bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Case Study of an Independent Third Party Review of Subsea HPHT Technologies Designed and Qualified by a Joint Development Agreement
Authors: Rettie Stuart Douglas , Badam Srinivas , Urquhart Robert James , Walz Gregg 
Published: April 2019

For new High-Pressure High-Temperature (HPHT) subsea technologies deployed in the United States Gulf of Mexico (GoM), the Bureau of Safety and Environmental Enforcement (BSEE) currently requires an Independent Third Party (I3P) review of the design and qualification. When these technologies are developed through a Joint Development Agreement (JDA) and involve a significant scope of new product development, the I3P review can become complex, and a lengthy endeavor. This paper outlines the management lessons learned through a case study of an I3P review performed on a JDA for subsea HPHT production equipment.
In 2014, an Original Equipment Manufacturer (OEM) and four Operators formed a JDA to develop new subsea production technologies for use in the GoM. The OEM has designed the JDA equipment suitable for 20 ksi / 350°F operation subsea, and performed activities to verify and validate the design. An I3P began reviewing the OEM's JDA work in 2016 to verify it meets the acceptance criteria established by industry standards, practices and procedures. Key management lessons from the JDA I3P review's organization, methodology, and practices were studied from an Operator's perspective.
This paper describes the selection of the I3P for the JDA. The selection criterion includes the I3P's qualifications, experience, and resource availability. This paper identifies critical leadership attributes required of the I3P review participants: enforcing ground rules; using a common language across the teams; and deploying robust performance management tools. These attributes drive the convergence of the OEM and I3P review activities. Also discussed, are the importance of a mature OEM document register for timeliness and completeness of document availability for I3P review, and the need for streamlined procedures with a collaborative working approach to manage Findings from the I3P review. It discusses the value of standardizing I3P review reports, to convey the results of verification and validation activities to BSEE clearly and concisely. The paper concludes with identifying some pitfalls to be aware of when executing an I3P review.
The results of studying an ongoing JDA I3P review as described in this paper provide useful guidance for Operators or OEMs in planning and executing I3P reviews of HPHT technology development programs. The case study's key lessons can aid others to implement an I3P review effectively and efficiently for BSEE's acceptance of new HPHT technology.
A Class Perspective for Wind Load Assessment
Authors: Guha Amitava , Boppudi Srimanth , Rousseau Joseph 
Published: April 2019

Abstract
This study describes the purpose, scope, and acceptance criteria for wind load assessments that are used in the Classification of offshore units and installations. Wind loadings are applied as external environmental forces when evaluating afloat stability, structural strength, and mooring system integrity for mobile offshore units and site-specific installations. Existing criteria in the Rules and industry standards are identified to show the usage of the wind loads and their varying characterization depending on purpose, such as time averaging period and vertical speed distribution. The current requirements are placed in historical context based on the development of the offshore Classification Rules over the last 50 years, and the evolution of tools and technology to carry out the computations over that period are discussed.
Practical aspects of calculation and independent analysis are illustrated by applying the standard methodologies in example calculations, using a geometric model that is of similar layout and complexity compared to existing offshore units. Sample calculations are presented as typically performed by Class in an independently developed model, and sensitivity analysis is used to point out areas where results may diverge depending on the approach by the assessor. The effect of these modeling decisions to evaluate wind moment is put in perspective by showing the change in the allowable vertical center of gravity, which relates directly to the deck load capacity of the platform.
The result is a consolidated illustration of the Classification methodology for wind load analysis, which has been uniformly applied to a large number of offshore units and installations over a significant period of time. The importance of common assumptions and approach is highlighted, based on the effect that varying certain parameters has on overall results of the wind load calculation. The resulting impact of wind load changes on the stability, mooring, or structural analysis will be further shown. This will assist in providing visibility to industry on what constitutes a complete report of the wind loads for Classification purposes, how detailed a model should be for basic and detail design purposes, and how to improve confidence in the submission and approval process during design.
Session 46 Phased Deepwater Field Developments - Pros and Cons of Phased Developments
Authors: Duesund Jon Marsh , Martinsen Audun , Fitzsimmons Matthew 
Published: April 2019

