bluuebunny/crossref_metadata_2025 huggingface dataset:
Hot Water: An Economical Approach to Increased Diver Performance and Safety In the Offshore Oil Industry
Authors: Long Richard W. , Smith N. Eugene
Published: October 2008

Since the beginning of diving, cold has been one of the limiting factors to man's performance in the sea. An economical approach to solving this problem was introduced utilizing hot water to replace the heat normally lost by the diver to the cold water. Since its introduction in 1965, several improvements have been made to insure efficient diver performance in the offshore oil industry. This system has supported divers in the open sea for periods in excess of eight hours, and in depths down to 850 feet.

This approach increases the diver's performance when properly applied and makes an everyday reality of what was once considered technically and economically impossible.

Introduction/Origin

The most readily available heat transfer medium for keeping a diver warm cheaply and effectively anywhere in the world is the very water in which he is swimming. The divers worst enemy, cold water, can be his best friend, warm water, once it is heated and flooded over his body. In this way the water's properties of high specific heat and high thermal conductivity can be utilized to form thermally protective barrier within which he can comfortably perform useful work. The first use of hot water to keep a diver warm is not known, although a recorded attempt was made in France in 1935. The inspiration for this probably occurred as a result of swimming in the discharge of a water-cooled marine engine, with an intermediate step of sticking the end of a hose carrying hot water inside a diver's suit at dockside. In this country lobster divers in New England and abalone divers on the West Coast used variations on this theme with some success.

The first really successful use of hot water to keep a working diver warm was in 1965 by the Westinghouse Cachalot team headed by Jerry O'Neill and Alan Krasber. In preparation for the first commercial saturation diving job at Smith Mountain Dam, Virginia, they designed, built, and tested an open-circuit hot water suit and support system. It was recognized that supplemental heat must be supplied the diver if the longer bottom times offered by the saturation diving technique were to be utilized. Since decompression from saturation is the same regardless of time spent in the water, a diver could theoretically spend six to eight hours working each shift. However, in 400 F water a diver using the then conventional wet or dry suit could perform useful work for only one or two hours. Utilizing the hot water system, the Westinghouse team was able to work routinely for two to three hours with the longest dive in excess of five hours.

The hot water system was then introduced to the offshore oil community when the Westinghouse Cachalot System was brought to the Gulf of Mexico in the spring of 1966. The job was to salvage two oil production platforms toppled by Hurricane Betsy off the coast of Louisiana. The hot water system was used extensively over the next five months and was instrumental in compiling 4,600 hours in underwater work.
New Technique Using Superconducting Magnetic Separation to Remove Oil From Water
Authors: Isogami Hisashi , Mochizuki Akira , Harada Susumu
Published: October 2008

Our new technique for produced water treatment removes the oil rapidly and uses a compact system comprising a flocculation unit, a rotating filter, and a magnetic separator with a superconducting magnet. The strong field of the superconducting magnet enables oil to be removed from oily water continuously at a high rate. After preliminary laboratory tests we constructed a prototype treatment system that can treat 100 m3/day. Field test results agreed with the laboratory test results and showed that this system reduced to effluent concentrations less than 5 mg/L. This technique is suitable for use on offshore platforms because the treatment system is compact and the high removal rate it provides prevents environmental pollution when the effluent is dumped into the sea. This technique is applicable to the treatment not only of produced water but also of sewage, industrial waste, and polluted water.

Introduction

Offshore oil production is normally maintained by injecting seawater into oil reservoirs, increasing the oil pressure but also increasing the water-to-oil ratio year by year. Furthermore, since the water extracted from the oil contains much oil, it has a large impact on the environment when it is dumped back into ocean. Thus, there is a need for high-performance equipment separating oil from water. And because space is at a premium on offshore oil platforms, this equipment should be compact.

New Oil-Separation System

System Flow.

Figure 1 shows a flow diagram for our new oilseparation system, which is designed to treat the water initially removed from the raw crude and should thus be installed downstream from a two-phase or three-phase separator. As shown in Figure 1, it consists of four components: a flocculation unit that gathers the oil particles in the water and generates magnetic flocs, a rotating filter that filters the magnetic flocs from the water, a magnetic separator that attracts the magnetic flocs from the surface of the rotating filter and collects them as highly concentrated oil sludge, and a sludge treatment unit that decomposes the oil sludge and recovers oil. The chemicals added in the flocculation unit are also recovered in the sludge treatment unit and recycled. Figure 2 shows samples of the influent and the effluent, which is so clear that it can be dumped into the sea with little impact.

Flocculation Unit.

The flocculation unit is where ferromagnetic particles, a coagulant, and a polymer are injected into the influent, which is then stirred and mixed to generate magnetic flocs containing oil particulates and ferromagnetic particles.

