TechnipFMC (Norway)

Abstract The perforated polymer-lined pipeline (PLP) is a rigid carbon steel pipeline with internal polymer liner for internal corrosion prevention. The liner is perforated to prevent liner collapse during depressurization. Although the perforations expose the carbon steel to the corrosion fluids within the bore of the pipeline, extensive small-scale and full-scale tests have demonstrated that corrosion at the bottom of each perforation is much less than the corrosion in an un-lined carbon steel pipeline. Based on experience gained on the evaluation and modelling of corrosion in the highly confined environments of flexible pipelines, we have developed a corrosion model to simulate carbon steel corrosion rates corresponding to the perforated PLP system geometry. Predictions from this model could help evaluate corrosion risks at and within perforated liner / steel interfaces. This paper presents an overview of the model and compares its predictions against a variety of experimental data that reproduce the conditions, the geometry, or both, found at the bottom of a PLP perforation. This 1D model considers diffusion and chemical reactions inside an inert hole and incorporates non-ideal thermodynamics (i.e., gas fugacity effects) to describe the aqueous solution chemistry. Electrochemical corrosion equations are compared with experimental data to support validation. This model could serve as a useful tool that complements qualification testing and help validate the PLP technology for a variety of field applications.

Carbon capture and storage (CCS) is necessary to achieve the long-term temperature goals of the Paris Agreement. The mass of CO₂ that will be transported for permanent storage by 2050, to meet the International Energy Agency (IEA)'s Sustainable Development Scenario, is of a similar scale to the current global market of natural gas. Such trading levels require significant and expedited technological efforts. The urgency of the climate goals requires technological innovations to build from existing technologies operating in similar environments. The present work aims to be a stepping stone towards the realisation of the CCS business, which relies on accurate metrology and tight control systems. Here, various established technologies are screened, and for each principle, their possible niches of operation within CCS are identified. Eight technologies were shortlisted and assessed against selected benchmarking criteria. The most promising solutions for the various operative scenarios encompassing bulk flow measurement, structural flow identification, composition, and leak detection are described. All surveyed technologies require further experimental verification for one or more of the operating schemes throughout the CCS value chain. A roadmap to further explore the applicability of various measurement principles in CCS is also provided.

Abstract The objective of this research and development program is to qualify for 3000 mWD the chemical injection pump, one of the main key components of the subsea chemical storage and injection station (SCS&I). The development of the SCS&I system responds to the need to develop oil and gas reservoirs at deeper water depths and further distances from host or from shore and to reduce CAPEX and GHG released associated. Indeed, one of the high CAPEX of a subsea project and a weak point during operation is the umbilical chemical lines. Storing the chemicals close to the wells will reduce the umbilical cross section and cost and avoid plugging of those lines. The development of the SCS&I is an enabler for "all electrical" simplified architecture, reducing both costs and GHG emissions. This qualification is a first for a high dosage chemical pump under subsea environmental conditions. The HAMPRO® 70V injection pump from Hammelmann was selected as the most promising pump for marinization and qualification for 3000 mWD. Its big advantage is that the contact between the oil used for lubrication and cooling of the pump and motor is separated from the chemical pumped fluid by sealed bellows. The other advantage is that its duty allows the injection of high rate, batch injected chemical products like methanol, and at the same time its design allows reducing the piston diameters and stroke giving the flexibility to inject low dosage chemical products. The pump has been modified for its marinization. For installation subsea, it is capital to ensure its robustness regarding the high external pressure and discharge pressure, but also reliability of the chemically exposed parts, the pump and motor rotating parts and the impact of lubricant performance, the reliability of the electrical components and finally the impact of transient behaviors on the pressure compensation system. To assure all these aspects, a complete R&D qualification program has been launched. This program includes short term batch operation with high flow rate and high differential pressure, long term continuous operation with low or high differential pressure and finally, transient operation with large variation in differential pressure but also different strokes imposed to the pump. The program is to be completed with a hyperbaric performance test and specific endurance tests performed to ensure the bellows robustness. For endurance testing, the pumps have already been running for more than 2000 hours. This paper will describe the main findings and support the qualification required for subsea use.

Abstract Flexible pipelines are often subjected to cover requirements on the seabed due to protection or stability issues. These requirements may be satisfied using a range of techniques, e.g. covering the pipe with rocks or soil. Due to pressure and thermal expansion in operation the pipe may be susceptible to lateral or upheaval buckling (UHB) out of the cover which may violate the cover requirements and could ultimately be detrimental to the flexible pipe. The present paper is concerned with the design of reliable and cost-efficient cover solutions for unbonded flexible pipes. A new DNV guideline will introduce “Allowing Irreversible Displacement” design approach which allow for the pipe to move within the cover provided that the end-of-life limit states for pipe and cover are satisfied. The paper includes a description of how a model following that approach may be defined, including considerations on load case matrix and a discussion on relevant sensitivity cases to ensure conservatism in the cover design. A case study is included to show how the principles of the guideline may be applied in UHB design.

