bluuebunny/crossref_metadata_2025 huggingface dataset:
Naive Rat Amnion-Derived Cell Transplantation Improved Left Ventricular Function and Reduced Myocardial Scar of Postinfarcted Heart
Authors: Fujimoto Kazuro L. , Miki Toshio , Liu Li J. , Hashizume Ryotaro , Strom Stephen C. , Wagner William R. , Keller Bradley B. , Tobita Kimimasa
Published: July 2009

Stem cells contained in the amniotic membrane may be useful for cellular repair of the damaged heart. Previously, we showed that amnion-derived cells (ADCs) express embryonic stem cell surface markers and pluripotent stem cell-specific transcription factor genes. These ADCs also possess the potential for mesoderm (cardiac) lineage differentiation. In the present study we investigated whether untreated naive ADC transplantation into the injured left ventricular (LV) myocardium is beneficial as a cell-based cardiac repair strategy in a rat model. ADCs were isolated from Lewis rat embryonic day 14 amniotic membranes. FACS analysis revealed that freshly isolated ADCs contained stage-specific embryonic antigen-1 (SSEA-1), Oct-4-positive cells, and mesenchymal stromal cells, while hematopoietic stem cell marker positive cells were absent. Reverse transcription-PCR revealed that naive ADCs expressed cardiac and vascular specific genes. We injected freshly isolated ADCs (2 × 106 cells suspended in PBS, ADC group) into acutely infarcted LV myocardium produced by proximal left coronary ligation. PBS was injected in postinfarction controls (PBS group). Cardiac function was assessed at 2 and 6 weeks after injection. ADC treatment attenuated LV dilatation and sustained LV contractile function at 2 and 6 weeks in comparison to PBS controls ( p < 0.05, ANOVA). LV peak systolic pressure and maximum dP/dt of ADC-treated heart were higher and LV end-diastolic pressure and negative dP/dt were lower than in PBS controls ( p < 0.05). Histological assessment revealed that infarcted myocardium of the ADC-treated group had less fibrosis, thicker ventricular walls, and increased capillary density ( p < 0.05). The fate of injected ADCs was confirmed using ADCs derived from EGFP(+) transgenic rats. Immunohistochemistry at 6 weeks revealed that EGFP(+) cells colocalized with von Willebrand factor, α-smooth muscle actin, or cardiac troponin-I. Our results suggest that naive ADCs are a potential cell source for cellular cardiomyoplasty.
DAPI Diffusion after Intravitreal Injection of Mesenchymal Stem Cells in the Injured Retina of Rats
Authors: Castanheira Paula , Torquetti Leonardo Torquetti , Magalhãs Débora Rodrigues Soares , Nehemy Marcio B. , Goes Alfredo M.
Published: July 2009

To evaluate DAPI (4′,6-diamidino-2-phenylindole) as a nuclear tracer of stem cell migration and incorporation it was observed the pattern of retinal integration and differentiation of mesenchymal stem cells (MSCs) injected into the vitreous cavity of rat eyes with retinal injury. For this purpose adult rat retinas were submitted to laser damage followed by transplantation of DAPI-labeled BM-MSCs grafts and double-labeled DAPI and quantum dot-labeled BM-MSCs. To assess a possible DAPI diffusion as well as the integration and differentiation of DAPI-labeled BM-MSCs in laser-injured retina, host retinas were evaluated 8 weeks after injury/transplantation. It was demonstrated that, 8 weeks after the transplant, most of the retinal cells in all neural retinal presented nuclear DAPI labeling, specifically in the outer nuclear layer (ONL), inner nuclear layer (INL), and ganglion cell layer (GCL). Meanwhile, at this point, most of the double-labeled BM-MSCs (DAPI and quantum dot) remained in the vitreous cavity and no retinal cells presented the quantum dot marker. Based on these evidences we concluded that DAPI diffused to adjacent retinal cells while the nanocrystals remained labeling only the transplanted BM-MSCs. Therefore, DAPI is not a useful marker for stem cells in vivo tracing experiments because the DAPI released from dying cells in moment of the transplant are taken up by host cells in the tissue.
A TWO STRAIN TUBERCULOSIS TRANSMISSION MODEL WITH THERAPY AND QUARANTINE
Authors: Bhunu Claver P. , Garira Winston
Published: July 2009

A two strain tuberculosis model with treatment which allows TB patients with the drug sensitive of strain Mycobacterium tuberculosis to be cured is presented. The model is further extended to incorporate quarantine for active TB cases with multi‐drug resistant TB strains. The model assumes that latently infected individuals develop active disease as a result of endogenous activation and exogenous reinfection. Qualitative analysis of the model including positivity, boundedness and persistence of solutions are presented. The thresholds and equilibria quantities for the models are determined and stability of the solution is analyzed. From the study we conclude that quarantine of the multi‐drug resistant tuberculosis cases reduces the multi‐drug resistant tuberculosis induced reproduction number to values below unit, thus this intervention strategy can control the development of multi‐drug resistant tuberculosis epidemic. Also effective chemoprophylaxis and treatment of infectives result in a reduction of multi‐drug resistant tuberculosis cases since most multi‐drug resistant tuberculosis cases are a result of inappropriate treatment.
MODELLING OF THE EFFECT OF A THIN STIFFENER ON THE BOUNDARY OF A NONLINEAR THERMOELASTIC PLATE
Authors: Rahmani Leila
Published: July 2009

