There is growing interest in ‘cold based' operations which dispense completely with the gases, ignition sources, flames and hot work associated with welding for piping repair construction, modification and tie-in work, especially on ageing offshore infrastructure. Quickflange CEO Rune Haddeland discusses recent applications of his company's eponymous piping connection technology.
While most maintenance attention tends to concentrate on ‘critical application' pipelines which deliver oil & gas from the reservoir to shore, operators today must also focus on the often complex network of piping systems that are prevalent on offshore platforms. Such piping systems support everything from fire fighting, cooling and water injection through to compressors and scrubbers.
Furthermore, as fields and platforms become that much older, so the challenges increase with piping repair construction, modification and tie-ins often having to take place around ageing and often interdependent infrastructure, where the threats of leaks and corrosion are high, and where activities often take place against the backdrop of continuing production.
Some estimates suggest that as much as 20% of total investments in piping infrastructure over the next decade will be spent on maintaining and upgrading existing infrastructure.
With many platforms facing harsh and remote conditions aligned with regulatory, environmental and safety pressures, as well as the need to manage costs, maintaining topside piping integrity is a key issue for today's operators.
So are today's piping connection technologies addressing these challenges? For many piping managers and engineers, the prominent technology for ensuring piping connections and installing flanges is that of ‘hot-based' welding where access to heat sources is required. Welding today, however, comes with a number of limitations.
First, there are the safety implications and regulatory requirements. With the need to test for flammable gases, the risk of fires from ignited materials, the importance of ensuring adequate ventilation, and the need to isolate areas of operation, welding can be a highly labour-intensive process. Permission to conduct hot work on site, for example, often requires up to two weeks' advance notice and often necessitates a significant amount of paper work before people have even started to be mobilised and the first pipes cut.
In addition, while there may be occasions where a piping tie-in may be relocated onto a line that can be temporarily isolated, production shutdown is often the only option with welding, making it an even more expensive process.
With these issues in mind, there's a growing demand for lower impact and more flexible piping connection solutions and for alternative engineering approaches to traditional piping connections on offshore platforms.
Cold solutions
The last few years have seen a growing interest in ‘cold based' operations which dispense completely with the gases, ignition sources, flames and hot work associated with welding, but are still able to provide a highly secure and leak-free mechanical and pressure-tight connection. The result is safer and more secure operations with no fire or explosion hazards.
The ‘Quickflange' solution, for example, which has ABS and DNV approval as well as ISO 9001:2008 accreditation, consists of a modified standard weld neck flange with a patented internal groove profile. There are no moving parts, with simplicity of construction a key benefit. This starting point of having a standard flange is particularly appealing to conservative pipeline engineers who want to avoid anything too radical and like to remain in their comfort zones.
Another benefit in modifying from a standard flange, unlike many other mechanical connection solutions, is that it can be delivered to the operator within hours without production delays and without the need to access specific materials and suppliers. Some of the cost savings associated with this solution, when compared with traditional welding, are outlined in Figure 2 .
With Quickflange, the flange is machined in such a way that it can slide onto the pipe itself without the use of heat or other potential ignition sources and a hydraulic tool is then used to activate the flange, resulting in a mechanically robust flangeto- pipe connection and a less onerous installation compared to other more cumbersome mechanical systems. A cutaway of the flange and the installation process are shown in Figure 3 (right). The metal-to-metal seal also ensures that there are no gaskets that can be affected by temperatures and fluids. Third party qualification has also demonstrated that the process has no detrimental effects on the pipe and performance.
Typical applications to date include pipework and new spool tie-ins; the replacement of existing flanges; fitting flanges in space-restricted areas; replacing damaged or corroded piping; and the insertion of valves. Sometimes, it has just been used to avoid welding in inaccessible areas. Flexibility is also increased by its greater size coverage and its applicability to a wide variety of pipe materials, ratings and flange types. In addition, with the operation often taking place in a confined area, there is no adverse impact on production and no need for hot-work permits, pressurized welding habitats, and the resulting paperwork and costs.
