I live in a country using metrics but work in a business that uses imperial/US units of measurement. Experience has taught me that the Norwegian oilrigs use US units and the Scottish uses imperial. That is not saying this is always so. I am sure there are cases where it’s reverse.

I lied, the Norwegian oilrigs uses a hybrid of units. A drill pipe can be 5 ½" with 4 ½" inner diameter and a 7" Tool Joint and 3 ¾" tool joint ID. The connection threads can be 6" but the pipe length is 9, 35 meters (Range III) or 14 meters (Range II).