Abstract
In light of the deep industry downturn that started in 2014, there was a drastic reduction in the number of deepwater projects being sanctioned. Among the few projects that were sanctioned, many of them were tie-backs or smaller production facilities that potentially can be built out in phases. There are both pros and cons related to this trend of more phased and smaller developments and the purpose of this paper is to highlight these differences. We identify five pros and five cons. The pros are relatively intuitive, e.g. they lower the initial capex, payback period and overall project risk as you are committing fewer resources into the development project. On the other hand, the potential cons are less explicit and typically only visible longer term, including potentially lowering the long-term value creation, limiting the flexibility for future upside projects through e.g. increased/enhanced oil recovery (IOR/EOR) initiatives or tie-backs. By performing some sensitivities, it is possible to give examples where operators may miss some value creation by choosing phased and/or scaled down development solutions. We have looked at three project examples; Buckskin in the US Gulf of Mexico (GoM), Johan Castberg in the Norwegian Barents Sea and Liza offshore Guyana. For these three examples, the results of the sensitivity analysis suggest that overall value creation could have been increased 4-12% if the operators had chosen concepts with higher capacity. However, this increase is contingent on achiveving 20% savings on the capital expenditure (capex per boe) compared to the original concept. Additionally, these enlarged concepts would have created more risks, but from a subsurface and project execution point of view. As such, the pros may outweigh the cons of choosing a more phased and/or scaled down concepts for these examples. Nevertheless, it is important that the industry makes the proper assessments, including longer-term benefits, before making final investment decisions and not overlook potential value creation opportunities.
Hydrate Agglomeration in Crude Oil Systems in Which the Asphaltene Aggregation State is Artificially Modified
Authors: Costa Salmin Davi , Delgado-Linares José , Wu David T. , Zerpa Luis E. , Koh Carolyn A. 
Published: April 2019

Abstract
Some crude oils contain naturally occurring surfactants that avoid hydrate agglomeration. Natural hydrate anti-agglomeration has been linked to different crude oil fractions, including asphaltenes and petroleum acids. Asphaltenes are known to promote the formation of stable water-in-oil emulsions due to their high interfacial activity. The surfactant-like behavior of asphaltenes is directly related to their aggregation state. Asphaltenes are strong interfacial agents when in a colloidal aggregation state, but weak interfacial agents when either precipitated or well dispersed in the bulk oil phase. The asphaltene aggregation state may be artificially modified (changing the interfacial activity) by mixing crude oil with heptane-toluene mixtures (heptol). This work investigated the influence of the asphaltene aggregation state on gas hydrate agglomeration. Results show that the hydrate dispersing capability of crude oils is highly dependent on the asphaltene aggregation state. For instance, if asphaltenes were induced to be solubilized into the bulk oil phase (i.e. toluene rich heptol), the hydrate dispersing behavior was diminished. However, when asphaltene precipitation was induced (i.e. heptane rich heptol), gas hydrates were efficiently dispersed. These new findings could have important implications for the ultimate implementation of novel hydrate management strategies that can eliminate/reduce the need for external interventions and hence minimize capital and operational expenditures.
Method Uncertainty for Five Axial Pile Capacity Design Methods
Authors: Liu Zhongqiang , Nadim Farrokh , Lacasse Suzanne , Lehane Barry , Choi Young Jae 
Published: April 2019

Abstract
The paper describes two approaches for deriving the mean, standard deviation and probability density function of the method uncertainty for five axial capacity pile design methods, namely the API, Fugro, ICP, NGI and UWA methods. A new unified database of pile load tests recently developed in a joint industry research project (Lehane et al., 2017) is used for the quantification of method uncertainty. The focus of this paper is on the statistical description of the method uncertainty parameters for each of the pile design methods for predicting the axial capacity of piles in sand and in clay. Probabilistic calculations of the axial pile capacity for typical offshore piles using the above five design methods (API, Fugro, ICP, NGI and UWA methods) showed that method uncertainty is a major contributor to the uncertainty in pile foundation capacity. The method uncertainty has therefore a strong influence on the calculated annual probability of failure, and thus on the associated safety level. Establishing the statistics of the error in a capacity prediction model from the measured values (Qm) in pile load tests and the calculated values (Qc) of pile capacity requires careful consideration of several factors. Issues of importance to the derivation of method uncertainty statistics include the effect of different sized databases for the different pile design methods, the effect of case histories with particularly low Qm/Qc values and the possible dependence of method uncertainty on pile length and/or pile diameter. The paper presents two different interpretations for the characterization of method uncertainty and demonstrates their application through a case study for an offshore piled jacket. The effect of method uncertainty on the calculated annual probability of failure is illustrated.
AUV Integrated Cathodic Protection iCP Inspection System – Results from a North Sea Survey
Authors: Kowalczyk Matthew , Claus Brian , Donald Craig 
Published: April 2019

