bluuebunny/crossref_metadata_2025_split huggingface dataset:
Extending Conventional Pipe-Soil Interaction Models to Include Bundle Effects for Arctic Subsea Pipeline Design
Authors: Georghiou Andreas E. , Davis Amy , Eskandari Farzad , Paulin Mike 
Published: March 2015

Abstract
As the demand for energy resources continues to grow, the oil and gas industry is looking north for the discovery and extraction of offshore hydrocarbon resources. The Arctic region has significant discovered and undiscovered hydrocarbon resources and is an important area for energy development. In these cold areas however, the integrity of offshore structures such as pipelines is at risk from various geohazards. Burial under the seabed is the common practice of protecting offshore pipelines and these pipelines are often installed as bundles for many reasons including economic considerations, short installation windows, and technical issues. A bundle configuration can decrease the cost of project by reducing the installation time to one season and they may have certain design advantages.
Bundles have been used in all of the developments utilizing subsea pipelines offshore the North Slope of Alaska. In this paper, the state of practice of analyzing buried pipelines using pipe-soil-interaction elements on individual pipelines is extended to account for the effects of the different pipelines in the bundle. By modeling the individual pipelines in the bundle as opposed to an equivalent pipeline, it is possible to have a more accurate load distribution in the system and define the pipe-soil interaction more realistically. In addition, the behavior of each pipeline can be examined separately in the bundle.
One common geohazard of Arctic and subarctic regions, permafrost thaw settlement, is introduced and its effects on pipeline bundles are studied through FE models and compared with methods used in past projects. When analyzing permafrost thaw settlementin the past, each pipeline was modelled separately. These assumptions could result in inaccuracies due to the pipe-pipe, and bundle-soil interactions which cannot be modelled on an individual pipe. The newly developed finite element models couple the individual pipe-soil interactions together with the pipe-pipe interactions and provide a more accurate assessment of the pipeline and bundle behavior, which in turn can reduce potential conservatism in designs.
Probabilistic Modelling of Marine Icing: an Estimation Method for Spray Water
Authors: Aalbers Albert B. , Poen Gerard J. 
Published: March 2015

Abstract
In view of the SALTO JIP (Safe Arctic Logistics, Transport & Operations) a pre-study started to develop a probabilistic model for icing due to spray water over the bow of a ship. The investigation has two stages: a probabilistic model for volumes of spray water (and the break-up in droplets) rising above the freeboard and,a probabilistic model for the ballistic and thermodynamic process of these droplets when falling and freezing to the ship.
The present paper concerns the first stage. The calculation model uses a novel combination of ship motions and wedge impact modelling, taking into account the above water hull shape and non-linear effects in the wave. For droplet break-up empirical spray nozzle modelling appeared useful to derive mean droplet diameters and size distribution.
The results from the calculation model seem realistic when comparing to the scarce validation data. Spray is normally no problem, so the subject has seen little interest. Also -due to scaling problems- model test results are hardly applicable and full scale measurements virtually impossible. The present modelling takes realistically into account the effect of sea state, bow shape, speed, freeboard and ship size, i.e. it reflects that marine spray is a threshold phenomena, with sharply increasing volumes if a given condition is exceeded.
Remote Health Care: A Game Changer for the Arctic
Authors: Berg J. , Toner S. , Stilz R. , Klein S. , Williams H. , Pearson J. , Fraser A. , Norman N. 
Published: March 2015

Abstract

Description of the Proposed Paper
Remote Health Care strategy (RHC) is an integrated approach, developed for delivery of health care in Arctic operations. It meets medical emergency response requirements and supports our principle "No harm to people". RHC includes aspects of: prevention; technology; supplies/equipment, competence and communication. It brings a virtual hospital to a patient, rather than taking a patient to a hospital. We will present outcomes of implementation in Greenland, Siberia and W-Africa. We will add to these experiences with comparative data analysis of global cases in expatriates, business travellers and Marine Operations where RHC was not in place. We will discuss how RHC could have impacted these outcomes and look prospectively at benefit in future Arctic operations.

Application
RHC is uniquely applicable in the Arctic but it is also applicable in any remote area of the world. In less geographically remote regions where the main restriction is lack of infrastructure, it can improve access to health by improving prevention, networking, decision support, access to external resources and education. It was designed to support operations but can be adapted and scaled to support community health and underpin strategic social investment. RHC is one model to move towards the recently articulated goal of the International Maritime Organization of delivering the same quality health care off shore as on shore.

Results, Observations, and Conclusions
We will demonstrate how one can improve health outcomes in the absence of local health infrastructure by employing RHC. We will show how our strategy is supported by a retrospective analysis of original data and vindicated by early experiences of deployment. We will demonstrate how RHC is supporting pilot projects in community health in a region with lack of access to health care. We will showcase results of an original review in our marine operations and how this supports a future RHC approach in our vessel fleet.