We consider a dynamic nonlinear model for a heterogeneous thermoelastic plate consisting of a thin highly rigid body of high thermal conductivity perfectly glued on a portion of the boundary of an elastic plate. This model, which describes the nonlinear oscillations of a plate subjected to thermal effects is referred to as the “full von Karman thermoelastic system”. Our aim is to model this junction and reproduce the effect of the thin body by means of approximate boundary conditions, obtained by an asymptotic analysis with respect to the thickness of this body.
Journée d'étude ADBS
Authors: Le Moal Jean-Claude , Masse Claudine
Published: July 2009

Résumé Le considérable essor de l’information numérique ne doit pas faire perdre de vue l’absolue nécessité d’en assurer la pérennité. Cet impératif conduit à reconsidérer la place de l’archivage dans l’entreprise. Pour faire le point sur l’état de l’art en matière de technologies d’archivage électronique et pour réfléchir aux conditions de mise en place de cette fonction dans l’entreprise, une journée d’étude était organisée par l’ADBS, en partenariat avec l’Association des professionnels de la GED (APROGED), le 5 octobre 2005 au CNIT, dans le cadre du Forum de la GEIDE.
Journée d'étude ADBS-Santé
Authors: Cornec Nathalie , Martin Armelle , Masse Claudine , Vaillant Hélène
Published: July 2009

Résumé C’est principalement pour faire le point sur les différents types de veille dans le domaine de la santé et faire connaître des méthodes grâce à des retours d’expérience que le secteur Santé de l’ADBS, en liaison avec le groupe régional PACA de l’association, proposait une journée d’étude le 6 octobre 2005 à Marseille. Cette rencontre a permis de préciser le concept et la pratique de la veille en santé, d’examiner l’évolution en cours des outils disponibles sur Internet et de présenter plusieurs exemples significatifs, notamment l’expérience de veille sur Internet de l’hôpital du Mans et le projet de veille en réseau de la BDSP.
Journée d'étude GFII-ADBS
Authors: Ferchaud Bernadette
Published: July 2009

Résumé Les constantes transformations qui affectent le marché de l’information ne sont pas sans conséquences sur la tarification des produits et services proposés. Co-organisée à Paris le 17 novembre 2005 par l’ADBS et le Groupement français de l’industrie de l’information (GFII), une journée d’étude proposait une réflexion sur les logiques de prix, l’impact des nouveaux acteurs dans les négociations tarifaires, celui de l’information gratuite sur les usages et sur la tarification des services payants. Des exemples concrets ont illustré les modalités de tarification des prestations proposées par des professionnels de l’information.
Journée d'étude MMSH
Authors: Battisti Michèle
Published: July 2009

Résumé Organisée le 22 novembre 2005 à Aix-en-Provence par le pôle Image, Son, Recherche en sciences humaines de la Maison méditerranéenne des sciences de l’homme, une journée d’étude était consacrée aux complexes questions juridiques relatives au traitement et à la valorisation des documents oraux. Puis à la présentation de diverses expériences de valorisation de fonds sonores et à l’examen de problèmes rencontrés lors de la mise en œuvre de ces travaux.
Journée d'étude SCIP-France – APIL. Les outils avancés de veille sur Internet
Authors: Mesguich Véronique
Published: July 2009

Résumé Le 10 mai dernier, SCIP France organisait, pour la quatrième fois depuis 2001, une journée d’étude consacrée aux outils avancés de veille sur Internet. Proposée cette année en collaboration avec l’APIL, cette manifestation a permis de dresser un panorama de l’offre actuelle et de découvrir plusieurs outils aux fonctionnalités variées et complémentaires, avec leurs innovations les plus marquantes, souvent prometteuses. Et enfin de faire le point sur les besoins et attentes des utilisateurs.
Les rencontres 2006 des professionnels de l'IST. Les archives ouvertes et la veille scientifique, deux axes de réflexion
Authors: Chazelas Martine , Courtial Francine , Dassa Michèle , Janik Joanna , Jannès-Ober Emmanuelle , Martin Caroline
Published: July 2009

Résumé Les rencontres 2006 organisées par l’Institut de l’information scientifique et technique (INIST/CNRS) à l’intention des professionnels de l’IST se sont déroulées du 19 au 21 juin 2006 à Nancy où se sont retrouvées plus de quatre cents personnes exerçant principalement dans le monde de la recherche et de l’enseignement. Outre les présentations de différents projets de l’INIST et d’autres organismes de recherche et de nombreuses séances de posters, deux grands thèmes ont été abordés lors des conférences : « Archives institutionnelles et archives ouvertes » et « Veille scientifique, veille stratégique »
IFLA 2006 : Congres mondial des bibliothèques et de l'information
Authors: Battisti Michèle
Published: July 2009

