bluuebunny/crossref_metadata_2025_split huggingface dataset:
Case Study: Oil Recovery Beneath Ice
Authors: Allen Alan A. 
Published: October 2008

ABSTRACT
Approximately 6,000 gala of No. 2 diesel oil were spilled during the winter of 1977 from an onshore storage tank in Nome, Alaska. The oil saturated the snow and soil adjacent to the storage tank and penetrated the ice cover of Snake River. Oil containment and recovery operations involved the removal of contaminated snow, soil, and ice; sorption of oil with 3M sorbent materials and with available snow at the site; and the collection of oil from beneath an ice cover 3 to 4 ft thick using an oil mop. The oleophilic, closed-loop rope mop was fed beneath the ice between two holes, one for the oil mop wringer assembly and collection reservoir and the other for the system's tail pulley. Recovery totaled approximately 2,000 gal over a period of 1 week with air temperatures approaching -30 °F (-35 °C). Recovery rates of 2 gal/min were achieved with the rope mop beneath the ice, while oil-water ratios were in excess of 95 percent.

INTRODUCTION

Setting
On March 22, 1977, 6,000 gal of No.2 diesel oil were spilled in Nome, Alaska, when a 25,000-gal storage tank was filled beyond its capacity. The storage tank, one of two used for fuel storage at the City of Nome Power Plant, is located adjacent to the Snake River just about a mile and a half from its mouth on the northern coast of Norton Sound (Fig. 1).
Since the spill was not detected until the following day, the nearly 6,000 gal of diesel oil were allowed to move freely out over the snow-covered terrain, up and over a modest bank along the river, and down into an open melt zone created by a hot water discharge from the nearby power plant (Fig. 2). The oil had sufficient time to saturate the snow and soil between the storage tank and the river, and to move into and beneath the ice layers surrounding the exposed melt zone.

Environmental Conditions
The air temperatures before and during the spill and the subsequent cleanup activities were consistently at or below 0 °F (-18 °C). Temperatures frequently dropped to -20 to -30 OF (-29 to -35 °C) and remained there for days at a time. Cloud cover, reduced visibility, and precipitation were minimal throughout the operations except for a few hours of light snowfall. Winds normally were light during the cleanup efforts, except for a few brief periods during which winds approached 15 to 20 knots.
One to 2ft of snow covered most of the ground near the storage tanks, while lesser amounts were typical over open areas where drifting was less pronounced. Snow at the spill site and over the ice-covered river was loose and dry in consistency, granular in structure, and yet sufficiently compactible to form effective barriers (or berms) for the temporary containment of oil.
Tests On Two High-Strength Shori Tubular Columns
Authors: Marzullo Marc A. , Ostapenko Alexis A. 
Published: October 2008

ABSTRACT
As part of an investigation of the local buckling of high-strength steel tubular columns as used in offshore construction, two 1.52-m (60-in.) diameter, 2.43-m (8-ft) long columns were tested.
One column was made from nominal 345-MPa (50ksi) yield stress steel and had a transverse weld located at midheight. The buckling stress of this column when plotted against ? = (Et)/(FyD) fell on a smooth curve formed by the test results of other columns fabricated from-345-MPa (50-ksi) steel that had no transverse welds and were tested previously at Lehigh U. This indicated that the presence of a transverse weld had no apparent effect on the buckling stress.
The second column had only a longitudinal weld and was made from a higher-yield stress, 690-MPa (l00-ksi), steel. The buckling-stress value relative to the yield stress of this column when plotted against a fell, above the curve, formed by the 345-MPa (50-ksi) columns. This indicated that the effect of the yield stress may not be non dimensionalized by the popular parameter a and that local buckling stress of 690-MPa (100-ksi) tubular columns may be higher than the stress that would be predicted on the basis of the 345-MPa (50-ksi) tests.
Both tests as well as other Lehigh tests demonstrate that the present API and AIST rules for local buckling of tubular columns are quite conservative.
The paper gives a description of the specimens, the test setup, the test procedure, and the general specimen behavior. In addition, the initial imperfections of one column and the effect of prebuckling lateral deformations on the location and pattern of initial local buckling are described.