Furthermore, as well as the cost savings through reduced paperwork and personnel requirements, the flexible, long-term rental model also ensures that costs are more predictable with no additional costs relating to rental equipment and increased personnel requirements if a particular job is delayed or moved. And the flexible nature of the solution as part of a complete connection system, rather than an ad hoc series of products, means that it can fit easily into any maintenance or fitting scenario.
The Quickflange solution was first supplied in 2005 to Statoil's Gullfaks platform offshore Norway and the most recent deployments include Fairfield's Dunlin Alpha platform in the UK North Sea, in response to corrosion issues on a flare header drain; a three-year hire agreement with Apache North Sea; and installation on BHP Billiton's Pyrenees project, offshore Western Australia.
In January this year two Quickflanges were installed on a ZADCO (Zakum Development Company) accommodation platform in the Middle East. After hydro testing, the fabricated spools were sandblasted, painted and installed on the discharge line of the platform's fire water jockey pump to replace the existing corroded spool. This solution is expected to significantly reduce the work scope and duration in connecting flanges to utility piping systems in a live environment on the Upper Zakum field in the future.
Heading subsea
The same flexible, piping connection solution could also be deployed on subsea piping, with additional benefits. For example, since the flange is a third of the length of many other mechanical-based products it is easier to handle and requires less diver time to install. Less time would also be needed for removing coatings, cleaning and deburying, and no specialist pipe preparation is required.
Funding was secured last year via the Petromaks research programme, coordinated by the Research Council of Norway, to further develop the product's subsea capabilities. This work is ongoing and includes extending operating pressures to 250 bar, researching material properties, ensuring that the flanging tools are suitable for operating in water; and increasing pipe diameters. Other collaboration partners in the programme include the University of Agder, based in Kristansand and Grimstad; DNV; the independent research organisation Sintef; Scotland's National Hyperbaric Centre, and Brazilian operator Petrobras.
Initial subsea testing took place in partnership with Petrobras, with Quickflange deployed and activated in a specialist water tank and divers supporting the installation process. Key criteria, such as speed of installation and ease of use, were measured. To date, testing has gone well, with installation times of only 50 minutes. Further testing is to take place to confirm sealing and joint integrity.
A 4in solution is also being tested at the National Hyperbaric Centre in Aberdeen, simulating 250m water depth. The R&D programme is also looking into the development of mathematical models, optimization of connection methods, and the potential for working on subsea pipe diameters up to 30in. OE
Rune Haddeland joined Quickflange as CEO in June 2011. He has 15 years' oil & gas industry experience, having held senior level post in Norway with Roxar Flow Measurement, TD W Offshore Services and Ymir Energy.
Pressure measurements at the double
Schlumberger last month announced the availability of two high-temperature additions to its reservoir characterization portfolio: the PressureXpress-HT reservoir pressure service and MDT Forte-HT qualified, rugged, high-temperature formation sampling and pressure system. Rated to 450°F (232°C) the PressureXpress-HT tool provides accurate pressure gradients and overall data quality not achievable by conventional high-temperature formation tester tools, said Schlumberger. The tool's dynamically controlled pressure pretest system enables precise control of volume and drawdown rates, making pressure testing possible in tight formations common in HP/HT reservoirs. The tool design also eliminates the need for gauge temperature stabilization, thus significantly improving overall operational efficiency.
In field testing in Thailand and the North Sea, the enhanced pretest system enabled successful pressure measurements at multiple depths to produce profiles of pressure versus depth and establish accurate reservoir pressure gradients to determine fluid contacts.
The new MDT Forte-HT system has been designed to provide greater all-round robustness in formation sampling and testing operations up to 400°F (204°C). It boasts a redesigned electronics system, incorporating surface-mounted components on a ruggedized chassis to protect sensitive electronics when operating in harsh high-shock and high-temperature logging conditions.
There is also a new-generation HP/HT quartz gauge, high-performance packers for the dual-packer module and advanced sealing technology; and a high-temperature Quicksilver Probe focused fluid extraction tool that provides near contamination-free fluid samples.
