bluuebunny/crossref_metadata_2025_split huggingface dataset:
Accelerated Development of Subsurface Safety Valve Technologies
Authors: Edwards Jason Wade 
Published: August 2021

Abstract
Described is a methodology for accelerating the development of innovative and high-risk technologies, specifically, subsurface safety valve technologies. Focus is on methods of mitigating technical and commercial risks that can delay or prevent successful development of new technologies. Example risk assessment and risk mitigation strategies are provided from a recent subsurface safety valve technology development project. Mitigation strategies include fixture level testing, design changes, and deep client collaboration. In the example project, it is estimated that the total development time was reduced by as much as 50% by implementing these strategies. While a subsurface safety valve development is used in this example, it is believed that many strategies are applicable to other domains.
Cyberdefence of Offshore Deepwater Drilling Rigs
Authors: Rossi Paola , Sela Itai , Rizika Adam , Angelidis Diogenes , Duck Mark , Morrison Ron 
Published: August 2021

Abstract
An alternative methodology using new preventative technology to manage cybersecurity exposure on deepwater drilling rig assets is presented. For the past two years Shell's Deepwater Wells business has been evaluating typical cyber defence approaches and undertaken cybersecurity risk assessments and penetration tests. These activities have demonstrated the challenges attaining cybersecure drilling rig environments. Whilst cyberattacks increase in frequency, adaptability, and become cheaper to launch, regulatory and liability insurance requirements are also evolving. To achieve the goal of cyber-resilience, a major Operator has collaborated with a cybersecurity firm to trial technology for rapidly and reliably protecting deepwater rigs.
The paper presents aspects of the numerous challenges faced and offers a different approach using new technology applied to both supplement and accelerate the attainment of a cyber-resilient environment onboard deepwater drilling rigs. It shares the deep dive lessons learnt leading to a more comprehensive understanding of how to protect drilling rigs and their safety critical control systems. Aside from addressing technical attributes using risk vs. maturity based methods, the approach also caters to business demands of short term rig contracts, managing multi-vendor legacy systems and satisfying increasing digitalisation/remote access needs with associated reductions in overall cybersecurity CAPEX spend.
Taylor Bubbles of Viscous Slug Flow in Inclined Pipes
Authors: Dafyak Longtong Abednego , Hewakandamby Buddhika , Fayyaz Ahad , Hann David 
Published: August 2021

Abstract
Unique structures are formed when gases and liquids flow simultaneously in pipelines. The geometric characteristics of these structures are fundamental parameters in intermittent flow regimes. The length of liquid slugs and Taylor bubbles are inputs to mechanistic and empirical models for pressure drop estimation, slug catcher sizing and determination of the periods of no or low liquid in pipelines. Although slug flow has been studied for decades, there still exists a lack of comprehensive understanding of flow structures dynamics due to the complex interactions between the gas and liquid phases in two-phase flow. This study investigates the influence of pipe inclination on the length and hydrodynamics of large gas structures in intermittent flows, particularly, ‘Taylor bubbles’ in slug flow regime. An experimental study was conducted in a 67 mm ID pipe to estimate the bubble lengths of an air-silicone oil mixture from void fraction measurement using a twin-plane Electrical Capacitance Tomography (ECT) tool. The results show that the pipe inclination, gas and liquid flow rates have a substantial effect on the length of large bubbles in slug flow. Taylor bubbles get longer when the void fraction increases, or the pipe inclination deviates towards the horizontal pipe orientation. The influence of pipe inclination on bubble length is quite significant; this variation in bubble length with pipe inclination is attributed to the expansion or compression of large gas structures when there is an alteration on the forces acting on the bubble nose. The weight of the liquid column above the bubble nose which has been often neglected in earlier models was identified to have a notable effect on the volume occupied by the large bubbles and consequently, its length. A semi-mechanistic model is proposed based on the analysis of forces acting on the Taylor bubble nose in a quiescence liquid phase. A comparative analysis of the model and previous models shows that the proposed model outperforms existing mechanistic and empirical models across all pipe inclinations. This study gives an insight into the effect of pipe inclination on the length of large bubbles during slugging in pipes, as these bubbles can be up to 10 times longer in horizontal pipes compared to vertical pipes at the same flow conditions. The proposed model has the potential of estimating the length of large bubbles across all pipe inclinations in upward slug flow with acceptable accuracy, particularly for pipelines installed in undulating terrains.
Wandoo B: Application of Advance Reinforced Concrete Assessment for Life Extension for Non-Jacket Structures
Authors: Sheppard Robert , O’Brien Colin , Moslehy Yashar , Roberts Rachel 
Published: August 2021

