Is there any one bit that will do it all? Nope. But there is a bit that will drill what YOU drill better than any other one, explains Wayne Nash.
Is there a bit for every application? Well, pretty close. If you run a Spang or Acme conventional cable tool bit under a Bucyrus-Erie 22W, you can pretty well drill any formation on earth. But there are a few other things you should consider during the bit selection process. Whether or not a given bit will drill a formation usually is secondary to the economics of drilling. Lots of bits will eventually rub a hole in the ground, but if they're too slow, they aren't economically practical. Bit selection starts with the drilling process itself. Cable tool drilling, air rotary and mud rotary all have a vastly different set of bits to choose from.
Since I've spent the majority of my years in the business drilling with the mud rotary method, I'm going to limit this discussion to mud rotary bits.