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Collaborating Authors
Sicily
Abstract Oil and gas offshore facilities are subject to time varying loads, which are mainly due to environmental conditions and secondly to operational conditions. The measurement of winds, waves, currents and the facility dynamic response to the time varying loads allow to estimate the fatigue damage that the facility has undergone since the beginning of its operational life. Monitoring of all these parameters allow to endorse the facility design inputs as well as to confirm or, better, extend the facility design life. If a monitoring system is not installed this activity is much more complex and can only rely on assumptions. In fact, the implementation of the environmental loads in the facility Finite Element model allows to identify the more stressed location of the facility. To this extent, the continuous monitoring of the meteo-marine parameters and the best estimate of the induced loads represents a remarkable tool that allows the asset Owner to plan the necessary maintenance activities, inspections and, ultimately, to predict the residual asset life. Meteo-marine monitoring systems can also be integrated with large scale model to provide local short term weather forecasts allowing a best estimate approach for the assessment of day-by-day operating windows. For unmanned installations, meteo-marine monitoring systems provide remote access to the local environmental condition and generate alarms when critical conditions occur. This paper presents the technology and the features of two meteo-marine monitoring systems designed and installed on the jetty and the offshore installations of a refinery (API Falconara) and on an offshore platform (Vega "A" – Sicily). Introduction In offshore engineering, the need to provide real-time monitoring for static/dynamic response of fixed & floating structures is nowadays becoming more and more important. Its benefits are:early detection of structural degradation and critical failures; calibration of meteo-marine and structural models to improve prediction performances and update design inputs; guarantee adequate operational HSE standards; optimization of inspection maintenance and repair plans based on asset real performance; assessment of life extension beyond the original design life.
ABSTRACT Dredging operations are an important source of sediment resuspension at sea. The finest fraction of the resuspended sediment is often transported by the local regime of currents, and the extension of the resulting plumes may affect large portions of sensitive marine environment and possibly induce its alteration. In this context, a specific modeling study has been conducted with a particular focus on the environmental impacts due to sediment dispersion during post-trenching operations for a submerged pipeline (sealine) offshore Sicily (Italy). The sealine has a length of about 70 km, and it crosses a very steep bathymetry, varying between 20m and 650m. The study is based on 3D modelling with an unstructured mesh approach. This allows coarse spatial resolution far from the dredging area and very high spatial resolution for the detailed representation of the sediment release, both in terms of magnitude and position, which can vary in time according to the planned schedule of dredging operations. The hydrodynamic component, which is the main forcing for the transport of fine material, has been modelled using realistic marine conditions as a combination of a local high resolution model and a general circulation model at basin scale, during several time windows possibly planned for the operations. As a result, the project showed how relevant suspended sediment concentrations (SSC) are confined to an area few hundred meters wide along the sealine, only involving the deepest layers of the water column. The deposition at seabed is negligible, in the order of millimeters, progressively decreasing with the distance from the sealine. The present study provides an example of realistic and physically based approach for the assessment of the effects of post-trenching operations at sea, thus providing quantitative answers to the requirements of the Environmental Authorities. INTRODUCTION Dredging operations are an important source of sediment in marine water. This happens, for example, during excavation works related to submerged pipeline trenching: the sediment released along the water column during the operations is advected and dispersed by the local regime of currents, and the resulting plume may affect large portions of sensitive marine environment and possibly induce its alteration.
