In previous articles, I wrote about the various factors that drill pipe design engineers consider when specifying the drill pipe for a particular rig or particular job. Does the drill rod’s diameter provide for a good uphole velocity for the desired hole size? Do the connections have enough torque strength to withstand the rig’s capabilities? Can the tube’s tensile strength withstand expected hook loads?
As rig manufacturers come out with newer rigs with newer capabilities, the factors in drill pipe design can change. These rig improvements can change drill pipe requirements from the “old-school standards.” For example, consider drill pipe run on larger blasthole rigs. The larger-diameter hole sizes demand larger tricone bits, which require a hefty amount of bit weight to operate properly. Bit weight in blasthole operations is typically supplied by the rig’s pulldown capabilities.