bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bijupira’ & Salema: An Innovative Integrated Approach to Subsea Field Re-Development
Authors: Herdocia O. , Delescen K. , Sbordone A. , Cribley L. , Garcia B.G. , Felipe L. , Lacourt R. , Nunes H. 
Published: October 2015

The Bijupira' & Salema Fields were discovered in 1990 in Brazil and are located 250 km east of Rio de Janeiro, in water depths between 480 and 880 m. The field was one of the first to be developed by a foreign operator, and was also one of the first turnkey developments in the country. It started production in 2003, and in 2013 went through a re-development program presenting all the challenges of a typical brownfield project. It included the hook-up of 4 new wells, installation and commissioning of the production bundles, subsea control modules and hydraulic, electric and gas-lift flying leads. Production from 4 unproductive wells was suspended and some of the corresponding hardware such as production flexibles were decommissioned. The project also included topside modifications like the replacement of the master control system and of the electrical power unit, followed by the re-commissioning of the entire subsea system.
An innovative approach was taken by the Operator for the re-development program: project engineering, marine support and subsea operations were delivered as an integrated project by the selected contractor, FTO Services, which brought together the individual companies already working separately on the project. This presented significant advantages for the Operator, because it simplified the interfaces between equipment supplier and installer and also aligned the schedule of the installation vessel Island Enforcer with the other support vessel already operating in the field, the Holiday.
The close interaction and teamwork of the companies involved, together with the quality and commitment of the team members, enabled significant gains in efficiency and effectiveness during all phases of the project.
In the Planning phase, the companies collaborated to develop a novel optimized installation method: simultaneous use of the Island Enforcer´s cranes allowed a simple but yet safe and efficient method of constructing and installing the well jumper flexible bundles. The resulting strategy eliminated the need for a jumper fabrication worksite, eliminated the use of a transport vessel and thereby the number of vessel-to-vessel heavy lifts, and eliminated the use of a large spreader bar and risk to subsea assets during recovery.
During the Execution phase, the installation activities in the tight and congested drill centers of the 2 brown fields were completed in record time when compared to the original installation campaign. This was the result of significant improvements in the hardware design, as well as the selection of a state of the art vessel, ROV systems and tooling.
The paper details the scope of the project and its execution, pointing out the benefits brought by the integrated approach and by the unique capability of the contractor to deliver the full range of integrated subsea services along the whole life of the field.
Development of Rolled H-shape Steels for Low Temperature Applications
Authors: Ito H. , Ichikawa K. , Fujioka M. , Sugiyama H. , Mitsuyasu K. 
Published: October 2015

Abstract
In recent times, demand for steels, such as H-shaped steel for offshore structures for the world energy market is rapidly increasing. Such beams are often manufactured with steel plates and are welded to ensure the toughness, which is represented with Charpy V-notch energy, at low temperatures of -40 °C in H-shape steel. However, welded beams have several disadvantages, e.g., requirements of cost and operation period for welding fabrications and inspections and quality control in heat affected zones. Rolled H-shape steels enable to overcome these difficulties if they satisfy the mechanical property requirements such as Charpy V-notch absorbed energy at -40 °C.
In previous studies, grain refinement by facilitating intragranular ferrite nucleation on inclusions in steels has been analyzed to improve strength and toughness. For example, vanadium-nitride is reported to be particularly capable as ferrite nucleation sites. Furthermore, precipitates and inclusions can be useful for rolled H-shapes to improve the toughness by the refinement of ferrite grains. Chemical composition, particularly of microalloying elements, which form precipitates and inclusions, has to be carefully optimized to satisfy alloy ranges identified in EN10225 classification.
This study attempts to reveal the effects of microalloying elements in H-shapes for the low temperature applications. Series of experimental ingots were casted in a vacuum melting furnace and were laboratory rolled to plates. These test materials were investigated by mechanical tests and metallographic observations such as optical and transmission electron microscopy. The results of these experiments suggested that the toughness can be improved by the ferrite refinement using vanadium-containing nitrides on prior austenite grain boundaries.
Based on these experimental results, actual H-shapes were examined in the practical production line and it was confirmed that these results could meet the EN10225 Class S355 classification, where the Charpy V-notch minimum average impact energy at -40 °C required were 50 J in base metals and 36 J in weld heat affected zones.
Alternative Lost Circulation Material for Depleted Reservoirs
Authors: Luzardo J. , Oliveira E. P. , Derks P. W. J. , Nascimento R. Vega , Gramatges A. Perez , Valle R. , Pantano I. Gianoglio , Sbaglia F. , Inderberg K. 
Published: October 2015

