[BigV]

Having got to the site then it has to be prepared, among other things we need to have a way of getting the cuttings that come out of the hole separated from the drilling mud, and then having a place to put both them, and to store the mud until it can be drawn back into the pumps and circulated back into the hole. And we need to create an initial hole, or cellar, where we can start the drilling pipe into the ground. (You can see a layout of this here or here. This initial part of the well has to be fairly large, for reasons explained below.

Maybe this is one of the search triggers!