bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ice Load Calculation for Arctic Structures Using 3-D Dynamic Non-Linear Finite Element Analysis
Authors: Akinci N.O. , Lu Q. , Sari A. , Nguyen H. 
Published: June 2014

Abstract
Guidelines to predict ice loads on arctic structures have been covered in ISO 19906 [1] based on some empirical equations. This study aims to calculate ice loads for various types of structures using an analytical approach and comparing results with those calculated according to ISO 19906. The scope of this study covers floating structures subjected to ice loads. Structure considered in this study and ice are modeled using finite element (FE) analysis software ABAQUS [2]. Material non-linearity for investigated structures, contact, non-linear crushing and fracture behavior of ice are captured in the analyses.
Use of high end modeling approach is considered as a key element for obtaining a refined solution to this non-linear and dynamic impact problem. The findings and conclusions presented in this study are expected to show advantages of using advanced analysis approach in calculation of ice loads. There weren't many comprehensive studies explaining advantages of an analytical approach over a code equation approach for calculation of ice loads at the time of this study.
This study was developed to fill a gap in the industry so that engineers, owners and operators of arctic facilities can make informed decisions about the method to calculate the ice loads pertaining to their structure. It is typical to have a conservative approach when empirical code equations are used to calculate loads. However, level of conservatism or accuracy of code equations should be evaluated to ensure that target level of safety is attained.
First Year Ice Rubble: Shear Resistance and Rock Berm Interaction
Authors: Phillips Ryan , McAffee Rodney , Barrett John 
Published: June 2014

Abstract
Typical rock berms used to protect submarine pipelines may be damaged under shear by a first year grounded ice rubble keel. Physical model tests in a centrifuge have indicated that such damage occurs under loads less than those typical of actual design conditions. These novel tests have reproduced both failures of the rock berm and identified failure criteria for the ice rubble. The tests are of a preliminary nature given the discrete, rather than continuum, nature of the interaction event. The model freshwater ice rubble behaved as a frictional granular material under the shear test conditions with a peak friction angle of 38 degrees. Measured ice rubble shear strengths exceeded 65 kPa.
First year freshwater ice rubble large scale tests were conducted as part of the Pipeline Ice Risk Assessment and Mitigation (PIRAM) and Development of Ice Ridge Keel Strength (DIRKS) Joint Industry Projects. New finite element analyses of the PIRAM test set up indicate the boundary constraints on the test results. The measured PIRAM ice rubble shear strengths exceeded 35 kPa.
The first two test series indicate that ice rubble shear strength may exceed currently accepted design limits.
Gaps in Knowledge and Analysis Technology of Ice-gouge – Pipeline Interaction
Authors: Eltaher Ayman 
Published: June 2014

Abstract
Application of advanced numerical modeling to simulate ice gouge events has been based mostly on partial calibration, over a narrow range of parameters, with an emphasis on free-field events. A more comprehensive and systematic approach is required to calibrate and validate numerical models. This approach will need to include physical testing and advanced numerical simulations, to achieve better understanding of underlying and constituent processes, with best results requiring collating and sharing knowledge accumulated in previous (some of it being proprietary) work. The proposed presentation will identify and discuss gaps in the knowledge and numerical modeling of ice gouge-pipe interaction currently in need to be addressed, such as high quality (e.g., centrifuge or full-scale) test data for different types of soil (e.g., sand, clay, gravel, etc.); physical testing that include pipe; development of suitable soil constitutive models that suit the level of deformation involved especially close to the mudline; validation and calibration of elements and processes in the numerical tools (e.g., soil constitutive models and the behavior of the interface between ice and soil); development of a rational simplified analytical models of ice gouging that reflects the physics involved, so it is better validated and applicable to wider ranges of conditions and parameters; and development of guideline for offshore pipeline design in ice gouge environments.
Increasing Role of Marine Support in Arctic Offshore Exploration Drilling
Authors: Connelly Don , Brovkin Alexander 
Published: June 2014

Abstract
The remoteness of Arctic well sites, lack of infrastructure and severe environmental conditions dictate a high level of self-sufficiency in an offshore exploration drilling project.
Chevron employs the concept of an Arctic Drilling System that, in addition to the appropriate Arctic Mobile Offshore Drilling Unit (MODU), will comprise of a number of marine vessels providing multi-functional support for drilling operations. The recent Macondo incident in the Gulf of Mexico has significantly impacted the conventional view on the multiple functionality of Arctic marine support by adding an in-field independent well containment capability that also has many functions.
This paper will look into the range of functions and tasks that are expected of muti-purpose vessels supporting an Arctic offshore exploration drilling project and will demonstrate the major considerations that need to be taken into account when compiling a highly effective marine support fleet.
The scarse supply of existing Arctic multi-support vessels versus expected industry demand will be demonstrated to emphasize the requirement for new designs and new construction.
Development of Icebreaking Ships
Authors: Wilkman Göran , Mattsson Tom 
Published: June 2014

