bluuebunny/crossref_metadata_2025_split huggingface dataset:
Accounting for VIV in Wake Induced Motion of Risers in Tandem at High Reynolds Number
Authors: Saint-marcoux Jean-Francois , Blevins Robert D. 
Published: April 2012

Abstract
As production of oil and gas from deepwater and ultra deepwater increases, riser interference becomes critical for engineering design and analysis. Theuse of seafloor space must be optimized and the size of the floating unitsreduced. For example SCR's are closely spaced at the FPU and lay in close rangeat the seafloor. Similarly for decoupled riser systems, jumpers are located atshort distances at the FPU level.
Blevins provided the seminal paper on the forces and stability of a cylinder ina wake. One of the major conclusions of his paper was that accounting for dragas per Huse should be refined to be able to assess the potential instability ofa downstream cylinder in a wake.
To be complete it was necessary to expand the theory to the case of an upstreamcylinder in cross vibration about its steady position. This took more timebecause the wake behind a vibrating cylinder does not follow the classical bellshape curve. Obtaining reliable experimental data to be able to describe it wasdifficult, especially at high Reynolds number (105).
The paper presents experimental data for a wake behind a vibrating (and - forbenchmarking - a fixed) cylinder from 2D downstream to 50D downstream. Arelatively simple extension of the Blevins original theory allows accountingfor the modified shape of the wake.

Role of Interferences in the Design of Deepwater Riser Systems
Deepwater and ultra deepwater developments require a close spacing of therisers and flowlines in order to optimize the seafloor. Examples of suchpractical configurations are:–Decoupled risers (Bundle-HRT and SHR);+interference between the BHRT or SHR risers themselves as they are locatedclose to each other+Turret-moored FPSO's with Bundle Hybrid Riser Towers (Bundle-HRT);interference between the top jumpers that run from the top of the Bundle HRT tothe turret-FPSO+For submerged buoy such as the BSR (Boia de Suporte de Riser - risers supportbuoy), interference between the risers as the spacing governs the length of thebuoy (this applies to SCR's as well as Flexibles)
– Coupled risers (SCR's, Flexibles):–For spread-moored FPSO's; interference between the risers at the FPSO side, as the spacing of the risers is critical. This is because the further away fromthe center of the vessel, the higher is the excitation provided by the pitchand roll of the FPSO
This is also referred to as Wake Induced Motion (WIM). As a generalguideline DNV (2009), recommends analyzing riser interference in the range ofup to 25 diameters downstream. For a typical riser of 0.3m (outer diameter), this corresponds to a 7.5m range, whereas this corresponds to about 60m for aBundle-HRT. Clearly those are ranges of actual engineering applications.
The general case of interference of arrays of risers is simplified in practiceby using strip theory and considering the two closest risers at any given time. Also the time-average hydrodynamic excitation forces are considered.
Experimental Study on Wax Deposition Characteristics of a Waxy Crude Oil Under Single Phase Turbulent Flow Conditions
Authors: Dwivedi Priyank , Sarica Cem , Shang Wei 
Published: April 2012

Abstract
Crude oil, having a paraffin nature, has been studied extensively in thesmall-scale flow loop at Tulsa University Paraffin Deposition Projects (TUPDP). The effects of turbulence/shear and thermal driving force on wax depositioncharacteristics were experimentally studied using a waxy crude oil from theGulf of Mexico. The test matrix consisted of a total of 15 experiments whichinclude 12 short term tests and 3 long term tests. The tests were conductedunder different operating conditions with a wide range of Reynolds numbers from3,700 to 20,500. The shear stress ranged from 5.4 to 53.9 Pa.
It was observed that paraffin deposition is highly dependent on the thermaleffective driving force which is the temperature difference between oil bulkand initial inner pipe wall and also on turbulence effects. The depositthickness obtained using both the pressure drop method and a direct measurementwas found to decrease with increasing shear stress and decreasing thermaldriving force. The wax content showed a gradual increase with an increase inflow rate. For the short term tests, the deposit mass with no entrained oilseemed to increase and then decrease with an increase in initial shear stressand decrease in effective thermal driving force whereas the total deposit masswas found to decrease with an increase in initial shear stress or decrease ineffective thermal driving force.

