TUBOSCOPE research has identified the principle causes of failure in sucker rods and has devised inspection techniques to help you eliminate your defective rods in time. Here are the common defects.

Fatigue Cracks & Corrosion Pitting

Fatigue cracks are transversely oriented and result from the cyclic stress to which sucker rods are subjected in service. Corrosion pitting enhances the probability of fatigue cracks by concentrating the stress to which the rod is subjected.

Damage to Couplings

Mechanical damage to couplings such as gouges and hammer marks are common in the oil field.

Pin End Cracks

Deformed threads hamper proper makeup, often causing fatigue cracks to form in the roots of threads.

Mechanical Damage

Sucker rods are frequently damaged by gouges, cuts, kinks, bends and hammer marks (on couplings). Mechanical damage is occasionally severe and can severely shorten the service life of the rod.

Structure Change

Repeated pulling and dropping of rods (during a time of failure) often create drastic structure variations that can accelerate corrosion and result in failure.