Résumé Le dernier congrès, organisé du 19 au 25 août 2006 à Séoul par l’International Federation of Library Associations and Institutions (IFLA), proposait comme à son habitude une multitude de conférences et ateliers. Les thèmes proposés couvraient l’ensemble des problématiques auxquelles sont aujourd’hui confrontés les professionnels de toutes les bibliothèques et, dans l’acception la plus large de cette expression, tous les professionnels de l’I-D entre lesquels la société de l’information tend à assouplir les cloisons. Voici des aperçus sur quelques sessions choisies en considération de leur intérêt général ou de l’intérêt particulier qu’elles présentent pour les documentalistes.
Removal of a Hydrate Plug from a Subsea Xmas-Tree Located in Ultradeepwaters with the Aid of a Heat-Releasing Treating Fluid
Authors: Evangelista Eliezer , Chagas C.M. , Melo Jose Antonio Fonseca , Filho Ney Brandao , Rocha Jose Dante Henriques , do Carmo Marques Luiz Carlos
Published: July 2009

The paper describes the actions taken to re-entry a well located in ultra-deep waters (1541 m water depth) whose sub sea Christmas-tree was blocked by a solid hydrate plug and therefore could not be liberated by means of its standard releasing tools.

A heat-releasing treating fluid - the so-called self-generated nitrogen (SGN) fluid - was successfully applied to heat and dissociate the hydrate plug, which was totally blocking the locking mechanism of the Production Vertical Connection Mandrel (PVCM) of the tree. The heat applied around the Xmas-tree body was conveyed by the pumped SGN fluid batches. By doing so, the hydrate plug was completely dissociated (melted down) and then the unlatching mechanism became operational again.

This paper comprehensively describes the steps of this different hydrate treatment job. In broad terms, a technically challenging job which encompassed the following issues: - development of a " tailor-made?? environmental-friendly SGN formulation, - heat exchange simulations to design the optimum volume for the SGN treatment batch, - a review of the theoretical aspects of hydrate formation/dissociation, - use of an instrumented/insulated drill pipe riser (DPR), - and job safety procedure reviews. A PLT logging tool (PLT) was also used to keep a record of the temperature profile inside the DPR.

In view of the pioneer aspects of the operation, the combined use of an ROV and PLT was of paramount importance to monitor every step of the operation since its very beginning. Along the job, the Christmas-tree, the reactivity of the treating fluid batches, the temperature changes, and the hydrate blockage, were monitored on a permanent basis. The combination of these two tools has provided precious pieces of information that have enabled us to gain insight into what was going on along the job and take the necessary measures to its real-time optimization.

Introduction

Hydrate and paraffin blockages are currently the major causes of oil production losses in Campos Basin´s deepwater scenarios. In many instances, these blockage problems have been solved by means of a treatment with the heating-releasing SGN fluids.
Deepwater Subsea Tie-In Between Chevron Blind Faith and Devils Tower Export Pipelines
Authors: Phan Huy Thanh , Tarlton Oran , Charalambides John
Published: July 2009

This presentation will concentrate on the design challenges, experience and learning from the SIT and offshore installation of two deepwater pipeline tie-ins using first-of-its-kind subsea technology and installation methodologies on the " Blind Faith?? project. The Blind Faith Subsea Tie-Ins join the Blind Faith oil and gas pipelines with the Canyon Chief gas pipeline and the Mountaineer oil pipeline in 5100 feet of water. Both of the Blind Faith oil and gas pipelines are terminated with conventional PLEMs providing a horizontal connector for the tie-in and a vertical connector for a future tie-in connection point. The connectors are ROV operable / installable clamp style connectors.

The method of joining to the DT oil and gas export pipelines and the type of jumper employed are unique to the tiein. An ROV operable / installable mechanical pipe end connector connects the bare ends of the Canyon Chief and Mountaineer pipelines. The mechanical pipe end connector is fitted with an integral clamp connector hub and rests on an ROV installed mud mat. After installation of the mechanical connector, metrology was performed to create a neutral state horizontal jumper for joining the mechanical connector hub and the Blind Faith PLEM.

The neutral state horizontal jumper is a compliant " Z-Bend?? design. During installation the jumper was elastically pre-deformed using a bowstring system. Pre-deformation of the jumper provided installation clearances and facilitated the neutral stress state after installation. Once landed the jumper bowstring was relaxed, allowing the jumper to expand to fit between the hubs. After expansion and make-up, the clamp connectors were tightened via an ROV operated hydraulic torque wrench. A seal test verified the integrity of the connections. After installation the jumper remains in a minimal residual stress state atypical of most horizontal jumpers.