Significance of Subject Matter
The RHC strategy is a game changer for the industry, allowing it to operate safely despite lack of local health infrastructure, lack of rotary wing support and in harsh conditions where access to traditional modes of medical care is foresee ably not available. With highly-elliptical orbit satellite, sensor, near patient technology and streaming imaging rapidly improving, the real challenge lies in combining technology with enhancing capacity, competence, mind-set and behaviours of on-site medical practitioners, distant medical top side cover and even for recipients of care.
Mapping the Surficial Geology of the Arctic Ocean: A Layer for the IBCAO
Authors: Mosher D.C. , Courtney R.C. , Jakobsson M. , Gebhardt C. , Mayer L. 
Published: March 2015

Abstract
The purpose of this paper is to show early results of surficial geologic mapping of the Arctic Ocean. Analysis of subbottom profiler and multibeam bathymetric data in conjunction with the regional morphology rendered from the IBCAO data are used to map nine surficial geologic units in the Arctic Ocean. For a relatively small ocean basin, the Arctic Ocean reveals a plethora of margin and basin types reflecting both the complex tectonic origins of the basin and its diverse sedimentation history. Broad and narrow shelves were subjected to a complex ice-margin history in the Quaternary, and bear the sediment types and morphological features as a result. Some shelf areas are heavily influenced by rivers. Extensive deep water ridges and plateaus are isolated from coastal input and have a long history of hemipelagic deposition. The flanks of the basins demonstrate complex sedimentation patterns resulting from mass failures and ice-margin outflow. The deep basins of the Arctic Ocean are filled with turbidites resulting from these mass-flows and are interbedded with hemiplegic deposits.
Simulations of the StationKeeping of Drillships Under Changing Direction of Ice Movement
Authors: Sayed Mohamed , Kubat Ivana , Watson David , Wright Brian , Gash Robert , Millan Jim 
Published: March 2015

AbstractThe ability of a drillship to maintain its heading to face oncoming pack ice is crucial under situations involving changes in pack ice drift direction. The performance of a vessel employing a Thruster-Assisted Mooring (TAM) system under such conditions is examined in this paper. Numerical simulations were used to determine the stresses and deformations within the moving pack ice cover, as well as the response of a drillship with characteristics similar to published information on Stena's DrillMAX. A turret mooring system is assumed to resist surge and sway direction offsets, but provides no restoring moment to vessel's yaw. In such system, thrusters would be used to provide damping and to apply the corrective moment that controls the heading of the vessel. The pack ice cover is assumed to consist of managed floes of sizes ranging from 30 m to 50 m, and with a uniform thickness of 1 m. The ice cover moves against the vessel at a steady velocity of 0.5 m/s. Simulations start with the vessel at a heading inclined to the oncoming ice direction. The simulations predict the evolution of the distributions of ice thickness and pressures, ice forces and moments, as well as the response of the vessel. Test cases examined a range of values of the initial heading of the vessel and limits on available yaw moment that can be generated by the thrusters. The results illustrate the manner in which the vessel can correct its heading, and give the corresponding offsets, ice forces and moments.
Simulation of Physical Ice Management Operations Including Trajectory, Power and Manoeuvrability Estimation
Authors: Hisette Q. , Reimer N. 
Published: March 2015

AbstractThe present paper describes a simulation tool for physical ice management operations. Resistance in level ice or in floes and manoeuvrability in ice are estimated thanks to semi-empirical methods and validated through comparison with model test data. From a target floe size, trajectory of management vessel is calculated in order to protect a structure against drifting ice according to linear, sector and circular management techniques. The tool produces visualization of the operations, with indication of the requested power level and distributions of the resulting floe size.
Preventing Thaw Settlement of Oil Pipelines Buried In Permafrost
Authors: Ali Muhammad A. 
Published: March 2015

Abstract
Buried pipelines in permafrost may undergo thaw settlement over a period of time. It depends on the type of soil. The innovative technology outlined in this paper solves the problem of thaw settlement of buried pipelines. With this technology expensive soil exploration will not be needed. Using a very thin walled secondary pipe in between two separate layers of insulations will effectively divert any heat escaping through the first layer of insulation in a direction away from the permafrost.
Tubular Integrity: Analytical Approach and Modeling of Optimum Performance Envelope in Presence of Gas Hydrates
Authors: Anand Kumar Dinkar , Samuel Robello 
Published: March 2015

