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Results
Features of Modeling the Load from Hummocks in the Ice Basin
Bekker, Alexander T. (Far East Federal University, Vladivostok) | Anokhin, Pavel V. (Far East Federal University, Vladivostok) | Sabodash, Olga A. (Far East Federal University, Vladivostok) | Nechiporenko, Grigoriy Yu. (Far East Federal University, Vladivostok) | Kornishin, Konstantin A. (Arctic Research Centre, Moscow) | Efimov, Yaroslav O. (Arctic Research Centre, Moscow) | Tarasov, Petr A. (Arctic Research Centre, Moscow) | Demidov, Valentin A. (Arctic LNG 2)
_ This article deals with the modeling of the impact in the ice basin on offshore oil and gas structures (OOGS) from the hummock, the field data of which were studied during Arctic expeditions in the Khatanga Bay of the Laptev Sea. The ice basin is located in the ice laboratory at the Far Eastern Federal University (FEFU) in Vladivostok. The room is equipped with a modernized freezer, which allows one to maintain a given temperature regime quickly and in a wide range to control the mode of freezing ice. The ice basin allows for the modeling of hummocks on an acceptable scale. A rectangular steel indenter was used as a model of the structure. Models of hummocks were made according to a specially developed technology. The methodology for conducting model tests in the ice basin included the manufacture of hummock models, testing by introducing an indenter into the body of a hummock model with a given speed, registration of the required parameters of the experiment (contact force, speed of movement of the indenter, geometric dimensions of the hummock model, and physical and mechanical properties of the ice formation model), and photo and video fixation of the process of interaction of the indenter with the model hummock above and below water. A total of eight experiments were conducted. The study was carried out in compliance with the similarity criteria—geometric, kinematic, and dynamic—to recalculate the results from model tests to full-scale values. The results obtained can be used in the analysis of the processes of ice load formation at the OOGS on the shelf of freezing seas.
- Europe (1.00)
- North America > United States > California (0.46)
- Asia > Russia > Far Eastern Federal District > Primorsky Krai > Vladivostok (0.24)
- Research Report > New Finding (0.66)
- Research Report > Experimental Study (0.48)
The solid crust is the outermost and thinnest layer of our planet. The crust averages 25 miles (40 kilometers) in thickness and is divided in to fifteen major tectonic plates that are rigid in the center and have geologic activity at the boundaries, such as earthquakes and volcanism. The most abundant elements in the Earth's crust include (listed here by weight percent) oxygen, silicon, aluminum, iron, and calcium. These elements combine to form the most abundant minerals in the Earth's crust, members of the silicate family – plagioclase and alkali feldspars, quartz, pyroxenes, amphiboles, micas, and clay minerals. All three rock types (igneous, sedimentary, and metamorphic) can be found in Earth's crust.
- Geology > Mineral > Silicate (1.00)
- Geology > Structural Geology > Tectonics > Plate Tectonics > Earthquake (0.59)
- Information Technology > Knowledge Management (0.40)
- Information Technology > Communications > Collaboration (0.40)
Summary Accurately estimating the failure probability is crucial in designing civil infrastructure systems, such as floating offshore platforms for oil and gas processing/production, to ensure their safe operation throughout their service periods. However, as a system becomes complex, the evaluation of a limit state function may involve the use of an external computer solver, resulting in a significant computational burden to perform Monte Carlo simulations (MCS). Moreover, the high-dimensionality of the limit state function may limit efficient sampling of input variables due to the “curse of dimensionality.” To address these issues, an efficient machine learning framework is proposed, combining polynomial chaos expansion (PCE) and active subspace. This will enable the accurate and efficient evaluation of the failure probability of an offshore structure, which typically involves a large number of uncertain parameters. Unlike conventional PCE schemes that use the original random variable space or the auxiliary variable space for building a surrogate model, the proposed method utilizes a reduced-dimension space to circumvent the “curse of dimensionality.” An appropriate coordinate transformation is first sought so that most of the variability of a limit state function can be accounted for. Next, a PCE surrogate limit state function is constructed on the derived low-dimensional “active subspace.” The Gram-Schmidt orthogonalization process is used for making basis polynomial functions, which is particularly effective when input random parameters do not follow the Askey scheme and/or when a dependence structure between the input parameters exists. Therefore, a nonlinear iso-probabilistic transformation, which makes the convergence of a surrogate to the true model difficult, is not required, unlike traditional PCE. Numerical examples, including limit state functions related to structural dynamics problems, are presented to illustrate the advantages of the proposed method in estimating failure probabilities for complex structural systems. Specifically, the method exhibits significantly improved efficiency in estimating the failure probability of an offshore floating structure without compromising accuracy as compared to traditional PCE and MCS.