INTRODUCTION
Tubular columns fabricated from high-strength steels by cold-rolling and welding are used in many engineering structures. Of particular interest are the columns having thicknesses greater than 3 mrn (1/8 in.) in which local buckling is expected at stresses between the proportional limit and the yield stress. In this stress range, the design of fabricated members with respect to local buckling is very uncertain because of considerable discrepancies between the current design recommendations as indicated in Fig. 1.
The principal design curves shown are: AISI (American Iron and Steel Institute,1 API (American Petroleum Institute),2 DNV (net Norske Veritas),8 Donnell and Wan,4 and Plantema.7 The ordinate is the ratio of the buckling stress to the yield stress, Fcr/Fy, and the abscissa is the nondimensional parameter.
(Mathematical equation available in full paper)
The small open circles in the figure represent the pertinent test results obtained by Wilson and Newmark9,10 on mild steel specimens, Fy = 214 to 280 MPa. In spite of the wide scatter, these results together with those on specimens manufactured by other means (not shown) served as a basis for the design curves.
In order to investigate how well these test results and design curves apply to tubular columns made of high-strength steel, eight tests were conducted at Lehigh U.
Behavior Of Anchors In Different Soil Conditions
Authors: Puech Alain , Meunier Jacques , Pallard Michel 
Published: October 2008

ABSTRACT
The application of soil mechanics concepts to the problem of anchor holding power clearly illustrates the insufficiency of the concept of efficiency by itself, in that it is merely an empirical relationship between the weight of the anchor and its holding power. Laboratory and in-situ tests have been performed to analyze the behavior of special adjustable-configuration anchors as a function of the nature of the soil and to determine the influence of leading geometric and mechanical parameters on the kinematics. Holding power appears mainly linked to fluke surface area, depth of anchor burial and the mechanical properties of the soil. In-situ tests performed on small-sized anchors confirm the general analysis and provide bases for comparing the leading anchors used in offshore operations.

INTRODUCTION
The anchoring of floating supports (barges or semi submersible platforms) used during operations associated with the exploration for or production from offshore hydrocarbon fields raises specific problems that are essentially different from the anchoring problems encountered in traditional offshore operations:tensions on anchoring lines are especially great in excess of 100 tonnes for drilling platforms;the movements tolerated for the support are extremely limited so that anchoring points must be absolutely fixed (no dragging);anchoring time, which may vary with the type of operation, may be relatively long (several months in the case of drilling supports or several years for production supports).
On the other hand, the mechanical properties of sea floor soil are generally known as the result of geophysical and geotechnical surveys.
The rational calculation of an anchoring system involves:choosing a type of anchor especially suited to the problem at hand, i.e. taking the above-designed criteria into consideration;making an accurate estimate of the holding power of the type selected as calculated from soil data.
Lack of information concerning anchor behavior and. the insufficiency of the concept of efficiency, as is lamented by most users, do not enable a satisfactory answer to be given to these two questions of prime importance.
The joint research project undertaken in 1976 by the Institut Français du Pétrole (IFF) and the Centre National pour l'Exploitation des Oceans (CNEXO) had the following two main objectives :gaining better understanding of the phenomena characterizing anchor behavior and kinematics;improving ways of predicting anchor holding power as a function of the soil encountered.
The complexity of the problem required the is plementation of highly diversified experimental and theorical methods :laboratory tests on scale models,in-situ tests of medium sized anchors,development of a computerized program for calculating holding power by finite elements,two dimensional analogical model testing to calibrate the numerical model.
This paper reviews the leading experimental findings made during this project. The numerical findings will be published later on.
Experimental Study On The Liquefaction Of Sandy Seabed Under Offshore Oil Storage Tanks
Authors: Kobayashi Hiroshi , Nagatsuka Makoto 
Published: October 2008

ABSTRACT
As one of activities of the 1977-fiscal year for the R&D project of offshore oil storage system being conducted under the supervision of Japan Ocean Industries Association and in the budget of Ministry of International Trade and Industry, a series of experimental study on the liquefaction of sand foundation have been performed to investigate the aseismatic stability of offshore oil storage tank of gravity type. Acceleration of shaking table, tank model, sand bed, pore-water pressure of sand bed and settlement of tank model etc. are measured to describe experimentally the phenomenon of liquefaction and study the liquefaction potential in relation to the stability of structure. Excess pore-water pressure can be expressed with equations to a good degree of accuracy and liquefaction potential of ground is assessed on the basis of soil test in laboratory. In addition to the improvement of physical information of ground for better assessment of liquefaction potential, prevention of liquefaction and anti-liquefaction design of structure are the problems for further discussion to be solved according to situations. The results will be reflected upon the recommendations for the aseismatic design of offshore oil storage system prepared by Japan Ocean Industries Association (JOIA).