Abstract
The problem of lost circulation occurs almost permanently during drilling operations. When drilling highly permeable, highly fractured, and depleted zones, large drilling fluid losses lead to increased operational expenses. Lost circulation may have several consequences, including fluid inflow, wellbore collapse, formation damage, nonproductive rig time, and environmental issues. In the last century, lost circulation has presented great challenges to the petroleum industry, requiring large capital expenditures and time to address the problem. A particular challenge is depleted reservoirs. As the reserves decline, pore pressure decreases, resulting in weakened hydrocarbon-bearing rocks; nearby or inter-bedded low permeability rocks, however, may maintain their pore pressure. This situation can make the drilling of certain depleted zones extremely difficult. Generally, the fluid density necessary to support the shale above exceeds the fracture resistance of the sands, silts, or carbonates below. Consequently, it is vital to design the drilling fluid to minimize mud invasion into formation and prevent lost circulation, and to provide the possibility of removal at a later stage (completion).
To mitigate circulation loss risks, a broad range of treatments and preventive methods using lost circulation material (LCM) have been tried and recommended over the years with varying degrees of success and efficiency. This paper presents an extensive review of the applications of various technologies, both proven and potential, in LCM for sandstone and carbonate depleted reservoirs. It describes the state of the art, advantages, limitations, and suggested specific applications. It also presents recent references of their uses in the petroleum industry and discusses the application and the status of the technologies.
For sandstone, the materials discussed focus on LCM in the form of flakes, granules, fibers, blends of these materials, particulate materials, polyglycolic acid (PGA) and polylactic acid (PLA) materials, as well as nanoparticles (NP) and nanocomposites. For carbonate formations, the scope includes conventional LCM, such as cement plugs, settable plugs, polyurethane grouting and other new technologies, such as gels, viscoelastic surfactant gels (VES), and crosslinked gels.
This review compiles crucial information necessary to design and formulate the fluid using LCM for the depleted reservoir challenges.
Experimental Investigation on the Influence of Liquid Cargo in Floating Vessels Motions
Authors: Rocha Thiago P. , Dotta Raul , Vieira Daniel P. , Mello Pedro C. de , Malta Edgard B. , Nishimoto Kazuo 
Published: October 2015

The offshore exploration of gas requires the use of new platforms design called FLNG (Floating Liquefied Natural Gas). Nowadays just a few number of FLNG are in advanced stages of design or under construction. This type of vessel requires large tanks to storage the liquefied gas and in some cases the movement of the liquid inside the tanks can modify the vessel behavior in waves. The work objective is to obtain the influence of liquid cargo in the floating vessels motions.
An experimental setup was proposed to investigate this influence. A FLNG model was tested for two configurations: with fixed dry cargo and with liquid cargo. For the latter, the model was equipped with tanks which were filled with water in three different levels. In total six different tests were carried out in the Hydrodynamic Calibrator from University of Sao Paulo, a tank with 14 m long, 14 m wide and 4 m depth equipped with 144 flaps capable of generating waves with different angles of incidence. The vessel motion was obtained for the six degree of freedom using an optical system. Furthermore, numerical models were made in WAMIT for both configurations with and without free surface effect due the liquid inside tanks.
Results presented significant differences in the RAO curves. Basically, amplification in surge and sway motions was observed and changes in the roll natural period were obtained, both due the presence of liquid cargo. Furthermore, some limitations were obtained for numerical model mainly in cases with tanks filled at low levels. In these cases, the viscous forces presented significant influence and some effects as breaking waves (sloshing) inside tanks were observed. Both breaking waves and viscous forces are not considered in WAMIT model, once it uses the potential linear wave theory. Discussions are concerned in the comparison of motions obtained for the two tested configurations and in the limitations and applications of numerical model.
R&D in Reservoir Geomechanics in Brazil: Perspectives and Challenges
Authors: Serra de Souza A. L. , F. O. Lima Falcão 
Published: October 2015

Reservoir Geomechanics is an important tool to study phenomena like compaction, fault reactivation and fracture propagation, which occur in several offshore sandstone and carbonate reservoirs in Brazil. This work summarizes the main R&D works developed in reservoir geomechanics in Brazil in recent years, as well as the main challenges the company will face in the next decades.Amongst others, the following subjects with their main challenges are discussed:A typical work to develop a Mechanical Earth Model (MEM) for geomechanical studies;Studies for compaction and dilation in sandstone and carbonate fields;Fault reactivation and its main implications, like the connection of different layers or even different fields;Numerical studies developed for some special fields;Studies for Injection with fracture propagation pressure;Works in progress to monitor faults and fractures;Studies made together with universities in Brazil and other countries;The main conclusion is that several progresses have been made in reservoir geomechanics, but a lot of work and investment in R&D must still be done in order to solve the problems related to reservoir geomechanics in the main fields of the company, particularly those located in deep water environment.
Ultra-Deepwater Blowout Well Control and Abandonment Operations Through Relief Well Under Capping and Containment Scenario After Worst Case Discharge
Authors: Terra F. , Lage A. , Yoiti T. , Yuan Z. , Bueno D. 
Published: October 2015