- Data Science & Engineering Analytics > Information Management and Systems > Artificial intelligence (0.70)
- Facilities Design, Construction and Operation > Offshore Facilities and Subsea Systems > Floating production systems (0.61)
- Facilities Design, Construction and Operation > Facilities and Construction Project Management > Offshore projects planning and execution (0.61)
BM-C-33 Project Large Diameter Pipeline Direct Tie-In PLEM in Ultra-Deep Water
Strandbakken, T. (IKM Ocean Design AS, Norway) | Nystrøm, P. R. (IKM Ocean Design AS, Norway) | Gilbu, E. J. (IKM Ocean Design AS, Norway) | Fosse, A. (Equinor ASA, Norway) | Valeriano, I. A. (Equinor Brasil) | Fridriksdottir, V. (IKM Ocean Design AS, Norway)
Abstract The BM-C-33 field is located in Campos Basin 200 km offshore of the Rio de Janeiro state in Brasil. The field development will comprise an offshore development and an onshore development with a gas export pipeline connecting the two installations. The development concept includes subsea installations tied back to a Floating Production Storage and Offloading (FPSO) unit for crude storage and offloading to shuttle tankers. Gas will be exported to shore via Gas Export Pipeline (GEP). The water depth at the field is nearly 3 000 m, making the field one of the deepest developments in the world. Pipeline tie-in architecture at such water depth is pushing the boundaries of current design codes, component design and installation vessel capacity. There is a need to ensure that the design limits the installation loads and ensures an installation friendly design. As a consequence, the BM-C-33 project has explored a design for a direct tie-in Pipeline End Manifold (PLEM) for the GEP system at the deep-water end. This paper discusses the PLEM and tie-in architecture proposed for the connection of two 10.5″ ID Steel Catenary Risers (SCR) and the 22″ ND GEP in 2 735 m water depth. In addition, this paper discusses the background and processes leading to the selected concept.
Ultimate Strength Reliability Analysis Applied to the Design of Cement Sheaths in Oil Wells
Estrela, Gabriela Alves (LACEO/COPPE/UFRJ) | de Sousa, Fernando Jorge Mendes (LACEO/COPPE/UFRJ) | Lopes, Guilherme Kronemberger (LACEO/COPPE/UFRJ) | Gonzaga e Silva, Ana Beatriz de Carvalho (NUMATS/COPPE/UFRJ) | de Andrade, Henrique Conde Carvalho (NUMATS/COPPE/UFRJ) | Rocha, José Marcelo Silva (PETROBRAS) | Moreira, Rafael Peralta Muniz (PETROBRAS) | da Silva, Ingrid Ezechiello (PETROBRAS)
Abstract In offshore wells, cement sheaths are responsible for isolating the casing from the formation, protecting the latter from corrosion, and preventing fluid migrations that can cause severe blowouts in extreme situations. The most usual methodology applied in the structural evaluation of cement sheaths is deterministic, where characteristic values are employed to model material properties and loads. At the end of the analysis, stresses (or any other derived parameter) are compared to allowable limits. Although this design methodology is relatively simple, it doesn't consider uncertainties regarding material properties and loading conditions. Moreover, no information is provided concerning how far the structure is from failure. These issues can only be addressed using a statistical approach. In this way, this work aims to propose a reliability-based methodology to be applied to the design of cement sheaths. Using the FORM method and a structural analysis computer program (TENCIM-1D – Toledo Filho et al. 2020), failure probabilities can be easily accessed with low computational costs. These values can then be compared to target failure probabilities specified in offshore standards. In addition, the FORM method can also improve the design quality, as one of its subproducts – the derived importance factors – may help to identify the properties and parameters that most contribute to the obtained failure probabilities. Therefore, these properties and parameters are the ones that need to be better described statistically, either through experiments to survey physical properties or through field measurements. The obtained results indicate the feasibility of the proposed methodology and the need to develop studies to determine the probability distributions, mean values and standard deviations of some physical properties and loads.
