Restoring Pipeline Integrity |
March 2010 |
A Q&A on Rehabilitation Techniques with Pipe Wrap’s Drew Cleaver
Compiled by NAP staff
Oil and gas pipeline construction is an expensive endeavor with most projects costing millions of dollars — sometimes billions — depending on the length and diameter of the line. If a pipeline were to fail, replacing it could add another few hundred thousand dollars to the price tag. Not to mention the revenues lost for down time. That’s why pipeline rehabilitation is an important consideration for pipeline owners who need a solution, but can’t afford to shut down transmission and rip out miles of severely corroded pipe.
North American Oil & Gas Pipelines spoke to Drew Cleaver, inside sales manager at Pipe Wrap LLC, which specializes in composite pipeline rehabilitation. The company has provided composite repairs and pipe remediation for more than 10 years, solving such problems as corrosion mitigation, splash-zone protection, pinhole leak repairs for low pressure pipeline, dent repairs, bend repairs and complete hoop and axial strength reinforcement.
North American Oil & Gas Pipelines: How would you define pipeline rehabilitation?
Drew Cleaver: Pipeline rehabilitation is the process of restoring a damaged piece of pipe to perform as it was originally intended. Depending on the purpose of the line and its governing body, our materials are capable of making the pipe as strong as or stronger than it was when it was new, or we can reduce material costs and restore the pipe based on original design pressure instead of maximum allowable operating pressure (or MAOP).
NAP: What are some of the different methods of pipeline rehab?
Cleaver: Active and inactive leak repair (Pipe Wrap) for low pressure pipes, structural reinforcement (A+ Wrap) for high pressure pipeline, corrosion prevention (Pipe Sock and SplashGard), insulation, coatings and more.
NAP: Why is pipeline rehab important for the oil and gas market?
Cleaver: Pipeline rehab is critical to the oil and gas market because the old saying that “time is money” is probably most fitting in oil and gas. Not only is the actual cost of material and labor for replacing an entire piece of pipe incredibly expensive, it would require the line to be inoperable for the length of the repair process. Composite repairs are an excellent alternative solution for the oil and gas customers because the line can remain active, the material and labor costs are drastically reduced, and there is a varying amount of materials that can be used for special circumstances. We can tailor the materials necessary for individual jobs, or customers can buy pre-calculated kits that are designed to restore a “worst case scenario” (80 percent wall loss) pipeline.
NAP: What are some of the more common instances that require rehab?
Cleaver: General external corrosion that has eaten away a piece of steel pipe over time, girth weld corrosion, bell and spigot gaskets wear out and fitting joints leak and third-party damage, such as when a backhoe cracks a line while digging.
NAP: Who typically commissions this kind of work?
Cleaver: Corrosion engineers, pipeline integrity management crews and health, safety and environment (HSE) inspectors.
NAP: Who typically performs this kind of work? Do pipeline contractors do the work or do they subcontract to companies like Pipe Wrap?
Cleaver: Field service contractors, general maintenance personnel, and when we do structural reinforcement jobs, only certified A+ Wrap installers can perform the work.
NAP: How do you know if you need to rehab a pipe?
Cleaver: Visual inspection, traces of liquid leaks and smart-pig inspections.
NAP: Are certain rehab methods better for certain situations?
Cleaver: Absolutely. Pipe Wrap is our original leak repair wrap for low pressure refinery, municipal or residential pipelines. A+ Wrap is specifically for structural reinforcement on larger diameter pipe.
NAP: Does rehab extend a pipeline’s life or is it just a stop-gap?
Cleaver: A+ Wrap is tested to a 20-year design life when used for external corrosion structural reinforcement. Because we have no control over stopping internal corrosion, we cannot accurately predict how long an internal corrosion repair scenario will last. We can plug a leak that is caused by internal corrosion, but the corrosion may continue to grow around the repair zone and therefore springing new leaks.
NAP: What kind of advice would you offer pipeline owners who may be considering a rehab method?
Cleaver: Composite repairs are incredibly versatile and effective in restoring pipes regardless of repair scenario, pipe material, etc. Our Pipe Wrap and A+ materials are non-hazardous so they do not require any expensive freight, storage or disposal. The resins are pre-impregnated so the field techs do not have to worry about mixing the resins in a precise, weather-dependent ratio. Composite repairs are simple, cost effective, fast, dependable and smart pig detectable.
NAP: Is there a limit to how much of a pipeline can be rehabbed?
Cleaver: Our testing shows that our A+ Wrap can safely restore a pipeline that has lost up to 80 percent of its original wall thickness.
NAP: What methods of rehab does Pipe Wrap offer?
Cleaver: Structural reinforcement, leak repair, corrosion prevention, insulation, pre-impregnated fiberglass and carbon fiber, epoxy wet-layup fiberglass and carbon fiber.
NAP: Explain how and why each are used?
Cleaver: All material recommendations are based on the repair scenario itself. We try to offer as much engineering and technical support as we can. Most all materials we sell have multiple applications. Because we have such a wide array of products, we can mix and match the best groupings to most effectively repair the pipe or satisfy the customer.
NAP: How much does it cost to rehab a pipeline? Can you give an estimated cost per foot/mile?
Cleaver: This varies based on whether we’re talking leak repair or structural reinforcement and always depends on the scale of the job. With our system, the necessary materials are calculated on square and linear footage with considerations to the repair scenario. Sometimes we need only a few layers of A+ Wrap, but if the defect is severe (such as a scenario involving 80 percent wall loss), we will need more layers of material, thus more square/linear feet of fiberglass.
NAP: How does Pipe Wrap assure that its products meet the requirements of the industry?
Cleaver: Pipe Wrap composite repair systems have been tested by leading third-party testing laboratories servicing the oil and gas industries. All testing has been completed using ASTM, ASME and NACE protocols. However large or complex your piping problem may be, any repair is possible with the right team and products. Pipe Wrap has the people, product inventory and infrastructure assistance to get the job done. Pipe Wrap offers engineering support and training before, during and after your pipe remediation project.