Abstract
Wandoo B is a concrete Gravity Base Structure (GBS) and is the main production facility for the Wandoo field offshore NW Australia. It was installed in 1997 with a design life of 20 years. The structural assessments discussed in this paper are part of a comprehensive life extension project encompassing wells, subsea systems, marine and safety systems, topsides facilities and structures to demonstrate fitness for service through the end of field life (EOFL).
The challenge was to demonstrate compliance efficiently and effectively for a large structure with a range of materials (steel, reinforced concrete (RC)) and operations supported (oil storage, drilling, production) under increased loading criteria compared to the original design. There is comprehensive industry guidance for assessing existing steel jacket structures, but far less for a concrete GBS such as Wandoo B. Demonstrating compliance required a combination of computer model results, project-specific tools to check reinforced concrete sections, and engineering judgement to define how much damage constitutes failure.
A number of global and local structural models were developed to assess the linear and nonlinear performance of the reinforced concrete and steel structure. A phased approach was employed using basic, conservative approaches in initial phases to demonstrate code compliance, and progressing to more advanced, less conservative approaches for those components under higher stress.
Developing models that more accurately simulate the behavior of the different structural components and materials was a large part of the project scope, particularly for the nonlinear behavior of the reinforced concrete and the interface connections between the steel and reinforced concrete structures. It was inefficient to develop a detailed steel and reinforced concrete solid model of the large GBS shafts and base, so an equivalent shell model was developed and tested to determine the global behavior and onset of damage. This equivalent model aimed to predict behavior accurately for metocean and seismic loads under material tension and compression. Local detailed models were then developed including a constitutive model of reinforced concrete and used to define the extent of the damage and predict where failure would occur.
Recent Developments in The Use of Hip for The Offshore Industry
Authors: Shipley James , Beamer Chad , Gårdstam Johannes 
Published: August 2021

Abstract
The use of additive manufacturing (AM) technology is growing rapidly for offshore use, whilst established production technologies such as powder metallurgy near-net-shape (PM-NNS) continue to be used. New standards are being introduced and many of the oil and gas majors are now developing supply chains to ensure rapid supply of high-quality complex parts. Environmental concerns are helping to drive this with use of near-net-shape technologies to reduce carbon dioxide emissions through more efficient designs and metal forming methods.
Hot isostatic pressing (HIP) has been used to remove shrinkage porosity and internal defects in cast products for many years, predominantly to improve mechanical properties and fatigue resistance. Recently, there has been an increasing focus on AM processes for demanding applications where localized corrosion and similar internal defects and porosity are a concern. HIP technology is being used to either produce PM-NNS parts, or for the post processing of AM produced components to ensure defect free material prior to service in demanding environments. This paper will present a broad overview in the use of HIP equipment to produce parts and components to the offshore industry.
Fatigue Monitoring and Life Extension for Top Tensioned Production Riser Systems
Authors: Mercan Bulent , Campbell Mike , Thompson Clay 
Published: August 2021