The horizontal jumper was chosen over the vertical jumper because it provides a more compact and lighter weight connection system. This also allows a wider choice of installation vessels. In addition the horizontal " Z-Bend?? provides the greatest amount of compliancy for the neutral state jumper. Lastly, the successful installation (and deployment) of the jumpers (and tooling packages) proved out the desired goals of installation by any medium size MSV vessel retrofitted with any work class ROV system.
Deepwater In-Line SLED Installation Methods and its Application to Frade Project
Authors: Huang Kevin , Ji Andy , Uribe Edgar
Published: July 2009

Flexible flowlines and risers have been increasingly used for deepwater and ultra-deepwater field applications, partially because of its low submerged weight and better dynamic characteristics comparing to rigid pipelines. The offshore installation of flowline itself is fast. However, its low bending stiffness brings challenges for installation when it contains heavy subsea equipments to be tied-in. Recently we have successfully installed a total of more than 100km flexible flowlines with 24 in-line SLEDs/PLETs in water depth up to 1300m. This paper reflects these subsea equipments installation experience and lessons learnt during the Frade project.

In this paper we highlight the installation issues and solutions during the in-line SLEDs and PLETs installation. First we discuss three of the possible installation options. For each option we modeled the whole installation sequence with finite element analysis software tools and analyzed each critical stage to ensure the product and equipment integrity. Based on each option's pros and cons we defined their application scopes. Then we present some of the installation concerns such as current drag forces, rigging snatching loads, SLED-sea floor interaction during landing, etc, their analysis investigation, and adopted solutions. After that we present the high level installation procedures used for offshore installation, including different flowline type and installation scenarios, such as flowline installation with single or multiple in-line SLEDs, flowline initiation with PLET, and flowline laydown with PLET. Some of the lessons learnt are also discussed as well. Finally, the conclusions are drawn.

It is concluded that the present SLEDs/PLETs installation methods are effective and efficient, and proven by successful field operations. These methods are also applicable to the tie-in operations of all other similar subsea equipments for flexible flowlines in deepwater fields.

Introduction

The Frade field is located in the northern Campos Basin approximately 76 miles (120km) from the nearest Brazilian shoreline and 135 miles (220km) north-east of Macae. Chevron Corporation, through its affiliate Chevron Frade Limited Liability Company, along with partners Petrobras and Frade Japao Petroleo Limitada (FJPL), a joint vehicle company of INPEX, Sojitz and JOGMEC, developed the Frade oil field offshore Brazil. The Frade Field contains an estimated 200 million to 300 million barrels of recoverable oil and has a water depth range from 1000m to 1300m. It is expected to begin production in early 2009, with production capacity of approximately 100,000 barrels of crude oil per day and estimated peak annual production of 85,000 oil-equivalent barrels and 300 million cubic feet of natural gas per day. Crude oil export will be by tanker, while natural gas will be transported through the local natural gas pipeline infrastructure.
Materials, Manufacturing and Testing Requirements for Offshore Mooring Steel Wire Ropes, Sockets and Pins
Authors: Lohne Per William
Published: July 2009

The trend to produce oil at constantly deeper water has led to the development of floating production solutions for the exploitation of the energy resources in these areas. Steel wire ropes have been used and are being proposed used, as line segments in the majority of the mooring systems of these units. Typical applications covered are mobile offshore units and permanent moored floating production, storage and offloading systems.

Choice of wire rope construction and extent of corrosion protection is of vital importance and should be evaluated as a function of field design life and possibilities for replacement of the wire rope segments.

Performance criteria should be specified for the socketing compound. During production these criteria should be verified by relevant tests. Socketing procedures should be established and controlled before casting of resin.

Steel material for the wire ropes and sockets should be properly documented and be subjected to relevant tests. Mechanical test samples should be taken from full size sockets or from test coupons specially approved.

A design assessment including prototype testing of the wire rope construction and socket should be performed. Wire rope manufacture and manufacture and assembly of sockets and accessories should be according to a Quality Plan accepted by the parties involved.

This paper may serve as a technical reference document in contractual matters between the purchaser and manufacturer. It may also serve as a guideline for designers, purchasers and contractors.

Introduction

Steel Wire Rope Constructions

Steel wire rope segments of mooring lines could be of various constructions as shown in Figure 1. Other type of constructions may also be used if relevant experience can be documented.

The stranded rope constructions include a number of strands wound in the same rotational direction around a center core to form the wire rope. The number of strands and wires in each strand (e.g. 6×19, 6×36, 6×61) are governed by required strength and bending fatigue considerations for the wire rope. This construction generates torque as tension increases.

The torque balanced spiral rope constructions (spiral strand, half locked and full locked coils) do not generate significant torque with tension changes. These constructions use layers of wires (or bundles of wires) wound in opposing directions to obtain the torque balanced characteristics. The half locked and full locked coil constructions consist of one or more layers of shaped wires over the basic spiral rope construction resulting in a design more resistant to the ingress of corrosion media. The shaped layer(s) of wires will also prevent any outer wire fracture from unwinding. These constructions will normally give higher load capacity related to nominal diameter due to the increased metallic area, compared to other constructions.
SS: Tahiti On-Line Monitoring System for Steel Catenary Risers and Flowlines
Authors: Karayaka Metin , Chen Jen-hwa , Blankenshipp Curtiss , Ruf Wolfgang , Podskarbi Mateusz
Published: July 2009