Micrographs of the emulsified oil in the influent water and of the magnetic flocs after flocculation (Fig. 3) show that although the emulsified oil particles are typically only a few micrometers in diameter, most of the magnetic flocs are more than one hundred micrometers in diameter.
Offshore LNG Transfer - A New Flexible Cryogenic Hose for Dynamic Service
Authors: Witz Joel Aron , Ridolfi Matthew Vernon , Hall Gerard Anthony
Published: October 2008

This paper reviews flexible cryogenic hose constructions aimed at the ship to ship transfer of LNG in an exposed marine environment. This application requires a large bore hose to meet minimum flow rate requirements and it must be sufficiently compliant in flexure so that it may be deployed with relative ease between the two moving vessels. A new flexible cryogenic hose is presented that meets the pressure and inner diameter requirements while offering a relatively small operational bend radius in dynamic service.

Introduction

A number of marine applications require a compliant link for the transfer of cryogenic fluids between two units that experience relative movement such as the offloading of LNG from a FSRU to a tanker, ship to ship transfer of LNG from an FPSO to a shuttle tanker in an exposed location and ship to shore LNG transfer. This is a challenging requirement as the low temperatures involved (e.g. 77 K associated with LN2 testing) severely restrict the range of materials available that can be used for this service in bulk form. Austenitic stainless steel 316L and fluoropolymer PTFE are respective examples of suitable metals and polymers for cryogenic service. There are two main methods for providing a conduit for conveying cryogenic fluid between two moving bodies. These are (a) linkage mechanisms incorporating "hard" stainless steel pipe work with articulated joints (swivels) and (b) flexible hoses. The use of linkage mechanisms is a geometric solution where relative motion between two linking elements is restricted to planar rotation by the swivel. The length and orientation of the links are designed to accommodate the required motion envelope. The complexity of the linkage mechanism reflects the number of individual fluid paths and the extent of the relative motions. The key component of such a system is the swivel. A number of swivel designs have been proposed and in one of its simplest manifestations consists of a stainless steel spring energised U-shaped ring made from PTFE resin between the metallic male and female cylinders undergoing relative rotation about their common longitudinal axis where the male cylinder passes through a set of bearings housed within the female receptacle. As with any cryogenic equipment including flexible hoses due account needs to be taken of the common and differential contraction of the components as a result of the change in temperature from ambient to cryogenic conditions. Large bore (16" ID) cryogenic loading arms are examples of linkage mechanisms that have been in service for a number of years.

The alternative technical solution is to use a flexible hose for the cryogenic fluid transfer and this is the subject of this paper. The main types of flexible hose for cryogenic service are presented with a discussion of their performance characteristics.
Design and Analysis of West Seno Floating Structures
Authors: Korloo Jafar , Black Jared , Wu Chunfa , Treu Hans
Published: October 2008

This paper describes the metocaen data, design and analysis of the West Seno TLP, the mooring system design for the Floating Production Unit, and the coupled TLP and the drilling tender assist vessel.

The paper is divided into the following sections:The collection of metocean data, extrapolation, and application to design. Particular emphasis is given to current data.The model test program in a deep water basin facility with capability of generating steady current, with all the risers and tendons modeled. Application of test results to design.Method of analysis and validation of analytical tools and procedures. The analysis was based on fully coupled time domain simulations with all the risers and tendons modeled.FPU mooring system design and analysis.Fully coupled drilling tender vessel and TLP mooring system design and simulations.

Metocean

Wind design criteria was developed from 16 years of wind data recorded at the Sepinggan airport, site measurements carried out by the Institute of Technology Bandung, wind measurements by the Navy in the Makassar Strait, and wind and wave measurements from the drilling vessels and fixed installation.

There were no specific wave measurements, the wave data were determined from the wind by hindcasting. The wave growth in each direction was determined by the water depth, the wind speed, the duration of an event and the directional spreading. The hindcast modeling was verified by applying the same procedure to one of the wind and wave measurements from an offshore platform in the area.

The current conditions in the strait were of prime concern, both for their effect on the floating facilities as well as on the sub-surface elements such as tendons, well conductors and the steel catenary risers for intrafield and export oil and gas pipelines. To determine the design current data, a long term current measurement program was initiated lasting 13 months with data collection intervals in four phases. The data were obtained from six instruments mounted on a subsurface buoy mooring. These consisted of a near surface ADCP, three current meters, temperature/depth recorder, and a pressure sensor.

There is a persistent southward flow through the strait from the Pacific Ocean on the sorth through the Java Sea to the Indian Ocean on the south, which are referred to as the Indonesian Through Flow (ITF) (Figure 1). The flow, however, is complicated by the geometry of the strait, which at the Seno site produces an eddy and a flow that is intermittently counter to the southward flow. The strongest currents in the region flow northward, parallel to the bathymetric (depth) contours. Bottom currents were oriented perpendicular to the depth contours, running back-and-forth through the slope canyon. Most of the current variability was identified as currents that change slowly over periods of weeks or months, which appear to be linked to larger scale of the ITF. The extreme current measured during the campaign is presented in Figure 2.
A Nonlinear Analysis of a Soil Supported Frame
Authors: Hays Clifford O. , Matlock Hudson O.
Published: October 2008

A discrete element method for the nonlinear analysis of plane frames has been developed which considers nonlinear supports, material properties, and geometric effects. The associated computer program can analyze frames supported by battered piles which have axial and lateral restraints. The solution of a plane frame in an offshore drilling platform is presented and the nonlinear effects of supports, material properties, and changes in geometry are demonstrated.

