bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abandonment of Offshore Exploration Wells using a Vessel Deployed System for Cutting and Retrieval of Wellheads
Authors: Sørheim Odd Inge , Ribesen Bjørn Thore , Sivertsen Trond Eggen , Saasen Arild , Kanestrøm Øystein 
Published: December 2011

Abstract
Plug and Abandonment (P&A) can contribute with 25% of the total drilling costs of exploration wells offshore Norway. Cost efficient P&A technology is therefore necessary. In this paper, qualified technology for cutting and retrieval of wellheads using a separate vessel is described in detail. It is shown how to use this technology to significantly reduce the costs of exploration drilling. The technology has now been used on several abandonment operations on the Norwegian continental shelf.
During the P&A phase of the North Sea offshore exploration well, Trolla, the rig was unable to pull the 9-5/8" production casing and was therefore unable to secure and abandon the well according to plan. This incident prevented the wellhead from being retrieved in accordance with Norwegian legislation. The required barriers were reestablished by squeezing cement through cuts in the production casing. Then the well was permanently plugged; leaving the wellhead temporarily abandoned by installing a trawl protection. This is used while waiting for a vessel to arrive for completing the operation. A high pressure abrasive water jet cutter was run from this vessel.
The abandonment operation with this vessel, the world's deepest multistring conductor cut using such a system, was successful. It is shown how the casing was cut, and how the complete wellhead including the guide base was retrieved with the vessel active heave compensated crane.
On a different Norwegian Sea well, a spud foundation "can" was used at a water depth of 274 m MSL to preinstall a wellhead foundation on the seabed. The paper show how the surface casing was cut approximately 12.5m below the top of the wellhead by using water jet cutting technology and how the wellhead together with the can was retrieved in the P&A operation.
Use of a Wireline Formation Tester to Optimize Sampling and Production Testing Operations in Environmentally Sensitive Drilling Environments
Authors: Weinheber Peter , Danilova Darya , Galkin Maxim , Ayan Cosan , Deliya S. V. 
Published: December 2011

Abstract
Production tests are usually taken to be the gold standard by which to appraise the reservoir. The ability to flow the zone after it has been cased and perforated provides the best approximation to what actual reservoir performance will be. The complete interval is perforated, usually with the same completion technique that the reservoir will be developed with. Large volumes of fluid can be flowed which ensures representative samples are acquired and also allows for deep depth of investigation during the pressure transient analysis of the build-up. However, such a wealth of information does not come easily. In certain environments a full production test can takes weeks and cost many millions of dollars. And in addition to the cost is the reduced drilling efficiency – in environments with limited drilling seasons the time taken to perform a production test will reduce the number of wells that can be drilled in a season.
An alternative to the above approach is the wireline formation tester (WFT). The pump-out WFT has been in use for over twenty years. Although these tools can never hope to fully replace the production test, a judicious combination of WFT and DST data can answer many of the pertinent issues for reservoir evaluation and in some cases address the requirements of state or financial regulatory bodies.
In this paper we present a reservoir analysis based on data acquired with a conventional DST and compare this to an analysis with data acquired using a wireline formation tester. The strengths, weaknesses and applications of each are discussed.
The Challenges of Russian Arctic Projects
Authors: Barnes Richard J. 
Published: December 2011

Abstract
Building an oil or gas project in the Russian Arctic is one of the most challenging projects to complete successfully. The project team must overcome extreme conditions in a region which is environmentally sensitive, ecologically fragile, extremely remote, and with little or no infrastructure. Frequently tasks must be scheduled to be completed in narrow weather windows. Even after the facility is built, the operational phase poses at least as many challenges in keeping the facility running safely and efficiently at design capacity in very cold temperatures and far away from technical support and spare parts.
Getting men and materials to site and exporting the crude oil or gas is a particular challenge due to the remote location and extreme distances. Road and rail transport is near non-existent. Ice roads can be used during the winter, but sea transport is frequently only possible during the summer months.
Special design and construction techniques must be used to ensure that the facility can operate at extremely low ambient temperatures.
This paper provides:
A brief discussion on different concepts for field development and highlights some of the advantages and disadvantages of the concepts. A review of some of the projects that have been executed in the Arctic and other extreme environments, both onshore and offshore, and describes some of the challenges they faced and how these were overcome.
The paper will be of interest to anyone new to or with limited experience of executing projects in the Russian Arctic region, either onshore or offshore.
Geomagnetic Referencing in the Arctic Environment
Authors: Poedjono Benny , Beck Nathan , Buchanan Andrew , Brink Jason , Longo Joseph , Finn Carol A. , Worthington E. William 
Published: December 2011