Abstract
Gas hydrates are crystalline compounds that occur under appropriate pressure-temperature conditions when water forms a cage-like structure around a smaller guest molecule. The guest molecule can be methane, ethane, nitrogen, carbon dioxide etc. Gas hydrates are found in natural environments such as sea bottoms, under permafrost areas etc. Gas hydrate prospects on earth are the biggest unlocked recourses of energy in the world. The estimated amount of organic carbon in the form of gas hydrate in earth is 10000 giga tones which is equal to 100,000 to about 300,000,000 trillion cubic feet of gas reserves [4, 5]. Over the years several countries have started research programs aimed at discovery and production of gas from offshore gas hydrate deposits. Deep drilling, operation of oil and gas wells, and operation of oil and gas pipelines in the deep sea are vastly complicated by the presence of natural gas hydrates. The necessary requirements for formation of gas hydrates are; presence of water or ice, suitable sized gas/liquid molecule and suitable pressure-temperature conditions. Temperature and pressure condition is a function of gas/liquid and water compositions. Gas hydrate formation in the production tubing can cause severe safety problems. Pressure and thermal stimulation, inhibitor injection and a combination of these methods can be used in gas recovery from gas hydrates.
Scope of this paper is to analyze effects on tubular integrity due to pressure and thermal simulation in recovering gas from the gas hydrate bearing formation. The vertical well is producing through the production tubing and production liner is the final casing in the wellbore. Increasing the system temperature (temperature stimulation - steam injection from an offset well to gas hydrate bearing reservoir [14]) and reduction of system pressure (depressurization) helps in preventing gas hydrate formation in production tubing. This is attributed to shifting of phase equilibrium away from formation of gas hydrates. System pressure and temperature induces tri-axial stresses (hoop stress, radial stress and buckling stress) in production tubing. The von Mises Criterion, also known as the maximum distortion energy criterion, is used to estimate the yield of production tubing. von Mises stress is further compared with the yield strength of the tubing off set by the factor of safety. The factor of safety gives the safe margin for operation avoiding the tubular failure. This paper is aimed to analytically study the effects of system temperature and pressure on mechanical strength of the production tubing inside production liner. This paper also proposes performance envelope of system temperature and pressure which enables gas production avoiding gas hydrate formation ensuring tubular integrity. In this paper maximum system temperature and pressure is also established beyond which production tubing will yield.
Improving Ice Pressure Forecasting for Operational Purposes
Authors: Eriksson Patrick B. , Lensu Mikko , Haapala Jari , Lehtiranta Jonni 
Published: March 2015

Abstract
Compressive ice is considered to be amongst the worst operating conditions when navigating in ice and demanding for icebreaker assistance. Compression is a manifestation of ice cover stresses and a phenomenon physically different from convergence. Indeed, severe compression is often experienced in an inert ice cover and is reduced by the onset on convergence. This paper presents investigations to reach better understanding of processes generating ice compression by analyzing model forecasting methods and direct field observations.
Producing relevant information on compressive conditions to shipping and ice management by enhancing numerical ice forecast modelling. Products comprise specific areal characterization, pressure along channels or routes and in the vicinity of critical areas.
Predictability of compression in sea ice by numerical modelling encounters considerable challenges. Local stresses can be forecasted from deterministic model results, but these do not easily capture the rapidly fluctuating nature of the stress propagation. This has been concluded through extensive in-situ stress measurements, drift buoy measurements and ship observations and comparisons to numerical sea ice model results.
To be able to serve shipping in ice with sensible information, study results support an ensemble forecasting approach and provide probabilistic ice pressure products. The ensemble averaged mean compression fields in such a forecast appears reliable and is easily adoptable by the end users. This kind of a forecasting approach is completely new and has (to authors' knowledge) not been carried out for this purpose before. Systematic studies of compression, involving the whole chain from ice cover dynamics to the ship experiences, have been lacking.
Ice pressure has in some applications been claimed to be obtained from satellite image analysis. One should be cautious with such interpretations, since even if there is an obvious coupling between converging (or compacting) ice and pressure, they represent different physical phenomena. This has also been noted in the most recent updates of WMO definitions of ice features, making a distinction between these two features.
A comprehensive approach has been made to forecast ice pressure, an issue which until now seems to have been avoided by the ice modelling community due to its complex nature. Inclusion of compression in real-time operative ice forecasts in an adaptable form substantially improves decision making.
Probabilistic Seismic Hazard Analysis of an LNG Storage Facility in Warm Permafrost
Authors: Thornley John D. 
Published: March 2015

