Repair of degraded structural members with substantial corrosion damage is a critical job of structural integrity management of oil and gas structures for both offshore and onshore. Conventionally cutting and welding repairs of damaged/corroded structure members are generally used in the industry and allowed from regulatory requirements. However, such repair method is considered as a hot work repair method. Once the hot work repair is planned, there is the safety requirement that the subject tank/location and adjacent tanks be in a gas free condition. In such cases, it may cause a significant impact on the continuous operation of the units.
Therefore, adhesively bonded composite repairs of damaged/corroded steel structures have been increasingly used for onshore and offshore oil and gas structure repairs due to favorite considerations of safety and continuous operation as the repairs can be done without cutting and welding. The repair method utilizes a new steel plate bonded to the existing damaged/corroded steel plate by specially selected adhesive polymer(s), known as sandwich composite plate repair technology. The repair can be done from one side of the structure to be repaired and the other side of the structure would remain unaffected during the repair. This paper introduces the bonded sandwich plate repair technology and requirements/recommendations from classification and industry standards/guidelines on the bonded composite repairs of steel structures.
Both onshore storage tanks and offshore/marine vessels and units (such as floating production storage and offloading (FPSO) units, Floating Storage and Offloading (FSO) units) for oil and gas drilling, production, and transportation generally experience very corrosive environments. Even some corrosion prevention systems, such as applicable cathodic protection, protective coatings, and/or liquid/vapor phase inhibitors, are usually used for corrosion protection, severe corrosion to the structures still happens due to lack of corrosion protection and corrosion management. Repair of degraded structural members with substantial corrosion damage is critical to maintain structural integrity for safety and continuous operation.