Abstract
Top tensioned production riser (TTR) systems are exposed to fatigue loading in deep water as a result of vessel motions and high currents. The accuracy of predictions of the in-place fatigue response, which is a key input for any life extension requests, is dependent on the operating condition during the life of field including fluid contents and top tension. One solution to reduce this uncertainty is to deploy a fatigue monitoring system to assure the long-term integrity and performance of these riser systems. This paper presents results from a recent TTR monitoring campaign and focuses on the impact of top tension variation on riser motion and fatigue response in the field.
Standalone and ROV deployable motion loggers offer a low cost and robust method of fatigue monitoring. The motion loggers are installed at discrete locations along the TTR to measure riser motions and then determine fatigue accumulations. During one of the recent monitoring campaigns, riser top tension was changed due to operational requirements, which in turn affected the riser fatigue response in the field.
Field data is collected from two periods for two TTRs. The top tension was adjusted between each campaign allowing the effect of tension on riser fatigue response to be better understood using field measurements. The resulting riser motions and fatigue accumulations will be presented to demonstrate the sensitivity to top tension and highlight the importance of maintaining good records during the field life.
Currently, there is no single guideline in the US that addresses TTR life-extension programs in detail. The results from this monitoring program are one step forward in better understanding system behavior of deep water TTRs and assessing the feasibility of an extended service life.
Cost-Effectively Modernizing Offshore Drilling Line-Ups with DC Power Grids and Energy Storage
Authors: Steenberg Thomas , Settemsdal Stig , Valen Alf Olav 
Published: August 2021

AbstractThis paper outlines an approach/solution which enables offshore operators to economically upgrade (i.e., modernize) drilling drive lineups with direct current (DC) based power grids and energy storage.Many legacy drilling rigs in operation (and ones that are currently stacked/idled) utilize drilling drive technology that is currently obsolete or will be in the near future. Modernizing these rigs can often be an arduous and expensive undertaking. Most drilling setups feature lineups of individual variable frequency drives (VFDs) equipped with dedicated rectifiers, which control power output to motor/consumers, such as mud pumps, the top drive, draw works, rotary table, etc. These alternating current (AC) based setups have been used with success for decades. However, as fuel consumption and emissions, as well as space and weight, have become priorities, DC grid systems have gained interest.The solution described in this paper is designed to enable drilling rig operators to upgrade to a modern DC power distribution system using the same footprint as the existing drilling line-up and with minimal modifications to cabling. Energy storage, such as batteries or supercapacitors, can also be integrated within the footprint to enhance the performance of drilling operations – for example through peak shaving and blackout prevention.The solution/approach is highly flexible/modular and is derived from proven concept that has been deployed on hundreds of marine vessels worldwide. The paper provides a description of a solution that is being implemented on a jack-up rig in the Middle East. The new integrated drilling drive setup uses the same footprint, cable network, and communication principles as the rig's existing system and will be comparatively less costly and complicated to implement than simply swapping out existing drives (i.e., one for one replacement).
Improving Mooring Integrity through Standardized Inspection Practices – A DeepStar® 19403 Project
Authors: Ma KT , Spong Robert , DeBroeck Daniel , L’Hostis Didier , Gabrielsen Øystein , Valeixo Loreta , Chen Yong , Roberts Craig , Gordon Robert , Byatt David 
Published: August 2021

Abstract
In-service inspection is a critical element in confirming the integrity of permanent floating production unit mooring systems. Over the unit's operating life, which will typically span 20 years or more, these inspections provide the majority of the condition information on the mooring components and overall system. This information enables operators to proactively address mooring issues caused by degradation mechanisms or deviations in mooring line tensions that could reduce the system capacity and potentially result in premature failure. However, detailed guidance on inspection intervals, and in particular inspection scope, is limited for permanent mooring systems. To address this identified industry need, the DeepStar® technology consortium initiated Project 19403, "Improving Mooring Integrity through Standardized Inspection and Fit-For-Service Assessment" to develop best inspection practice guidance for permanent mooring systems [1]. This paper describes the content and benefits of this new mooring inspection guidance document developed as part of the DeepStar® 19403 project [1] with the support of subject matter experts from major operator companies, Class societies and mooring consultancies. The paper will describe how this new guidance compliments and expands current industry Recommended Practice (RP) guidance. Key aspects related to in-service survey intervals, component inspection work scopes and inspection methods will be discussed as well as the execution planning of in-service mooring inspections. To facilitate inspection work, the predominate deterioration mechanisms are introduced which are corrosion, wear and fatigue. Other types of deteriorations are also summarized. Default in-service survey intervals (frequencies) and component inspections are recommended. In-service inspection methods are reviewed, from General Visual Inspection (GVI) and Close Visual Inspection (CVI) to advanced Non-Destructive Testing (NDT). Guidance on assessing the residual capacity of a damaged or flawed mooring component, known as fitness-for-service, is also covered within the new mooring inspection guidance.
Concrete Breakwater for the Greater Tortue Ahmeyim Project for BP in Mauritania and Senegal
Authors: Replumaz Alexis , Julien Yann , Bellengier Damien 
Published: August 2021

