bluuebunny/crossref_metadata_2025_split huggingface dataset:
Probabilistic Assessment of Multi-Year Sea Ice Loads on Upward Sloping Arctic Structures
Authors: Thijssen Jan , Fuglem Mark , Croasdale Ken 
Published: November 2016

AbstractMulti-year (MY) ridge and level ice interactions with sloping and conical structures involve complex ice feature shapes and ice failure mechanisms. The limited available field data makes calibration of associated load models difficult. To account for associated randomness and uncertainty, models may tend to be on the conservative side.New deterministic algorithms were recently developed to calculate loads more accurately for interactions of MY level ice and MY ridges with an upward sloping structure. This paper presents the application of these recently developed formulations in a probabilistic framework using SILS. SILS is a Monte-Carlo type simulator developed by C-CORE following the general procedures outlined in ISO 19906. Ice and metocean input parameters are defined by the user either as a fixed value (e.g. friction coefficients) or a random distribution (e.g. ice drift speed, floe size). The yearly encounter frequency is first estimated for these ice features for the site of interest. The ice loads are then determined for each of simulated interaction event occurring over the model timespan, using the deterministic load formulations. By simulating a large number of years of ice interactions, design ice loads can be determined that correspond to various low annual probability of exceedances.This paper demonstrates how complex loading scenarios, modelled in terms of idealized deterministic models, can be incorporated within a Monte-Carlo framework to provide design level loads. During the model implementation and analysis of results, significant improvements were identified and implemented in the deterministic model, resulting in a more robust model and better design estimates. The results provide valuable insights regarding model inputs and behaviour corresponding to the extreme design ice loads. An example of a full probabilistic analysis is presented in the paper to illustrate the models. Here the probabilistic framework of SILS is used to assess a Base Case scenario and a number of sensitivity cases using different environmental inputs and model parameters.
Labrador Deepwater Exploration Insights into its Prospectivity From Broadband Seismic AVO Analysis and Seabed Coring
Authors: Wright Richard , Atkinson Ian , Carter James 
Published: November 2016

Abstract
The Labrador Sea, extending from the Davis Strait in the north, through the Saglek Basin and down to the Hopedale Basin in the south, is one of the largest under-explored areas along the eastern Canadian Margin. Exploration of this region has focused on the continental shelf with 30 wells drilled during the 1970's and 1980's. Most of the wells targeted shelfal structural traps. No exploration has occurred in the slope and deepwater areas. From 2011 to 2015, long offset, broadband 2D seismic data (42,400 km) has been acquired by TGS-PGS in the slope and deepwater regions. The broadband image quality has led to the identification of significant new plays and leads in a region that was never before considered prospective. Several of these leads have the potential for large accumulations of oil and gas. The possibility for oil plays in the area is supported by the presence of natural oil seeps along the slope that were identified by satellite surveys in 2010. The long offset (8 km cable) seismic data has identified AVO anomalies on the far stacks. A new regional rock physics study (2014-15) has permitted the careful analysis of these AVO leads and this is helping to reduce exploration risk factors. The analysis shows the importance of the long offsets to identify and characterize these Class II AVO anomalies. In 2015, a seabed coring survey was conducted to target areas near the oil seeps and over large potential traps. Early results from this work are positive and analysis will continue through the spring of 2016. Heatflow measurements taken during the coring survey are providing inputs for a basin modelling study. In addition, several of the shelfal wells were resampled and fluid inclusion analysis was performed. Early results are showing the presence of liquid hydrocarbon inclusions. All of this work has led to the identification and analysis of large potential traps that could hold major oil accumulations. This paper will provide insights from the new seismic data and the recent studies and analyses to demonstrate this prospectivity.
The Ford’s Bight Diatreme A Cretaceous Alnöite Pipe from the Northern Labrador Coast and Possible Onland Remnant from the Opening of the Labrador Sea
Authors: Wilton Derek , Burden Elliott , Greening Adam 
Published: November 2016