ABSTRACT Rapid CUBE is a deepwater blowout intervention tool designed to capture the hydrocarbons in close proximity of the leak, minimizing environmental consequences of the spill for the time necessary to regain control of the well. The system does not require any interface with the wellhead or BOP and is applicable to the most subsea incident scenarios. The design process of Rapid CUBE took advantage of lessons learned from the history of major incidents, specifically addressing deepwater operations and the weaknesses showed by open systems, such as hydrate blockage and very high seawater intake. The operating principle is based on quick separation of liquid and gas phases of the blowout, with the liquid hydrocarbons pumped to surface and gas released subsea. Innovative solutions had to be devised to overcome a number of technical challenges, such as the control of the gas/liquid interface inside the separator. From an engineering point of view, logistic requirements were among major design drivers to allow the system to be air-freightable and shipped worldwide in a few days. The paper outlines the development of Rapid CUBE, from an innovative idea to industrial application. Rapid CUBE is now stored in its logistic base in Sicily. INTRODUCTION In the last seven years the Oil&Gas industry, offshore drilling sector in particular, had to cope with the heavy heritage of the Deepwater Horizon incident, as will probably be the case also for some years in the future. The number of studies analyzing the independent causes, the technical, human and organizational factors as well as their combination grew in time, pushed by government agencies, academic institutions or independent firms. Industry was very responsive and investigation of the lessons learned came in parallel with the development of technical solutions, which of course took step from the results of the exceptional effort put in place during the emergency. In time, the capping stack technology, which allowed to stop the leak at the Macondo site, has been optimized and evolved in a dedicated business sector, with both oil companies and third party service providers as players.
Corrosion Behavior of Al 6082 T6 Hard Anodized Aluminum Alloy Specimens in Deep-Sea Environment
Canepa, Elisa (Institute of Marine Sciences, National Research Council) | Stifanese, Roberto (Institute of Marine Sciences, National Research Council) | Traverso, Pierluigi (Institute of Marine Sciences, National Research Council)
Abstract Al 6082 T6 hard anodized aluminum alloy specimens were exposed in deep sea, at a depth of approximately 3,350 m, off the Capo Passero (Sicily, Italy) in the KM3NeT project framework. All specimens-as retrieved from the sea after 6, 12, and 18 months of exposure-showed visible corrosion products on the thin lateral faces and on the edges, while the tops and bottoms of the samples remained nearly uncorroded. This confined hard anodization failure was ascribed to surface inhomogeneity that determined a reduction of corrosion protection. Introduction The interest in resource exploitation of the deep sea is continuously increasing. Despite this, field studies about corrosion of materials in the deep-sea environment are quite uncommon in the available literature (Traverso and Canepa, 2014) due to technical challenges and experimental cost. To the authors' knowledge, solely Reinhart (1976) has exposed specimens of anodized aluminum alloys (Al 2024 T3, Al 2024 T81, Al 7002 T6) in the deep sea. This work shortly describes the results of the deep-sea immersion of Al 6082 T6 hard anodized aluminum alloy specimens in the frame of the Cubic Kilometre Neutrino Telescope (KM3NeT) project (; accessed March 23, 2016). Experimental Setup Specimens were exposed for 6, 12, and 18 months off the Capo Passero (Sicily, Italy), at the NEutrino Mediterranean Observatory (NEMO) site (Meccia et al., 2015), at a depth of approximately 3,350 m, at approximately 55 m from the sea bottom. They were installed on three specially designed cylindrical anodized aluminum cages deployed with the help of three mooring lines (experimental design is described in more detail in Traverso and Canepa (2014)). Chemical composition (in weight percentage) of the Al 6082 T6 alloy was 0.7%–1.3% Si, 0.50% Fe, 0.10% Cu, 0.40%– 1.0% Mn, 0.6%–1.2% Mg, 0.25% Cr, 0.20% Zn, 0.10% Ti, and the rest is Al. The size of the specimens was 100 mm x 100 mm, with 3 mm thickness. Specimens were sulfuric acid anodized after cutting and drilling (Type III, 50 .m nominal thickness).