The Riser and Flowline Monitoring (RFM) project deployed one of the most comprehensive subsea structural monitoring systems to date on a Tahiti infield (production) Steel Catenary Riser (SCR) and associated flowline. State-of-the-art motion and strain measurement devices are optimally placed along the SCR to continuously measure and store real-time full scale riser response. In addition, RFM project is the first to implement monitoring devices on a flowline to measure the flowline buckling, a phenomenon that is predicted during repeated start up/shut down. The project goals are two-fold:Understand fundamental hydrodynamic behavior of SCRs and flowlines, specifically, floater motion induced response of catenary risers, Vortex Induced Vibration of catenary risers, riser behavior at the pull tube exit region, riser-soil interaction at the touchdown region, flowline buckling, flowline axial walking, and flow assurance characteristics of infield flowlines. The information generated will be used in future riser designs.The information will be used to validate Tahiti riser and flowline system robustness and conduct " health checks?? on the fatigue critical risers and flowlines, particularly after significant environmental or operational events.

This paper describes the monitoring system configuration, the technology deployed, and the installation methods.

INTRODUCTION

The Tahiti field development is located in the Gulf of Mexico at 4,000 feet of water. More detailed information about the field and the riser systems can be found in References [1], and [2], respectively. Steel Catenary Risers (SCRs) have a proven track record and have been successfully installed in water depth of up to 8,000 feet. However, there is industry wide acceptance that a reasonable level of uncertainty exists with respect to the ability to predict riser performance. Calibration of analytical SCR response prediction models with full scale field measurements will improve design methods, design allowables, and operation integrity. RFM project's main drivers for development of a full scale monitoring system are to understand fundamentals of riser hydrodynamics with full-scale field measurements, calibrate design tools, and validate Tahiti riser system robustness. The monitoring devices and locations are specifically selected to characterize SCR behavior with respect to:Vessel Induced Motion (VIM)Vortex Induced Vibration (VIV)Effectiveness of VIV suppression devices (strakes)Riser behavior at the pull tube exit regionsRiser-soil interaction at the touchdown regionFlowline buckling, axial walkingFlow assurance characteristics of infield flowlines
Choices For LNG FPSO's
Authors: Festen Leo J.F.M. , Leo Jos
Published: July 2009

An estimated quarter of the world gas reserves is presently " Stranded?? in offshore gas fields.

The energy markets and dwindling oil reserves show the necessity to find new ways for offshore gas production.

LNG FPSO's will be required to develop the fields that are too far from the market for pipelines or in too deep water. Despite many design studies, technical and economic constraints have prevented LNG FPSO's from being developed as fast as Oil FPSO's.

A guide on the main choices in the development of a LNG FPSO is given based on a decade of development work by CB&I Lummus.

The following questions are crucial in realizing an offshore LNG production development:

-Which gas fields will be the preferred candidates for early development? -What type of storage tank to use? -Which offloading system? -What liquefaction process shall be selected? What is the lay-out philosophy? What are the options for power generation? How should the project be organized?

Eventually it will be possible to develop sour or high-nitrogen gas fields, fields in harsh environments, and very large gas fields, but these fields will initially not be selected.

The process on a FPSO will be determined by the feed gas composition and the sales spec of the LNG. For storage tanks both membrane and self-supporting types have their advantages; but newer types shall also be considered. Selection of offloading system follows from metocean data: in harsher environments tandem offloading with hoses will be the most flexible but requires dedicated carriers. First projects will use side-by-side offloading with conventional carriers. In the future, remote buoy offloading systems will become available.

Power generation could be dual fuel diesel engines or gas turbines; larger fields favor combined cycle power plants. Safety considerations should determine the layout of the FPSO. Safety and availability will strongly favor electric motor driven compressors.

Choice of liquefaction process is related to capacity; small and medium size will strongly favor expander processes.

For project approach, the choice is between leased and owned units.

The experience of an integrated design team is crucial for both.
SS: Testing in the offshore: Preprocessing of Offshore Platform Integrated Marine Monitoring System Data: What to Do With Unusual Values or Trends?
Authors: Prislin Igor , Maroju Soma , Delaney Kevin
Published: July 2009

Full-scale measurements provide indispensible information for validating behavior of an offshore oil platform; however, they often contain some observations that deviate from a majority of other values. This paper addresses the challenge posed by such data. Specifically, the paper discusses measurements obtained by offshore platform integrated marine monitoring systems such as metocean data, GPS data, and structural data that at a glance have unusual values or trends. In each case, a solution for how to treat unusual values is presented. The paper discusses some unusual episodes in full-scale measured data and suggests possible treatments for such unusual values. Proper treatments of the measured data can help marine assurance engineers to make right decisions, avoid possible damages to the system, or even a shutdown of the production due to faulty alerts.

Introduction

Measured data that contain unusual or unexpected values cannot be used directly in automatic data analyses and results interpretation because the values could be erroneous for a variety of reasons. Detecting and understanding data errors and " rare?? event syndromes are particularly important when statistical techniques are applied to the measurements. If data are used unconditionally, the calculated statistics may be biased. It is important to differentiate between errors in the data and unexpected values that are products of real but rare events. It is unquestionable that interpretation of rare events is a challenging task, particularly if no numerical simulation or model test results are available.