Abstract
Geomagnetic referencing is becoming an increasingly attractive alternative to north-seeking gyroscopic surveys to achieve the precise wellbore positioning essential for success in today's complex drilling programs. However, the greater magnitude of variations in the geomagnetic environment at higher latitudes makes the application of geomagnetic referencing in those areas more challenging.
Precise, real-time data on those variations from relatively nearby magnetic observatories can be crucial to achieving the required accuracy, but constructing and operating an observatory in these often harsh environments poses a number of significant challenges. Operational since March 2010, the Deadhorse Magnetic Observatory (DED), located in Deadhorse, Alaska, was created through collaboration between the United States Geological Survey (USGS) and a leading oilfield services supply company. DED was designed to produce real-time geomagnetic data at the required level of accuracy, and to do so reliably under the extreme temperatures and harsh weather conditions often experienced in the area.
The observatory will serve a number of key scientific communities as well as the oilfield drilling industry, and has already played a vital role in the success of several commercial ventures in the area, providing essential, accurate data while offering significant cost and time savings, compared with traditional surveying techniques.
Multilateral Wells Reduce Capex and Opex of Gas Development in Russia’s Arctic in an Environmentally Responsible Way
Authors: Quereguan Rene , Grossmann Andreas 
Published: December 2011

Abstract
The use of multilateral technology (MLT) reduces the number of production wells required to effectively drain a reservoir; consequently, it saves time and reduces costs. Fewer discrete surface locations significantly reduces both investment capital and footprint. Although reducing the infrastructure cost is the primary benefit of multilateral well architecture, in remote arctic environments, additional benefits include reduced project execution time (in this case, approximately 50 less days), which reduces the costs associated with the heating of fluids and equipment and the costs for cuttings disposal.
To take full advantage of the benefits, the appropriate MLT must be selected to avoid introducing additional risk and nonproductive time (NPT) to the project. The requirements for the multilateral system in the Yamal-Nenets area included constructing a mechanically strong junction and preventing communication between the two reservoirs. The TAML Level 4 multilateral technology, which provides hydraulic and mechanical isolation of the connected wellbores, meets this requirement. Although this was the first time that this level of junction was used in the Yamal-Nenets area, it has been used extensively in various geographical areas during the last 10 years.
Capital Costs Estimation Method for Arctic Offshore Oil Projects
Authors: Kuznetsov Mikhail , Sevastyanova Kristina , Tarasov Petr , Zilber Vladimir , Nekhaev Sergey 
Published: December 2011

Abstract
This paper describes an approach to offshore oil field development capital costs estimation on the early stages of a project life. The proposed methodology is based on the use of parametric methods and correlations derived from the worldwide actual project data. The result of research is a group of models, which statistical error is acceptable for a conceptual design.
Approaches to Development of High-Viscosity Oil Fields in Arctic Conditions using the Example of the Russkoe Field
Authors: Edelman I , Ivantsov N.. , Shandrygin A.. , Makarov E.. , Zakirov I.. 
Published: December 2011

Abstract
The article discusses approaches to developing the Russkoe gas and oil field and results of pilot operations. The field is unique in terms of both hydrocarbon reserves and problems associated with its development. It is located above the Polar Circle and is characterized with a complex geological structure of highly permeable poorly cemented reservoirs saturated with high- viscosity oil (250-300 mPa*s). Significant factors making field development difficult include presence of tectonic faults, extensive gas cap, and underlying water. Field development was started with pilot operations whose results lay the foundation for the full field development strategy. The article describes technological solutions used and development scenarios considered.
Mathematical Modeling of Floating Anchored Objects Behaviour Under the Level Ice of Ridges Influence
Authors: Bolshev Alexander , Shkhinek Karl , Frolov Sergey 
Published: December 2011