Introduction

The analysis of offshore structures for the effects of gravity, wind and wave forces is one of the most complex problems facing the structural engineer today. A three-dimensional space frame is supported on piles which are driven into a non-homogeneous and highly nonlinear soil medium. The material from which the frame is constructed is nonlinear or at best bilinear. The change in geometry of the structure during loading causes additional nonlinearities. The dynamic and cyclic nature of the loading makes inelastic unloading of the frame material and soil important.

The development of a closed-form or "exact" analysis for such frames does not seem likely in the foreseeable future. However advances in computer technology and matrix methods of structural analysis make possible the numerical solution of the problem using finite and discrete element techniques.

As a step in the development of a complete analysis package, a static analysis of plane frames supported on nonlinear Winkler-type springs was developed which considers both material and geometric nonlinearities. The discrete element solution allows the entire structure, including the piles, to be solved internally in the computer and requires no costly and time consuming external iterations.

Sources of Nonlinear Behavior

A plane frame on batter piles such as might occur in an offshore structure is shown in Fig. 1. The solution of a single pile as a member in a non-homogeneous and nonlinear half space is such a complex and costly problem (Ref. 16) that it does not appear feasible to solve a complete frame supported by a number of such members. However, it was shown in Ref. 12 that the soils' restraint on the pile could be modeled using distributed nonlinear Winkler type springs. That is to say, the soil is assumed to be composed of independent layers in providing lateral and axial resistance to the movement of the pile.

The properties of the springs are described by curves of distributed force (q) versus displacement (w) as shown in Fig. 1. These curves are almost always highly nonlinear, particularly for soft clays. Criteria for determining the lateral q-w curves for clays subjected to static and cyclic loads are available (Ref. 12). Criteria are also available for determining static nonlinear q-w curves for the axial response of clayey soils (Ref. 2) and the axial and lateral response of sandy soils (Ref. 15).

Axial end-bearing forces Q are developed which are a function of the pile end displacement was shown in Fig. 1. Criteria for the development of such curves are available (Ref. 18).
Ultrashort Laser Pulse Uses In Environmental Monitoring
Authors: Phillips Ronald L.
Published: October 2008

Recent advances in laser technology have led to the production of coherent optical pulses having duration in the picosecond (10− 12 second) regime. These time intervals are comparable to or shorter than the phase memory times associated with many atomic systems. This allows the pulse to propagate through a medium such as the atmosphere unattenuated. Ultrashort pulses of particular wavelengths might propagate through clouds unattenuated. Hence ultrashort light pulses might be used to "see" through clouds. The reflection of ultrashort laser pulses might also be used to sense sea state from very high altitudes. Since light travels only 0.03mm in one picosecond these pulses could also be used to measure distances of many miles to a thousandth-of-an-inch.

I. Introduction

Laser sensing techniques have been developed that allow monitoring at very great distances. Recent advances in the development of ultrashort laser pulses have now greatly expanded the possible uses of lasers in environmental monitoring. Laser systems have now generated pulses in the picosecond (10− 12 seconds) regime. Analytical studies based on experimental evidence show that these ultrashort pulses might propagate through most atmospheric conditions with no or very low loss. This phenomena is called self-induced transparency. Also, since light travels only 12 one-thousandth of an inch in one picosecond, these laser pulses can be used to resolve distances to 6 one-thousandth of an inch over a range of many miles. This would allow monitoring of movement--fast or slow--accurately. Also, using range gating techniques atmospheric monitoring could be done at desired altitudes very accurately. The power reqUirements for such systems would be significant but such laser systems have been built with power outputs in the terawatt (10−12) regime.

In this paper the propagating phenomena of ultrashort, called self-induced transparency will be discussed as applied to " seeing " through clouds. The pulse shape and time of flight measurements as applied to reflections from surfaces will also be discussed. Finally, atmospheric monitoring using Raman backscattering and range gating techniques will be considered.

