Patent ID: 6047997
Filing Date: 2000-04-11
Classification: E21B,F16L

Abstract:
A drill string having an inner diameter and an outer diameter, comprising:a first pipe having a pin end including:an external thread member formed thereon;a first radial end extending from said external thread member;an exterior shoulder formed on the outer diameter of the first pipe having a first groove forming a first surface;a second pipe having a box end including:an internal thread member formed thereon;a second radial end extending from said internal thread member and havinga protuberance forming a second surface;an interior shoulder formed on the inner diameter of the second pipe;said first and second surfaces being rounded increasing metal-to-metal contact between said pin and box ends as torque is applied upon make-up;said first radial end and said internal shoulder engaging as torque is applied upon make-up; andsaid first groove receiving said protuberance and said internal and external thread members forming a substantially common taper upon make-up of said pin and box ends.