Charles Tavner, COO Magma Global, considers how TCP can increase profitability in marginal fields.
Thermoplastic composite pipe (TCP) has turned a corner in industry acceptance over the past year. Major operators agree that composite risers will deliver significant reductions in cost and installation time for deep water systems. TCP offers the possibility of deploying flexible pipes in water depths beyond 3000 meters in high pressure, highly corrosive environments. It’s therefore surprising that exactly that same high-performance m-pipe technology can reduce costs in all kinds of less demanding applications. In particular, the benefits of composites for operators employing infrastructure-led development strategies are notable in terms of cost and time. So how did we come to develop m-pipe in its current form and where can operators use this relatively new pipe technology to their advantage?
m-pipe is a simple, standard product that uses an on-demand lean manufacturing process and offers multiple advantages in terms of corrosion resistance, flexibility, weight and flow rate. When developing m-pipe we took a decade to find the right materials and manufacturing method that would produce a subsea pipe that could be standardized for a wide variety of upstream hydrocarbon transfer needs. During this time we investigated the behaviour of many different polymers under different heat and chemical conditions. PEEK and PVDF came out as the only viable options for our purposes but further investigation revealed that PVDF had shortcomings from chemical reactions at sustained high temperatures which would reduce strength over time. PEEK was found to be the superior choice as it is unaffected by chemicals at sustained high temperatures, which ensures the strength of the material is stable over time, and also benefits from a far higher resistance to gas permeation which makes it ideal in Brazil’s pre-salt.
We also conducted detailed analysis across different fibre types. with different fibre materials and selected carbon fibre over glass fibre as it offers the best heat resistance which improves stability. Despite carbon fibre being more expensive than glass fiber it has strength advantages which means that less fibre and polymer are required to reach a specified pipe strength. This translates to a thinner pipe wall which requires less time to manufacture and results in a lighter end product.
From a technical and commercial point of view, close co-operation with the supplier of these materials speeds up qualification, optimises raw material logistics and reduces wastage. Ultimately, we settled upon a single material combination of PEEK and carbon fibre for m-pipe. This allowed us to focus on developing one standard product and perfecting the production methods.
One of the areas where operators have found cost savings with m-pipe is in short length jumpers of 5 to 500 meters. Production of m-pipe can be set-up in a matter of hours to produce lengths as short as a few meters for individual client orders. This flexible process means we can respond quickly and cost-effectively to customer demands whereas traditional pipe manufacturing methods are optimised for larger length production runs.
There are several other surprises when people see m-pipe in manufacture for the first time. It only requires two people to operate and runs cleanly and quietly 24 hours a day. In many respects the combination of highly automated process with minimal human interaction is more akin to a high-tech car plant than a traditional oil and gas pipe manufacturing process.
We start with an extruded length of pure PEEK pipe with the required internal diameter. This is passed back and forwards through an additive process that uses a laser to fuse a PEEK impregnated carbon fibre tape around the pipe layer by layer. The only variable m-pipe has is wall thickness which is what gives the pipe it’s pressure rating. This wall thickness is simply created by adding more layers. If a customer requires a shorter length, say 20 meters of 6inch 15ksi pipe, we can easily fit that in and make that order viable.
Further cost savings are achieved through installation. The light weight, flexibility and strength of m-pipe simplifies the project design, transport and installation including the deployment, pull-in and subsea connection phases. The flexibility of the pipe eliminates the need for precise metrology and accurate pipeline fabrication, simplifying offshore operations and reducing schedule-critical activities. Its low weight allows the use of smaller vessels and easy handling on deck and with ROVs. Once installed, it has a high fatigue performance in subsea motions. The use of PEEK means it does not corrode from contact with saltwater or sour service which minimises the need to monitor over time. Furthermore, the smooth bore enables high flow rates and the PEEK surface provides better overall performance than clad stainless steel in resistance to wax and hydrate build-up reducing intervention costs. When it becomes time to decommission m-pipe the same benefits of light weight, easy handling and lack of corrosion make it a very straight forward procedure.
The prevailing industry interest in TCP is for deep water exploration, where it enables production in water depths beyond 3000 meters in high pressure, highly corrosive environments. Magma, along with other TCP manufacturers, is qualifying product to these high specifications and industry bodies are working hard to keep up with the different quality specification needs for this material.
To meet the challenges and demand in Brazil, TechnipFMC is developing a hybrid flexible pipe that combines the benefits of a steel-armoured flexible pipe with a Magma’s PEEK carbon fibre composite pipe to enable a free-hanging catenary riser in ultra-deep waters. Also aimed primarily at the Brazil pre-salt is Ocyan’s CompRiser, which is comprised of m-pipe risers coupled to a central steel support, a design that can be rapidly assembled at the water’s edge and towed out. Transocean also sees the benefits of composite pipe. It has identified m-pipe for continuous spooled auxiliary lines to enable the next-generation of deep-water drilling risers.