II. Self-Induced Transparency

Recent advances in laser technology have led to the production of coherent optical pulses haying durations in the picosecond (1012 seconds) regime. Such time intervals are comparable to or shorter than the phase memory times associated with many atomic systems. The high frequency polarization induced in a medium by such a pulse can therefore retain a definite phase relationship with the incident pulse. The novelty of the effects that may occur as a result of the coherent response of a medium to an optical pulse has been brought out quite strikingly by the recent discovery covery of self-induced transparency.
A National System for Oceanic Monitoring, Assessment, and Prediction to Support the Trans-Alaska Pipel ine System (Marine Leg)
Authors: Landis Robert C.
Published: October 2008

A concept for a national program for oceanic monitoring, assessment, and prediction (OMAP) is described. Initial emphasis is placed on services to support the marine leg of the Trans-Alaska Pipeline system (TAPS) in the form of warnings of hazardous phenomena, forecasts of marine weather and the physical ocean, and prediction and assessment of marine pollution. Monitoring, services, research and development are described as the four major elements of OMAP.

INTRODUCTION

For more than a century, man has felt the need to predict changes in the ocean and marine atmosphere. This need has evolved out of the increased use of the ocean as a major transportation medium and as a source of food. More recently man has turned to the ocean bottom as a source of oil and other minerals. In the future we will, to an even greater degree, rely on many other ocean resources.

Until now, the major thrusts in oceanography and marine meteorology have been almost exclusively in the area of research. As a result, an embryonic understanding of these sciences is available for providing operational services to the vast and rapidly growing community of users in the marine environment. This is not to say that research and development efforts are completed, but instead can now be better directed along a mutually supportive parallel effort of operational oceanic applications.

The concern of increased "operational"oceanic science was reflected by the Commission on Marine Science, Engineering and Resources (Stratton Commission) in 1969 when it noted that, "The Nation must have a comprehensive system for monitoring and predicting the state of the oceans and atmosphere."

The Stratton Commission pointed out that increased monitoring and improved predictions and information services are needed so that the oceans can be used more safely, productively and enjoyably.

The concept of a national integrated program for oceanic, monitoring, assessment and prediction in response to recognized user needs is needed to provide the following:warnings of oceanic environmental hazards,routine predictions of the physical ocean and marine atmosphere,assessment of trends in the ocean's environmental quality andenvironmental information for national security, coastal zone and ocean dumping management, port and ship design, and other users of the marine environment.

Individual and separate programs to predict and assess specific aspects of the ocean environment for coastal population, marine industrialization, marine recreation, fishing, marine pollution, and other national programs within presently available national resources would appear to be extremely costly. However, with a total integrated program drawing together the capability of governmental agencies, private industry, and the academic community, an OMAP concept could be made tractable as well as cost beneficial.
A Simulated Dive at 2001 Feet
Authors: Agarate Christain A. , Jegou Alain J.
Published: October 2008

The "PHYSALIE VI" deep simulated dive was carried out as part of the C.N.E.X.O. - COMEX research program in COMEX HYPERBARJC RESEARCH CENTER from MAY 18 to JUNE 2, 1972.

Two professional divers were progressively pressurized with an oxy-helium mixture to 2001 feet which they reached on MAY 24 at 1. 20 A.M. where they stayed for 80 minutes before decompression.

The various physiological results obtained during this experimental dive permit to be optimistic with regard to the feasibility of industrial underwater work in the 1500 feet range.

In view of the results obtained during the simulated deep dives "PHYSALIE V" (at 1706 feet) and "SAGITTAlRE II" (100 hours at 1640 feet), it was estimated that it should be possible to pressurize men to an equivalent depth of 2000 feet of sea water.

This was investigated during the PHYSALIE VI deep diving experiment which took place in COMEX HYPERBARIC RESEARCH CENTER in MARSEILLES, from MAY 16 to JUNE 2, 1972.

This experimental dive forms part of the Centre National pour Exploitation des Oceans (C. N. E. x. 0.)COMEX research programme and was carried out with the collaboration of several scientific teams from the University, the french Navy and Air Force, and the participation of the Centre National de la Recherche Scientifique (C. N. R. S.), and the Direction des Recherches et Moyens d'Essais (D. R. M. E.) for the neurophysiological aspects of the study.

Two subjects were selected among the 5 COMEX divers who had already participated in experiment in the 1700 foot range and these were:–Patrice CHEMIN, aged 24, "world-recordman" at 1706feet.–Robert GAURET, aged 30, who had already participated in a 17 hours saturation dive at 1640 feet.

On TUESDAY, MAY 16, at 4.00 P.M., Compression began according to a schedule resulting from the data collected during the "PHYSALIE V" and "SAGITTAIRE I" experiments.

On MAY 18, at 2.54 A.M., a depth of 1148 feet was reached. They stayed 46 hours at this depthand on MAY 20 at 1.00 A.M., were further compressed down to 1755 feet which they reached on MAY 21 at 5.54 P.M. They spent the night at this depth and on MAY 22, between $.00 A.M. and 6.06 P.M., were compressed to 1854 feet where they stayed overnight.

On MAY 23, at 8.00 A.M., the scientists responsible for the experiment decided it was possible to proceed deeper and compression was started again according to a specially designed schedule which brought the two divers to:2001 FEET, on MAY 24, at 1.20 A.M.