Abstract
The Ford’s Bight Diatreme is an apparently rare feature on the Precambrian coast of Labrador. Originally described as a Jurassic-Cretaceous sedimentary breccia cut by lamprophyric dykes, an early report of marine microfossils in the strata poses an interesting sedimentary and petroleum geology problem. In revisiting the area, the succession is now viewed as a rift related diatreme with a Cretaceous (ca. 137 Ma) radiometric age. In earlier work, this rock was dated from assemblages of poorly preserved Jurassic and early Cretaceous marine microfossils. Our own lengthy search for fossils in igneous rocks and clasts and carbonate matrix was fruitless. Some apparently carbonized debris is identified in microscopy and with some oddly shaped (non-biologic) microcrystalline structures seen under SEM. With an age and origin for this feature established from basic geology and radiometric dating, this therein leaves an unresolved petroleum exploration risk - and, namely, did Jurassic marine conditions cover this part of the Labrador coast before earliest Cretaceous volcanism?
Analysis of First Year Ice Surface Ocean Current and Ice Floe Drift Speed and Motion Offshore Newfoundland and Labrador from Satellite-Tracked Buoys During the 2015 Ice Season
Authors: Rahman M. S. , Turnbull I. D. , Taylor R. S. , Veitch B. 
Published: November 2016

AbstractThis paper presents an analysis of the dynamics of ice, current, and wind based on the data collected on land-fast ice and ice floes from the offshore environment of Newfoundland and Labrador during April-August 2015 using satellite-tracked beacons. The beacons were deployed in three sets of three as follows: fast ice beacons (FIB) 2, 3, and 5 were deployed in a triangular array on the land-fast ice offshore Makkovik; fast ice beacons (FIB) 1, 4, and 6 were deployed in a triangular array on the landfast ice offshore Nain, and ice floe beacons (IFB) 7590, 1590, and 0650 were deployed on drifting ice floes offshore Makkovik. Ten ocean drifter beacons were deployed on May 22, 2015 in open water in the vicinity of ice floe beacons 1590 and 0650 to study the characteristics of surface ocean current dynamics. The drift velocities of the two ice floes have been compared with the wind velocities measured by the two weather stations deployed on the ice floes. The buoy drift rose and exceedance probability plots have been presented to analyze the dynamical characteristics of first year ice and ice floes in the offshore Labrador ice environment.
Improved Equations for the Actions of Thick Level Ice on Sloping Platforms
Authors: Croasdale Ken , Brown Tom , Wong Chee , Shrestha Noorma , Li George , Spring Walt , Fuglem Mark , Thijssen Jan 
Published: November 2016

Abstract
In ISO19906 (2010) (Arctic Offshore Structures) specific algorithms are provided for level ice loads on sloping structures; they are based on the separate work of Ralston and Croasdale. These methods were developed decades ago and comparisons with full scale data, especially from Confederation Bridge, suggest that certain idealizations can be improved; more importantly that they may be over-predicting the measured loads. For these reasons it was decided to critically review the existing Croasdale et al algorithm (as specified in ISO) and update it based on learnings from Confederation Bridge, other experience and new ideas.
During the study, over 50 ice interaction events at Confederation Bridge were chosen as geometrically similar to thick ice acting on an Arctic structure. The interaction process and relevant parameters (such as ride-up height) were documented in detail and the measured loads compared with predictions for each event. The model, as currently specified in ISO, generally over-predicted by a factor of about 1.6. The model was improved in the course of the work; especially the physics of breaking and ride-up. The new model is capable of matching the Bridge measurements without bias.
This paper presents the final methodology and equations which resulted from the study which was conducted over several years and resulted in an extensive report and documentation. The equations are closed form and can be applied relatively simply. Examples of using the method are provided. A more comprehensive description of the complete study is given in KRCA (2014) and Croasdale et al. (2016a).
Integrated Design and Analysis for Virtual Arctic Simulation Environment
Authors: Hamilton Matthew , Maynard Aaron , Jujuly Muhammad , Adeoti Ibraheem , Rahman Aziz , Adey Matthew 
Published: November 2016

Abstract
We present an integration of new capabilities of simulation and visualization for subsea analysis and design into an existing virtual arctic simulation environment (VASE). The existing system (previously presented) provides interactive, high-fidelity simulation capabilities for remotely-operated vehicles (ROV) in arctic environments for subsea trenching along with support for visualization of integrated data from sub-bottom and multibeam sonar imaging devices. This paper describes integration of the existing VASE with computation fluid dynamics (CFD) simulation capability for simulation of flow assurance and fluid-structure interaction design issues relevant to arctic subsea oil and gas field design.
The presented integrated simulation system allows for rapid, streamlined evaluation of pipeline designs in an integrated data, whole-field context. In particular, detailed analysis of pipeline fatigue risk factors due to slugging and effects of hydrate formation can be performed through integrated CFD analysis capabilities. The system's intuitive pipeline design allows for rapid alteration of pipe and flow lines in response to feedback from bathymetry and soil data, ROV accessibility requirements and structural analysis through flow induced vibration and fluid structure-interaction simulations.
It is demonstrated how various pipeline and jumper designs can be rapidly created in the VASE with design strategies motivated by the integrated whole field data visualization environment. Once pipe and jumper designs are specified, they can be exported for external analysis. We demonstrate this analysis through two fluid-structure interaction models (slugging and hydrate formation model). This allows for effective design in arctic environments, including design of pipeline routes in context of trenching and general management of cold water conditions. Overall, the system can also serve to function as a planning and data management system for subsequent training of pilots for inspection as part of asset integrity management.
Improvement of Visibility and Severe Sea State Forecasting on the Grand Banks of Newfoundland and Labrador
Authors: Bullock Terry , Isaac George A. , Beale Jennifer , Hauser Tristan 
Published: November 2016