It is common practice to validate the most recent measured data by comparing it with the previously measured data under similar conditions.

When previous measurements are few, or simulated results are not available, unbiased techniques for detecting unusual values or trends in the data, such as Artificial Neural Networks (ANN) and Kalman filters are useful additions to common statistical trend analyses.

Unusual data need not always indicate a platform integrity failure. Rather, they may originate from instrumentation failures. For example, a sudden " jump?? in the GPS data can indicate an instrumentation issue as simple as a change in satellite constellation or a change of atmospheric conditions. On the other hand, the " jump?? can indicate a sudden drift of a platform due to breakage of a mooring line. The latter is a real event that indicates a serious platform integrity issue requiring immediate attention. An ability to differentiate between the two is essential for deciding on a proper course of action.

This paper discusses some unusual episodes in full-scale measured data and addresses possible treatments for such unusual values. Proper treatments of the measured data can help marine assurance engineers to make right decisions and to avoid possible damages to the system or even a shutdown of the production due to fault alerts (Prislin, et al., 2005).
Parametric Study of Ice Class Ship Structure
Authors: Abraham Jacob , Daley Claude
Published: July 2009

The new IACS Polar Rules for Ships contain plastic limit state models of frame capacity. Those limit states were analytically derived using relatively simple energy methods, validated by finite element analysis. This paper examines an expanded range of frames and employs a technique called Design of Experiments (DOE) and non-linear finite element analysis to examine the plastic capacity of frames. The results are compared to the IACS Polar Rule limit states. The paper may serve as the basis for discussing an update of the Polar Rules. The paper also provides owners/designers/regulators with a methodology to examine a wide variety of alternative plastic designs within a broad design space.

Introduction

Stiffened plates are the basic structural building blocks of many onshore and offshore structures, where high strength to weight ratio is a major criteria dictating design. The behavior of stiffened plate in the elastic region is well understood. In the recent years there has been a renewed interest in estimating plastic response of ship structures.

Ship design rules are changing from traditional working stress approach to new rules which allow plastic limit states, particularly in the case of ice class vessels. The rationale behind this move is the recognition that structure tends to have a large reserve capacity after it yields and before it finally collapses.

The capacity of a frame is currently estimated using the IACS rules. The pressure causing collapse in the case of a beam fixed at two ends and loaded at the center is given by IACS Polar Rules as (Daley, 2000):

Equation (1)

Equation (2)

The above pressure reflects the onset of significant plastic deformation and it ignores contributions from large deformations and membrane stresses. Hence the analytical solutions may not accurately estimate capacity of all frames. The reliable methods to estimate capacity are either to conduct a full scale experiment or a nonlinear finite element analysis. These methods are either very expensive or too complex. There is a need for a simple regression equation which can predict capacity taking into account all the non linear behavior of the structure.
Gimboa, Angola Block 4 - First Deep Water Challenge for Sonangol P&P
Authors: Wime H. , Nogueira Yuri A. , Fernandes Lucas Kiteque , Eriksen Gunnar , Bondevik Jon Olav
Published: July 2009

The deep-water (700 m) Gimboa field in offshore Angola was discovered in 2004. With approximately 50 million barrels of recoverable oil in place, this project is marginal at best. The development required accurate resources determination, cost effective implementation, and maximum recovery of the reserves. This is also the first deep water development by Sonangol Pesquisa & Produção, the National Oil Company of Angola, as Operator.

The short-term project (approximately 4 years from discovery to production) was loaded with uncertainties and risks. Among the technical challenges were performing the conversion of an oil trading tanker to an FPSO, the manufacturing and deployment of subsea production facilities as a tie-back to the FPSO, and the solution of issues related to low reservoir pressure, gas lift, water injection and insulation.

In order to tackle these difficulties and quickly build expertise, the Operator formed a technical assistance agreement with one of the concession partners. Engineers, geoscientists, and managers from both companies worked together, as one co-located team with shared objectives. Effective communication using the web and management were key factors to ensure that the project team and the globally distributed team of vendors could focus on the work at hand. After successfully meeting all the challenges, the field is scheduled to enter into production at the start of 2009.

An equally important result of the Gimboa development was the self-realization by a relatively young national oil company that they could manage and develop complex projects in difficult environments. This project also demonstrates that regional and global organizations can equally benefit from the introduction of innovative and more open partnership models.

The paper summarizes the Gimboa experience, and describes how national oil companies, with the appropriate focus and technical assistance, can successfully and quickly develop their marginal discoveries, making the most of the available fiscal incentives, using national resources, and promoting local content.

General Overview and Description of the Field

Focus so far by the Operators in West Africa has been on major oilfields, initially in the shallow water regions or on land in the north of Angola. But, in the last decade this has moved into the deep water environment. However most of the major discoveries, being in deep water are currently under development or are already in production. Focus, will therefore soon be turning to develop fields of smaller sizes in this type of environment.