They remained at this depth for 80 minutes, the necessary time for performing various physiological tests as well as a blood-sampling.

The ambiant pressure was 61.61 ATA, and the breathing mixture contained:–0.6510 Oxygen; 0.1710 Nitrogen; 99.1510 Helium–0.0310 Water and a few ppm carbon dioxide.
Brittle Lacquer Studies and Recommendations for Strengthening Rectangular Tubular Joints
Authors: White Arais , Patel Narsing M.
Published: October 2008

There are serious structural deficiencies in less-than-full-width hollow rectangular joints, and this paper investigates in some detail, using brittle lacquer techniques, the nature and seriousness of these deficiencies. Alternative methods of strengthening such joints are discussed, and actual tests were performed and quantitative values obtained between strengthened and non-strengthened joints for one method.

INTRODUCTION

Considerable interest has arisen in recent years in the use of rectangular hollow sections (RHS) and structural design criteria are being developed. In this regard an ambitious research program has been initiated at the University of Houston and the material presented in this paper was obtained from some work done as a part of that program. Most of the work done to date has been concerned with punching shear characteristics of less-than-ful1-width non strengthened joints, and has been reported in a doctoral dissertation and a paper entitled "Punching Shear Characteristics of RHJ", presented at the April, 1973, meeting of the ASCE in San Francisco. In the earlier work, questions arose regarding the pattern of flow of the load from a branch member of an RHJ into the -main member, and the brittle lacquer method seemed a logical choice for study of this phenomenon.

Four specimens were chosen (one of which was a full-width specimen) for the brittle lacquer work and Figures 1 and 2 and Table I provide all pertinent information regarding these specimens. Specimens B-3, L-2, and L-6 were subjected to direct punching load and LB-4 was subjected to a combination of punching load and bending. In each case, the specimen was supported only along the longitudinal edges of the main member by a special loading base. Such a base provided free interaction among the sides of the main member. The load was applied through the branch member by means of a universal testing machine.

Use of Brittle Lacquer

The use of brittle lacquer is an excellent procedure to obtain overall information regarding the behavior of a structural element such as the joint discussed herein. In this work, conventional techniques were followed, except that the new aerosol type of Stresscoat was used. Otherwise, the usual procedures of cleaning, application of undercoating and strain sensitive coating, curing, and testing were followed.

After curing of a Stresscoat specimen, it is carefully examined before application of initial loading to make certain that no cracks exist at that time. The usual procedure then involves application of a small load (usually 1/10 of the maximum load to be used), and the examination for any cracks which have appeared under that loading.
Elementary Theoretical Considerations for a Digital Far-Seeing Side Scanning Sonar System (FARSSSS)
Authors: Neidell Norman S.
Published: October 2008

Borrowing from exploration seismology the basic common reflection point stacking process (CRP)1 and from remote sensing the analogous synthetic aperture method2 it should be possible to develop a far-seeing side scanning sonar system. A preliminary system of this nature, FARSSSS, is described in the following text. Although the entire analysis for the system is based on first order assumptions, it should be possible using FARSSSS to obtain sonic images of the sea bottom (and if desired - the upper subsea bottom) in nominal real time. For a survey vessel moving at 6 knots, the transverse scan extent should be about 5 mm on either side of the vessel with an effective resolution of about 75 ft.

All components proposed for the system are standard items and the digital processing techniques are analogous to those used in exploration seismic data processing. In addition, the data acquired should contain information of importance to more sophisticated studies which attempt to determine the acoustic characteristics of the sea floor and upper strata of the subsea bottom.

INTRODUCTION

A vessel which travels at 6 knots is proposed as the vehicle for the digital FARSSSS survey. Figure 1 shows a diagram of the vessel along with its towed hydrophone streamer. A two-sided transducer array is shown attached to a fin below the vessel and later on some elementary theory relating to the array design will be presented. At 15 second intervals the source array is activated, alternately to the starboard and portsides of the vessel. Hence each side of the survey track is insonified at 15 second intervals corresponding to a distance along course of about 150 ft. Owing to the multiplicity and regularity of reception paths however, an effective resolution along course of about 75 ft. can be obtained after digital processing.

