Carpenter Technology Corporation
Double-Shouldered Connection for Drilling Tubulars with Large Inside Diameter

Abstract:

A threaded connection for drilling tubulars includes a tubular box section having a sidewall. The box section has a tapered box portion of an inner surface of the sidewall between a first end and a second end. The tapered box portion has internal threads, a first torque shoulder on a first side of the tapered box portion, and a second shoulder on a second side of the tapered box portion. A threaded collar having internal collar threads is positioned between the second end and the second shoulder. A threaded insert having a tubular body with an inner surface and an outer surface having external insert threads is configured for threadably connecting to the internal collar threads. A direction of the internal threads of the tapered box portion is opposite to a direction of the internal collar threads and the external insert threads.