For ultra-deepwater wells, the ability to control and plug the blowout well is more and more important as regulatory agency has more strict rules to issue a drill permit. After the blowout well is killed, cement plugs need to be placed in the borehole to prevent migration of fluids between the different formations. Because of the mixing and contamination process of the cement slurry pumping through relief well, to ensure required cement height and good quality for blowout well, is more challenging than the topside intervention well plugging operations.
In this study, dynamic simulations are carried out to assess the difficulties faced during blowout well control and abandonment. In the selected scenarios, the capping stack system is installed on the wellhead of the blowout well and three vessels are used to capture the oil with risers connected to each vessel separately. Through the relief well, sea water is pumped to the blowout well, increasing the hydrostatic pressure and reducing the rate of production. The injection of sea water together with the manipulation of choke outlet pressures on the vessels provides proper conditions for controlling the blowout well, keeping the liquid flow rates within the limits imposed by the processing capacity at surface. As sea water accumulates in the blowout well, reducing oil production rate, each vessel is shut down accordingly. Once the blowout well is completely filled up with sea water, kill mud is used to replace sea water to ensure static kill. Cement slurry is then pumped to blowout well to set the cement plug. The displacement is specially studied when the cement slurry is flowing into the blowout well. In the sensitivity analysis, borehole enlargement, cement slurry rheology, and flow rate are considered to investigate the contamination of the cement slurry.
The presented outcomes allow engineers to better understand the operation procedures for blowout well control with capping, containment and zero discharge to the environment under capping and containment scenario after worst case discharge, and the methods to mitigate cement slurry contamination and ensure good cement plug for well abandonment.
Flow Assurance Aspects and Optimization of Subsea Choke Valve – Sand Management and Erosion
Authors: Gharaibah E. , Zhang Y. 
Published: October 2015

In Subsea production systems (SPS), choke valves can be considered to be the heart of the system and are typically set up to control the hydrocarbon production flow and injection of gas and water during both steady-state production and transient flow scenarios. The control functionality of subsea choke valves comprises several aspects: balance of the subsea manifold pressure (when fed from multiple wells with different reservoir pressures), reduction of the flowline pressures (and cost), mitigation for reservoir collapse during startup, adjustment of the flowrates to extend production life and support the functionality of the subsea gate valves to avoid high-pressure drops during startup and shutdown.
Safe and reliable operation as well as the controllability performance of the subsea choke valve depend on the effectiveness of the sizing and selection process as well as on the positioning of the choke in the SPS when designing the SPS. The optimum location of the choke valve in the SPS and the arrangement of the piping system upstream and downstream of the choke, including any intrusive probes, are crucial and can impact the operation of the choke valve itself and affect the SPS integrity. The optimized location must consider the production profiles and operation philosophy of the wells, as well as the associated flow assurance issues. Sand particle production and erosion risks, flow induced vibration, hydrates and other deposit hazards are major flow assurance challenges that can affect the choke valve performance and in turn these effects can be amplified by the choke valve and impact the SPS integrity. This mutuality should be considered when designing the SPS and positioning the choke valve in it.
This paper summarizes GE Oil & Gas experience in sizing and selection of the subsea choke and its placement in the SPS. The focus is on the integration of a subsea choke valve in the SPS to achieve safe and reliable operation and extend the life of the valve and SPS. In general, the paper provides an overview of flow assurance aspects related to sand production and erosion that should be considered when designing the SPS and optimal positioning of the choke valve. It describes methods to examine erosion issues associated with the subsea choke valve by the means of Computational Fluid Dynamics (CFD) simulations. Numerical experiments were performed on various choke and SPS arrangements to explore these issues and provide best practices.
The results show that details of the fluid composition and operating conditions strongly affect the fluid/particle flow patterns in and around the choke and trim, suggesting the necessity for erosion analysis to ensure safe and reliable operation and emphasize the benefit from using CFD tools for system optimization.
Improvements in the Practices for Mooring Integrity Management
Authors: Kilner A. , Washington D. , Carra C. , Potts A. 
Published: October 2015

