-300m average between 75 to 150m per day.

Medium deep holes 300-700m average between 50 and 100m per day. Performance drops off quickly after 400m.

Deep* holes 700M+ anywhere from 30 to 100m per day

* as holes get deep everything takes longer. Pulling core can take an hour+. To replace a drill bit when you are down 1500m can take most of a shift. So if you put on a new bit and proceed to strip it after 10m your productivity is down to a couple of meters for the day.

Deviating a new hole from the mother/master hole its now done with directional drill bits instead of metal wedges. It can take you a day or two to get the 'wedged' hole started off the master hole then its back to regular drilling rates (whatever they may be).

So at the end of the day no one knows what the drilling rates are going to be. Even after the first hole is drilled you don't know if the second will drill the same way.

The good news is that once they have the main/master/mother/pilot hole (whatever you want to call it) the wedged holes will only be an extra 200-400m long holes off the main hole. They won't drill any faster per meter then the 2000m hole but you don't have to re-drill that first 1200-1800 m each time.

... Been There