Abstract
The present paper covers the methodology of mathematical simulation of floating anchored structures behaviour under the external loads influence. The paper also describes the realization of the dynamic ice loads calculation method. The technique can be used in research or design works related to the development of the new floating objects for the Arctic conditions. The paper considers the mathematical models of the floating anchored structure behaviour under the influence of the level ice, the consolidated part and the keel of ridge. All listed models are combined into one algorithm for the description of floating structure behaviour under the influence of the ice formations. There are some results of comparative calculations which confirm the working capacity of the offered techniques presented in this paper. The paper also provides the results of some floating anchored structures modelling under the influence of the level ice and ridges. They confirm the importance of the dynamic effects in the task level in question as well as the necessity of using the offered mathematical modelling methods to adequately describe the anchored structures behaviour under the influence of ice.
Experience of Designing Offshore Pipelines during Development of of Arctic Offshore Fields
Authors: Mansurov M. N. , Lapteva T. I , Velikodnev V. Ya , Skrepnyuk A. B. 
Published: December 2011

Abstract
Development of offshore hydrocarbon (HC) fields is today’s oil and gas industry priority in the Russian Federation. Water areas of the Arctic shelf are considered to be potential offshore HC production regions. When designing pipelines for such fields it is necessary to take into account the impact of specific Arctic conditions including hazardous ice impact (ice gouging), possible presence of permafrost on the seabed, lithological and geomorphological distinctive features of bottom soils. All main parameters ensuring safety of offshore pipelines must be determined and validated at the early design stage.
The paper reviews one of the main conditions that influences reliable operation of underwater pipeline systems, namely, stable position of the underwater pipeline at design reference marks.
Calculations of offshore pipeline stability on the seabed use the following main conditions: –environmental conditions;–geotechnical conditions of the seabed;–bathymetrical conditions (water depth);–pipeline parameters (diameter, wall thickness).
Criteria of pipeline stability on the seabed include: floating up or submerging of pipeline;transversal stability;longitudinal stability.
Soils with weak strength properties, especially when they are used for backfilling, may be potentially dangerous due to liquefaction under hydrodynamic forces. It is especially dangerous in the first years of operation when the soil is not consolidated enough. Relief in a local zone of diluted soil causes longitudinal stresses in pipeline, which may result in offshore pipeline stability loss. Liquefied soil potential depends also on backfilling process technology. This operation is performed by special ships – dredgers. Such ship has two pipes, one for soil suction, and the other equipped with water injection nozzles - for washing out and backfilling. When a trench is backfilled with controlled soil flow, "front" of backfill material is formed under pipe working head and a layer of fluidized material appears in the upper part of this "front". Therefore, if weak soil is used as backfill material, a size of liquefied soil layer will be considerable, as well as its impact on the pipeline. This process may lead either to floating up or submerging of pipeline into the soil. To stabilize offshore pipelines position the following measures can be taken: backfilling with soil not subject to liquefaction; pipeline laying below the layer of liquefied soil to eliminate risks related to soil liquefaction; using different methods of ballasting.
Trenching of Pipelines for Protection in Ice Environments
Authors: Paulin Mike , Humby Damien , Cocker Joseph , Lanan Glenn 
Published: December 2011

