Oil Well Down Hole Drilling Tool Inspection

Application: Detection of cracking in Rotary Shouldered Assemblies (RSC) of down hole drilling tools.

Background: The depth of oil and gas wells range from 3,500 to 30,000 feet (1175 to 10,000 meters) vertical depth. Oil well drilling equipment is exposed to extreme conditions including tension, corrosion and cyclic loading while being exposed to elevated temperatures and damaging gases captured within layers of the earth. Because of the loads and environmentally influenced damage mechanisms failure of the Down Hole Drilling Tools (referred to as drill stem) are common. Failure of a drill stem component usually results in enormous cost due to drilling rig cost per day, potential lost drill stem components and even having to abandon the oil well.

Drill stem components are joined together end-to-end to form a continuous string. The connection is referred to as a "Rotary Shouldered Connection" (RSC). Failure of drill stem components usually happen in the connection as a result of cyclic loads driving fatigue cracks to a point of total separation and parting of the drill string in the oil well. The area of the drill string near the drill bit is known as the "Bottom Hole Assembly" (BHA). This is where connection failure is most frequent.