In a pioneering effort to optimize subsea infrastructure design and installation, Saipem launched an R&D program [Ref. 1] to produce a Wire Arc Additive Manufacturing (WAAM) Tee Branch (TB) component with an integrated substrate and a novel square base design. This project, developed in cooperation with Vallourec, aimed to investigate the feasibility and advantages of using WAAM technology to create complex subsea components that meet stringent industry standards. The methodology involved printing the TB component at manufacturer's facility, followed by comprehensive characterization at its own R&D center in France. Adhering to the DNV-ST-B203 guidelines, the component was qualified to meet contractor's specific requirements. The base pipe, a seamless pipe, was prepared and used as a substrate for WAAM deposition. Post-printing, the component underwent precise machining to facilitate non-destructive testing (NDT) inspections, including Liquid Penetrant Inspection (LPI) and Ultrasonic Testing (UT). The innovative square base design allowed for thorough inspection of the interface between the base pipe and the WAAM addon ensuring the detection of any potential defects. The NDT results were crucial in confirming the integrity of the component. An accurate inspection could be performed thanks to the square base design and shown no defect. Following NDT, a series of destructive tests were conducted in both the WAAM region and at the interface between the base pipe and the WAAM material. These tests included chemical analysis, tensile testing, hardness measurement, Charpy impact testing, macro and microstructural analysis, porosity rate assessment and bend testing. The results were promising, demonstrating that the TB component globally fulfilled contractor's specifications. The innovative square base design facilitated comprehensive NDT inspection and could contribute to the overall structural integrity of the component. Destructive testing revealed interesting mechanical properties, confirming the robustness and reliability of the WAAM-produced TB. This project provides significant insights into the application of WAAM technology for subsea infrastructure, showcasing its potential to improve the manufacturing of complex components. The successful integration of the substrate with the WAAM underlines the feasibility and advantages of the WAAM, such as the complexity of the geometry and the cost/benefit advantage coming from the optimization of the size and weight of the produced component. From a contractor point of view, the initiative represented a first step toward the industrialization of the innovative manufacturing process for subsea applications.
The primary objective of this paper is to describe the process adopted by a third-party to validate the methodology proposed by an Offshore Contractor for assessing the performance of materials of offshore pipelines intended for gaseous hydrogen transportation, with a specific focus on hydrogen embrittlement. Indeed, while offshore natural gas pipelines are a well-established technology, the unique challenges posed by hydrogen service need to be addressed through a formal Technology Qualification (TQ) process. The validation process involves two subsequent phases: (1) Approval In Principle (AIP) and (2) Technology Qualification (TQ). The main objective of AIP phase is to assess the methodology before its application to a real project. The proposed approach consists of two tasks: Performing a dedicated material testing campaign according to a protocol specifically designed for offshore hydrogen pipelines. Executing an Engineering Critical Assessment (ECA) considering the outcomes from the testing campaign and typical applied loads for an offshore pipeline. Afterwards, the application of the methodology to a real project / case study is reviewed to verify its adequacy and soundness. The work describes the results of the two key phases of the technology qualification process. The initial AIP phase assessed the adequacy of the proposed testing protocol and the ECA methodology before their application to a real project. In the subsequent TQ phase, the case study presented by Offshore Contractor has been thoroughly reviewed to verify its compliance with the methodology stated in AIP stage and the soundness of any technical assumption and calculation detail not previously explicitly stated. The selected case study has been developed to demonstrate the proper and conservative design for an offshore pipeline destined to hydrogen service. The ECA study is based on fracture mechanics principles and take advantage of the laboratory testing campaign conducted as per the Contractor protocol, which provides quantitative information about the material properties in the hydrogen environment. The third-party review concludes that the proposed methodology is suitable for assessing materials of offshore pipelines for hydrogen transportation and verified Contractor's compliance and proficiency in applying the methodology issuing a final Technology Qualification Statement. The Approval in Principle and Technology Qualification paves the way for large-scale deployment of Saipem's protocol for qualifying the performance of materials used in the construction of subsea pipelines transporting hydrogen, a key solution for the energy transition.
