National Subsea Research Initiative Coiled line pipe as a potential solution to all pipelines, WI & production risers for small pools, with a focus on installation methods from low cost vessels of convenience. Jamie McCallum 2016
Overview Generic Technology Overview Benefits Key Stakeholders Potential Specific Solutions Barriers Concluding Remarks Recommended Further Work Appendix
Generic Technology Overview Coiled line pipe is a continuous length of steel or composite tubing, spooled on a large reel. Multiple lengths can then be welded together as required. Coiled line pipe is typically available in ODs of 1-5 and ready coated by the manufacturer. Coiled line pipe is manufactured from a formed steel strip joined along it s length by high frequency induction (HFI) welding. https://www.youtube.com/watch?v=_wa5zg8bqao Picture from Global Tubing
Benefits Project turnaround HFI manufacturing process allows for quick project turnarounds. Apache Forties pipeline replacement with HFI line pipe (not coiled) fabricated, coated and delivered within 9 weeks of order placement with Tata. Allows tight lay windows to be met. Faster installation Coiled line pipe can be reel laid at a fast rate due to the reduction in offshore welding, field joint coating and NDT testing required compared with other lay methods. Installation alternatives Installation can either be carried out straight from the reel that the pipe is supplied on or multiple reels can be consolidated onto a larger installation carousel e.g. Global Tubing installed a 30km tie-back in the Gulf of Mexico, 10 x 3km spools with only 9 welds required in around 1 week. Vessels of convenience Simplified installation procedure means that specialised pipelay vessels are not required thereby potentially providing a significant cost saving.
Benefits Offshore weld rejection rate Number of offshore welds rejected is reduced with the number performed meaning less time on critical path repair. Reduced crew Fewer personnel required with reduction in offshore welding, field joint coating and NDT testing. Safety Depending on pipe size, fewer lifts may be required to complete installation since large lengths of pipe equivalent of potentially 100 or more line pipe lengths can be supplied on each reel. Coating integrity Each offshore weld requires repairs to the coating system. The reduction in the number of offshore welds required for line pipe therefore increases the integrity of the line pipe coating.
Key Stakeholders Line Pipe Manufacturers Tenaris Vallourec Tata Steel Coiled Line Pipe Manufacturers Tenaris Global Tubing FlexSteel Termoplastic Composite Pipe Manufacturers FlexPipe Systems Airborne Magma Global SURF Manufacturers Technip Wellstream NOV Installation Contractors Subsea 7 Technip Bibby Harkand
In this presentation, technologies were assessed using NASAs Technology Readiness Scale. TRL Levels
Coiled Line Pipe Overview of Scope Flat steel strips are joined into long continuous lengths, formed into a round pipe shape and joined along their length by high frequency induction welding. Coatings Fusion Bonded Epoxy, Polyethylene, Polypropylene are available from manufacturers to provide external corrosion resistance and mechanical protection. Removes critical path items such as joint welding greatly reducing installation times and the associated costs with large offshore installation crews and vessels. Available in outside diameters of up to 5 inches and a range of steel grades (X52, X65, X70, X80, X90). Supplied on offshore reels (sizes from Global Tubing below) which can be used for installation or pipe can be consolidated onto a larger carousel.
Coiled Line Pipe Technological Maturity TRL Level 9 Technology is proven with a track record of subsea installation around the world. Not yet been used in the North Sea for the transfer of hydrocarbons which is the intended use for small pools. Time to Market Already available in a variety of sizes from a number of suppliers e.g. Tenaris, Global Tubing. Qualification Tenaris and Global Tubing certified to; DNV OS-F101 Submarine Pipeline Systems. API SPEC 5LCP Specification for Coiled Line Pipe. No mention on either manufacturers website of compliance to BS PD 8010 - Pipeline systems Part 2: Subsea pipelines Code of practice, although this standard is referenced in DNV OS- F101 Costs Significant cost savings compared with traditional steel pipelines from reduction in offshore welds and the potential to use vessels of convenience.