Abstract Near the offshore production platform Vega A, the tanker FSO Leonis is moored to a steel column with circular section, 130 meters high and 10 meters in diameter, installed in 1988 in the Sicilian Channel, the connection is via a bridge structure with welded steel sections that make up the system SPM (Single Point Mooring). The structural system in steel box girders and column, with its cylindrical hinges, is subjected to the actions of the sea that induce cyclic stresses and fatigue. The paper presents the monitoring system of the structure connecting the ship to the column, installed in October 2009. The system is composed of fiber optic strain gauges sensors and biaxial inclinometers that detect rotations of the column and the bridge. The research concerns the method of collecting and interpreting statistical data, to determine the structural behavior under the action of the wind and sea. Through the processing/interpretation of the data it was possible to identify the dynamic response of the system SPM, count the number of fatigue cycles and conduct the structural verification in welded sections of the column and the hinge joints. The results allowed us to evaluate the conditions assumed in the project and made it possible to define a program of inspection and maintenance of steel structures. Introduction The VEGA field is located approximately 12 miles south of the southern coast of Sicily, off the coast of Pozzallo. It includes a platform called VEGA-A for the exploitation of the oil field and a 110,000 ton floating deposit obtained from the transformation of the former oil tanker Leonis in FSO (Floating - Storage - Offloading). The float is moored at SPM (single point mooring) located about 1.5 miles from the platform and connected to it via pipelines. In Fig. 1 the ship Leonis and the SPM (column and yoke) are shown. The SPM is constituted by a column that is bound to the seabed by means of a universal joint which allows rotations in two orthogonal vertical planes, and a reticular arm (Yoke) that is bound to the column via coupling triaxial joint allowing rotations around all three axes, and to the ship by two aligned cylindrical hinges.
- Asia > Middle East > Turkey (0.28)
- Europe > Italy > Sicily (0.24)
Clean Sea hybrid ROV/AUV for Asset Integrity Operations
Grasso, T. (Tecnomare SpA) | Bruni, F. (Tecnomare SpA) | Filippini, M. (Tecnomare SpA) | Gasparoni, F. (Tecnomare SpA) | Maddalena, D. (Tecnomare SpA) | Miozza, L. (Tecnomare SpA) | Cioffi, P. (ENI SpA) | Lainati, A. (ENI SpA) | Rimoldi, A. (ENI SpA) | Gentile, L. (Eni Med) | Di Fede., G. (Ionica Gas)
Abstract Clean Sea is an underwater robot developed by Eni and Tecnomare for Asset Integrity and Environmental Monitoring in oil & gas offshore plants. It is composed of a commercial hybrid ROV/AUV (Sabertooth DH by SAAB Underwater Systems) and a set of interchangeable payloads (e-pods by Tecnomare) that feature a common power& data interface for data logging and intelligent autonomous mission online reprogramming according to payload measurements or other external events. The innovative modular architecture, along with a comprehensive environment and asset integrity sensing system and the on-board intelligence, allow implementing very advanced capabilities. During summer 2015, Clean Sea was adopted for the execution of two pipeline network surveys (Sicily Channel and Ionian Sea) and the activities were carried out both in AUV and ROV mode. Technical results are very encouraging, fulfilling Company specifications and Authorities requirements, and proving to be comparable or better than those collected by classical ROV-based methods. Due to the dimensions and easy maneuverability of the system, light ships of opportunity have been used to support operations, resulting in significant cost reduction with respect to traditional methods. Introduction Clean Sea is an advanced robotic tool, based on an autonomous underwater vehicle and a set of specific payload assemblies providing services for asset integrity and environmental monitoring in Oil & gas subsea plants. One of the main characteristics of the system is its easy reconfigurability here intended as the capability to interchange the payload required by the specific mission with very quick operations. The addressable tasks are listed below:environmental monitoring tasks automatic water sampling detection and accurate localization of hydrocarbon leakages (from flowlines, SPS templates, etc.) seabed acoustic surveys visual inspection of pipelines, SPS, jackets cathodic protection surveys pipe tracking (buried and exposed) An extensive trials period has been carried out between 2013 and 2015 in environmentally different sites such as Lake Vattern (Sweden), offshore Hammerfest (Norway), Caspian Sea (Kazakhstan), Sicily Channel and Adriatic Sea (Italy), in which the capabilities of the system to execute the required operations have been demonstrated. Presently, Clean Sea is moving to fully operational deployment for the execution of many asset integrity tasks normally carried out by ROVbased systems. Main improvements, basically aiming at a consistent cost reduction of the operations, are related to:the reduced dimensions of the required support vessel, due to the relatively small dimensions of the Clean Sea system the required equipment onboard vessel for system management during operations, due to the available working modes (e.g. no TMS required) capability to easily address multiple tasks with one system instead of requiring specialized solutions for each task (e.g. acoustic surveys, pipeline monitoring…)