The transducer array suggested operates at a central frequency of 200 Hz corresponding in good approximation to a 25 ft. wavelength in water. Since such frequencies propagate well in water, problems of sufficiency of energy (or equivalently considerations of range) become secondary matters. However, these frequencies propagate well also in the sea bottom and sub-bottom reflected energy will be returned along with the side-looking scans of the ocean floor. We shall distinguish between sea floor events and subsea reflections by their ‘move-out’ characteristics in appropriately gathered collections of reflection traces. By summing such traces along selected wavefronts, the sea floor events are enhanced at the expense of all other signals be they incoherent or coherent along other wavefronts. The essentials of this technique and its derivation from the common reflection point and synthetic aperture methods will be developed in the next section.
The Green Canyon Event as Recorded by the Atlantis OBS Node Survey
Authors: Dellinger Joe , Ehlers Jerry , Clarke Richard
Published: October 2008

Because of its location, the magnitude 5.2 Green Canyon earthquake of 10 February, 2006 has been of considerable interest to the oil industry. Unfortunately, because the nearby stations were all located to the North (onshore), its location and depth were only poorly constrained by the traditional worldwide seismic network. Fortunately, the Atlantis 3D survey happened to be ongoing at the time of the earthquake and recorded it on over 500 4C ocean-bottom nodes. The Atlantis array was closer to the event than any station on shore, and recorded the event from the South. These data thus provide an opportunity to dramatically refine our knowledge of the earthquake's location.

We preserved 2.5 hours of data spanning the time of the earthquake and analyzed it for signals, both man-made and natural. Although there are a large number of overlapping signals in the data, they can be clearly separated by their distinct arrival times, temporal frequencies, and phase velocities across the 10km × 6km array. At frequencies of 5Hz and above repetitive air-gun signals from 4 ongoing seismic surveys dominate the data. These account for all the surveys shooting in the Northern Gulf of Mexico at the time. At frequencies of 1Hz and below there is a nearly continuous background noise coming primarily from the South and East that rumbles along for the entire 2.5 hours, with a phase velocity across the array of about 2000 m/s. This is most likely ocean wave-generated noise.

At frequencies below 2Hz the earthquake signal dominates the data from 04:14:34 UT to about 04:20. It begins with several discrete arrivals from the NNW over a span of about 20 seconds, which are then followed by a drawn-out coda from the NW lasting over 8 minutes. At 04:22:13 a second event arrives from the SE, which is in turn followed by its own coda from the SSE, which lasts about 3 minutes. (It's not yet clear what this second event might be.) At about 04:27 a 3rd arrival, a weak, diffuse event from the ESE, fades in and lasts about 3 minutes. These data have been provided to earthquake experts and we expect to have a revised location for the event by the time of the OTC meeting in May. Preliminary indications are that the earthquake was well to the North of the originally published position.

Making use of the Atlantis OBS-node array

The geometry of the active nodes at the time of the earthquake is shown in Figure 1. We have a large, dense array (at least at low frequencies!) in this dataset, which allowed us to recycle a program called "Radar" for analyzing the signals in the data. "Radar" was originally written for examining surface-wave noise in land seismic data. It performs planewave stacks across the array and produces a graphical result showing the time, phase velocity, and azimuth of arriving energy. Figure 2 shows that "Radar" was able to correctly determine the azimuths of all the active air-gun surveys in the Northern Gulf of Mexico shooting at the time of the dataset.
A Floating Pipeline - Producing Ekofisk Crude into Tanker
Authors: Wheeler R.J. , Taylor A.A. , McKenna H.A. , Linehan J.J.
Published: October 2008

During the period August, 1967 to September 1970, Phillips, as operator for a group holding acreage in the Ekofisk area of the North Sea, drilled four exploratory wells. These wells, having proved the existence of a commercial field, were properly plugged and the rig moved on to exploratory work in other areas. No thought was given at the time to producing these wells, which were considered to be purely exploratory.

In June of 1971, however, it was concluded that an investigation should be made of the possibility of producing these wells. The formal program for producing the field was in the process of development and indications were that production could not be started before 1973 or 1974. As discussions on the possibility of producing the four exploratory wells progressed, it became apparent that production, in the range of 40,000 barrels per day, could be achieved perhaps by early 1971. Therefore, a serious study of the problem was set up.

The first look showed, of course, several immediate challenges. The four wells had been sealed and by this time the well heads had probably been covered by the shifting sands of the sea bottom. Merely locating them again would be like looking for the proverbial needle in the haystack. The wells were located in about 245 feet of water about 180 miles from the nearest land. Obviously, any production from the wells would have to be loaded into tankers; there would be no possibility of producing into a pipeline for delivery to a market. So the problem basically divided itself into two separate areas. The first concerned the methods to be used in completing and producing the wells as well as in separating the gas from the crude and the second, delivering the crude to the tankers at a temperature and vapor pressure which could be accepted. The way in which this challenge was met and overcome has been described in numerous papers and articles, and will not be dwelt on here. As background for the subject of this paper it should be sufficient to say that plans were made to use sea-floor completion for the wells, and to pipe the produced crude to a self-elevating drilling rig, the "Gulftide", which would be positioned in a central location between the wells, and used as a production platform, with the necessary equipment for treating the crude, flaring the gas, and pumping the crude to the tankers. So the study team split into two separate groups, one attacking the problem of producing the crude, and the other looking at the question of how to get the crude into the tankers which would take it to the users. It is the activities of the latter group which will be described in this paper.
3D/4C and 4D Ocean-Bottom Seismic Surveys in the Caspian Sea
Authors: Bouska Jack
Published: October 2008

The signal to noise problems inherent in towed streamer data associated with mud volcanoes, subsurface heterogeneities and distributed gas in the Azeri, and Gunashli structures of the Caspian sea prompted the use of three dimensional four component ocean bottom seismic (3D/4C OBS) to improve imaging. The introduction of several innovative enhancements to the traditional ocean bottom cable technique, when applied cohesively across both acquisition and processing, resulted in cost savings compared to conventional OBS acquisition and improved final data quality compared to towed streamer seismic.