‘Providing a full suite of HP/HT evaluation tools is a major engineering focus within Schlumberger. These two tool systems expand our capabilities to deliver reliable downhole fluid analysis, fluid sampling, pressure measurement and interval pressure transient testing,' said Catherine MacGregor, president, Schlumberger Wireline.
Ultrasonic scanning in depth
Automated ultrasonic inspection specialist Sonomatic is hailing its new MAG-Rover as the first remotely steerable ultrasonic scanner capable of deepwater operations.
Designed and developed in-house over the past four years, the innovative scanner is capable of carrying out topside, splash zone and subsea inspection tasks and working in areas with restricted access around offshore structures, pipelines, caissons, pipework, pressure vessels and columns.
A ccording to SECC the Max Flow hot stab has been designed to achieve the highest stab connector flow rates in the industry with exceptionally low pressure drops. Unlike traditional hot stabs, it is based around a straightthrough bore with no obstacle or change of bore angle to throttle the rate at which fluids can travel through it. Measuring 1/4in to 4in and with zero head loss caused by directional change, the innovative design is said to enable operators to achieve very high flow rates using a smaller equivalent diameter bore without having to pump at higher pressures or use larger and heavier connectors and lines. T he Max Flow stab uses pressure-balanced technology to eliminate net forces that would otherwise push the stab out of position and creates reliable connections. A simple J-latch is used to align the ports and protect the connection against loads on the attached hose. Gareth Black, engineering manager at SECC Oil & Gas, said his company's high-flow solution was ‘ideal for subsea injection and pumping projects, including those involving high viscosity fluids and high flow requirements, such as tooling, intervention, testing and flooding'. It ‘also helped reduce the risks associated with working at high pressures', he added. ‘Ultimately, we are helping service companies and operators to achieve high flow rates more efficiently and increase potential flow rate thresholds with significantly smaller bores than they might traditionally use.' |
Sonomatic subsea manager Ryan Phipps expects the company to complete its first contracts with the MAG-Rover in 2012. Further work will also be carried out this year to upgrade the scanner's subsea capability from the current 2000m water depth rating to 3000m.
Phipps said a key advantage was the scanner's versatility. ‘Our goal, when we designed the MAG-Rover, was that it would address the health and safety issues surrounding high-risk inspection in difficult to access areas and could be used to inspect areas currently out of reach, such as in deepwater subsea fields and splash zone inspections.'
Incorporating the latest developments in ultrasonic performance and signal processing algorithms, the scanner provides ‘exceptional accuracy and reliability of inspection information, allowing operators to make integrity management decisions that are more closely aligned to the actual condition of the equipment inspected', added Phipps.
Handling the heat
The recently launched Pelagic CLEO high temperature subsea control fluid is hailed as breakthrough technology by its developer Niche Products. Developed to bridge the technology gap between water-based fluids and the extreme offshore HP/HT developments anticipated in future, the new fluid is said to offer excellent stability at high temperatures and be capable of maintaining temperatures in excess of 250°C for a project lifetime.
‘In addition, with the potential future requirements for closed loop systems in some sectors, this environmental oil is acceptable for direct discharge to sea,' said Niche Products technical director Tom McKechnie. He added: ‘What's more, it is designed to offer all the technical properties of traditional oil-based fluids in closed loop systems. This product will assist the production of oil in subsea control systems at temperatures never seen before, all while causing minimal environmental impact.'
High-capacity subsea power cables
A range of robust subsea power cables qualified for long life and low life cycle cost applications has been launched by BPP Cables, a subsidiary of BPP-Tech. Targeting subsea, downhole and pipeline flow assurance applications, the advanced cable designs have been developed, tested and qualified with the long-term support of leading offshore operators.
In November 2011, BPP Cables completed an equity partnership with KV Enterprises, a subsidiary of Keppel Offshore and Marine. BPP Cables technology director Darren Patel said this partnership would enable his company to work with a leading designer and fabricator of offshore drilling rigs and wind farm installation platforms to deliver customised, integrated cable design, supply and installation solutions.
Circumferential MFL joins pipe integrity line
Circumferential magnetic flux leakage (MFL) inspection technology, which enables pipeline operators to identify anomalies in pipeline long seams and more effectively manage the risk associated with cracks in long seam welds, has been added to the Baker Hughes pipeline service portfolio.