Abstract
Subsea pipelines located in ice environments need to be protected from potential ice gouging (also known as ice scouring) created when a moving ice keel interacts with the seabed. The integrity and operability of the pipeline can be affected by direct contact between the ice keel and the pipeline, or from loading imposed on the pipeline through soil deformation caused by ice gouging. The typical method considered for protecting against the risk of damage caused by ice gouging is through pipeline burial.
Conventional methods of pipeline burial use equipment such as ploughs, mechanical trenchers, and jetters, the majority of which have been designed to accomplish a maximum of 2 to 3m of pipeline burial. Dredges can be used but they have water depth limitations and limited productivity. Land based equipment has been used for shore crossings, but is limited to shallow water depths where temporary construction berms can be used as a working platform.
The capabilities of existing technologies are based on current industry practice developed for pipeline burial in ice free environments. Pipeline burial requirements have generally been for improved hydrodynamic stability, mechanical protection (e.g. from anchors), controlling pipeline movements (e.g. expansion and buckling) and/or for flow assurance purposes (reducing heat loss). A 2 to 3m burial depth has been generally adequate to satisfy these conventional requirements. As developments are proposed for areas that experience relatively deep ice gouging (up to 5m), burial depth requirements will exceed the capabilities of current pipeline burial technologies. New technologies capable of working in deeper water, achieving greater burial depths, achieving reasonable trenching advance rates, operating in harsh environments, and trenching through variable and difficult seabed soils will be required.
This paper highlights the issues and challenges surrounding pipeline trenching and burial in ice gouge environments. Current state-of-practice is discussed along with the technology gaps that need to be addressed to prepare for future offshore developments in ice covered waters where there is the potential for seabed ice gouging.
An asymptotic approximation of Wallis’ sequence
Authors: Lampret Vito 
Published: December 2011

Abstract
An asymptotic approximation of Wallis’ sequence W(n) = Πk=1n 4k
2/(4k
2 − 1) obtained on the base of Stirling’s factorial formula is presented. As a consequence, several accurate new estimates of Wallis’ ratios w(n) = Πk=1n(2k−1)/(2k) are given. Also, an asymptotic approximation of π in terms of Wallis’ sequence W(n) is obtained, together with several double inequalities such as, for example,
$W(n) \cdot (a_n + b_n ) < \pi < W(n) \cdot (a_n + b'_n )$
with
$a_n = 2 + \frac{1}
{{2n + 1}} + \frac{2}
{{3(2n + 1)^2 }} - \frac{1}
{{3n(2n + 1)'}}b_n = \frac{2}
{{33(n + 1)^{2'} }}b'_n \frac{1}
{{13n^{2'} }}n \in \mathbb{N}
$
.
Developmental expression of P5 ATPase mRNA in the mouse
Authors: Weingarten Lisa , Dave Hardi , Li Hongyan , Crawford Dorota 
Published: December 2011

AbstractP5 ATPases (ATP13A1 through ATP13A5) are found in all eukaryotes. They are currently poorly characterized and have unknown substrate specificity. Recent evidence has linked two P5 ATPases to diseases of the nervous system, suggesting possible importance of these proteins within the nervous system. In this study we determined the relative expression of mouse P5 ATPases in development using quantitative real time PCR. We have shown that ATP13A1 and ATP13A2 were both expressed similarly during development, with the highest expression levels at the peak of neurogenesis. ATP13A3 was expressed highly during organogenesis with one of its isoforms playing a more predominant role during the period of neuronal development. ATP13A5 was expressed most highly in the adult mouse brain. We also assessed the expression of these genes in various regions of the adult mouse brain. ATP13A1 to ATP13A4 were expressed differentially in the cerebral cortex, hippocampus, brainstem and cerebellum while levels of ATP13A5 were fairly constant between these brain regions. Moreover, we demonstrated expression of the ATP13A4 protein in the corresponding brain regions using immunohistochemistry. In summary, this study furthers our knowledge of P5-type ATPases and their potentially important role in the nervous system.
From a Tb3+ chelated compound to a hybrid material: selective emission responses to anions
Authors: Zhang Zheng-Yang , Wang Qian-Ming , Wu Jian-Zhong , Cai Wei-Sheng , Yu Yi-Fei 
Published: December 2011

AbstractA novel terbium 2-hydroxymethyl-benzoimidazole-6-carboxylic acid complex has been designed and unique emission changes to fluoride anions in comparison with HSO4−, AcO−, Cl−, Br−, and I− were observed. Then, the complex was encapsulated into an inorganic matrix. The novel hybrid material, with strong green emission was successfully synthesized as an anions receptor in water. More importantly, this hybrid material not only gave luminescence response to F−, but also to HSO4−. Spectroscopic studies demonstrated that the recognition process for fluoride ions can be mainly ascribed to its hydrogen bonding interactions with hydrogen bond donor units (NH and OH). In case of hydrogen sulfate, the sensing effects can be probably attributed to its acidity instead of hydrogen bonding interactions.
Determination of impurities for controllable growth of high quality optical fluorite
Authors: Mouhovski Jordan , Detcheva Albena 
Published: December 2011