Thermoplastic Composite Line Pipe Overview of Scope Flexible, composite pipeline solution made up of a thermoplastic liner, a helically wound reinforcement layer and an external thermoplastic jacket. Used in applications where corrosion resistance is beneficial. Further configurations available for high temperature applications. Technological Maturity TRL Level 7 Airborne have qualified a 6 ID TCP flowline as a pilot project for Petronas in 30m water to link 2 platforms for transfer of hydrocarbons with minimum working pressures ranging from 100 to 375 bar. Will be installed offshore Malaysia early 2016. Length is of the order of 550m only. Time to Market Available Airborne (4 7 ID, 5m installation MBR) and Magma (2 12 ).
Thermoplastic Composite Line Pipe Qualification Airborne s flowline worked to a client specific qualification programme to the requirements of API RP 15S Spoolable Composite Pipeline Structures, API RP 17B Recommended Practice for Flexible Pipe and DNV-OS-C501 Composite Components. This included extensive testing requirements and the development and testing of integrated optical fibre condition monitoring and upscaling of technology to 16 ID. Magma is backed by a DNV GL qualification programme and DNV GL F119 Recommended Practice for Thermoplastic Composite Pipe. Airborne have developed a recommended practice with DNV in lieu of an appropriate standard. Costs Same significant cost savings as steel coiled line pipe with regards to installation, although these may be offset by issues around on-bottom stability. Product hardware cost will likely be significantly higher that steel pipe so upfront costs expected to be higher. Operational expenditure savings as thermoplastic liner eliminates the need for inspections and corrosion inhibitor programs as well as reducing the likelihood of costly premature pipeline replacement.
Barriers - General Outer diameter limitations Have proved a barrier in the past with larger fields. May also be a flow assurance issue particularly with heavy oil and HP/HT developments. Limited by spool size. Manufacturers could make larger OD coiled pipe but the installation time savings reduce as the length on the spool decreases. Spool size Limited by size of spools that manufacturers can supply and transport logistics. Balance to be struck between big spools for longer lengths and less welds, with the desire to use smaller vessels of convenience. On bottom stability: Pipe will require something to give it on-bottom stability, perhaps being trenched or buried. This adds complexity and cost to the installation process and potentially prevent use of vessel of convenience. Installation familiarity: Installation contractors who are unfamiliar with the product could possibly add to project risk or reluctance to specify. Dynamic response: Coiled line pipe hasn t been designed for dynamic applications. Will be a challenging design due to lower ODs and higher drag to weight ratio than traditional flexibles making it subject to greater hydrodynamics.
Barriers - Steel Internal corrosion Can manufacturers deal with Carbon Dioxide and Hydrogen Sulphide? Can a suitable corrosion allowance be built into the wall thickness of such small pipelines? What happens if operating life of pipeline is increased? How are smaller diameter pipes inspected for internal damage? Is it possible for them to be pigged? High frequency induction welding There is a perception in the industry that because HFI welding is cheaper that it is an inferior weld, despite no recorded failures of coiled line pipe attributable to the HFI weld. Low temperatures: Coiled line pipe can t handle low temperatures so there may be a requirement to design in a section of conventional pipe or flexible pipe where temperature drops occur. Lay tension: A limiting factor during installation of coiled line pipes is their ability to handle tension. Installing through the moonpool rather than off the back of the vessel should help.
Concluding Remarks Coiled line pipe has the potential to reduce life-of field costs for some subsea applications. The major cost savings are expected as a result of less welding and NDT operations resulting in faster lay rates over traditional methods. Currently steel coiled pipe is limited to 5" OD. Larger sizes are possible but the benefits over traditional pipe would reduce with increasing size. Further work is required to better understand the technical and economic benefits of spooled pipe in relation to small pools. Composite pipe for subsea flowlines is being piloted in a shallow water, hydrocarbon application for Petronas. Composite spooled pipe could reduce flowline OPEX (chemicals and inspection programmes) compared with steel pipe. It could be a useful technology for small pools but further work is required to better understand the technical limitations and determine any potential cost benefit for small pools. More work required to prove viability for use as a replacement for flexible risers as evidence found to date suggests that fatigue life would be a limitation even for small pools with 6 8 years production. Wood Group Kenny have previously investigated steel coiled line pipe as a free hanging catenary off a fixed platform and found that the fatigue life of the pipe was exceeded from environmental loading alone.