Abstract
Fog in northern climates and Arctic environs can be a risk to helicopter operations and shipping interests, as are high seas from severe storms that frequent these regions. Visibility conditions and forecasts determine whether helicopters can safely land on offshore facilities, or if personnel will need to be transferred by ship. High sea state conditions can affect offshore oil and gas exploration and production operations, including drilling, logistics, crane operations and emergency response.
A workshop on Metocean Monitoring and Forecasting for the Newfoundland & Labrador Offshore, held 22-24 September 2014, identified the need of improving the visibility and severe sea state forecasting for Grand Banks which can have a positive contribution to safety and operations in the harsh North Atlantic Canada offshore environment. This has led to an open and collaborative multi-year Metocean Research and Development Project that is presently in its third year. Some twenty government, academic, and industry agencies are participating in this project.
Detailed buoy and offshore installations-based scientific measurements have been collected over the past three years where previously there has been a lack of good quality observations. A climatology of low visibility (less than 1km) events shows a high frequency (about 55% of the time) during summer months. A "conceptual model" of Grand Banks fog has been developed, that defines the physical conditions under which fog develops, is maintained, moves and dissipates. The conceptual model will be the basis for the development of new visibility prediction systems which currently are not well established or verified. High seas, with wave heights over 6m, occur more frequently during winter. Sea state prediction systems are being evaluated for severe ocean wave conditions where they have reduced predictive skill. Currently, work is underway to establish the accuracy and consistency of several existing visibility and sea state prediction systems.
This paper will illustrate results from the climatological studies and some of the unique metocean monitoring data being collected. The forecasting techniques (e.g. numerical atmospheric and oceanic prediction models, satellite-based schemes, and rules based systems) being evaluated, are outlined.
Numerical Simulations of Ice Loads on Fixed and Floating Offshore Structures using the Discrete Element Method
Authors: Liu Jiancheng Jessie , Liu Xiang , Chen Yingying , Long Xue , Ji Shunying 
Published: November 2016

AbstractExisting standards and codes do not comprehensively address and provide all necessary guidance and requirements for the design of Arctic offshore structures. Reliably assessing ice loads on offshore structures remains a challenge for industry, especially as "new" Arctic platform concepts are proposed for deployment in lighter ice operations, e.g. Arctic SEDU (Self- Elevating Drilling Units) and Arctic CSDU (Column-Stabilized Drilling Units). As a pragmatic solution, a comprehensive approach including relevant field measurements, physical model tests and numerical simulations is usually adopted in assessing the ice loads for a particular design. Field measurement results are limited in number and there is often uncertainty concerning actual ice conditions and load measurement techniques. Furthermore several data sets are constrained with proprietary restrictions. In particular no direct field data is available for the example "new" structures (SEDUs and CSDUs). Physical model tests always present challenges due to scale issues, ice property calibration, measurement uncertainties and high costs. Therefore, numerical simulations using the validated DEM tool based on the related field/model test data are anticipated to provide supplementary information for standards/rule-based designs.ABS has expended efforts to develop practical and advanced tools to assess the ice loads on offshore structures for several years. One promising numerical approach, a graphic processing unit (GPU) based Discrete Element Method (DEM) model, processes the computations in parallel and solves the DEM model with millions of particles for complicated ice-structure interaction problems, e.g. ice simultaneously loading on multiple legs and ice loading on a large CSDU. The paper presents details of the developing ABS GPU-DEM tool, status of the verification program, plans for the current and the future developments and applications. Included are brief descriptions of background technologies, an approach to derive the DEM model bonding strength inputs, and validation studies of ice breakage simulations based on the Bohai Bay Jacket ice data. The ice load simulations for fixed and floating structures, i.e. jack-up legs and the Kulluk floating drilling platform, are also shown to demonstrate the tool's capability and feasibility for Arctic offshore structure design. The interactions of ice and fixed/floating structures were analyzed, which provides useful references for future ice load modelling and offshore structure design.
Modeling of Heat Loss from Offshore Buried Pipeline through Experimental Investigations and Numerical Analysis
Authors: Chakraborty Suvra , Talimi Vandad , Muzychka Yuri , McAffee Rodney 
Published: November 2016

