Remaining Life Determination of Cylindrical Oil Pressure Vessel Using UT Technique: Case Study

Abstract

Pressurized pressure vessels utilized in the upstream sector of the oil and gas industry commonly experience in-service deterioration caused by factors such as corrosion and process-related issues. Most current research has emphasized the significance of calculating remaining lifetime (RLT) but with a little concentration on the Ultrasonic test (UT) for remaining life assessment. In this work, a case study of the pressure vessel unit (20-v-200) belonging to Basra Oil Company (BOC) at Hammar Mishrif Degassing Station (HM-DGS) is conducted. A nondestructive test (NDT) by UT technique was employed over the suspected area of the pressure vessel. Where it was identified the condition monitoring locations (CMLs) around the shell and heads of the pressure vessel, were marked twenty-one locations to obtain their wall thickness measurement. The results of the remaining lifetime showed that for shell and head were computed as 52.9 years and 56.8 years, respectively. Therefore, based on the present result, it can be deduced that the pressure vessel can remain in operation or continue to be in service for the next 52.9 years under the same process conditions. This assessment considers the existing condition of the vessel and indicates that it can meet the required safety and operational standards for an extended duration. However, as an experienced entrepreneur, I would advise that thickness measurement inspections should be conducted within a timeframe that does not exceed either half of the remaining life of the vessel or a maximum of 10 years, according to API 510. This recommendation ensures that regular assessments are performed to monitor the thickness and condition of the vessel. By adhering to this practice, timely maintenance and necessary repairs can be identified and carried out, contributing to the continued integrity and safety of the vessel throughout its operational lifespan.