INTRODUCTION
Quantitative observation of liquefaction of sandy seabed is performed by means of experimental study of offshore oil storage tank model of gravity type in order to study liquefaction potential of seabed and stability of overlying structure. The influence of existence of structure and sea water around structure upon liquefaction potential of seabed are also discussed.
There are such problems of the ground underlying structure as shear failure, settlement due to consolidation, sliding of structure and liquefaction. The studies on these for conventional structure have been applied to the design and construction of marine structure and contributed to the improvement of safety.
Liquefaction of ground has been well known in earthquake region as such phenomena as blowup of sand, unusual settlement of structure, etc. The study on liquefaction has been gradually promoted up to date. However, it is scarcely performed on the liquefaction of seabed for offshore structure of gravity type. The structure of this type are going to be constructed in earthquake region and the liquefaction of seabed will be one of the important items for discussion.
Rise of pore-water pressure due to seismic shake causes reduction of vertical effective stress, leading up to liquefaction of ground when such damages as settlement of overlying structure and surfacing of embedded structure will occur. Liquefaction of ground was already taken up for study by Taylor(l) and Mogami et al(2) in the 40's and 50's. Sunami(3) made a detailed observation of liquefaction and settlement of sand bed in a shaking box. Seed(4) tried to predict liquefaction of ground with applying the result of cyclic triaxial compression test.
Nitrogen-Oxygen Saturation-Excursion Diving
Authors: Lambertsen Christian J. 
Published: October 2008

ABSTRACT
Isobaric inert gas counter diffusion is an unusual, hazardous and newly discovered circumstance of modern diving in which differential rates of inert gas movement in opposite directions in a tissue can lead to gas super saturation and gas bubble disease without change in pressure (isobaric state) (1)(2). The expressions of the phenomenon include severe cutaneous itching, development of gas lesions in the skin, incapacitating vertigo from vestibular derangement, and lethal gas bubble embolism. Since the problem has been recognized for only a few years, it is not yet commonly understood. Because it has implications to safety in diving operations, in decompression and in therapy of decompression sickness, this description will define conditions in which potential hazard due to isobaric counter diffusion exists and conditions in which it does not.

BACKGROUND
Over the more than 100 years that decompression sickness has been known, the gas used in most diving has been air. When helium diving was introduced in about 1935, it was used, with necessary oxygen, from start to finish in a dive, without gas switching during decompression. Such use of helium alone continued in naval diving, and then expanded with increasing interest in deep diving for commercial purposes. Its use in conjunction with other inert gases was suggested to facilitate deep diving or decompression from it.

GAS SWITCHING AND "DEEP TISSUE COUNTERDIFFUSION"
Among the methods proposed to complement use of helium-oxygen alone were those providing for speeding the elimination of helium by breathing another inert gas-oxygen mixture during decompression (3)(4). In this manner, switching to air breathing during decompression after a deep helium dive enables the more rapidly exchanged helium to be eliminated faster than the more slowly exchangingli1trogen is taken up by the same tissue compartments. The advantage - a more rapid lowering of tissue total inert gas pressure is aimed at providing more rapid decompression or safer decompression. While more rapid elimination of helium must result, it has been noted that the switch to nitrogen may be associated with development of vertigo, indicating vestibular dysfunction (5). This occurrence does not yet have a clear or demonstrated explanation. The method should be a rational and effective procedure for reducing tissue total gas pressure in all tissue compartments as long as abrupt switch of airs is avoided, precautions are taken against isobaric counter diffusion, and the pressure of the switch to air is low enough to avoid prominent nitrogen narcosis or oxygen toxicity. It differs entirely from the use of nitrogen in a mixture with helium for voice modification or other purpose.
The second form of gas switching involves changing to helium breathing after prolonged periods of work while breathing air or nitrogen oxygen mixtures at increased pressure (Fig. 1). This procedure has been employed experimentally (6)(7)(8)(9), in excursion from nitrogen saturation states and in special situations in the therapy of decompression sickness.
Remote Acoustical Mud-Gas Ratio And Density Sensor
Authors: Roberts L.R. 
Published: October 2008

INTRODUCTION AND ABSTRACT
The prompt and accurate measurements of mud properties are well known drilling-response indicators.1,2 An automatic, remote sensing instrument is under development which will measure the following parameters when installed in riser joints down to 3,000 feet depth: mud/gas mass ratio, mud flow rate, and mud density. Measurements will be multiplexed along a single cable and interfaced to the computer-display system of the data recording system.
The purpose of this paper is to discuss the theory of operation, the engineering factors to be considered, and the experimental development fixture which is nearing completion. The test results will be a subject of a subsequent paper when available.
The evolving concept is directed to finding the engineering solutions to the many anticipated environmental and physical problems. These include high pressures, cuttings, and abrasives in the riser, interference from the drill stem, ambient noise conditions, gas bubble size distribution, gas solubility and water density cutting.