- South America > Brazil (0.70)
- North America > United States > Texas (0.46)
An Innovative Modular Approach for Design, Fabrication and Installation of Offshore Wind Farms Fixed Foundations in Midwater Depths
Stefano, Giorgio (Saipem S.p.A.) | Castelnuovo, Luca (Saipem S.p.A.) | Monti, Paolo (Saipem S.p.A.) | Del Balzo, Matteo (Saipem S.p.A.) | Piazzi, Luca (Saipem S.p.A.) | Mischel, Antoine (Saipem S.A.)
Abstract Offshore windfarms are moving towards deeper and deeper locations to exploit stronger and more constant winds and decrease their visual impact. New emerging floating concepts are promising to cover future windfarms lying in very deep locations but in the next decade there will be also a consistent portion of wind farm fields in midwaters, i.e., between 50m and 100m water depth, likely to be built on fixed foundations. One of the main issues of fixed foundation is that construction and installation costs dramatically rise as water depth increases. Moreover, the introduction of new powerful wind turbines will require stronger and heavier foundations able to bear environmental and operative loading throughout the overall plant lifetime. Innovative and cost-effective new concepts are then required to reduce overall LCOE of future offshore wind farms and meet future market expectations. A modular approach, consisting of splitting the fixed foundation in two or more parts, is presented in this paper. Such approach has been already used in the past in the traditional Oil & Gas business to overcome feasibility issues in mid to deep waters and, once applied in renewable energies market scenario, looks to be very promising by improving the design and fabrication flexibility as well as widening the fleet of the vessels with the lifting and handling capacity required for their installation.
Applications of the Structure from Motion Photogrammetric Technique to Solve Geotechnical Problems at Different Scales
García-Luna, Ramiro (E.T.S.I. de Caminos, Canales y Puertos, Universidad Politécnica de Madrid, Spain) | Senent, Salvador (E.T.S.I. de Caminos, Canales y Puertos, Universidad Politécnica de Madrid, Spain) | Jimenez, Rafael (E.T.S.I. de Caminos, Canales y Puertos, Universidad Politécnica de Madrid, Spain)
ABSTRACT: The Structure from Motion (SfM) photogrammetric technique has been widely used, due to its ease of use and low cost, as an excellent alternative for remote 3D rock mass characterization. This technique uses only the information obtained from the digital images acquired with a regular camera to generate very high-resolution 3D models. However, this technique is widely influenced by environmental and physical conditions (degree of luminosity, distance to the target, geometry, etc.) of each case. In this work, we present our previous experiences, from a micro-scale application (in the laboratory) for small-scale roughness analysis, to a large-scale application (in the field) for the characterization of long slopes using drones. For each application, different methodologies have been proposed, adapting the SfM technique and developing innovative solutions. The obtained results confirm the applicability of SfM to efficiently solve rock engineering problems at different scales and under different conditions. INTRODUCTION The multi-scale characterization of rock masses –from intact rock to rock joints, to rock masses– is important in rock mechanics and rock engineering, and several methods have been proposed for such task, such as the suggested by ISRM Commission on Standardization of Laboratory and Field Tests (1978). More recently, efficiency and safety reasons have promoted more advanced characterization technologies –such as photogrammetry or LiDAR– to obtain 3D models of rock joints or rock masses, which can be employed as a basis for engineering characterization of rock joints and rock masses and, hence, to solve rock engineering problems at different scales. This article explores the use of the Structure from Motion (SfM) technology to that end, and it presents recent examples of SfM application to (i) characterize rock joint roughness at the laboratory scale; to (ii) characterize roughness at field scale to solve rock slope stability problems; and (iii) to characterize rock slopes at a larger scale, and to estimate their associated risks.
- Research Report > New Finding (0.35)
- Research Report > Experimental Study (0.35)
Develop a Fast Analysis Solver for Welding Sequence Optimization
Yang, Yu-Ping (Huntington Ingalls Industries – Ingalls Shipbuilding ) | Scholler, Steven T. (Huntington Ingalls Industries – Ingalls Shipbuilding ) | Feng, Zhili (Oak Ridge National Laboratory ) | Chen, Jian (Oak Ridge National Laboratory ) | Huang, Hui (Oak Ridge National Laboratory ) | Walks, John P. (Huntington Ingalls Industries – Ingalls Shipbuilding )
During the shipbuilding manufacturing process, materials are exposed to significant stresses, as induced both thermally and mechanically, that alter the intended design and significantly affect the production schedule, labor hours (fitting, welding, rework, etc.), and material structural performance. The type and magnitude of deformation of a given structure depends on many factors such as the material, thickness and quality of components, the process heat input, preheat and inter-pass temperatures, type and size of welds, welding sequence and direction, location, sequence, and degree of fixturing. Numerical simulations using finite element analysis (FEA) have long been used to analyze welding-induced structural distortion. For large assemblies, transient thermal elastic-plastic analysis (TEPA) can take days or weeks to run, and optimization of welding sequence is not feasible. Simplified analysis methods were developed to reduce computational time. However, it is challenging to use these techniques to fully optimize welding sequencing because of their applied simplifications in modeling weld details. A fast analysis solver that could be used by the shipbuilding industry is being developed for optimizing welding sequences by taking full advantage of modern GPU-based HPC hardware and incorporating patented acceleration schemes. The accelerated processing factors are up to 2200 times greater for large, multi-pass welded structures.
