Instead of trucking light crude oil on a hundred miles of dirt roads in a remote area of Australia, it is now being conveyed underground using a thermoplastic, flexible composite pipe. This undertaking was recently awarded the Project of the Year by the Plastics Pipe Institute, Inc. (PPI) for its Energy Piping Systems Division (EPSD).
The project was selected for the honor due to the advanced technical composition of the pipe, the elimination of the environmental impact of heavy truck traffic, plus the extreme logistics that were met. PPI is the major North American trade association, representing all segments of the plastic pipe industry.
The 105.6-mile (170-km) reinforced thermoplastic pipe (RTP) was installed in 2013 to transport light crude oil from Queensland to a processing facility in South Australia. The 4-inch diameter line had to meet the design pressure of 1,500 psi and a design temperature of 1800 F (820 C). The RTP line provided a 50% savings compared to steel pipe, was easy and fast to install and also met the technical requirements of Australia’s pipeline standard AS 2885.1 Pipelines – Gas And Liquid Petroleum.
“Aside from being able to convey hot crude oil in an austere area of Australia, the pipe had to withstand chemicals, high heat, rough soil conditions and even termites,” said Tony Radoszewski, president of PPI. “HDPE pipe is always a top consideration for the tough jobs, but I think this is the first time I have ever seen an RFQ stating that a pipeline had to be termite-proof.”
He presented the award to PPI member company and manufacturer of the pipe, Flexpipe Systems, Inc. (Calgary, Alberta), a division of ShawCor Ltd., during the association’s annual meeting held last spring in Palm Springs, CA.
The Flexpipe Systems FP601 HT RTP has an outer jacket and an inner liner of HDPE-RT (raised-temperature resistance) and two layers of wound fiberglass. Manufactured at the Flexpipe plant in Calgary, the 100 miles of pipe journeyed 10,500-plus miles across the ocean, then more than 900 miles inland to the site. The reel-less, coiled pipe was installed by plowing at a depth of 30 inches to 6.5 feet at major roads, dunes and major creek crossings.
The average rate of plowing achieved was 2.42 miles a day and, at peak times, as high as 5.5 miles a day. Because RTP could be plowed into the ground, the time and cost of installation were drastically reduced. Other types of pipe, such as glass reinforced epoxy (GRE) or steel, were unable to meet all the criteria of capability, ease of installation, time to install, ongoing maintenance and environmental impact. There was a capital cost reduction of nearly 50% compared to a steel pipeline.
“The RTP was a high-temperature variant to withstand the high inlet temperatures of the transported fluids,” said Randy Knapp, director of engineering for the Energy Piping Systems Division of PPI.
The construction of RTP isolates aromatic fluids from the reinforcement layer, which provided the pressure containment for the pipe. This allowed continuous aromatic content up to 25% by volume in the pipeline at the required inlet temperature of 1580 F (700 C). Also, the corrosion resistance of HDPE coupled with the pressure capability of RTP made it the best option for the project.
The fittings used in this RTP system are nickel coated to protect from internal corrosion and have sacrificial anodes and tape wrap to protect against external corrosion.
The Flexpipe RTP passed a thorough compliance assessment, as well as a risk assessment to cover any sections that were not addressed by AS2885.1 due to the material type. A detailed technical assessment of the design basis and qualification process of the pipe and jointing system was done based on API RP 15S Recommended Practice for the Qualification of Spoolable Reinforced Plastic Line Pipe.
This included a comprehensive set of short- and long-term tests to validate RTP resistance to the anticipated service conditions of the pipeline. This included a long-term pressure capability test as per ASTM D2992 and conducted for 14 months at the pipe-rated temperature, in addition to chemical resistance testing, temperature cycling testing, elevated temperature testing and external loading capability.
“The RTP provided distinct advantages when compared with rigid, fixed-length traditional pipe. Installing more than 100 miles of the pipe using low-impact plowing took just 95 days with a small crew and protected sensitive environmental areas,” said Radoszewski. “Now instead of trucks making somewhat dangerous 14-hour round trips, there is a cost-effective pipeline that also solves production shutdowns that frequently occurred due to wet weather closing the clay and dirt roads.”
Randy Knapp, director of engineering for the Energy Piping Systems Division of PPI, discussed further aspects of the Australian project and the use of Flexpipe Systems.
Q: How does Flexpipe Systems FP601 HT RTP compare to steel pipe in terms of service life?
Knapp: Over 65 million feet of Flexpipe has been installed in demanding oil and gas applications. Service life relates to the length of time the pipe and system can meet the performance requirements of the application and is dependent on many factors. Flexpipe exceeds all the performance requirements of ASTM and API standards, including long-term pressure ratings.
RTP has a service life at least equal to steel pipelines, but in many cases will outlast steel pipes due to the elimination of corrosion issues and superior impact resistance. In addition, long continuous flexible pipe lengths limit the number of connection points further enhancing system integrity.
Q: What are some of the other applications for Flexpipe Systems FP601 HT RTP?
Knapp: These RTP systems are routinely used in gas flow lines for liquid hydrocarbon gathering, Gas gathering, CO-2 injection, as well as water injection, transfer and disposal.
Q: What challenges, if any, did the plastic pipe encounter during the project that required major adjustments?
Knapp: This project presented a number of unique issues that the engineering team at Flexpipe had to solve. The production/shipping time requirements were extremely tight, requiring 100 miles of production and shipping in coils without reels.
The South Australia environment provided its own challenges – remote location, high temps and wildlife that required a product that could be handled by small crews. The requirement for very small right of way (ROW) was critical to minimize environmental impact and could be accomplished using flexible RTP pipe and plowing techniques.
Q: Since the plastic pipe was used in a unique project, did this require any special training for the workers?
Knapp: Yes. The installation crew was trained in installing Flexpipe using plowing technique (about 2.5 miles/day), and was also trained on using mechanical joints to join the long sections. Flexpipe offers training and certification to contractors in joining, handling and deployment.