Abstract
The OFG AUV non-contact integrated Cathodic Protection (iCP) inspection system enables a fast and reliable approach to monitoring the state of cathodic protection systems on subsea pipelines. By measuring the electric field, the system monitors directly the change in electrical currents in the pipeline due to anodes or damage. This approach allows for improved monitoring of anode energy remaining, predicts anode end of life earlier than stab methods alone and pinpoints problem areas on the pipe that need attention. When combined with the camera imaging, multi-beam measurements, synthetic aperture sonar (HISAS), and chemical sensors, the OFG AUV iCP system provides a compelling set of measurements for pipeline cathodic protection monitoring and pipeline inspection.
The advantage of the OFG AUV iCP system over traditional ROV CP systems is the speed with which these surveys can be undertaken, coupled with the dramatic increase in sensitivity which is approaching 100 times the sensitivity of the traditional ROV CP survey systems.
Ocean Floor Geophysics (OFG) has a successful history of developing numerous magnetic and electric field instruments for ROVs, AUVs and deep-tow systems. Based on the success of these programs, and in collaboration with ISES Technical Services (ISES), OFG & ISES have developed an electric field measurement system which mounts onto a pipeline inspection AUV.
Initial testing of the system in 2017 on OFG's 3000m depth rated Hugin AUV "Chercheur" demonstrated that the intrinsic electrical noise of the "Chercheur" with motors and all survey sensors running, was well below the threshold needed to successfully measure CP signals from the AUV. This was further supported through the development of a first principles model of the electrical fields generated around a generic cathodically protected pipeline.
These supporting measurements and calculations led to the first operational field test of the system on a North Sea pipeline in April 2018. During these trials we were able to demonstrate the responsiveness of the system to the cathodic protection currents in the pipe at a variety of ranges and orientations up to 10 meters distance from the pipe. Furthermore, by performing repeated surveys of sections of the pipeline in both directions, we were able to confirm the repeatable detection of extremely small electric field gradient signals (less than 0.025μVrms/cm difference). The results show levels of sensitivity and detection hitherto unattainable using any other currently available CP survey method. These measurements were taken concurrently with all the other onboard survey sensors running, including the HISAS, Sub-bottom, Multi-beam, Camera system, and USBL, while running at the nominal survey speed of the vehicle of 3-4 knots.
Importance of Wind Loads for Floating System Designs
Authors: Wang Tao , Wu Yongyan , Løken Rolf , Haug Nora , Eide Rolf 
Published: April 2019

Abstract
Wind represents a driving factor for floating system designs, not only for stability, but also for platform global performance including offset, heel and airgap, and thus for mooring, riser/umbilical, structure, topsides equipment and personnel habitability. Wind load evolves as metocean criteria, topsides layouts, design requirements, and estimation methods, and can be in continuous development from concept, design, execution to operation phases. The impact needs to be considered from operability to survivability of floating systems.
A case study of semi-submersibles in worldwide regions will be considered. It is first developed a semi-submersible in the Gulf of Mexico for hurricanes up to 1,000-year return period. Wind speeds in other representative locations worldwide, i.e., the North Sea, and offshore Northwest Australia, are then applied to reconfigure the semi-submersible hull and mooring. The impacts of wind loads are evaluated by changing the wind speed and associated wind profile, but maintaining the other design parameters. The North Sea case is for relatively less severe winds of up to 10,000-year storms, while the offshore Northwest Australia case is for strong tropical winds of up to 10,000-year cyclones.
The hull configuration, including main dimension, displacement, GM, and mooring sizing, are compared for the worldwide cases. For the Gulf of Mexico case, wind load is not only crucial for stability in 100-year environment, but also for survivability in 1,000-year hurricane. Comparably, wind load governs the North Sea case for stability although its 100-year wind speed is less severe, while 10,000-year cyclone wind is critical to survivability for the offshore Northwest Australia case. For mooring system, wind contributes to the majority of environmental loads, especially for the offshore Northwest Australia case. It is presented as a result of wind speed, and can be used to interpret uncertainty in wind load estimation from empirical method, model testing, CFD and design requirements.
This paper evaluates the impact of wind loads for floating system designs from operating, extreme to survival conditions, identifies the governing factor in worldwide regions, and provides a view of systematic approach to the integrated system.
Subsea Demulsifier Injection to Enhance Crude Oil Production in Offshore Brownfields - A Success Case
Authors: de Oliveira Marcia Cristina Khalil , Alevatto Monica , Sampaio Tatiana Pitchon , Dias Plínio Martins 
Published: April 2019

In Brazil oilfield scenario, there are large, clearly identified brownfield sites, many of which with high additional oil production potential. The lifting costs and conventional breakeven price per barrel associated with an existing producing field offshore, even those in decline and requiring some recompletion & workover jobs, are – in many situations - less investiment demanding than brand new greenfield development.
The formation of water in oil (W/O) emulsions is ubiquitous in oilfield production. As the water commingled in crude increases, the emulsions' stability and viscosity also increase, thence generating flow restrictions due to higher friction losses. The subsea demulsifier injection has proven to be an interesting alternative to overcome this flowing constraint in mature wells, thus maximizing the productive capacity of existing brownfields. This paper presents some results and challenges faced to implement the routine of subsea demulsifier injection, from the development of testing protocols to come up with a tailor-made chemical solution, to the hurdles associated to chemical injection through subsea umbilical- and gas lift-lines.
Libra's FPSO - Conceptual Design Challenges
Authors: Queiroz Fabio Vieira de , Araujo Fernando B. C de , Fernandes Mylene Marques , Vaz Juliana Casaccia 
Published: April 2019