Recent high oil prices driven by several factors is providing the opportunity for small and independent Operators such as emerging national oil companies to be able to develop those smaller fields which otherwise would be deemed uneconomical especially if they are located in deepwater or far away from offshore infrastructure.
A Cyclone-Based Low Shear Valve for Enhanced Oil-Water Separation
Authors: Husveg Trygve , Bilstad Torleiv , Guinee Peter , Jernsletten Jo , Knudsen B. , Nordbø Hans Tore
Published: July 2009

Turbulence and shear in conventional choke and control valves do mix and emulsify petroleum fluids. A typical consequence is reduced separation efficiency of downstream gravity separators, resulting in retarded oil-water separation. A new cyclone-based low shear valve is developed, enhancing oil-water separation and reducing environmental impacts from petroleum activities. Five years of experimental and theoretical studies are reviewed, including recent tests involving six different North Sea crude oils. For a majority of oils the cyclonic valve has a significant positive effect on oil-water separation. Moreover, it is documented that the cyclonic valve has an overall positive effect on both oil-in-water and water-in-oil concentrations, across a large range of water cuts. The cyclonic valve has a consistent positive effect on oil droplet size for all crude oils in produced water. Typically, oil droplet effluent from a cyclonic valve has twice the size of droplets exiting a standard valve. The effect is largest for the smallest volumetric fraction of droplets. This new valve technology is realizing great potential in petroleum processing; i.e., less droplet break-up and less fluid emulsification. This paper demonstrates quality improvements for both crude oil and produced water. Replacing choke valves might be the ultimate application for cyclonic valves. However, experimental results demonstrate that control valves upstream any gravity-based separator are potential targeted applications for cyclonic valves.

Introduction

Valves in Petroleum Production

Valves are widely distributed in petroleum production and hydrocarbon processing facilities (Figure 1). In their operation throttling valves possess an effective restriction to flow. Choke valves and control valves are typical throttling valves used to regulate flowrates and pressures of fluids in a petroleum process.
Flow Assurance Benchmarking--Bridging the Gap Between Initial Design and Ongoing Operations
Authors: Ng Chris , Tadimeti Krishna , Lowry Timothy
Published: July 2009

A brief overview of the flow assurance benchmarking process is presented, followed by a discussion of typical flow assurance problems identified during benchmarking studies, a couple of examples showing how benchmarking adds value to field operations, and lessons learned that can be applied to flow assurance studies for ongoing operations and future projects. The types of computer models described in this paper could be used to track and interpret field data, evaluate and improve field performance, and to identify and mitigate potential flow assurance problems during subsea production operations.

Actual field data are incorporated into the two examples of flow assurance benchmarking. Specifically, the first example involves malfunction of a subsea tree choke valve during the first few months of production. The second example involves potential failure of flowline insulation or sensor malfunction. This paper adds to the current body of knowledge regarding the modeling of subsea production operations and provides guidance on improving models used in flow assurance analysis.

Introduction

The flow assurance challenges and mitigation strategies typically associated with deepwater projects have been discussed at length in multiple papers [1,2]. Production fluid behavior during steady-state and transient operations need to be understood adequately in order to maximize production, minimize costly downtime, and develop effective strategies to prevent flow assurance problems.

The flow assurance benchmarking process is a key step in bridging the gap between engineering design and successful field operations. The primary goal of this process is to develop an accurate and integrated quantitative model of the production fluid behavior within the constraints of the as-built field architecture and actual environment. With a reliable model, engineers and operators can better understand the actual operating limits, identify and monitor deviations from operating targets, anticipate and avoid operational problems, implement effective operating strategies and procedures, and plan for future operation and field development.

An overview of the benchmarking process is presented in this paper, together with a couple of examples demonstrating how effective benchmarking can be used to alert operators to potential equipment failure and avoid unexpected downtime.

Benchmarking process

A typical benchmarking process involves the following high-level steps:Define the scope, objectives and acceptance criteria.Gather required model input data, including operating data.Develop thermal-hydraulic model (steady-state and/or transient).Compare operating (measured) data to model-calculated values.Revise model until acceptance criteria are met.
Flexible Riser Outer Sheath Full Scale Wearing Simulation and Evaluation
Authors: Clevelario Judimar Assis , Sheldrake Terry H. , Pires Fabio , Falcao Gelson , Souza Italo , Aquino Fabio
Published: July 2009

The interface between the flexible risers and I tubes is being considered by the market as a critical region due to its geometric characteristics and high contact loads between the flexible risers and I tube interface equipment. During the past few years several instances of outer sheath damage were reported by the offshore industry. Such damage was a result of wear against steel parts and occurred in the regular design adopted by the industry, causing riser annulus flooding which significantly reduces service life.

Some of the most severe riser failures reported indicate the rupture of the outermost tensile armour layer. Wellstream has designed and patented a new concept for riser interface equipment by adopting a split and replaceable polymeric insert designed to be in direct contact with the riser's outer sheath.

