ABSTRACT
Despite a number of disadvantages, rotary drilling rigs are still basic ones while drilling deep oil and gas wells. The wells depth is 5 km and more; the wells diameter is hundreds mm; and the drilling pipes weight is hundreds tons. While rotating, boring column consisting of a set of heavy-weight drilling pipes (HWDP), columns of drilling pipes, and their conjunctions consumes more power if the well depth is more than 2000 m.