Identifying relationships between entities in data is a central topic across various industries and businesses, from social networks to supply chain and heavy manufacturing industries. In this paper we present data from a database of machinery represented in terms of machine parts. The machine parts are originally organised in tree structures where the vertices are machine part types, and the edges are “part-of” relations. Hence, each tree represents a type of machinery broken down into its machine part constituent types. The data we present is the union over these trees, making up a directed acyclic graph describing the type hierarchy of the machine parts.The motivation for publishing the dataset is the following real-world industry problem: Each tree represents a mechanical design, and over time some designs have been copy-pasted with minor modifications. The new instances have been given new identifiers with no reference to where from they were copied. In hindsight, it is desirable to recover the copy-paste links to for interchange between essentially identical designs. However, telling which parts are copies of which other parts has turned out to be difficult. In particular, the metadata has a tendency of displaying higher similarities within a composite part than between a part and its copy. Due to non-disclosure, we cannot provide the metadata, but we provide element wise dissimilarities that are generated based on the metadata using classical methods such as Jaccard similarity on description texts, material types etc. The dissimilarities are obtained from a data science project in the company owning the data, trying to tackle the very problem of recovering the copy-paste links.Availability of labeled data on this data set is limited, so based on our in-depth knowledge of the problem domain, we present a data synthesisation method that can generate arbitrarily large problem instances of the copy-paste problem based on the sample data, that provides a realistic representation of the real world problem. The problems are presented as planted partitions of vertices of directed acyclic graphs with vertex dissimilarities, and thus constitutes a typical classification problem along the lines of graph- or network clustering.The type of industry data we present is usually company confidential, bound by intellectual property rights, and generally not available to scientists. We therefore publish this anonymised dataset to offer real world sample data and generated problem instances for researchers that are interested in this type of classification problems, and on which theories and algorithms can be tested.The data and the problem generation methodology are backed by a Python implementation, providing both data access and an API for parameterised problem generation. The data is also available as raw files.

Abstract The assessment of the risk arising from multiphase flow induced vibrations in subsea production systems is strongly affected by the accuracy of data and modelling for the production conditions, flow induced loading and estimate of the damping of the structure, both structural and flow induced. These uncertainties in the flow conditions and fluid structure interaction analyses are further compounded by uncertainties in the capacity of the structure to withstand vibration and fatigue damage. As most calculation codes rely on deterministic analysis, these uncertainties are often addressed by their characteristic input and through safety factors, which are intended to ensure sufficient safety level. Subjective judgements, with unknown degree of conservatism, may be difficult to avoid. A need to address the associated uncertainties and provide a prediction of the accumulated probability of fatigue failure, using a consistent and sound methodology, has been expressed throughout the industry. Structural Reliability Analysis (SRA) offers a framework to take into account, based on the same modelling basis as the deterministic approach, the uncertainties in all relevant parameters. Moreover, the framework allows for simultaneous consideration of these identified uncertainties when modelled by probability distributions and enables calculation of the probability of fatigue failure. This article describes a general approach to implement reliability principles in the analysis of multiphase flow induced vibrations, discusses the use of the methodology, both in design and in operations. It also concludes on the feasibility of using Bayesian analysis, based on the results of subsea inspection, to update the probability assessment and provide updated input to the risk evaluations for future operations. The methodology may also be used to determine operational limitations for future production.

Abstract Computational Fluid Dynamics (CFD) simulations are used to predict the flow-induced forcing in high-pressure multiphase pipe flow. Furthermore, empirical correlations from the literature is compared and validated against computational and experimental results. Based on the CFD results and in conjunction with the reference 6” (internal diameter (ID)) data, new scaling rules are proposed.

Abstract In this paper, the authors present an alternative methodology to improve (or at least to reduce) the uncertainty level within the prediction of the life time of subsea structures. The focus is made on rigid spool & jumper (or any piping system) prone to internal intermittent multiphase flow (currently named slug flow) and any potential Flow-Induced Vibrations (FIV) phenomenon. As it will be more exhaustively detailed here below, the proposed modelling aims at recovering at the best both (i) the multiphase flow kinematics (i.e. both gas pocket & liquid slug) to be expected in the flow loop and (ii) the resulting loads seen by the structure. The considered multiphase flow solver is based on the well-known Unit Cell Model (UCM, refer to Nicklin et al. (1962), Wallis (1969)) and coupled with usual commercial Finite Element (FE) solvers to recover the expected vibratory levels within the mechanical system. With rigorous purpose, a step-by-step validation process is presented within this paper to progressively validate the different step changes in regard to the current Best Practices (as e.g. reminded by Payne (2015) or Ancian (2016)). Both Computational Fluid Dynamics (CFD) model and experimental database, as extracted from the literature, have been considered to assess the ability of the proposed methodology to recover the expected multiphase flow kinematics and the loads induced by a Taylor bubble flowing within a rigid spool. Once validated, the multiphase flow solver has been coupled to a Finite Element (FE) model to properly assess the Flow-Induced Vibrations (FIV) of the spool resulting from such intermittent slugging solicitations. As here below underlined, the presented comparisons with the Industry Standards suggest (i) the need to challenge the recommended practices to ensure safe and reliable design and (ii) to properly manage the safety Design Fatigue Factor (DFF) to be considered within engineering phases.