To further guide cost effective designs of future ocean bottom seismic (OBS) for 3D, 4D or permanent sensor time-lapse, surveys over the Azeri, Chirag and Gunashli reservoirs, a Figure 1: Location of study area shown within red box: Azeri Chirag Gunashli PSA, (ACG) Caspian Sea, Azerbiajan. (available in full paper) multi-faceted study was subsequently conducted evaluating both real OBC seismic data from Azeri and synthetic data from numerical modeling. This study evaluated sensor density requirements to properly acquire the PZ component of the wave field, as this component provides the best reflector S/N and, depending on rock physics, is sensitive to productionrelated fluid changes in the reservoir. Critical spatial sampling and acquisition parameters were established through a series of comparison tests including:Fold decimation tests - to establish the sensor density required to insure image quality and signal-to-noise necessary for time-lapse monitoring.Migration aperture tests - to establish the permanent array line length across the structure necessary to adequately image the hydrocarbon column.Repeatability tests - to establish if the noise floor from repeated data acquired in the Azeri OBC survey is adequate to allow effective time-lapse monitoring from OBC. Comparisons included data from fixed shots recorded on different receivers, and also data from reoccupied receiver locations recorded with different shots.Spatial resolution testing through numerical modeling - to understand the relationship of the shot and receiver spacing and resulting image resolution for different acquisition geometries including surface tow, roll-along OBC, and

Figure 2: Examples of areas where towed streamer data is compromised over the structure crest due to seabed scarps, mud volcanoes, and near surface distributed gas. (available in full paper) permanent OBS designs.

Qualitative and quantitative analysis of: seismic volumes, horizon amplitude maps, difference sections, S/N estimates and comparisons to synthetic seismograms were used to evaluate the adequacy of the various decimation levels. Results of these evaluations indicate that future OBS designs employing relaxed spatial sampling specifications, compared to the original OBS survey, would provide adequate balance between minimum seabed equipment (cost) and recording of high quality structural, or time-lapse seismic data.
Workover and Recompletion of Subsea Completion in the Gulf of Mexico
Authors: Brown Frank M. , Evans Charles C.
Published: October 2008

Eight subsea wells were drilled and completed in Eugene-Island Block 175 Field from 1966 through 1968. Average water depth of the field is 85 feet. Service work, similar to wireline service on conventional wells, has been performed using thru-flowline pumpdown techniques. Workovers were required on three wells because of normal depletion and mechanical problems.

Three phases of the workover operation will be presented: I. Planning phase, II. Actual performance of the work, and III. Evaluation and conclusions of the job success. The planning phase will include rig selection, subsea inspection prior to moving in the rig, and formulating a particular plan of attack as in any workover. The second phase or work phase will include subsea inspection while moving in the rig and establishing contact with the wellbores. The removal and reinstallation of the subsea tree and installation of blowout preventers will be covered. Diver assist operations are documented by 16 mm color underwater photography. Once the blowout preventers have been installed, the problems of normal workovers will be excluded.

Three subsea wells were approved as workover candidates. One well did not require removal of the subsea tree, because problems were solved by conventional wireline and 1 inch pipe fishing operations through the tubing bores once contact with the well was established. The other two wells required removal of subsea Christmas tree and installing of 10" high pressure riser to repair the wells. Once the well was worked over the subsea trees were reinstalled.

INTRODUCTION

Atlantic Richfield Company is now operating eight subsea wells in offshore Louisiana waters. These wells are located in Eugene Island Block 175 Field, approximately 70 miles southwest of Morgan City, Louisiana. Average water depth for the field is 85 feet. These wells were among the first to be installed as subsea completions in the Gulf of Mexico. These wells were drilled and completed as string completions between 1966 and 1968. All of the wells are producing from multiple pay zones and are flowing to a common production platform located from one to three miles from the wells. Routine service work on these wells, such as pulling and inspecting storm chokes, cutting paraffin, etc., is done by the flowline pumpdown techniques from the production platform. The wells were-originally completed with special cross-over ports that allow the tubing strings to communicate in the well just above the top packer in the well. This feature allows tools, similar to wireline tools, to be pumped down the flowline and into the tubing strings of the wells and to be pumped back out of the wells and returned to the production platform.
Results of New LNG Transfer Technology Developments and What Possibilities They Foretell
Authors: Cox Phillip , O'Sullivan Jim , Lehning Virginie
Published: October 2008

"Results of New LNG Transfer Technology Developments and What Possibilities They Foretell"

New LNG transfer technologies today cannot be introduced without addressing all of the potential associated risks, and demonstrating to a most conservative LNG Industry that all aspects have been addressed through comprehensive test and qualification programs. Indeed the new EN1474 standard, (now in 3 parts: Pt 1 - Design & Testing of Transfer Arms: Pt 2 - Design & Testing of Transfer Hoses: Pt 3 - Offshore Transfer Systems) clearly states that; "where novel transfer solutions (new technology or novel application of known technology) are intended to be used, this technology is to undergo a recognised qualification procedure".