Abstract
Offshore oil and gas production in arctic areas is challenging due to harsh environmental conditions. Pipeline burial and trenching in those areas are now one of the prime methods to avoid ice gouge risks and other threats. Thermal management becomes critical when the ambient temperature is low such as the typical seawater temperature on the sea bed. The flow temperature and pressure affect viscosity of the fluid traveling through the pipeline and determines the state of the fluid (single or multiphase). The effect of freezing around oil and gas pipes in the vicinity of permafrost is considered as another concern for flow properties of oil and gas in arctic regions. Theoretical shape factor model has been widely utilized to estimate heat loss from buried pipelines. This study examines the validity of using this method for flow assurance calculations. Several steady state and transient experiments have been carried out to model the heat loss considering different parameters such as burial depth, backfill soil, trench geometries etc. Natural convection can play a significant role in the overall heat loss process from the buried pipeline. The total heat loss increases significantly when the backfill soil is loose or sandy. This paper illustrates the effects of heat conduction and natural convection in the heat loss mechanism from buried pipelines. The outcome of this paper will provide valuable heat loss models based on experimental and numerical analysis results. These outputs can be used largely in petroleum industries for designing pipelines in offshore arctic areas and to mitigate several flow assurance issues (e.g. wax and hydrate formation in the pipeline effectively). The methodology used in this research i.e. analyzing the experimental data with two steps of validation will ensure the validity of the proposed model. Using different parameters such as burial depths, trench geometries, and backfill soil this paper provides an effective model for the offshore pipeline design.
Experimental Study on Shear Strength of Freeze Bonds in Freshwater Ice
Authors: Boroojerdi M. T. , Ghobadi M. , Taylor R. , Bailey E. 
Published: November 2016

Abstract
The strength of rubble mass depends on the degree of consolidation between the ice blocks as well as the strength of the ice blocks themselves. The origin of the contact forces between the ice blocks is uncertain, but has been attributed to thermal freezing and sintering. A series of freeze-bond tests were conducted on freshwater ice blocks to gain a greater understanding of the fundamental physical properties affecting ice bonding. The parameters investigated in this test program were the contact period/submersion time and the initial temperature of the ice blocks. Freeze bonds were made by putting two ice blocks in contact in a confinement frame and applying a normal load. The frame was then submerged in water at freezing point for a specific period of time before testing. The bond was sheared using Asymmetric Four Point Bending (AFPB) method, which produces a nearly pure shear stress state in center of the specimen. Results showed that varying the submersion time from 1 minute to 26 hours for ice samples with initial ice temperature of −18°C, the strength of the bond initially increased and reached the maximum at 5 minutes and then started to gradually decrease, reaching a constant value after 3 hours of submersion. The effect of initial ice temperature on the bonding process was also studied by varying the temperature from 0°C to −18°C, whilst the submersion time was kept constant at 30 minutes. As the temperature was decreased an increase in strength was observed.
A GIS Approach to Quantitative Ice Gouge Depth Mapping, Analysis, and Prediction
Authors: Haneberg William C. , Brumley Kelley , Kucera Michael S. 
Published: November 2016

Abstract
We describe and illustrate the application of a geographical information system (GIS) approach to map ice gouge locations and depths from high-resolution multibeam echo sounder (MBES) bathymetric surfaces by calculating residuals relative to spatially variable moving trend surfaces. The workflow can be used to rapidly characterize gouges over large areas and, because minimal human intervention is required, is especially attractive in heavily gouged areas where traditional manual measurement techniques would be tedious and produce highly uncertain results. The method produces maps showing gouge depth as a continuous field rather than point measurements or cross-gouge profiles, so that variations in depth along gouges can be easily visualized and analyzed. Once gouges have been delineated, gouge depth distribution statistics can be further used to estimate exceedance probabilities for gouge depths within local neighborhoods. Seafloor roughness maps can also be generated to highlight the spatial variability of seafloor disturbance and, in a relative sense, visualize the ages of different gouges if certain assumptions are satisfied. We illustrate application of the method using a sample MBES data set depicting a heavily gouged portion of seafloor.