bluuebunny/crossref_metadata_2025_split huggingface dataset:
SCR with FPSO Design Challenges Subject to Complex Bi-Modal, Bi-Directional Environment in Ultra-Deep Water
Authors: Shah Vinanti , Fales Raymond 
Published: April 2019

AbstractThis paper discusses steel catenary riser (SCR) design challenges subject to complex bi-modal and bi-directional seastates offshore West Africa in ultra-deepwater (2,600m). Metocean data is key to determining the design of SCRs. As offshore exploration continues in remote regions and deeper water depths, it is very important to obtain accurate and comprehensive environmental data for the field. Different locations around the world have distinct offshore environments such as hurricanes, typhoons, swells and squalls with seastates exhibiting a varying range of frequency content. The work in this paper describes effects of multiple seastate modes on the riser’s performance. The risers evaluated are 10 inch production and 18 inch export SCRs connected to a spread moored FPSO. Riser fatigue was particularly challenging given the unique environment consisting of up to four wave modes in a single sea-state. Several sensitivities were performed to improve the fatigue performance of the risers. Finally a feasible riser concept was selected which met all of the project design requirements. Work showcased in this paper will address the challenges of placing steel catenary risers in remote deep water fields with relatively unfamiliar metocean conditions. Several sensitivities are performed with the riser properties, platform motions and environmental data which help to reduce design conservatism and better understand the fatigue response of SCRs connected to a spread moored FPSO.
Residual Curvature Method of Mitigating Lateral Buckling for HPHT PIP System – A case study
Authors: Rao Venu , Sriskandarajah Turairajah , Charnaux Carlos , Roy Alan , Ragupathy Pasupathy , Eyssautier Stephan 
Published: April 2019

Abstract
Lateral buckling mitigation design for HPHT pipe-in-pipe system is technically challenging and at times the reliability of proven buckling mitigation options may come into severe technical scrutiny for some HPHT pipe in pipe systems on the undulating seabed. The Residual Curvature Method (RCM) presents as an alternative technical option for such cases. The technique comprises understraightening in intermittent sections of the ‘as-laid’ pipeline which form ‘expansion loops’ and provide a proven, reliable and cost-effective buckling mitigation. The method was successfully implemented in Statoil’s Skuld project in 2012 and subsequently a few other projects worldwide which are all single pipeline systems. However, the RC method was not used as a buckling mitigation method for a pipe in pipe system to date to the knowledge of the authors.
Residual curvature method could be proven superior for HPHT Pipe-in-Pipe Systems to other lateral buckling methods (thanks to controlled well-developed buckles at pre-determined locations) under some favourable design conditions. This paper shows the robustness of the technique for a typical 12" / 16" HPHT pipe in pipe system with an operating pressure of 300barg and 150°C operating in a maximum water depth of 2000m as a case study. The PIP system is considered to be laid by a reel-lay method, which is amenable to inducing the residual curvature at the pre-determined RC locations during pipelay process.
The study includes the special considerations required in deploying the method on an undulating seabed taking into account unplanned buckles or spans and the necessary adjustment to be made to pre-determined buckle sites. The study includes the effects of inner pipe snaking (with residual curvature) within a near straight outer pipe due to the reeling process and its impact on the lateral buckling behaviour. Other design features that may have a significant effect on the RC method are discussed.
Challenges from Soil Variability, Johan Castberg Field, Barents Sea
Authors: Forsberg Carl Fredrik , Solhjell Egil , Karlsen Viggo , Vangen Vibeke 
Published: April 2019

Abstract
As development concepts for the Johan Castberg Field matured, new locations required soil data. A harder layer has been identified from previous soil data and mapped on seismic profiles as Seismic Unit II. This layer may cause refusal of suction anchor penetration and should ideally be avoided. Predictions of the depth to this layer both along and between seismic profiles were used to optimize suction anchor locations to be investigated during the 2018 soil investigation. This campaign was furthermore optimized by taking earlier laboratory testing into consideration. The Nkt factors were given special attention and found not to vary much in the topmost soil layers. Greater emphasis could therefore be put on acquiring CPTU data, and to use these previously determined Nkt factors to find the soil strength.
The predictions of the depths to the top of Seismic Unit II were in general agreement with the data acquired during the 2018 investigation. The emphasis on collecting CPTU data and combining these with experience from the previous soil testing results saved both ship time and laboratory costs.
Field Development: Agile Value Optimisation
Authors: McLachlan Duncan James , Isherwood Jim , Peile Max 
Published: April 2019