Through a series of Joint Industry Programmes, Technip has developed cryogenic Pipe-in-Pipe technology that is now complete and being proposed on several projects, both for export & import terminals. Technip's cryogenic aerial flexible will be fully qualified through the Montoir JIP trials by the middle of 2007. Model tests on floating cryogenic flexibles have been successfully completed, and the results are being used to validate detail design tools. In-water trials are planned to take place during Q3 or Q4 2007.

The paper will summarize results of all these development programs including results from the full-scale Montoir tests. Emphasis will be given to describing the tools and methods used to qualify these new cryogenic components and systems. The paper will then go on and present some applications of these new LNG transfer technologies, both rigid and flexible, which today's terminal designers are currently requesting for nearshore & offshore developments.

Introduction

The transfer of bulk materials or liquids has been evolving for many centuries. With the advent of modern methods including hydraulics, electronics and new steel compounds this evolution was able to match industry requirements throughout the 19th and especially the 20th century, for the transfer from shore " ship " shore of a large range of refined liquids and chemicals, including, as from the 1960's, Liquified Natural Gas (LNG).

Figure 1 shows two examples of such early loading arms. (Available in full paper)

Today these LNG loading arms have evolved into a complex system, which has to respect increasingly stringent rules and standards whilst continuing to maintain high levels of safety and availability.

More recently another factor has been added to this mix of requirements. - that of real dynamic movement of the LNG Carriers in marine conditions. This paper will detail the development programme that has been carried out over the past 6 years to provide the LNG Industry with a viable and new method of LNG transfer, using cryogenic flexibles and rigid pipe-in-pipe technology, to meet this new requirement and allow the LNG Industry to further evolve into real offshore and nearshore transfer operations.
Perspectives on the New Energy Security: Consumers and Suppliers
Authors: Mobed Ron
Published: October 2008

Energy Security is at the forefront of geopolitics driven by the New Era of Supply Anxiety. Delivering energy for tomorrow has forced both consumer and supplier nations to heighten their roles in the energy arena. Consumer nations are re doubling their efforts to insure supply for their economies. New large fast growing consumer blocks have emerged in the last three years - India and China, along with the tradition ones. They seek diversity of supply, both in type and geography. Supplier nations are also feeling the pressure as things go global and new sources of supply emerge. As such, they are reasserting control of their assets both at home and abroad. Suppliers want to have long term market access and reasonable prices for their products. All this is leading to increased competition and a squeeze on fiscal terms and profit.

This paper discuss how some of the key consumer and supplier blocks work, and some of the issues they are facing.

The world's number one consuming nation, the US, is seeking diversification via supply and hydrocarbon type. Examples from Europe and Latin America provide insight into interdependence between consumer and supplier nations and highlight how hard it is to strike a balance. An example in Asia highlights how new partnerships are being formed between consumer and supplier nations which several years ago never would have been possible.

The result of the new dialogue on energy security has been identification of a set of benefits and challenges. Challenges include-a change in role of National Oil Companies; resource nationalism, surging capitol costs; while benefits are - regional and global delivery systems; renewed technology development; and addition of refining capacity and infrastructure.

Landscape and Definition

Currently we are in a period of "Energy Anxiety" brought on by the steep rise over the last 2 years in energy prices. The current price is attributable to an imbalance in supply and demand. Factors leading to constraints on supply are:Lackluster reserve replacement and discovery doldrums;Restricted access to remaining known resources and future exploration areas;Heightened political risk leading to "resource nationalism" and instability of contracts and fiscal terms;Delivery bottlenecks and aging infrastructure;Conflicts in the Middle East, Nigeria and Latin America;Rising costs and shortage of manpowerNatural disasters such as hurricanes and earthquakes

This paper focuses on the above ground risks to supply, which are dominantly driven by securing new supply, which is shifting from traditional regions. Access is thus a key issue and "resource nationalism" a prominent factor in determining access. Competition for access is being squeezed by "resource nationalism" leading to declining economic attractiveness of many regions. This in turn has lead to acceleration in portfolio rebalancing and large reshuffling of ownership. The return of "resource nationalism" is highlighting the greater need for cooperation among nations and market blocks.