Abstract
After Columbus has sailed to the West Indies also the search for the northern alternative to reach India became attractive. Over four hundred years ago Dutch Willem Barentz started to sail the North East passage towards east, but he did not get very far. After mapping Spitsbergen and Frantz Josef land he stranded on Novaya Zemilya. After this it took awhile until next expeditions became true, and even in the 19th century, nobody understood the northern environment and its challenges to people and equipment. Today we know perhaps too much. Today nobody would go and risk his life without having a heavily strengthened vessel around him. We have moved all the way from wooden sailing ships to nuclear powered vessels and year-round navigation. Part of this is due to climate change but also because the search for oil is moving further north. This paper brings us back from history to modern times and discusses the recent history what we have accomplished during the last decades and also tries to give some future views.
Arctic Sea Ice Thickness Observed by Moored Sonars
Authors: Hansen Edmond , Spreen Gunnar 
Published: June 2014

Abstract
Time series of sea ice thickness observed by moored sonars in the Transpolar Drift in Fram Strait show significant thinning during the 1990–2011 period. The thickness of old level ice is reduced by 25 %, while the fraction of (ridged) ice thicker than 5 m is reduced by 50 %. The combined effect on the mean ice thickness is a reduction from an annual average of 3.0 m during the 1990s to 2.2 m at the end of the record. Due to the steady advection of ice from many sites across the Arctic, the ice observed in Fram Strait carries an integrated signal of Arctic change. The thickness of old level ice is approaching values more typical for seasonal ice. While such low thicknesses prevail, larger areas of sea ice can melt away during the melt season. Hence conditions favorable to melt (or favorable winds) will result in new summers of very low sea ice extent. It is an important implication that the sea ice extent then depends more on the actual weather each melt season than previously. A relatively warm summer may remove much larger areas of ice than a slightly colder summer. This is exemplified through the relatively cold summer of 2013, which featured a sea ice extent nearly 50 % higher than the preceeding warm summer of 2012. This, again, implies that one may expect larger year to year variability in summer sea ice extent in the coming years, with the ramifications this has on human activity in the Arctic. In addition to this general reflection of the state of the Arctic sea ice cover, the Fram Strait ice thickness observations are of particular relevance to development of offshore petroleum fields on the North East Greenland shelf just downstream of the monitoring site. Most relevant design parameters may be deduced from this data set, such as level ice thickness and frequency and depth of pressure ridges.
Cluster Development of The Barents and Kara Seas HC Mega Basins From the Novaya Zemlya Archipelago
Authors: Efimov Yaroslav , Zolotukhin Anatoly , Gudmestad Ove Tobias , Kornishin Konstantin 
Published: June 2014

Abstract
The region of the Barents and the Kara seas is considered to be extremely rich for energy resources, primary gas. Nowadays this area is divided between two Russian majors – Gazprom and Rosneft. These companies have several projects with their foreign partners: Statoil and Eni in the Barents, ExxonMobil in the Kara Sea. All of these projects are in their early stages (feasibility study, exploration works) but both the experts and the management of the companies agree that production from this region requires enormous investments at a potential high-risk level. This is due to very harsh environmental conditions that put limits on usage of the earlier proved technologies and techniques, personnel, etc.
Moreover some of the regions might not be developed by means of only one company and to be bold enough to state it by the means of one country.
One of the very promising areas is the well-known Barents Sea with its unique fields like the Shtokman and others. Unfortunately the investment decision for the Shtokman project is regularly put off and there are certain reasons for it. Another area, which is now under active exploration, is the Kara Sea. It's not a secret that this sea is even more severe than the Barents – tremendous ice cover, icebergs, and challenging meteorological conditions.
The paper anticipates a new concept that proposes to use the Novay Zemlya archipelago as a cluster base for development of the whole region of the eastern Barents and western Kara seas. In this case the so called "unitization principle" can be implemented that might improve economics of field development due to less overall investments in common infrastructure.
It is proposed to build an LNG plant on the archipelago that will be capable to treat gas from several fields, a pipeline system and a port for LNG takers. The pipeline system should be optimized in order to meet production levels from the fields as well as the capacity of the LNG plant. The paper introduces an approach to the problem of pipeline route optimization which is based on multi criteria principle. Total cost of construction and maintenance of pipeline along certain route is determined as a function of several parameters (water depth, presence of ice/icebergs, soil conditions, slop, etc.) and has to be minimized in this model. The problem of optimum pipeline route is solved with the means of modified algorithms from the graph theory.
Precise GNSS Positioning in Arctic Regions
Authors: de Jong Kees , Goode Matthew , Liu Xianglin , Stone Mark 
Published: June 2014

