One of our Clients, an operator in the Mid East has experienced a concern with adverse internal corrosion (and corrosion rate) of many scraper trap barrels for their crude oil upstream gathering and downstream crude export pipeline system. The upstream gathering system gross fluids contain H2S, CO2, water, amoungst all the other "normal goodies", and the downstream stabilized export crude system scraper trap barrels also experience adverse corrsion rates. The pipelines themselves have also experienced high internal corrossion rates, but not to the extent of the scraper trap barrels.
As some of you may know, operations/maintenenace for oil & gas related facilities in the Mid East is generally a concern, for many reasons. It is obvous to me and also acknowleged by the Client that this is or may be an O&M and procedure issue regarding proper cleaning and "lay-up" of the traps after use, but is not going to be resolved any time soon in this context. However, the Client is of the opinion that this concern can be resolved and mitigated by design, specifically through implementaion of some "magical" scratch resistant internal coating of the scraper trap barrels. All the pipelines require periodic wall thickness inspection using intelligent pigs (i.e. magnaflux tools, etc.). I have advised that I am not aware of any proven internal coating that would scratch resistant to these tools, and that scratches penetrating through the coating to the base metal could encourage more active local corrosion cells and actually perturb the existing problem. Incorporating an additional corrosion allowance for the design of the trap barrels is not considered a solution, and the only other solution in line with the Client's reasoning is to fabricate the major and minor trap barrels using clad pipe.
I would seek advice from all the pipeline O&M experts out there as well as any other design colleagues who may have a practical solution to this issue, or is aware of any scraper trap vendors who can supply such "magical" scratch resistant internal coating of the barrels. In addition, anyone who can provide an appropriate cleaning and "layup" procedure after use of the traps whould be appreciated.
As some of you may know, operations/maintenenace for oil & gas related facilities in the Mid East is generally a concern, for many reasons. It is obvous to me and also acknowleged by the Client that this is or may be an O&M and procedure issue regarding proper cleaning and "lay-up" of the traps after use, but is not going to be resolved any time soon in this context. However, the Client is of the opinion that this concern can be resolved and mitigated by design, specifically through implementaion of some "magical" scratch resistant internal coating of the scraper trap barrels. All the pipelines require periodic wall thickness inspection using intelligent pigs (i.e. magnaflux tools, etc.). I have advised that I am not aware of any proven internal coating that would scratch resistant to these tools, and that scratches penetrating through the coating to the base metal could encourage more active local corrosion cells and actually perturb the existing problem. Incorporating an additional corrosion allowance for the design of the trap barrels is not considered a solution, and the only other solution in line with the Client's reasoning is to fabricate the major and minor trap barrels using clad pipe.
I would seek advice from all the pipeline O&M experts out there as well as any other design colleagues who may have a practical solution to this issue, or is aware of any scraper trap vendors who can supply such "magical" scratch resistant internal coating of the barrels. In addition, anyone who can provide an appropriate cleaning and "layup" procedure after use of the traps whould be appreciated.