The company recently acquired the assets and circumferential/transverse field (TFI) MFL technology of Intratech Inline Inspection Services. With this technology, now to be produced in the larger diameter pipeline sizes, complete with speed control and inertial navigation capabilities, the Baker Hughes Process and Pipeline Services group is looking to assist operators with locating specific pipeline seam threats, such as hook cracks, lack of fusion and long narrow-axial corrosion.
Lightweight cable first
The new Huisman-supplied ‘super fly jib' on the BigLift Shipping heavylifter Happy Buccaneer made its operational debut recently. Teijin Aramid's lightweight Twaron fibre, said to be five times stronger than steel, was employed for the first time in the vessel's FibreMax cable stays to help extend the crane's lifting height and outreach by around 50%.
According to Teijin Aramid sales & marketing director Christoph Hahn, using Twaron in these cables – which have a rated minimum breaking strength of 920t – enabled the crane's radius to be increased to 55m and extended its lifting capacity to 350t at 35m outreach. He added: ‘This is the first time that an aramid fibre such as Twaron is used in a marine heavylift crane application that complies to the requirements of Lloyd's Register as specified in its Code of Lifting Appliances in a Marine Environment.'
BigLift project engineer Gem Wender commented: ‘The specifications and conditions of Twaron exemplify the suitability of these fibres for heavy lift applications. Because of the strength, flexibility and light weight of Twaron stay cables, we were able to significantly shorten and simplify the installation of the super fly jib on the Happy Buccaneer.'
Scanning at speed
Point cloud collection speeds of up to 30,000 points per second and a range of 150m can be achieved with Topcon Positioning Systems' new GLS-1500 laser scanner. When the unit's built-in 2.0 megapixel digital camera is connected to a PC and used with Topcon's ScanMaster software, a live video feed of the jobsite can be streamed to aid in scan setup and data acquisition. Also, it has an onboard data collector with a keypad and LCD display that allows use as a stand-alone laser scanner. Data collected can be stored onboard on an SD memory card or logged into a PC. A built-in wireless LAN connection allows control of the scanner on a PC from the inside of a vehicle.
Gulf Coast surveying, mapping and laser scanning specialist Dale Stockstill & Associates (DS&A) recently developed an as-built survey of a vessel's five-storey accommodation module and helipad using the predecessor to the GLS-1500, the Topcon GLS-1000.
The structure was scanned on all four sides and top and the ‘point clouds' registered in DS&A's ScanMaster software. The company also provided color maps of the bulkhead walls, which showed the amount of ‘hogging and sagging' in the bulkheads. The 3D model of a given section and the cloud were placed together in PolyWorks software. The color map DS&A presented to its client revealed a color-coded picture of the structure represented by different colors for each specified measurement range. This allowed the client to define the deviations to a structural engineering firm to analyze the as-built structure in a global structural analysis in order to certify the integrity of the accommodation module. It was critical for fabrication tolerances to be within tolerance due to the direct relationship to the results of the initial structural analysis.
Waimea piles guided home: A newly developed subsea pile-stabilising template has been successfully deployed for the first time in Brazil's Campos Basin. The StabFrame, jointly developed by Large Diameter Drilling (LDD ) and German underwater hammer specialist Menck, was brought into play for Wellstream International during installation of an FPSO mooring system for the OG X Petroleo e Gas Waimea field development in 140m of water. Steered via a work-class ROV, the StabFrame is designed to reliably stabilize a vertical pile in varying soil conditions. Rather than relying on a release mechanism attached to the pile, its hydraulic release mechanism allows the pile to be driven further into the seabed, if required, before opening the frame. In this way, the system can adjust to unpredictable and challenging seabed conditions, say its joint developers, both members of the Acteon Group. A t Waimea, where Menck was contracted by Wellstream to drive ten 84in mooring piles using an MHU 500T hydraulic hammer, the StabFrame is reported to have worked well despite strong currents estimated at times to be more than 3.5 knots. The project finished without incident or injury and ahead of schedule, reported Menck project manager Thorsten Sprunk. |
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