There is no question that the industry is heading towards a future that includes composite pipe. Major operators, including Petrobras, have spoken publicly about their intention to use composites instead of steel as part of their riser solution portfolio in Brazil’s pre-salt.
While m-pipe is recognised as a high-performance pipe, particularly suited to the pre-salt challenges, it has also demonstrated cost-effectiveness in much simpler applications, both onshore and offshore. Eni, for example, used m-pipe for replacement gas injection jumpers for the Adriatic Coast where the existing subsea flexibles had suffered from corrosion and needed fast but long-term replacement. In the Middle East m-pipe was used in short lengths in well-head applications to replace rigid steel pipes in order to speed up installation and to allow movement between the well and production skid. Removing the need to manufacture bespoke, individual steel spools by replacing them with a section of equally capable and flexible m-pipe dramatically reduced hook-up time.
Having one standard product for all types of service is a bonus for Gulf of Mexico fields as it enables customers to order a standard m-pipe and then deploy on-demand. There’s also the possibility of buying a longer section of pipe and cutting it and terminating in-field as required. Some of our customers are starting to take advantage of this and are benefiting from those fast turn-around times which gives them a huge advantage. A prime example of this is a recent order for a six-inch replacement hydrocarbon jumper for the North Sea with a delivery lead time of four months. As well as the benefits of light weight for easy handling and installation, the ultimate decision driver in this case was the fact that we could deliver what they needed in a short timeframe and at a competitive cost. A vast array of applications could benefit from the multiple cost and time saving implications of this technology.
As part of a broader strategy the industry has seen many operators creating value without huge outlay in new infrastructure by extending expected production periods for as long as financially viable to do so. By choosing to focus on near-field discoveries where the financial outlay is smaller than for a major new field development, and where much of the infrastructure is already in place, infrastructure-led exploration through upgrades and tiebacks offer opportunities for rapid monetization with low CAPEX.
The strategy is being used extensively by independent operators and majors in the Gulf of Mexico, West Africa and the North Sea alike. Fields that had a life expectancy of 20 years are now entering double that age and may end up being three times that age by the end of field life . Thanks to improved well stimulation and water injection methods, and with investment in infrastructure, these fields are still proving productive and profitable. As well as minimizing costs and maximizing value, this approach has a direct impact on CO2 emissions for the life of the field. For example, the recent field extension of Stratfjord, Norway, is expected to reduce CO2 emissions per barrel from the field by half during the next five years due to higher production compared to ending the production earlier .
According to Equinor’s Nick Aston, its “infrastructure-led exploration on the Norwegian continental shelf has been successful for many years and provides a good basis for high profitability and a low carbon footprint.” Last year, drilling led to 17 discoveries with ten in the North Sea, six in the Norwegian Sea, and one in the Barents Sea. The majority of these are within close proximity to an existing facility. Even small finds are deemed worthwhile as they are cost-effective to tie-in to nearby platforms and pipelines . Thanks to increasingly accurate seismic imaging techniques success in finding nearby wells has improved and new discoveries can be brought on-stream in under a year.
With this popular strategy the challenge rests with the supply chain to be able to meet the demand for subsea equipment under short lead times and for relatively short pipe lengths. These developments are well positioned to benefit from the qualification of TCP that has been completed for far more demanding applications in ultradeep waters.
Inevitably if pipe and equipment is exceeding the supplier’s recommended lifetime it may need replacing. If a field has already doubled its life expectancy perhaps replacement pipe should be selected based on a much longer life expectancy. It is worth noting that because of its flexibility and resistance to degradation, it is feasible to take up m-pipe jumpers and tiebacks for re-use elsewhere. This is now proven technology, and the typical delivery time from order can be as little as a few months, as recently demonstrated. With many major operators divesting older assets to smaller operators, the need for maximising value but minimising cost is paramount.
As with the cases already mentioned, there are a wide variety of opportunities to exploit TCP technology in these simpler, shorter length applications. While operators wanting to use composites for demanding deep-water riser applications must wait for qualification, the technology is already in field use in diameters of 2 to 6 inch. Magma’s m-pipe is qualified to pressure ratings up to 15ksi and for operating temperatures of -20 to +110oc. Testing has shown that applications outside this envelope would are feasible with further qualification.
Infrastructure-led development is about cost effectively extracting oil from smaller pools. In order to do that you need to have a nice simple, standard product that’s quick to procure and cost effective to install, and m-pipe is a good example of that. Composite pipe is the riser solution of the future, and it is still considered new technology, but it is also a low risk and highly desirable solution for repair, tiebacks and jumpers by operators, regardless of the environment or geography. We think it’s going to be used as a more commonplace solution around this world and are readying our capacity ahead of the inevitable increase in demand.
As published in Oilfield Technology magazine
Statfjord A image credit Harald Pettersen (c) Equinor