Recommended Further Work Initiate a cost benefit analysis of using spooled pipe versus traditional lay methods to understand what if any cost savings could be realised for typical UKCS small pools development for a range of NPS, say 4-10 pipe sizes. Depending on the outcome of CBA then investigate in more detail the technical limitations and challenges for most likely pipe sizes. Investigate in more detail use of TCP pipeline for subsea hydrocarbon lines. Have an engagement event with manufacturers (Tenaris, Global Tubing etc.) and design consultancies (WGK, Xodus etc.) to ensure they are aware of the technology before pipeline systems are designed to help the technology break into the North Sea market. Have an engagement session with manufacturers and smaller installation contractors (Bibby, Harkand etc.) with case studies of previous line pipe installations. Helps smaller installation contractors break into a new market and opens up potential use of smaller vessels to reduce cost. Review which operators would be interested in using this technology as a solution for their small pools so that manufacturers can meet with them, start constructive dialogue and alleviate any concerns the operators may have. Investigate ways of making coiled line pipe a viable solution for the replacement of flexibles such as the use of composite pipes.
Acknowledgements Alan Foxton Independent Consultant Keith Anderson & Adrian Ledingham Wood Group Kenny Ivo Bozukov Global Tubing George Lawrence Tenaris Bart Steuten Airborne Oil and Gas Tim Martin Ramboll
Appendix Hyperlinks http://www.tenaris.com/en/products/offshorelinepipe/coiledlinepipe.aspx http://www.vallourec.com/surf/en/pages/default.aspx http://www.nov.com/segments/completion_and_production_solutions/fiber_glass_systems/oil_a nd_gas.aspx http://www.technip.com/en/our-business/subsea/flexible-pipe https://www.geoilandgas.com/subsea-offshore/flexible-pipe-solutions/flexible-pipe-solutions http://globaltubingpipeline.com/coiled_line_pipe_offshore_products.html http://www.flexsteelpipe.com/applications/oil-gas http://airborne-oilandgas.com/products/tcp-flowline-and-riser/ https://www.linkedin.com/pulse/major-independent-achieves-125-cost-savings-using-coiled-ivobozukov http://www.swagelining.com/ http://www.tatasteeleurope.com/en/products-and-services/long/tube/pipeline/hfi http://www.flexpipesystems.com/products/pipe/pipe.html
Appendix Meetings Alan Foxton Independent Consultant Keith Anderson & Adrian Ledingham Wood Group Kenny Bart Steuten Airborne Ivo Bozukov Global Tubing Tim Martin Ramboll
Appendix Minutes of Review Meeting. Attendees; Jamie McCallum - NSRI Christer Fjellroth - NSRI Gordon Drummond - NSRI Graham Whitehead - EnQuest Neil Duncan - OGA Concrete coating may be required for stability and insulation is a potential limitation and risk. Rename key vendors title with key supply chain and include Magma Global. Can t double / triple up for a variety of reasons. Flow Assurance, trenching, inspection, diameter vs. wall thickness and therefore flow rate vs. diameter. Tree connection is 5-7 OD so jumper will be around 6 OD. Below 5 flow rates will be unrealistic. Can CRA be done? Traditional reel lay cost vs. coiled line pipe cost comparison would be desirable to understand size of the prize. Consider life of field corrosion allowance, inhibitor or cathodic protection and which is most applicable. Understand limitation with thicker wall vs. higher MBR. Can OD be pushed to 6? What is the time to market? Where are the manufacturing bases? What are the lead times and are pipes made to order? Can thermoplastic pipe compete with steel? Hardware costs are higher than for steel and connections to make are time consuming. Worth checking if deferred production costs in case study would be as much of a concern for small pools with a short life. What temperature and pressure limitations do composite pipes have? Are they more susceptible to wet buckle? Would you have to trench and bury line pipe based on legislation and can legislation be amended? Is it required for stability? Expand further on Joules-Thomson Effect terminology. Would be useful to get Petronas lessons learnt from Airborne.
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