Introduction
When crude oil flows through the subsea and production pipelines, the oiltemperature drops due to the colder surroundings. It has been observed throughexperiments and postulated in literature that when the bulk temperature of thecrude oil in pipes is higher than the wall temperature, there exists adissolved wax concentration gradient between the bulk oil and the pipe wall. The n-paraffin components are considered to be mainly responsible for waxdeposition (Benallal et al. 2008). When the pipe wall temperature goes belowthe wax appearance temperature (WAT) of the oil, the liquid wax diffusestowards the wall. The liquid wax diffused towards the pipe wall crystallizes on the wall surface orat the interface between the bulk and deposit. The wax deposit may eventuallyblock the pipes. Hence, it is imperative to accurately predict wax depositionunder different operating conditions. The main problems associated with waxdeposition are the increased pressure drop in the pipeline, reducedproductivity and the risk of getting a pig stuck during regular maintenanceoperations.
The current paraffin deposition models can predict wax depositioncharacteristics with high confidence under zero or low shear rate conditionswhile they can grossly over predict and under predict paraffin deposition underturbulent flow or high shear conditions. Understanding of the physics behindparaffin deposition in single phase can help accurately model the behavioraiding in the prediction of paraffin deposition and in deciding the piggingfrequency.
Olympus TLP: PFP Optimization and Blast Mitigation
Authors: Popat Nilesh Rasik , Suardin Jaffee , Howell Steven 
Published: April 2012

Abstract
Shell designed, is building, and will operate Mars B Project Olympus TensionedLeg Platform (TLP) with Drilling and Completion Platform Rig to produce 100MBOPD oil and 100MMSCFD gas. Protecting people and environment is the toppriority for Shell. Initial design assumptions for Passive Fire Protection(PFP) application and blast design to protect people could result in the needfor significantly high weight allowances. Therefore, there is a need to find acomprehensive and structured approach to optimize PFP and blast mitigation todeliver reasonable weight allowances.
This paper demonstrates how, through the use of practical safety assessments, weight allowances for PFP application and blast design can be optimized. Itdescribes how the Mars B Project was able to demonstrate As Low as ReasonablyPracticable (ALARP) risks for the design of critical systems for Major Hazardson the Olympus TLP. Major Hazards such as blowout fires, large wellbayexplosions, and process releases are addressed. Optimization of PFPrequirements and blast mitigation is demonstrated for critical systems such asthe Temporary Refuge (TR), Drill rig, Flare Boom, Primary Structures, ProcessVessels, Occupied Buildings, and Crane. In the case of the Drill Rig, fire andblast assessment is aligned with a key recommendation from the United StatesCoast Guard Deepwater Deepwater Horizon investigation report.
Credible Design Scenarios are identified for Major Accident Hazards (MAHs) andused to assess the inherent strength of the proposed design through FireDegradation, Blast Structural Assessment, and TR Impairment studies. Whennecessary design improvements were identified, further work was undertaken tooptimize PFP application and blast resistance while delivering an ALARP design. In the process, full consideration was given to minimizing design changes, saving weight, and reducing maintenance problems during the life of thefacility. In some instances this produced a superior result relative to initialengineering assumptions about PFP application and blast design.
Overcoming Field Development Challenges in Depleting Ultra HPHT West Franklin Field
Authors: Jezdimirovic Slobodan , Marple Andrew , Maleyran Jean-Marc , Millancourt Francois Jean 
Published: April 2012

Abstract
West Franklin is an HPHT field in the Central Graben Area of the UK ContinentalShelf discovered in 2003. The field went into production in 2007 via a welldrilled from the Franklin Well Head Platform (WHP) of the existingElgin/Franklin facilities. Results from a second well generated the case for asecond phase of field development.
Development studies at the preliminary stage of the second phase eliminated theoption of further field development by drilling from the existinginfrastructure. Subsea development was also screened out due to technology gapsin subsea HPHT applications. A new WHP tied back to the existing Elgin/Franklinfacilities became the prime development candidate in the conceptual stage. However, time was of the essence as the two existing wells were still producingand depleting the reservoir, introducing uncertainty to the drillingfeasibility due to the phenomenon described as the "infill challenge". In orderto mitigate these drilling risks the development strategy was to pre-drill thewells. Drilling commenced from a subsea template and continued until a jacketwas designed, fabricated and installed in September 2012. The acceleration ofthe jacket installation minimized the number of wells to be reconnected from adeep set tie back and allowed the other wells to be completed from a wellaccess deck. The WHP topsides will be installed later in 2013.
In addition to managing multiple interfaces the project faced significanttechnical challenges generated by ultra HPHT reservoir conditions. Overcomingthese in time to optimize the design was difficult in itself i.e. topsideslayout/orientation and associated jacket appurtenances; design of the OverPressure Protection System and risers and their installation within the jacket. The list goes on and includes timely co-venturer and UK regulatoryapprovals.
This paper addresses the key challenges and decisions taken along a stageddesign and approval process for a development in an ultra HPHT environment.