Wellstream is currently performing a 12 month alternative dynamic test using a 9.13 inch gas export riser as part of the qualification programme; the interface between the outer sheath and the polymeric insert is under peer evaluation. As part of the test, the evaluation of the wear considers actual flexible riser service fatigue loads and actual relative displacement between the riser and polymeric insert in order to reproduce field service conditions. This paper presents the wear evaluation performed during the dynamic test, which also includes UT and laser scanning measurements to monitor and assess the wear on both the riser's outer sheath and the polymeric insert. The test results indicate that the proposed design, which adopts the polymeric insert, is capable of preserving the outer sheath throughout the riser's service life thus demonstrating that it resolves the problems reported by the industry.

Introduction

Floating production units used for offshore oil and gas exploration employ flexible pipe systems and may present two different kinds of configuration at the platform. In the first type, referred to as ‘direct’, the bend stiffeners and interface equipment are assembled directly onto the pipe's end fitting on the platform's riser balcony. This does not lend itself to wear-related problems since the distance between the end fitting and the interface equipment is so short that pipe axial deformation, due to service loads, may be considered negligible thus drastically reducing, or even eliminating, the possibility of damage to the pipe's outer sheath due to wearing.
SS - Application Of Artificial Lift Technology In The Giant Khurais Field
Authors: Al-Somali Abdullah Ahmed , Al-khanafair Nabil , Pomeroy Peter , Al-Towailib Assad , Al-Shammari Awayyid
Published: July 2009

This paper discusses the basis of selecting Electrical Submersible Pumps (ESPs) rather than the other methods of Artificial Lift in the development of the Khurais area, located in Saudi Arabia. It will also discuss the production strategy, project time line, design methods and well performance utilizing an online monitoring system.

Khurais oilfield development is the largest oil increment in the world scheduled to be placed on-stream in 2009. The Khurais increment will add 1.2 million bpd of high-quality Arabian light crude to Saudi Arabia's production capacity. To increase the field's production, several options were evaluated and Artificial Lift utilizing ESPs was chosen as the most viable option for optimizing the Khurais production.

Artificial Lifting by ESPs, in different Saudi Arabian fields including Khurais, was designed to serve several different objectives. The primary objective is the need to increase production from oil wells and fields. From a flow assurance point of view, ESPs have been used to boost wellhead pressures rather than enlarging gathering facilities to reduce the system backpressure. This mandated installation of surface control, safety shutdown, and surface & subsurface data acquisition systems along with supervisory control and monitoring equipment in control rooms.

Introduction

The Khurais area fields (Fields A, B and C) are located about 160 km from the Saudi Arabian capital, Riyadh. Khurais increment will have the capacity to produce 1.2 MMBCD of Arabian light crude by end of 2009. Field A will provide the majority of the production capacity with 1.0 MMBCD, Field B will provide 110 MBCD and Field C will contribute 90 MBCD. Prior to starting production, a six-month preinjection will be initiated to inject 2 MMBCD of treated seawater.

Field A is the largest field in the increment. It was discovered in 1957 and first produced in 1963. The field is about 90 km in length and the width ranges from 5 to 17 km. There are three oil-bearing carbonate reservoirs. Arab Light crude production started from the one reservoir in 1963 and in 1981 a second reservoir was put on line. The third reservoir was never produced.
SS: MODU Risk- Post Mortem Analysis of MODUS in Hurricanes Katrina and Rita
Authors: Sharples B.P. Malcolm , Stiff John James
Published: July 2009

A number of hurricanes have passed through the Gulf of Mexico resulting in MODUs parting moorings or collapsing, but none have come close to the devastation caused by Hurricanes Katrina and Rita which came through the Gulf of Mexico in August and September 2005. 20 semi-submersible MODUs suffered some level of significant mooring impairment, and 8 jack-ups were declared total losses (with many more suffering additional settlement and other damage). While this was a severe outcome for the MODU fleet, which had previously experienced relatively few failures1 due to storm overload, over 100 platforms were destroyed, and the hurricanes caused disasters and major regional devastation on land. This paper reviews the level of damage to the MODU fleet caused by the two hurricanes.

Much can be learned about the likelihood and consequences of future failures by studying past experience. Information on the location of where mooring component parted helps assess the consequences of those mooring lines parting, and the site details for the jack-ups help point towards the drivers for their survival. These can then be put into the perspective of other structures of the industry.

Semisubmersible MODUs in the Gulf of Mexico have changed their general usage since development of the API RP2SK [ref.1] to which their moorings are designed for individual locations. The consequences of MODUs drifting in an extreme hurricane are potentially much greater than in the past because of the recent development of the deep water, highly productive, platforms and their associated extensive subsea infrastructure. Damage to this highly productive infrastructure is detrimental to both the nation and industry.

In the aftermath of these hurricanes, which followed Hurricanes Lili, and Ivan, the industry re-examined and upgraded the standards for siting MODUs. An industry driven JIP was launched on moored semi-submersible MODUs which chronicled the incidents and provided guidance for the change in standards. The MMS commissioned a study on the jack-up failures and successes and industry developed a new standard for jack-ups, API RP 95J. Together with MMS-NTLs, these documents provide guidance for siting MODUs to avoid future multiple losses, minimize consequences of failure, and increase the probability of survival.