Clean Sea - Underwater Robotic Technology for Environmental and Asset Integrity Monitoring in Deep and Ultra-Deep Water
Gasparoni, Francesco (Tecnomare) | Aiello, Gennaro (Eni) | Lainati, Andrea (Eni) | Sechi, Armando (Eni Angola) | Maddalena, Danilo (Tecnomare) | Grasso, Tiberio (Tecnomare) | Bruni, Federico (Tecnomare) | Filippini, Michele (Tecnomare) | Miozza, Luigi (Tecnomare)
Abstract Clean Sea is an advanced robotic technology aimed at providing a cutting-edge and highly cost-effective solution to the increasing demand for both environmental and asset integrity monitoring in new and more challenging oil and gas developments, notably deep water and arctic areas. Clean Sea is built around a unique concept of hybrid, modular and low-logistics ROV/AUV, easily reconfigurable for several applications, including (but not limited to): environmental monitoring tasks automatic water sampling detection and accurate localization of hydrocarbon leakages (from flowlines, SPS templates, etc.) seabed acoustic surveys visual inspection of pipelines, SPS, jackets cathodic protection surveys pipe tracking (buried and exposed) This (patented) technology originates from a successful R&D project sponsored by eni and eni Norge and carried out by tecnomare between 2011 and 2013. Clean Sea technology was successfully proven over comprehensive trials carried out during 2014 and 2015 in environmentally different sites such as Lake Vattern (Sweden), offshore Hammerfest (Norway), Caspian Sea (Kazakhstan), Sicily Channel and Adriatic Sea (Italy). The successful trials have proven the viability of Clean Sea concept as well as the benefits that this technology will provide to the oil and gas industry in terms of operational flexibility, cost savings, asset integrity preservation, performances, safely operations in critical environments. Following the successful conclusion of the trials program, Clean Sea is currently transitioning to fully operational deployment, allowing the substitution of traditional ROV-based techniques and costly dedicated vessels. Moreover, the modularity of the system is fully exploited by continuous addition of new functionalities, in pursuit of the strategic evolution of the initial basic concept. The paper provides an overview of Clean Sea technology and advancements, and explains the basic concept of its operational capabilities. Examples of the most significant results achieved will be provided, including details on the on-going development program. Case studies for Clean Sea operation will also be presented and commented.
- Europe > Norway (0.69)
- North America > United States (0.47)
- Europe > Italy > Sicily (0.24)
ABSTRACT We have applied probabilistic inversion using a transdimensional hierarchical model to ocean-acoustic reflection measurements to recover shallow sediment structure including sound-velocity dispersion, frequency-dependent attenuation, and their uncertainties. Parameter and uncertainty inferences were obtained from Markov-chain simulations using the Metropolis-Hastings algorithm for transdimensional models where the number of sediment layers is unknown. Transdimensional algorithms often exhibit slow convergence that is greatly exacerbated by computationally intensive data predictions. Advances were made to improve the performance of Markov-chain simulation and data prediction. Chain-mixing across dimensions was addressed using a tempered sequence of interacting Markov chains, which substantially improves convergence rates. The acoustic recordings were processed to give seabed reflection coefficients as a function of frequency, grazing angle, and integration time (penetration depth). Such reflection-coefficient data cannot be generally described by plane-wave theory. Therefore, data were predicted using plane-wave decomposition and solving the Sommerfeld integral to compute spherical-wave reflection coefficients. This computationally intensive forward model was implemented massively in parallel using the compute unified device architecture on an inexpensive graphics processing unit, which substantially increases performance and allows transdimensional uncertainty estimation for complex layered seabeds. Velocity- and attenuation-frequency dependence were modeled using Buckingham’s viscous grain-shearing theory, which predicts frequency dependence similar to that of Biot’s theory at low frequencies but due to different physical causes. The algorithm was applied at two experiment sites off the coast of Sicily that exhibit different degrees of sediment complexity. The rigorous uncertainty estimation allows inferences that can distinguish between friction- and viscous-loss mechanisms in complex layered media. Results at both sites indicated dispersive sediments at some depths where the variability of velocity and attenuation as a function of frequency clearly exceeds the estimated uncertainties.