Abstract
For precise positioning in arctic regions with Global Navigation Satellite Systems (GNSS), such as GPS and Glonass, there are a number of issues to be resolved or taken into account. The most important ones are satellite geometry, ionospheric effects and distribution of correction data.
Precise Point Positioning (PPP) is currently the standard for precise offshore positioning. PPP requires a sparse global network of GNSS reference stations to estimate precise satellite orbit and clock parameters in real-time. These parameters are transmitted to users, who can compute their position with an accuracy of 0.1 m using code and carrier observations. The main disadvantage of PPP is that in general it takes a long time to converge to this accuracy, about 30–45 minutes.
GNSS carrier observations are similar to pseudo ranges, but have an additional bias which needs to be estimated. Under certain conditions, these biases are integer. This property is used in what is generally referred to as Real-Time Kinematic (RTK) positioning, a technique which uses corrections generated at reference stations to make sure these ambiguities are integer. Integer Ambiguity Resolution (IAR) results in RTK accuracies of 0.01–0.03 m or better and short convergence times, ranging from instantaneous to several minutes for long inter-station distances. The disadvantage is the limited area of applicability, because RTK in general does not use precise orbits and clocks.
Current research focuses on the combination of PPP and RTK techniques. The main goal is to achieve cm accuracy with a sparse network of reference stations. Another goal is to reduce convergence time. Applications are in the field of precise real-time offshore positioning in general, and subsidence monitoring and tidal estimation in particular.
Results will be presented from standard PPP and PPP combined with IAR for arctic regions and from a test bed in the Gulf of Mexico. These results, although preliminary, indicate centimeter level accuracy is indeed possible, also in the arctic. We will also look at further improvements, mainly in convergence time, using all operational satellites and signals from current and future navigation systems.
A NRT Approach to Accurate Ice Edge Information
Authors: Debien Annekatrien , Whitaker Paul 
Published: June 2014

Abstract
The melting of the Arctic ice has opened up many areas of interest for oil and gas, fishing and transportation. However, not all ships or rigs in these areas have the capacity to deal with moving ice. They try to avoid ice by staying just outside the ice edge, but ice movements result in damage to vessels and Search and Rescue operations that could have been avoided. Monitoring the ice edge and forecasting its movement is therefore of great importance for these operations.
Kongsberg Satellite Services (KSAT), in cooperation with University of Sheffield, has developed an algorithm to quickly detect the edge between open and safe water, and drifting ice, based on SAR imagery. This information is available in a compact format less than 15 minutes after image acquisition. When taking into account transfer to the ship, the user receives information on the ice edge that is only 30 minutes old. The ice charts created by national ice services are based on information that can be several hours old, and are only updated on a daily basis.
As ships and oil rigs operate near the ice edge, they can rely on this ice edge to get fast, accurate and frequently updated information about its location and movement. The ice edge product has been tested and approved in multiple environments including the Barents Sea, the Fram Strait and the Kara Sea, and has proven to be of use for fishing vessels and oil companies operating in or near the ice edge.
This paper will describe the generation of the ice edge product, and the validation of the ice edge created by KSAT in the Fram Strait, around Svalbard, and near the Kara Sea. The validation has been performed internally, based on statistical comparison of the ice edge product with the Arctic marginal ice zone created by the National Ice Center in the U.S. Further validation will be performed with higher resolution ice charting products from the local meteorological offices.
Managing Offshore Superstructure Icing
Authors: Ryerson C.C. , Tripp S.T. 
Published: June 2014

Abstract
Superstructure icing occurs when spray freezes on offshore platforms and ships. Though superstructure ice accumulates fastest on moving vessels that generate bow spray, stationary structures also ice in storms. And ice from atmospheric sources also accumulates, affecting parts of platforms and ships not affected by sea spray. Icing is often accepted as an inconvenience to offshore operators, but that tolerance can reduce safety, operational tempo, and productivity. This report shows how to evaluate the impact of superstructure and atmospheric ice to offshore platform and ship functions and components from work conducted for the Bureau of Ocean Energy Management, Regulation and Enforcement (BOEMRE), and for the US Coast Guard using questionnaires and observations. The report proposes a risk matrix approach for assessing the relative threat of ice from sea spray, frost, snow, rime and glaze to the safety and functions of platforms and ships, and demonstrates how to identify and prioritize areas requiring ice protection. It also briefly describes available ice protection techniques other than baseball bats and mallets. The goal is to provide a resource for offshore operators with superstructure icing-related safety concerns.
Innovative Kick Detection System for HP/HT Ultradeepwater Wells Using a Section of the BHA
Authors: Trivedi Parth P. 
Published: June 2014