Abstract
This paper presents the strategy behind the conceptual design for Libra FPSOs and the technologies being studied to be applied in the future. Considering new reservoir conditions when compared to other Pre-Salt areas in Brazil, such as high GOR, high CO2 content and high productivity wells, surface facilities team have faced new challenges to define the optimum process plant configuration. Concerns related to topside weight and footprint had to be addressed since the early project phase to make sure that the FPSO would be able to operate safely with high production efficiency in a very restricted area.
Right after Libra block contract signature, Libra Project Team elaborated the documentation to lease the first FPSO (EWT FPSO Pioneiro de Libra) and started conceptual studies for the design of the FPSOs that will develop the production of the field.
Besides the economic benefits related to the increase of the oil capacity, the conceptual studies at an early stage of the field development provided the project team more confidence regarding lead time and technical aspects of the FPSO. It is expected that new technologies development will add more value to the projects in the near future.
Stones - The World's First 15 Ksi Ultra-Deepwater Subsea Pump
Authors: Småland Hagland Arill , Skaar JC 
Published: April 2019

Stones is a phased development that began producing in September 2016 from two subsea wells tied back to an FPSO. Full-field development includes six additional wells from two connected drill centers, and a subsea boosting system to increase production and extend the life of the field.
This paper describes the technology qualification program (TQP) and execution experience, including the development, delivery and installation of the world's first ultra deepwater subsea boosting system. The paper also addresses the lessons learned from the project, from component qualification and engineering through to manufacturing and testing.
The Stones field is located in the Walker Ridge area, approximately 200 miles southwest of the Louisiana coast. It consists of eight ultra-deepwater blocks at 9,579 feet water depth. As the operator, with 100% interest in the field, Shell announced its final investment decision in 2013. With reservoirs located at extreme depths, at more than 29,000 feet, subsea boosting was identified in the original project execution plan as a means to enhance recovery due to rapidly decreasing reservoir pressures.
Multiple technology gaps were identified to meet the high-pressure, high-temperature (HPHT) design parameters for Stones. With a targeted design pressure of 15,000 psi, design temperature of 300 °F and nearly 10,000 feet of water depth, an extensive Technology Qualification Program (TQP) was executed to close these gaps. Six workstreams were developed to qualify the first article pump; these included valves and connectors, barrier fluid system, power system and controls. This was the start of a close cooperation between the operator and the pump system provider, whose common goal was to deploy the world's first 15 ksi ultra-deepwater pump. Following the TQP, in 2015, an engineering, procurement, and construction (EPC) contract was awarded that included a pump station with two 2.9MW pumps and a topside power drive system.
The pump system has been through an extensive execution and test phase that was completed without injuries. The complete system was handed over to the operator and has been partially installed.
The Stones boosting system has a daily production capacity of 60,000 bpd and will enable the operator to maintain and extend production at the field. Once the pump system is put into operation, it will significantly increase recovery at the field.
Aasta Hansteen Subsea Production System for Deep Water and Harsh Environment
Authors: Lindseth Severin , Røsby Elling , Vist Brynjar , Aarnes Knut Axel 
Published: April 2019

Abstract
The Aasta Hansteen Subsea Production System is a part of a new major deep water gas development located in the Norwegian Sea, north of the Arctic Circle and 300 km from shore, west of the city of Bodø in Norway. With a water depth of 1300m, this development is a new water depth record in Norwegian waters and it is characterized by its remote location and harsh environment.
The objective of this paper is to present the concept selections, technology development, design and fabrication for the subsea production system including umbilical and workover system. The paper demonstrates the importance of solid preparation in early phase planning, continuous implementation of lessons learned and an extensive test program in order to verify the new technical solutions for the Aasta Hansteen subsea deepwater development. This included development of a new mono-pile "toast rack" template designed for guideline less installation of manifolds and X-mas tree systems. This paper also presents a new deep water Workover system, involving an extensive qualification program and several new technical features such as a new safety joint, heave compensator and automated make-up of riser joints and more, in order to improve operational efficiency and increase safety under given challenging conditions. The paper also addresses a full scale wellhead testing in order to verify the design for fatigue performance.
Several novel technologies were qualified and implemented as part of the Aasta Hansteen Subsea Production System to adapt to deep water operations, to enhance HSE performance and improve efficiency of the system. The experience is that the new technologies and new system solutions have improved HSE performance, operational performance and installation friendliness.