- North America > Canada (0.28)
- North America > United States > California (0.16)
- Information Technology > Hardware (0.51)
- Information Technology > Modeling & Simulation (0.47)
Parameters of Ice Blocks and Their Relationship with the Structure of Hummocks in the Kara, Laptev, and East Siberian Seas
Kornishin, Konstantin A. (Arctic Research Centre, Moscow) | Efimov, Yaroslav O. (Arctic Research Centre, Moscow) | Tarasov, Petr A. (Arctic Research Centre, Moscow) | Guzenko, Roman B. (Arctic and Antarctic Research Institute (AARI), St. Petersburg) | Mironov, Yevgeny U. (Arctic and Antarctic Research Institute (AARI), St. Petersburg) | Porubaev, Viktor S. (Arctic and Antarctic Research Institute (AARI), St. Petersburg)
_ This article considers the relationships among different morphometric parameters (sail height, keel depth, and cross-sectional area) of ice ridges studied in 2013–2015 and 2017 in the Kara, Laptev, and East Siberian Seas. The size of the ice blocks that compose these ridges is the focus of this research. Different scenarios of ridge formation depending on different thicknesses of ice fields are considered, and the main scenarios of ridging in the Arctic areas are defined. Correlations between morphometric values for homogeneous, heterogeneous, and composite ridges are determined. A classification of ice ridges according to the relative thickness of the ice fields involved in their formation is proposed. Introduction The active development of hydrocarbon deposits on the shelf of the Arctic seas, beginning at the end of the last century, intensified research on the properties and parameters of ice features such as the parameters of ice blocks, which are the fundamental basis for the structure of ice ridges. Morphometric parameters of the ridges are undoubtedly related to the parameters of ice blocks, and the main aim of this work is to clarify and determine their relationships. To do this, from an entire sample of studied ice ridges, only those for which the connection of the external and internal structures with the parameters of the blocks and surrounding ice fields was the simplest were selected.
- Asia (1.00)
- North America > United States > Colorado > Cheyenne County (0.72)
- Europe > Norway > Norwegian Sea (0.24)
- North America > United States > Colorado > Ice Field (0.99)
- Asia > Russia > Siberian Federal District > East Siberian Basin (0.89)
- Asia > Russia > Kara Sea > West Siberian Basin > South Kara/Yamal Basin > Leningrad Field (0.89)
The objectives of subsurface hydrocarbon exploration often require integrating a variety of geophysical and geological information. The type and resolution of data can be vast, ranging from detailed examinations of well logs to generalizing broad regions from remotely sensed data. Here, we combine recently acquired state-of-the-art 2D seismic reflection data, vintage seismic refraction data from experiments conducted between 1957 and 1961 (Ewing et al., 1963), and both public and proprietary potential fields data to map the sedimentary and crustal rock layers beneath the Argentine coastal plain. We used the seismic reflection data to establish the basin framework, including interpreted syn-rift and pre-rift layers. These recent data closely correlate with the older seismic refraction data (Ewing et al., 1963), demonstrating the merits of incorporating all relevant information available, even legacy datasets. Regional basin structure and shape were approximated by integrating Moho and basement refractors with basin geometries interpreted from the reflection data into regional 2D gravity models.
- South America > Argentina (0.71)
- North America > United States > Colorado (0.48)
- Geophysics > Seismic Surveying > Surface Seismic Acquisition (0.85)
- Geophysics > Seismic Surveying > Seismic Modeling (0.71)
- South America > Argentina > Patagonia > Argentine Sea > Malvinas Basin (0.94)
- Africa > Namibia > South Atlantic Ocean > Orange Basin (0.94)
- South America > Argentina > Tierra del Fuego > Magallanes Basin > Cruz del Sur Field (0.93)
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