The requirement for improvements to existing practices for the management of mooring system integrity has been bought into sharp focus in recent years, with the failure rate for FPS mooring systems being significantly higher than expected. This paper will provide an overview of the recently published risk based guidelines for the management of mooring system integrity, developed by AMOG for DeepStar. The DeepStar Mooring Integrity Management (MIM) guidelines will be of interest to operators of a wide range of floating production systems, as well as to the designers of such systems.
This paper will outline the key aspects of the risk based process for the management of mooring system integrity set out in the DeepStar MIM Guidelines. The integrity management framework developed in the DeepStar MIM Guidelines includes the identification of required practices at each stage of a mooring system's life cycle, in order to minimize the risk of degradation mechanisms arising from design, construction, installation and operational practices.
The guidelines include two case studies to demonstrate how the model guidelines should be applied, at the design phase for a new system, and to a legacy system already in operation. In addition, the guidelines include a detailed industry survey of instances of mooring system failures or early replacement due to unanticipated degradation, which was undertaken to provide a more rigorous understanding of the failure probabilities of mooring system components.
This paper presents significant contributions to the effective management of mooring system integrity, through the development of enhanced design practices that better account for through-life integrity management of moorings for new systems, and development of enhanced inspection and monitoring/prediction practices for legacy mooring systems.
Evaluation of Clash Energy in Long Risers
Authors: Galgoul E. , Massa A. 
Published: October 2015

The subsea oil and gas industry in ultra-deep waters requires very long risers, flexible or rigid, which may clash due to their proximity in some field configurations. Clashing should be avoided whenever possible. However, when no mitigation is effective to avoid clashing in a chosen layout or configuration, it is critical to ensure that no damage will occur in any one of the riser sections.
The key to avoiding damage is to correctly evaluate the clashing energy, which is a function of the relative speed between the risers at the moment when clashing occurs, as well as the clashing stiffness and damping of each riser section. The correct evaluation of the clashing stiffness grows in importance when the possibility exists for impact between risers with a high relative velocity.
In order to evaluate the energy effectively absorbed by the riser sections, it is necessary to perform parametric analyses involving different riser types and diameters, riser configurations (single catenary, lazy wave), field layouts, water depths, and associating global clashing analysis with local analysis of the clashing sections using finite element software.
When high velocity impacts occur, part of the kinetic energy is transferred as strain energy at the contact point. Part of this strain energy occurs at the clashing section which will be deformed (local strain), while the other part is transferred to the surrounding area of the risers as axial and bending strains (global strain). This makes it extremely difficult to correctly evaluate the clashing stiffness of each riser. In order to obtain the local stiffness in the contact section, it is necessary to identify how much of the kinetic energy is locally transmitted by the sections.
The aim of this paper is to present a discussion about alternatives on how to evaluate the clashing energy based on the clashing stiffness of each riser. A methodology for the energy clashing calculation is presented in a way where it is possible to identify and separate the local strain from the global strain in a specific contact section based on the kinetic energy transmitted by each part.
Data Envelopment Analysis of Navigation Records Improve Ship Fleet Management
Authors: Cepeda M. A. Fun-sang , Caprace J. D. 
Published: October 2015

This paper describes the use of navigation data to generate a model in order to answer to the following questions. What is the ship with less efficiency in my fleet? What is the best strategy to improve the overall efficiency of my fleet? What is the ship that I should sell in priority? What is the influence of this maintenance policy on the performance of my fleet?
The application case of this paper is based on one fleet of 13 ships containing 223 trips that gather approximately 6844 traveling days. The developed mathematical model is using Key Performance Indicators (KPIs) based on Fuel consumption performance, Aging, Work performance, Sea condition, Steaming Time, Emissions, and Port Logistic. Afterwards a Data Envelopment Analysis (DEA) model is discussed. Both laden and ballast conditions are considered. Afterwards, a Multi Criterion Decision Analysis (MCDA) is proposed in order to assist the ship-owner in the improvement of the performance of their fleet.
A methodology to compare the efficiency of various ships in a fleet has been introduced in this paper and it provides a way to compare similar or different ship types and sizes during their operation. This study offers a method to exclude the engineer subjectivity by assessing the ship efficiency from different aspects using Data Envelopment Analysis. The results suggest that this new methodology can efficiently provide a multi-criteria decision framework to improve maintenance and fleet management strategies. The outcomes show a performance classification of the ships inside a fleet in a way that best and worst ships are identified at any moment.
These findings provide a new way to address efficiency and performance in ship fleet management. Developed methodology allows to minimize operational resources hence reduce costs.