Abstract
In 2011 78% of upstream oil & gas megaprojects faced either cost or schedule overruns according to an industry study by the Independent Project Analysis (Merrow, 2012). In 2014, research by EY found 64% of projects faced cost overruns (EY, 2014) and 73% of projects faced schedule overruns. In 2017 the UK Oil & Gas Authority (OGA) published a study of lessons learned from UKCS oil & gas projects between 2011-2016, which reported "since 2011 fewer than 25% of oil and gas projects have been delivered on time with projects averaging 10 months’ delay and coming in around 35% over budget." (OGA, 2017) This level of cost and schedule underperformance was not sustainable in the high oil price economic environment and is inconceivable in the lower oil price environment in which we now operate.
Both the EY and the OGA reports identify factors for these overruns and lessons that can be learned. These include organisational learnings, project management failings, inadequate planning and cognitive biases within the team. One of the key lessons identified in the OGA report was that high-quality Front-End Loading (FEL) is critical to project success. A successful FEL should develop sufficient strategic information to allow decisions to be made that maximise the chance of a successful project.
As part of its unique approach to field development, which brings projects to market faster and with more certainty, we have created a methodology, based on the approach developed by Professor Ronald A. Howard at Stanford University, to deliver a high quality FEL. This methodology is underpinned by a number of unique tools and techniques and draws on best practice from a variety of industries, including aerospace, smart cities and software development. The methodology paves the way for a digital project execution and the evolution of an operational digital twin.
Monotonic and Cyclic Soil Properties of Gulf of Mexico Clays
Authors: Liedtke Eric , Andersen Knut H , Zhang Youhu , Jeanjean Philippe 
Published: April 2019

Abstract
This paper presents a summary of over 25 years of laboratory data on the monotonic and cyclic soil properties of clays in direct simple shear, triaxial compression and triaxial extension tests, at 15 deepwater Gulf of Mexico sites.
The majority of the test results were obtained by three different laboratories. The data are summarized in numerous plots and diagrams, and correlations are presented to help derive soil properties relevant for deepwater foundation design. The database and guidance presented in the paper can be used in early design when site-specific soil samples are not available, or to optimize the scope of advanced laboratory testing on site-specific samples during detailed design.
Although the soil samples are all from the Gulf of Mexico, the guidance is believed to be valuable also for the characterization of other non-structured, high-plasticity marine clays.
Real-Time Cleaning of Time-Series Data for a Floating System Digital Twin
Authors: Agarwal Puneet , McNeill Scot 
Published: April 2019

Using accurate and high quality data is critical for any application relying heavily on the data, be it machine learning, artificial intelligence, or digital twins. Bad quality and erroneous data can result in inaccurate predictions even if the model is otherwise robust. Ensuring data quality is more critical in real-time applications where there is no human in the loop to perform sense checks on data or results. A real-time digital twin implementation for a floating system uses time-series data from numerous measurements such as wind, waves, GPS, vessel motions, mooring tensions, draft, etc. Statistics computed from the data are used in the digital twin. An extensive data checking and cleaning routine was written that performs data quality checks and corrections on the time series data before statistics are computed.
Various types of errors that typically occur in a time series include noise, flat-lined data, clipped data, outliers, and discontinuities. Statistical procedures were developed to check the raw time-series for all these errors. The procedures are generic and robust so they can be used for different types of data. Some data types are slow varying (e.g., GPS) while the others are fast varying random processes. A measurement classified as an error in one type of data is not necessarily an error in the other data type. For example, GPS data can be discontinuous by nature but a discontinuity in the wave data indicates an error. Likewise, checking for white noise in mooring tension data is not that meaningful. We developed parametric data procedures so that the same routine can handle different types of data and their errors. Outlier removal routines use the standard deviation of the time-series which itself could be biased from errors. Therefore, a method to compute unbiased statistics from the raw data is developed and implemented for robust outlier removal.
Extensive testing on years of measured data and on hundreds of data channels was performed to ensure that data cleaning procedures function as intended. Statistics (mean, standard deviations, maximum, and minimum) were computed from both the raw and cleaned data. Comparison showed significant differences in raw and cleaned statistics, with the latter obviously being more accurate.
Data cleaning, while not sounding as high tech as other analytics algorithms, is a critical foundation of any data science application. Using cleaned time-series data and corresponding statistics ensure that a data analytics model provides actionable results. Clean data and statistics help achieve the intended purpose of the digital twin, which is to inform operators of the health/condition of the asset and flag any anomalous events.
Field Implementation of Above Water Riser Robotic Inspection Tools - Reducing Safety Risk While Improving Efficiency and Effectiveness
Authors: Lou Jane , Hoor Azadeh , Zeng Wilson , Hull Meghan , Wei John , Walton Chris , Truch Dave , Silva Stan , Broman Bill 
Published: April 2019