AbstractNatural fluorite is used for growing CaF2 boules from melt by an improved technique. Chemical treatment of the starting ore decomposes the accessory minerals, thus producing small amounts of the oxides of Si, Al, and Fe insoluble in the melt, whereas the overall content of rare earth elements (REEs) of hundreds of μg g−1, remains unchanged. Analytical techniques and optical measurements provide for assessing the concentration range and trends in the distribution of residual metal impurities along the height of the boules. Solid sampling electrothermal atomic absorption spectrometry (SS-ETAAS) gives good reproducibility for impurities’ distribution within a large concentration range of 0.1–10 μg g−1. The concentrations of Zn and Cu determined were found to vary within the lowest tenths of μg g−1 range in the starting portions of chemically treated fluorspar and a batch of boules produced subsequently. The concentrations of both elements show a decreasing trend towards the top section within the confidential interval, the width of which confirms the definite in homogeneities in their distribution at those concentration levels. The Fe occurs in the boules below the detection limit, while the content of lead diminishes rapidly towards their upper section, probably due to a shorter path in the liquid phase before any vapour phase transition proceeds. A satisfactory correlation is found between the Pb concentration in ng g−1-range and light-absorption peak intensity at 204 nm, the precise determination of which is impeded due to the overlapping bands and the light-scattering effect. Reliable determination of impurities enables optimisation of the basic purification — growing stages for the production of high grade crystals.
Some argument inequalities for certain analytic functions
Authors: Liu Jin-Lin 
Published: December 2011

Abstract
For analytic functions f(z) in the open unit disk U and convex functions g(z) in U, Nunokawa et al. [NUNOKAWA, M.—OWA, S.—NISHIWAKI, J.—KUROKI, K.—HAYAMI, T: Differential subordination and argumental property, Comput. Math. Appl. 56 (2008), 2733–2736] have proved one theorem which is a generalization of the result [POMMERENKE, CH.: On close-toconvex analytic functions, Trans. Amer. Math. Soc. 114 (1965), 176–186]. The object of the present paper is to generalize the theorem due to Nunokawa et al..
Genre et migration : l'entrée dans la sexualité des migrants d'Afrique subsaharienne en France
Authors: Marsicano Élise , Lydié Nathalie , Bajos Nathalie 
Published: December 2011

Résumé Cet article analyse la recomposition des rapports de genre en contexte migratoire à travers un prisme particulier : l’entrée dans la sexualité de personnes arrivant d’Afrique subsaharienne en France, à partir d’une enquête menée en 2005 auprès de 1 874 migrants d’Afrique subsaharienne en Île-de-France. Il s’agit de mettre à jour l’impact des trajectoires migratoires des femmes et des hommes sur leurs premières expériences sexuelles ainsi que les éventuelles transformations des relations de domination dans la sexualité après la migration. La construction de profils migratoires permet d’opérer une distinction entre contexte de socialisation pendant l’enfance et l’adolescence et contexte dans lequel s’est déroulé le premier rapport sexuel. Si les capitaux socioculturels jouent toujours un rôle déterminant s’agissant des calendriers d’entrée dans la sexualité, l’influence des socialisations scolaire et religieuse diffère selon le contexte d’entrée dans la sexualité, de manière différente pour les femmes et les hommes. En outre, pour les personnes qui ont débuté leur vie sexuelle avant de migrer, les écarts d’âge entre partenaires ainsi que la fréquence des premiers rapports forcés, notamment pour les femmes, témoignent de contextes relationnels particulièrement inégalitaires. À l’inverse, le fait d’avoir migré pendant l’enfance dessine des conditions d’entrée dans la sexualité sensiblement moins inégalitaires, proches de celles des personnes nées en France.