Drill string design (slim hole wells)
Over the years a standard set of API sizes have evolved to reflect the materials and manufacturing technology, operating practices, and stress analysis techniques. Drillstring design for slim hole drilling has followed the two distinct paths of destructive and continuous coring although attempts have been made to achieve a compromise design suitable for both. Much engineering effort is put into thread and tool joint design.
1 Traditional oilfield tool joints
Traditional oilfield tool joints are designed to be at least as strong (for tensile burst and collapse rating) as the DP . . .