Patent ID: 8141656

Claim:
A subterranean drilling assembly comprising: a bit body defining a plurality of central bores configured to communicate drilling fluid; at least one cutting element fixedly coupled to the bit body; a sub apparatus coupled to the subterranean drill bit body, wherein the sub apparatus includes a plurality of central bores that correspond to the central bores of the bit body, each of the plurality of central bores of the sub apparatus extending substantially through an entire length of the sub apparatus and being configured to maintain any fluid flowing therethrough separate from any other bore of the plurality of central bores while flowing through the sub apparatus; a cooling system configured to cool drilling fluid to be communicated through at least one of the plurality of central bores of the subterranean drill bit body while avoiding cooling drilling fluid to be communicated through at least another of the plurality of central bores of the subterranean drill bit body.