SPRINGS® (Subsea PRocessing and INjection Gear for Seawater) is a technology for subsea water treatment and injection. The technology aims to unlock new tiebacks in deep water that previously would be unviable due to congested topside and/or long step-out. The subsea station can be connected to the topside with only a power and control cable, thanks to the following features: The control system does not require control fluid since all subsea valves are actuated electrically.The large subsea pumps do not require any barrier fluidRegular membrane disinfection is performed by a chemical, which can be stored directly subsea The scope of this paper is to describe the technology and illustrate the steps of the significant collaborative work performed by the technology partners to achieve the completion of the process qualification and industrialization. The qualification roadmap, which has been recently completed, not only progressively derisked the technology, but also offered design and operational insights to improve and optimize the original concept, conceived in 2009 specifically to address deepwater tiebacks applications. The process was fully qualified both with laboratory hyperbaric tests on membranes, conducted in 2010 and with an offshore deepwater campaign in 2014. Further process optimizations and improvements have been obtained in the subsequent years thanks to an onshore pilot, using raw water from a nearby basin, run in parallel with the industrialization of the subsea system components. The industrialization, started in 2016, has been successfully completed in 2024 with the qualification to API 17Q TRL 4 or greater of all the building blocks necessary to operate the system in an all-electric mode. The typical application scenarios for subsea water desulphatation are both greenfields (long, deep tiebacks to new/existing Topside), satellites and brownfields (debottlenecking of the existing facilities). The paper presents the results of the technical-economical evaluations conducted considering the deployment of the subsea seawater treatment and the related benefits and challenges. The outcomes of the qualification activities, including tests of equipment, and optimization of design and process parameters, show that the challenges posed by the subsea environment have been tackled and lessons learned are available for a project deployment. The paper presents the updated evaluations for the technology application, the latest outcomes of the industrialization program and the process optimization results from the onshore pilot that has been running over the last 5 years.
The objective of this paper is to demonstrate the successful qualification of a 3.0MW canned motor pump for subsea seawater applications via wet-pit testing. The canned motor topology ensures high reliability by eliminating the need for a barrier fluid system and mechanical seal. This topology uses the process fluid as the lone lubricant and cooling media in the motor resulting in an all-electric seabed barrier fluid-less pumping system for the subsea injection of treated seawater into a reservoir. To qualify canned motor technology for deployment subsea, a full-scale, 3.0MW canned motor water injection pump was tested in a wet-pit to demonstrate a Technology Readiness Level (TRL) of 4 per API 17Q. Pump performance was characterized across the entire operating speed range with a suite of instrumentation, recording parameters including flow, differential pressure, casing and rotor vibration, winding temperatures, and electrical parameters. The test program encompassed operation across a wide spectrum of envisioned conditions including over-speed conditions, cyclic testing, emergency shutdown conditions, and endurance testing at full load. Qualification was achieved via evaluation of the test results and post-test inspection of key components, including bearings. Canned motor pumps have a demonstrated track record for more than 50 years in various critical applications. This development and qualification program demonstrates how this technology has been adapted to serve as a subsea barrier fluid-less motor-pump system and its potential to optimize field economics through an all-electric power distribution system. The paper will demonstrate qualification unit performance and reliability under simulated operating conditions and transients. Presented data will show performance meets predictions, how the unit showed no observed change over time during replicated lifetime of service cycles, and endurance testing results. Inspection results, to be shared, showed all major components in good working conditions and that the bearings demonstrated no indications of rubbing or contact. These results support qualification to a Technology Readiness Level (TRL) of 4 per API 17Q, which has been endorsed by several end users who followed testing and reviewed the data. The implementation of a canned motor pump to this subsea application results in a non-conventional, barrier fluid-less pumping system creates the potential to optimize field economics. Elimination of the mechanical seal and barrier fluid increases reliability and prevents process water contamination. This topology also enables economic saving through removing the need for topside hydraulic power units (HPU), hydraulic lines in an umbilical, and enabling an all-electric subsea architecture including permitting longer step-outs. The canned motor topology is scalable and flexible, with demonstrated reliable operation in topside applications up to 5.5 MW, and utilized in pumping applications with multiphase fluids and highly abrasive solids.
In 2023 the world first resident underwater intervention drone (UID) had been operational for more than 5 months continuously, unlocking a revolutionary "vessel-free" way of conducting inspections and light intervention. A year later, the same drone is continuing its pioneering experience, introducing novel features and advanced capabilities. A comprehensive description of offshore operations and technological lesson learnt will be shared within this paper. Further to the first long-term resident campaign (see Cavallini, 2024, for details), the UID has been maintained and prepared for the second offshore campaign, in which the drone has been called to demonstrate not only the subsea resident capabilities, but also its ability to expand the range of tasks to be carried out while working at depth on a producing field. In this regard, the collaborative one-team approach between Equinor and Saipem has allowed the introduction and execution of novel tasks, gradually increasing the complexity and the intensity of the UID daily activities, in a series of industry first. The ambition of this paper is to share with the subsea energy community the remarkable operational results achieved by the UID while performing inspections and light intervention tasks at the Njord field, offshore Norway. By doing so, the authors will describe how daily activities are controlled from the onshore control station and executed in a full vessel-free configuration. This unique operational condition allows to constantly save not only costs but also fuel with associated emissions when compared to conventional vessel-based solution. Furthermore, a quantification of these savings will be provided together with concrete examples of how autonomous missions are compiled and executed by the drone, thus allowing the "hands-off" mode for the drone operators controlling and supervising the operations from remote. The Hydrone-R ongoing project is a unique example of how the implementation of novel technology can contribute to the future of offshore energy production and transportation: derisking offshore operations while allowing constant presence at the field for immediate intervention or troubleshooting are paramount objectives when considering the criticality of implementing sustainable ways to safely produce essential energy resources.
