Validated in Testing, Proven in the Field
Extensive programs have been completed on composite repair systems, putting them through rigorous tests to simulate the offshore environment and its demanding requirements. CSNRI has worked to lead those efforts on many fronts, whether it is by participating in JIPs (Joint Industry Projects) or conducting testing for specific needs and clients. The following are some examples of the various testing programs and studies CSNRI has participated in over the years. For specific details or information on any of the projects mentioned, please contact us to discuss in more detail.
- PRCI MATR-3-6 “Evaluation of Composite Systems for Subsea Pipeline Repairs”
(tested at Stress Engineering Services [SES])
- This study investigated the reinforcement of 10.75-inch x 0.375-inch, Grade X65 pipe samples with simulated corrosion. The test samples were repaired via composite repair and subjected to a pressure hold in a seawater environment for 10,000 hours. The primary objective of this study was to evaluate the performance of composite repair systems in reinforcing subsea pipelines and risers. The primary metric for evaluating the repair technology was the increase in performance over unreinforced samples.
- All repair work was performed underwater and the samples were pressurized during the duration of testing. After the designated hold period of 10,000 hours (approximately 420 days), the samples were subjected to destructive testing involving different combinations of internal pressure, axial tension, and bending.
- Testing evaluated the effects of combinations of static and cyclic internal pressures, axial tension, and bending loads.
- The primary observation from this study is that, when properly designed and installed, composite repair systems are an effective means for improving the integrity of damaged offshore pipelines.
- Offshore Pipelines and Risers Test Program by SES
- This testing program was conducted to evaluate the use of composite repair systems for reinforcing offshore pipelines and risers. As part of the study, SES conducted a series tests using pipe samples that were reinforced using composite repair systems. These tests were intended to simulate environmental and loading conditions that would be encountered during offshore operations. The activities completed as a part of this study are listed below:
- Simulated subsea installation and curing of composite repairs
- Examination of the effects of improper installation (forced delamination defects within composite repair to evaluate potential unbonded sections)
- Composite repair inspection
- 10,000-hr pressure hold in simulated seawater conditions
- 90-day UV exposure
- Cyclic thermal loading
- Cyclic pressure testing
- Pressure-to-failure (burst) testing
- Deep Sea Simulation Testing
- Multiple testing programs which evaluated the effects of deep-sea conditions on the curing and performance of composite repairs.
- Tests completed to simulate low temperature, subsea curing conditions, as well as high external pressures that can be experienced on the sea bed environment.
- Testing showed that a properly designed composite repair had the ability to cure to operational levels in deep sea environments, and pressure testing showed great results in performance of an installed repair system.
- Underwater tests w/ DNV witness ADMA (UAE)
- Multiple programs to test various needs and scenarios focusing on underwater repairs and internal defects on subsea pipelines.
- Several baseline tests were performed, with 2 primary full-scale tests occurring as a further practical validation.
- An 80% internal wall loss defect was machined into a nominal 8” ND X65 steel pipe for evaluation of composite pipeline repair system. The purpose of this test was to demonstrate the ability of the composite repair to reinforce an internal pipe wall defect in an entirely submerged environment.
- Testing of internal corrosion defects on a section of 12.75” OD, 0.5” wall thickness, X65 pipeline removed from the field. Repair made in tank of seawater from local body of water.
- In both tests, the composite repair system was installed while fully submerged in sea water.
- Underwater tests by clients with PTTEP (Thailand)
- Testing was conducted on a 6” ND, Schedule 40, Grade B pipe which had a machined external wall loss of 80% with dimensions of 4”x4”. The repair system was installed in fully submerged conditions to simulate an underwater repair.
- The repair system was pressurized in steps with incremental hold points until the pipe reached a pressure of 4500 psi. No signs of failure mechanisms were witnessed, and the repair system was subsequently approved as a long-term repair for use on subsea repairs of external corrosion up to 60%, and short term use for depths of 60-80% of wall thickness.
In addition to extensive testing, CSNRI has been successfully designing composite repairs for the offshore industry for decades and provides support through a rigorous training program designed to ensure the successful installation of the repair system. Combining our composite knowledge with decades of experience allows for a robust support system through training, field support, and consultation services. We have trained rope access technicians, divers, and leak sealing experts over the years, and for even more confidence in your repair, we have technicians and trainers fully qualified for offshore work who can be onsite to answer questions or assist with your repair needs. Visit our Training & Field Support page to learn more about getting trained and certified on CSNRI repair systems.