Abstract
In conjunction with the development of a LNG storage tank facility in Fairbanks, Alaska a geotechnical investigation and probabilistic seismic hazard analysis (PSHA) was performed. The site is located within a region in Fairbanks where warm permafrost soils exist (-1°C average soil temperature at depth). In support of the PSHA, field work included vertical shear wave velocity profiling using surface to down hole measurements and multichannel analysis of shear wave velocity (MASW) geophysical techniques. Shear wave velocity measurements suggested that the site be classified as a Seismic Site Class B to C, despite the fact that the soil temperature was just below freezing. A discussion of the PSHA, Fairbanks seismicity is provided. However, because very few shear wave velocity profiles have been developed in warm permafrost, the discussion of the results and how they compare to other studies in Fairbanks shows the unique nature of seismic site response evaluations in warm permafrost regions. LNG facilities are increasing in presence in the Arctic as natural gas is extracted and taken to market. Regions with high seismicity and permafrost soils will have to consider the effects of frozen soils on these facilities during seismic events. This study offers an understanding of those effects and provides insight into site-specific effects of permafrost on a probabilistic seismic hazard analysis.
Gigabytes, Terabytes, a LOT of Bytes? What to Do with Six Years of Chukchi Sea Environmental Studies Data
Authors: Cowee Christie , Eick Cindy 
Published: March 2015

Abstract
The Chukchi Sea Environmental Studies Program (CSESP) started 2008, beginning directly after Lease Sale 193 (MMS, 2008). A joint effort between ConocoPhillips and Shell, including Statoil from 2010-2013, the program offers a multidisciplinary, multiyear approach to understanding the Arctic ecosystems of the northeastern Chukchi Sea though environmental baseline data collection in support of oil and gas exploration and permitting.
Seven years of program data amounts to terabytes of zeroes and ones in many scientific disciplines. This paper focuses on the organization, storage, and distribution methods used for CSESP data, with an emphasis on metadata creation and preparation for public release.
Data organization begins on vessels with strict, standardized data capture methodologies and continues with well-defined longer-term data storage processes on shore. Scientific observations, final results, vessel instrument data, weather data, acoustic sound files, and photos are all part of the CSESP data universe. Documentation and metadata are crucial to keeping that universe intact and accessible, now and years down the road.
In 2011, CSESP sponsors signed a data sharing agreement with the US National Oceanic and Atmospheric Administration (NOAA). All datasets are submitted to NOAA for public archiving and access via the internet. The CSESP data were already well organized and documented, but public data sharing required a new level of effort to consolidate information from final reports, individual documents, and existing metadata into comprehensive metadata complying with the US Federal Geographic Data Committee (FGDC) standard (FGDC, 1998).
Porosity and permeability development in compacting chalks during flooding of nonequilibrium brines: Insights from long‐term experiment
Authors: Nermoen Anders , Korsnes Reidar I. , Hiorth Aksel , Madland Merete V. 
Published: March 2015

AbstractWe report the complete chemical alteration of a Liège outcrop chalk core resulting from a 1072 flow‐through experiment performed during mechanical compaction at 130°C. Chemical rock‐fluid interactions alter the volumetric strain, porosity, and permeability in a nontrivial way. The porosity reduced only from 41.32% to 40.14%, even though the plug compacted more than 25%. We present a novel analysis of the experimental data, which demonstrates that the geochemical alteration does not conserve the volume of the solids, and therefore, the strain is partitioned additively into a pore volume and solid volume component. At stresses beyond yield, the observed deformation can be explained by grain reorganization reducing the pore space between grains and solid volume changes from the rock‐fluid interactions. The mechanical and chemical effects are discussed in relation to the observed permeability development.
Water mass pathways to the North Atlantic oxygen minimum zone
Authors: Peña‐Izquierdo Jesús , van Sebille Erik , Pelegrí Josep L. , Sprintall Janet , Mason Evan , Llanillo Pedro J. , Machín Francisco 
Published: April 2015

AbstractThe water mass pathways to the North Atlantic Oxygen Minimum Zone (naOMZ) are traditionally sketched within the cyclonic tropical circulation via the poleward branching from the eastward flowing jets that lie south of 10°N. However, our water mass analysis of historic hydrographic observations together with numerical Lagrangian experiments consistently reveal that the potential density level of σθ = 26.8 kg m−3 (σ26.8, approximately 300 m depth) separates two distinct regimes of circulation within the Central Water (CW) stratum of the naOMZ. In the upper CW (above σ26.8), and in agreement with previous studies, the supply of water mainly comes from the south with a predominant contribution of South Atlantic CW. In the lower CW (below σ26.8), where minimal oxygen content is found, the tropical pathway is instead drastically weakened in favor of a subtropical pathway. More than two thirds of the total water supply to this lower layer takes place north of 10°N, mainly via an eastward flow at 14°N and northern recirculations from the northern subtropical gyre. The existence of these northern jets explains the greater contribution of North Atlantic CW observed in the lower CW, making up to 50% of the water mass at the naOMZ core. The equatorward transfer of mass from the well‐ventilated northern subtropical gyre emerges as an essential part of the ventilation of the naOMZ.