Flexible Connections

A threaded drill pipe comprising:

• an external mating shoulder having a first pitch with respect to a center-line of the pipe;
• an internal mating shoulder having a second pitch, different than the first pitch, with respect to the center-line of the pipe;
• an external thread form between the external mating shoulder and the internal mating shoulder, wherein the external thread form comprises:
• a stab flank having a stab flank angle of between 20° and 40° measured from the thread axis;
• a first load flank having a first load flank angle of between 60° and 80° measured from the thread axis;
• and
• a second load flank having a second load flank angle of between 100° and 120° measured from the thread axis.

A method comprising,

• providing a first tubular with a pin section comprising external threads formed between a pin external shoulder and a pin nose, wherein the external threads comprises
• stab flanks having stab flank angles of between 20° and 40° measured from the thread axis;
• and
• load flanks having first load flank angles of between 60° and 80° measured from the thread axis and second load flank angles of between 100° and 120° measured from the thread axis;
• providing a first tubular with a box section comprising internal threads formed between a box face and a box internal shoulder, wherein the box internal shoulder comprises a different pitch that the pin external shoulder;
• engaging the box and the pin to form a primary seal between the pin external shoulder and the box face, and a secondary seal between the pin nose and the box internal shoulder.