Abstract
We are today moving into deeper seas and more challenging areas for finding oil and as the quest continues we enter more areas with uncertainties and possibilities of greater disasters. Very soon, if the technological advancements lag behind, the price of a crude barrel might not cover for the risk that the explorers take for it. Having said that, there is a very crucial balance that we need to strike in terms of long term investments for better efficiency vs. the cost effectiveness of our systems. Risk especially in regions of exploratory drilling is very high and this paper deals with a technology of downhole mud evaluation for predicting the entrainment of formation fluid into the wellbore.
The innovative kick detection system proposed in the paper uses a small mud rerouting section just above the BHA after the LWD and MWD tool. The small section of the mud into the tool is passed from between two plates (of metal with v.high melting point and definite resistance curves at HPHT conditions) that are separated by a small distance and have a definite known (corrected) potential applied across them. As soon as there is entrainment of formation fluid bubbles/droplets into the flow, the medium between the two plates will undergo alteration (change in absolute mud parameters) which will result in a change in capacitance between the two plates that can be detected immediately using the currently available technology.
This change in potential can be coupled through a coil in order to produce a magnetic impulse that can easily be carried to surface and registered as a ‘count’ of abnormality in fluid. Greater the count more will be entraining fluid and hence a kick can be detected. For very fast flowing fluids, we can incorporate high temperature potential measurement systems that can help us quantify the capacitance between the plates and tell for certain whether or not a kick is present.
The tool can be calibrated for specific mud type used and the fluid behavior at down-hole conditions giving us a more accurate measurement.
Limitations of this technology might lie in the materials used for electronics development and type of transmission system in place for the signal to reach to the top in very deep wells but there is an added benefit of quantitative and definitive measurement.
University and Corporate collaborations: Great Data, Good Science and a Strong Geoscience Workforce for the Future
Authors: Wood Lesli J. 
Published: June 2014

Abstract
Student education today, more than ever is rooted in teaching applied interpretation skills as well as conceptual geoscience ideas. Programs need to produce students who are versed in the software of geoscience interrogation as well as the concepts that will allow rapid, thorough and creative investigation of scientific problems. The ability to train students using the most up to date tools investigating state of-the-art, real-world data sets is a luxury that is only made possible through the generosity of companies who pay millions to build the tools and collect the data that we speak of. Gifts of data and software were once handled with a handshake, most often facilitated through a professor with a relationship to a former student who had access to such data. However, changes in our business and the rise of nationalism in many countries in the past decade have necessitated altering the way we collaborate. No longer is seismic data acquisition done by individual companies. Rather today, most seismic is shot as spec surveys that are used by companies to do their business. This means academic organizations need to build relationships with vendors, or leverage existing relationships between vendors and major customers to encourage release of data to academic institutions. In addition, academic organizations need to build a reputation for research excellence, respect for legal and ownership issues, and be recognized as a strong educator of young people.
CastorOne and FDS 2: Getting Stronger for Laying Deeper
Authors: Faldini Roberto , Marchini Stefano , Oldani Andrea , Pellegrini Roberto 
Published: June 2014

Abstract
Reaching the ultra-deep installation scenarios beyond 2,000m WD means that the new generation of S/J-laying vessels will be capable of applying pipe holding tensions well beyond 500te, which may become twice or three times that value if an unexpected flooding of the pipeline or a wet buckle occurs. To meet the increasing holding tension demand, Saipem adopted two innovative solutions on its new deep-water laying vessels CastorOne and FDS2. The FDS2 J-Lay system has been equipped with new compliant pads. This innovative pad design allows the application of up to 2,000te of holding tension in both normal laying and contingency situations, employing standard friction clamps of relatively small dimensions. In case of a wet buckle or in a contingency flooded pipe scenario, the CastorOne S-Lay vessel has the capability of holding and then abandoning the pipeline in a controlled and safe way by applying a tension of 1,500te through the simultaneous use of the A&R winch, of the three tensioners and of the pipe holding indentation clamp, all rated 750te. Moreover, the CastorOne has been equipped with a next generation articulated stinger capable of being adjusted either in terms of ramp angles and of roller heights in active mode during laying, i.e. with the pipe on top of it. This innovative feature allows to change the stinger configuration in order to suit the different bending radii required when laying in shallow, deep and ultra-deep waters without abandoning the pipeline, therefore saving a considerable amount of time and reducing the risks. These capabilities have been successfully tested in the deep water sea trials that took place before the laying of the Jack St Malo export pipeline. Such innovative technologies and equipment required state-of-the-art control and management software: the Centralized Management System (CMS), the Ramp Management System (RMS) and the Pipe Lay Guidance (PLG) just to mention the most important ones. The ability of the Vessel Management Team (VMT) to remotely control at any moment the instant conditions on the vessel firing line and on the double/triple joint workshop is a unique feature ensuring safe and reliable monitoring of the whole pipe construction cycle onboard. These features make the new CastorOne and the FDS2 unique and distinctive vessels on the pipeline installation market for Steep-S/S/J laying technologies.