Objectives / Scope
During summer 2017, EIFFAGE GENIE CIVIL MARINE was invited by BP to bid for the construction of a concrete caisson breakwater protecting an offshore LNG liquefaction floating terminal which will be located 10 km west from Saint Louis, at 33 m water depth on the Mauritanian / Senegalese maritime border.

Methods, Procedures, Process
The basic design as originally proposed by BP was composed of 18 rectangular concrete caissons laying on an underwater rumble-mound foundation. Dimensions of the concrete boxes were approximatively 63,5 meters long, 32 meters wide and 30 meters high, on a design consisting of multi rectangular cells (128 units/caisson)
EIFFAGE GENIE CIVIL MARINE answered to the ITB by proposing under an EPC basis an alternate caisson shape optimizing drastically the concrete quantities.

Results, Observations, Conclusions
Alternate caisson dimensions were 54,5 m long, 28 m width, 35m height including a 3 m high crest wall at the top against extreme waves overtopping. The geometry of the caisson has been changed to a 10 lobes caisson. The weight of each caisson is around 16 000 tons.
As a result of the subsequent FEED studies performed from April 2018 to February 2019, including 3D model testing in basin, Eiffage was able to reduce the amount of concrete required by 40 % compared to the first design, leading to 124 200 cum of concrete and both financial as well as environmental benefits.

Novel/Additive Information
Execution plan involving Mauritania and Senegal
This infrastructure offers key local content components for this gas field development in each country, something Eiffage had key experience with thanks to an historical presence in the the region : Eiffage started its activities in Senegal more than 100 years ago.
The original execution plan as proposed by Eiffage for the EPC phase signed in February 2019 was to build the 21 concrete caissons in Dakar -Senegal. A dedicated yard of 15 hectares has been reclaimed besides the actual port of Dakar providing a safe direct access to the sea and the required water depth for the caissons towing.
As a result, at peak more than 600 jobs will be created in Senegal, with the reclaimed land for the fabrication yard left as a legacy for the port area.
The underwater rumble mound requires 2 million tons of quarry material. EIFFAGE's proposal was to produce, transport and load from Mauritania those materials. A specific logistics scheme between the quarry and vessels loading point has been developed including a bypass road around Nouakchott. The transport of the quarry materials requires the mobilization of 170 trucks. A special safety mitigation plan including dedicated training is being implemented in order to reduce identified risks linked to road transportation.
Replacing the Piled Foundations of the Houphouët-Boigny Bridge in Abidjan Cote d’Ivoire
Authors: Ameri Ashkan , Mercer Adrian 
Published: August 2021