Introduction
The Elgin/Franklin field is located in the Central Graben Area of the NorthSea approximately 240km east of Aberdeen in 92m water depth (Figure 1). Thereservoirs (shore face sandstone of Late Jurassic age) are 5,500m deep andpresent ultra high pressures (1,100bar) and temperatures (200degC).
A Force-resultant Model for Spudcans in Soft Clay and Application to Jack-up Push-over Analysis
Authors: Zhang Youhu , Bienen Britta , Cassidy Mark Jason 
Published: April 2012

Abstract
With the development of the offshore oil and gas industry, mobile jack-updrilling platforms are increasingly required to operate in deeper waters andharsher environments. The improvement of the jack-up site-specific assessmentpractice is vital for safely meeting this demand. In soft clayey seabeds, thespudcan foundations of the jack-up platform penetrate deeply into the soil, andcomplete or partial backflow occurs. In recent years, a number of studies haveinvestigated the performance of spudcan foundations in soft clay to improve therelevant recommendations in the industry guideline published by SNAME. In thispaper, a brief review of recent research in this area is first provided. Then,a force-resultant model that is suitable for performing integratedsoil-structure analysis is proposed. An example of the application of thismodel is finally provided, and important comparisons with the SNAME model aredrawn.

Introduction
Although they were originally designed and built for shallow waters, mobilejack-up platforms are now more broadly used for offshore drilling activities. Due to the development of the offshore oil and gas industry, the demand forjack-ups to operate in deeper waters and harsher environments has increased, requiring improved site-specific assessment practices for both economical andsafety considerations. In many offshore areas, such as the Gulf of Mexico, theseabed consists of soft clayey soil, which often features an increasingundrained shear strength profile with a small intercept at the seabed surface. Jack-up installation in such soil conditions often results in significantfoundation embedment; embedments up to several spudcan diameters are common. The SNAME T&PB 5-5A guidelines are often used by the industry to performsite-specific assessments for the suitability of jack-up platform (SNAME,2008). The recommendations in the SNAME guidelines, however, do not reflect themechanisms of a deeply embedded spudcan in soft clay, but they are derived fromthe observed behavior of shallowly embedded foundations. Conservatism in theSNAME guidelines exists and in practice this can result in an unfavorablesite-specific assessment for a jack-up platform. This paper will brieflyhighlight some recent studies on the behavior of spudcans in soft clay andcompare these to the SNAME guidelines. Then, a plasticity force-resultantfooting model appropriate for spudcans in soft clay is proposed. Examplejack-up analyses with the proposed new model are provided, highlighting thedifferences in prediction with this new model.
Results of Frequency Based Interpretations of Deep Water Passive EM Survey Data
Authors: Mes Marius J. , Bruns David Robert , Johnson Ed A. 
Published: April 2012

Abstract
Airborne 3D high resolution EM survey data were collected by eField in thenorthern Norwegian Sea. Survey areas included a producing field, a drystructure and other deep water areas. We confirmed with newly developedfrequency-based algorithms that:The 3D passive airborne system recognized areas with and without largehydrocarbon deposits,Relative depth information was obtained from a parallel interpretation withgeophysical data,Multiple hydrocarbon bearing strata were identified,Consistent survey results were found in 1200 meters of water.
Data interpretations supporting these claims are included.
We used the results for basin evaluations in support of a license applicationbecause the survey method allows us to optimize existing data (such asgeological and seismic data) interpretations with independent EM datainterpretations. Such combined interpretations can reduce the explorationrisk.

Introduction
The purpose of a high resolution electric and magnetic (EM) airborne surveyoffshore is to provide an economic basin evaluation for the presence of largedeposits of hydrocarbons. The resolution of this evaluation can go down to thedevelopment field level. We developed a novel survey system and a datainterpretation procedure to conduct such surveys and obtain interpretationsthat can be mapped. This paper describes the survey system and the validationresults.
Commercial capabilities exist to conduct aerial EM surveys. However, thecommercially available data interpretation capabilities are very limited. Wecompleted a three-year R&D project to develop a new frequency-basedinterpretation for the non-stationary 3D EM signals. We also defined the tunedE and M sensor, receiver and compatible interpretation systems speciallyadapted to the software development.
The EM interpretations can be used for independentbasin evaluations,prospect evaluations anddrilling site selections.
In the ideal case independent EM survey results should be integrated with otherinterpretations based on geological, geophysical and other data sources, suchas Fig. 1 depicts.
Subsea Technology: A Reflection on Global Challenges and Solutions
Authors: Liddle David 
Published: April 2012

