Failure Analysis of Plunger Rod and Barrel of Sucker Rod Pumps

This paper presents the results of a failure analysis of a plunger rod and a barrel of sucker rod pumps, which were used in an environment containing hydrogen sulfide. The chemical composition, mechanical properties and hardness of the details were studied to compliance assessment of the details material to technical documentation.The destruction of details surface was analyzed by optical electron microscopy. It was established that the plunger rod destruction occurred inside the adapter body on the first thread of threaded rod connection, and the barrel destruction was observed inthe area of threaded connection with the pump suction valve body. Results showed that the main cause of the failure was combined action of corrosive H2S environment and mechanical effects that led to the sulphide stress corrosion cracking. Suggestions were put forward to extend the service life of sucker rod pumps parts and reduce the likelihood of their destruction.