Abstract
Due to historical ground movement, increased traffic levels, and general degradation, this important road and rail bridge which provides an essential link between the interior of the country and the Port of Abidjan, required significant repair and reinforcement. This included strengthening the pre-stressed concrete box girders and replacement of the piled foundations. Replacement piles had to be adjacent to, and no longer than, the existing piles to not compromise the stability of the operational bridge during the works. The underlying geology, however, meant that the pile loads had to be predominantly transferred into the ground through end bearing. Rather than installing a greater number of piles or larger diameter piles, innovative thinking changed the usual mind-set of designing the piles to the prevailing ground conditions, to designing the ground conditions to suit the piles. Jet grouted columns were installed beneath the toes of the new piles to increase the bearing capacity of the ground. This significantly contributed to the sustainability of the project and reduced carbon emissions through saving concrete, steel, plus transportation and disposal of spoil.
Acoustic Evaluation of Annulus B Barriers Through Tubing for Plug and Abandonment Job Planning
Authors: Bose Sandip , Zhu Lingchen , Zeroug Smaine , Merciu Ioan Alexandru , Constable Kevin , Hemmingsen Pål Viggo , Berg Eirik , Wielemaker Erik , Govil Amit , Kalyanaraman Ram Sunder 
Published: August 2021

Abstract
The need to evaluate cement behind multiple casing strings has become critical in the context of well plug and abandonment (P&A) or slot recovery. A particularly important case, addressed in this work, is the application to optimize P&A operations in offshore wells where the capability to evaluate barriers behind casing using tools deployed inside an inner tubing would reduce the costs associated with rig time and potentially (in case the presence of barriers outside the casing is confirmed) the unnecessary removal of casing strings. We present an approach using a combination of sonic and ultrasonic tools deployed inside tubing to characterize the near well bore environment and in particular, the annular fill and bond behind the outer casing, i.e. in annulus B. Extensive modeling and experiments were used to characterize the sonic response in a dual string geometry and identify features that inform on the state of annulus B. Some of the complexities and ambiguities in this complex scenario are addressed by using the ultrasonic tool to characterize the annulus behind the tubing (annulus A) as well as the tubing location inside the casing. Additionally, we combine the single feature answers with those using deep machine learning to learn the complex relationship of the subtle features in the through tubing sonic response to the finer variations of the annulus B state as indicated by ultrasonic cement maps acquired in the outer casing. We test and validate these answers on a number of field jobs and show the results of the through-tubing logging answers with the reference cement evaluation maps obtained after removing the tubing.
Qualification of Wax Control System
Authors: Stangeland Øivind , Daasvatn Sigbjørn , Novoseltsev Yuri 
Published: August 2021

Abstract
A cold flow plant consists of a Water Management System (WMS) for separation and treatment of produced water, and a Wax Control System (WCS) for making solid wax particles that can travel through the long tieback line without further deposition on the pipe wall. Pre-conditioning to a level of 1-2% remaining water implies that avoidance of hydrate formation can be handled by reasonable volumes and traditional chemical methods.
The Wax Control System enable a temperature independent transport of oil dominated flows by continuous removal of deposited wax from the pipe wall, allowing the solid wax particles to travel with the flow in the export line without any risk of further deposition of wax along the export pipeline. The technical qualification work included design and operation of a Pigging Loop that allowed continuously removal / handling of wax within a bundled pipeline.
Satellite Observations for Better Characterization of Sea Surface Wind Field and Offshore Wind Energy Resource Assessment
Authors: Fragoso Mauricio , De Montera Louis , Husson Romain , Berger Henrick , Appelghem Pascal , Guerlou Laurent , Fabritius Gaetan 
Published: August 2021

Abstract
This paper presents a method to generate maps of offshore wind power at turbine hub height from spaceborne Synthetic Aperture Radar (SAR) data. Two techniques based on machine learning are presented. The first can be trained with metocean buoys and the second one, more precise, requires on-site profiling Lidars. If Lidars are not available, SAR surface winds at 10m are improved with machine learning. They are then extrapolated at 40m with a classical power law, and then at higher altitudes with an atmospheric numerical model. If profiling Lidars are available, parameters from the numerical model are added as input to the machine learning algorithm and the training is performed directly at turbine hub height with the Lidar data. Once the wind at turbine hub height is obtained, the wind power is then calculated using a Weibull distribution. The resulting maps are compared with the outputs of the numerical model. The maps based on SAR data provide a much higher level of detail and a better estimation of the coastal gradient, which is important to optimize wind farm siting and estimate the potential energy production. The accuracy of the wind power is found to be in the range ±5% compared to the Lidars.