Abstract
The research and development (R&D) of new technology is an essentialactivity for the oil and gas industry and is undertaken by a range oforganisations for a variety of reasons. These organisations may carry outR&D in order to reduce costs and increase profits, maximise recovery, findnew hydrocarbon resources, improve QHSE performance (Quality, Health, Safetyand Environment), or gain competitive advantage.
New technologies will be required to meet operational demands. Subject matterexperts from ITF members, major operating and service companies in the oil andgas sector, have met at two international ITF Technology Challenge Workshops inPerth (WA) and London (UK). They explicitly identified the current sharedchallenges they are facing in both the domestic and the internationalmarket.
ITF has sought solutions to the challenges in the areas of: Subsea Power; FlowAssurance; Subsea Separation; Temperature Management; Pipeline IntegrityManagement; Cost Reduction; Low Cost Intervention.
This paper reflects on the industry's solutions and achievements in the area ofsubsea technology, it identifies the technological challenges as currentlydefined by major industry players and that continue to elude and lie ahead ofus.
Field Deployment of the World's First Electrically Trace Heated Pipe in Pipe
Authors: Fisher Robert , Hall Scott James , Cam Jean-Francois , De La Porte Dominique 
Published: April 2012

Abstract

Description
This paper details the result of onshore industrialisation and offshore fieldtrials undertaken for Electrical Trace Heating solution for reeled Pipe-in-Pipe(ETH-PiP) as part of the overall delivery of the Islay Project, located in theNorthern North Sea. Specific attention is drawn to the onshorepre-commissioning executed through 2010 and 2011, the equipment developed toallow remote intervention and the performance of the system for a range offield conditions

Application
Long subsea tie-backs are increasingly considered for offshore " step-out" fielddevelopments, which often have intermediate or smaller reserves and complexflow assurance issues. In such cases, the flowline architecture can either meanprohibitive insulation costs or curtailment of prospect development due to thephysical limits of insulation systems being exceeded. Hence, in addition to thepassive thermal insulation, the heat losses must be compensated by ActiveHeating. The Total Group has identified, beside other available technologies, the Electrical Trace Heating of subsea pipelines as a promising solution, withhigher energy efficiency and the ability to be installed on a host platformwith a limited impact, thus leading to economic optimization.
During the last decade, anticipating the interest of the iIndustry, Techniphave has run a comprehensive R&D programme for the developed on an (ETH-PiPtechnology). Following a successful qualification programme of more than twoyears, Total and its partners now consider the technology mature enough to forthe next stages of development: industrialisation and field deployment.
The Islay Project, recently awarded by Total as a full EPCI contract toTechnip, has been selected to pilot the ETH-PIP technology.

Results, Observations and Conclusions
Field performance data from initial start-up trials and subsequent operationswill be presented. Information will include power input data, thermalperformance and correlation with bespoke design models developed for this newtechnology.

Significance of the Subject Matter
Whilst ETH-PiP is not the primary hydrate mitigation strategy for Islay Project- this being achieved by an innovative seabed conditioning scheme thatminimizes the methanol injection requirements - it presents an opportunity toperform " full scale" offshore field testing and can be considered as the finalqualification process for future large scale projects in the North Sea andworldwide.

Background and History of ETH-PiP
Technip began development of electrical trace heating (ETH) technology in thelate 1990's having identified a future need for efficient active heating ofsubsea pipelines in order to unlock reservoirs with complicated flow assuranceissues.
An Engineering Approach to Upstream Insurance: Risk Management or Poacher Turned Gamekeeper?
Authors: Gnanendran Athith , Hayes Martin James Stanfield , Watson David 
Published: April 2012

Abstract
Recent accidents in the Gulf of Mexico, East Timor Sea and North Sea are, amongst others, regarded as catastrophic events by the insurance industry dueto loss of life and financial loss. Traditionally, upstream insurance reliesheavily on underwriting judgement for decision making. It is evident that theupstream offshore energy insurance industry lags behind other specialistinsurance areas in assessing pure engineering aspects of a risk. This presentsa problem in an area that requires wide engineering expertise to perform a riskassessment. Such expertise covers construction, well control, property damage, pollution, business interruption and any combination of these.
Further, the impact on insurance companies has been almost overlooked by theExploration and Production (E&P) industry as they concentrate on fulfillingtheir owners and regulatory requirements. Catastrophic events are considered, even within the E&P industry, as being " unfortunate". However, for theinsurance companies and E&P companies they can be disastrous.
These events have highlighted the importance of detailed engineering riskassessment on each area of engineering including: structures, process, controlof well and construction. Within these areas, risk factors including;management and process systems, competency of personnel, technical and designdetails will be reviewed in detail together with pricing implications to theinsurance industry.
Insurance costs for E&P companies can form a substantial part of theirannual expenditure, especially for new projects and new companies. Effectiverisk assessment, together with correct pricing, could be of benefit to allstakeholders.
This paper discusses the factors relating to the risk assessment of upstreaminsurance projects and suggests ways of improving risk to both insurancecompanies and E&P operators by identifying best practice in each area ofengineering. This will assist E&P companies adapting or modifying theirexisting operational systems and enable them to enhance their own riskmanagement process by benchmarking against similar operators.