One of the largest gas processing plants operated by the Southern Area Gas Operations in Saudi Arabia processes both the associated gas received from oil wells and the non-associated gas (Khuff gas) received from gas wells. These gas streams are crucial to meet the growing domestic gas demand as well as of great significance for future mode of operation. The associated gas received from oil wells utilizes mostly carbon steel as the predominant metallurgy. On the other hand, the metallurgy used for handling the Khuff gas stream includes carbon steel with either chemical treatment or internal lining and stainless steel, depending on the operating envelope. This paper discusses the performance of these materials under different operating envelopes and the integrity concerns due to environmental cracking focusing on case histories related to hydrogen induced cracking, hydrogen blisters and chloride stress corrosion cracking. Moreover, this paper will also focus on the challenges associated in quantifying the magnitude of impact with the conventional Nondestructive Examination (NDE) techniques, ongoing efforts to manage the concerns by deploying advanced NDE technologies, and the options pursued to restore the integrity of these systems to ensure safe and reliable operations.
Uthmaniyah Gas Plant (UGP) in Southern Area Gas Operations of Saudi Aramco is one of the largest gas processing plants in the world. UGP was commissioned in 1981 as part of Master Gas System (MGS) to process associated gas from oil wells and expanded gradually to process non-associated gas (Khuff) received from gas wells. UGP has quite a large amount of underground pipelines in critical service, such as associated gas, nonassociated gas (Khuff gas), hydrocarbon condensate, hydrocarbon blowdown, fire and utility water piping systems. Each of these piping systems is an integral part of the operation and its integrity will have direct impact on either the upstream or downstream operations. This paper discusses the performance of these materials under different operating envelopes and the integrity concerns due to environmental cracking focusing on case histories related to hydrogen induced cracking, hydrogen blisters and chloride stress corrosion cracking. Moreover, this paper will also focus on the challenges associated in quantifying the magnitude of impact with the conventional Nondestructive Examination (NDE) techniques, ongoing efforts to manage the concerns by deploying advanced NDE technologies, and the options pursued to restore the integrity of these systems to ensure safe and reliable operations. Plant's Operational Criticality: Gas processing plants produce sales gas, natural gas liquids (NGL) and sulfur as the end products. These end products are produced as a result of processing the feed gas received from oil and gas wells through gas sweetening, sulfur recovery and NGL recovery processes. Due to increasing demand for sales gas and NGL, all the gas plants often operate at full capacity. ENVIRONMENTALLY-INDUCED CRACKING Corrosion that involves multiple variables includes environmentally-induced cracking, which can be the most devastating form of failure for process equipment or a component. In most cases, the reaction rates of other forms of corrosion enable detection by inspection.