THEORY
The measurement of the three properties will be discussed separately, beginning with the mud/gas mass ratio (?). We define ? as the ratio of the mass of mud to the mass of gas in a unit volume. Since mud is inherently much more dense than gas, even when gas is compressed at 3,000 feet depth, the normal operating range for ? is about 106 - 107. Values of 105 or lower would represent significant gas-cutting of mud.
The theory of operation is based upon the behavior of the speed of sound (c) in a mixture of fluids. For these purposes both mud and gas may be properly considered fluids since neither will support a shear stress. The speed of sound in mud itself as a fluid is determined largely by its porosity, the volume proportion of interstitial liquid to solid matter3. For porosity greater than about 0.5 the speed of sound is almost exactly that of the surrounding liquid. Normal drilling muds with density up to 20 lb/gal will thus behave as fluids acoustically.
Conceptually, as gas is added to the mud the speed of sound in the mixture will decrease from its nominal value of about 1,600 m/sec, since the speed of sound in any gas is much lower than this. When present, the solids in drill cuttings will have a slight opposite influence. The precise value of the speed of sound depends upon the type of gas, temperature and pressure in a known way; the relationship is4.
(Mathematical equation available in full paper)
A curve of c as a function of log10? for typical conditions is included as Figure 1.
The quantities ?1, ?2, c1, and c2 can either be directly measured or deduced from auxiliary measurements. The theory of operation is, therefore, to measure c and then to "compute" ?. Actually, rather than "compute," it is intended to use a statistical estimator for ? which not only handles the various uncertainties in the problem but also provides a predictor for future values.
Ultra Large Fire Fighting Installations In North Sea Emergency Support
Authors: Flyen T. 
Published: October 2008

ABSTRACT
As a result of the oil exploration activities in the North Sea, a number of new oil fields have gone into production. To protect these installations, new, heavier and more complicated fire fighting equipment and systems have been developed. This paper describes briefly various design criterias for Fire Fighting Vessels seth forth by Det norske Veritas and other public agencies and the solutions developed to comply with these requirements. One section is devoted to a theoretical study of a supply vessel hull movements in various sea states to establish a set of monitor control design parameters. Practical experience and recommendations are listed and a summery of present and future development is given.

INTRODUCTION
Recent years have shown a spectacular increase in fire fighting equipment for the protection of North Sea Oil field installations. Not only have the size of the equipment grown but the fire fighting systems have also become far more complex and requires more advanced engineering to give optimum performance.
The fire protection systems may be divided in two major groups:–Platform self protection fire fighting systems–Emergency Support Vessel based Rlatform Fire Protection Systems
This last group is the subject of this paper. We would like to emphasize however at this early stage that the Ultra Large Fire Fighting Systems are not designed for extinguish hydrocarbon fires, but to cool platform structures and prevent them from collapsing.
We have for some time felt the need for a classification of system requirements and engineering specifications in this field. The following is a summery of the experience we have gained from developing various equipment and systems for North Sea Fire Fighting Vessels.
It is not our intention to answer all questions. There is undoubtly room for improvement in existing equipment, especially concerning monitor hydrodynamics, jet performance and system controls. But we would like to establish a basis for further development and to point OUX some of the most common problems encountered in designing fire fighting systems for todays North Sea ESVs.

THEORY & DEFINITIONS

FIRE FIGHTING PROBLEMS
Offshore fire fighting problems may be divided into 5 major categories.Platform Fire ExtinguishingPlatform Structure Self ProtectionPlatform Crew Rescue OperationsPlatform Cooling by Emergency Support VesselsEmergency Support Vessel's Self Protection
The subject of this paper is category D with some references to category E. It should be remembered however that this is only one part of the fire fighting problems and that the intentions with the equipment and systems described herein are not to extinguish hydrocarbon fire, but to cool the platform structures to keep them from collapsing in a fire.