- North America > United States (0.28)
- Europe > Italy > Sicily (0.25)
- Reservoir Description and Dynamics > Reservoir Simulation > Evaluation of uncertainties (1.00)
- Reservoir Description and Dynamics > Reservoir Characterization > Seismic processing and interpretation (1.00)
- Reservoir Description and Dynamics > Formation Evaluation & Management (1.00)
- Data Science & Engineering Analytics > Information Management and Systems > Artificial intelligence (0.68)
- Information Technology > Artificial Intelligence > Machine Learning > Statistical Learning (0.95)
- Information Technology > Artificial Intelligence > Representation & Reasoning > Uncertainty > Bayesian Inference (0.93)
- Information Technology > Artificial Intelligence > Machine Learning > Learning Graphical Models > Directed Networks > Bayesian Learning (0.68)
ABSTRACT The structure of the existing offshore platform Vega A, operated by Edison in the Sicily Channel, has been subject to a reassessment process in order to extend its operating life beyond the original design life. Such requalification analysis has been focused on a fatigue verification of the jacket structure with the target of life extension, as well as other reassessment issues such as the actual status of structural components, present topside configuration, etc., all considerations aimed to eventually update a proper inspection and maintenance plan, everything considered as normal practice in the offshore field where the number of existing platforms subject to reassessment process due to expiration of the original design life is increasing. What is peculiar in this case is the availability of a large amount of significant information recorded during the occurred service life of the platform by the monitoring system mounted on the structure since early phases of installation, which has definitively increased the level of reliability in the new structural assessment. In particular, it has been possible to re-evaluate the platform's response to environmental loads (the governing loading for structural safety) whose characterization has been reviewed and updated according to a large amount of wave, wind and current data measured on site for a long term and, what is more, to calibrate the calculated dynamic response, which is the basis for the fatigue assessment, with respect to the actual jacket accelerations continuously recorded on field by relevant monitoring devices. In the following the different steps of the reassessment process carried out through the calibrated structural response are described, by highlighting how the monitoring effort, along with a proper maintenance, has facilitated the achievement of the goal of life extension.
Influence of the Heterogeneity of the Seismic Source On the Timely Detectability of a Tsunami: Implications For Tsunami Early Warning In the Central Mediterranean
Tinti, Stefano (Department of Physics, University of Bologna) | Armigliato, Alberto (Department of Physics, University of Bologna) | Pagnoni, Gianluca (Department of Physics, University of Bologna) | Zaniboni, Filippo (Department of Physics, University of Bologna)
ABSTRACT: This paper investigates two different scenarios of earthquake-generated tsunamis in the central Mediterranean. In particular, the studied tsunamis are generated along the Hyblean-Malta escarpment by two faults being identical in geometry and focal mechanism but having different slip distributions. Synthetic tide gauge records are computed along the coasts placed in the near-field (eastern Sicily) and in the far-field (western Greece). INTRODUCTION One of the main characteristics shared by the great tsunamigenic earthquakes occurred over the world consists in the highly heterogeneous distribution of the slip on the fault. Limiting our attention to the last decade, this characteristic has been recognized clearly for the Sumatra 2004, Chile 2010, and Japan 2011 earthquakes. In terms of tsunami impact, the parent fault slip heterogeneity can translate into a high variability of run-up and inundation on the near-field coasts. Opposite to the determination of the earthquake location and magnitude, that can be achieved within 3–4 minutes after the earthquake, though with accuracy increasing with time, calculating the details of the slip distribution requires time intervals that are typically much larger than the time needed by the tsunami waves to attack the coasts closest to the source. This poses an urgent and challenging problem in the Tsunami Early Warning (TEW) perspective, especially for basins such as the Mediterranean Sea, where the tsunamigenic sources are placed close to the shore and hence the time to detect and characterize the parent event and to issue the relevant warning is extremely limited. We tackle the problem by discussing a couple of numerical tsunami scenarios in the central Mediterranean involving different slip distribution on the parent fault, and by showing how a proper marine sensors coverage both along the coasts and offshore can help posing constraints on the characteristics of the source in near-real time.