Abstract
Integrity management (IM) is an ongoing lifecycle process for ensuring safe operation and fitness for service of offshore oil and gas production systems, including riser and flowlines. Riser and flowlines offer a means of transporting fluids between subsea wells and the host platform. A key component of the riser system is above water riser hull pipes. With their proximity to topside equipment and the people on the platform, these pipes are considered safety critical, and are therefore, subject to rigorous and frequent inspections followed by an engineering assessment of the findings. A thorough knowledge of the past and current conditions of these pipes is required to manage the risk to their integrity. Traditionally, these inspections are carried out by rope access technicians. Such activities are often limited by accessibility, weather, and/or Personnel on Board (POB) availability and involve risks to inspector's safety.
This paper discusses the motivation and business driver for developing and implementing new robotic inspection technologies for above water riser inspection. The technology management process of robotic inspection tools is outlined. Comparison is made between traditional and new inspection technologies based on BP Gulf of Mexico (GoM) robotic inspection campaigns. Examples are presented to demonstrate the reduction of safety risks and improvement of inspection execution and effectiveness. The paper also discusses the potential areas of future development, which include methods for pipe wall thickness measurement and data analytics, such as automated recognition approach to characterize and quantify features in the images.
Performance and Health Monitoring, Prognostics and Contingency for Electrical Completion Systems, Designed on Purpose
Authors: Nutakki Mihitha , Faur Marian , Viassolo Daniel , Gour Indrajeet 
Published: April 2019

Abstract
Electrical intelligent completion systems are designed for reservoir management and production control of different zones within a well. The operating conditions expose the tools (hereinafter referred to as "stations") within the system to harsh conditions—high temperatures, high pressures, gas, and sand particles. Over time, exposure to such conditions can lead to component, module, station, or system failure, resulting in the possibility of deferred production or nonproductive time. To improve system reliability, the downhole and surface components of the system are equipped with sensors. The capability of such systems to acquire and transmit data related to the health of the system, its modules, and its components is a novel approach.
Acquired data is transmitted through a cloud-based Internet of Things (IoT) framework for station health monitoring and health degradation predictions. The high frequency of data acquisition in combination with a large number of stations can lead to huge volumes of data. Manual monitoring and processing of large-scale data can become very inefficient and unmanageable and consequently, there is a need to develop intelligent algorithms for processing data to make actionable decisions and to adhere to a sustainable workflow.
This paper describes the data pipeline established through cloud-based architecture for automating the monitoring, dashboard creation, and health prediction for the electric motor actuator (EMA) module, using historical health data of the downhole electronics. In addition, a predictive approach consisting of feature engineering, event (actuation) extraction, and supervised machine learning algorithms is discussed and illustrated through example data sets and results.
Critical Production Pressure and Optimal Gas Production Rate to Avoid Hydrate Reservoir Disturbance
Authors: Yuan Chen , Ting Sun , Ying Zhao , Wen Wang Xing , Xi Qu Mo , Jie Wang 
Published: April 2019

Abstract
Natural gas hydrate is an ice-like crystal formed by methane and water, which is a new type of strategic energy with huge reserves. The exploitation of deep-sea hydrate will cause a large amount of decomposition of hydrate, which will decrease the sediment strength.
In this paper, firstly, the influence of three main distribution patterns of hydrate on mechanical parameters is analyzed and the hydrate reservoirs suitable for actual production are judged. Then, reservoir constitutive models and hydrate decomposition and flow models are established based on previous studies. Different distribution patterns of hydrate are established by changing the hydrate content in the reservoir. Finally, simulations are carried out under different production pressure, and parameters such as hydrate saturation are output. Then input those parameters into Mohr-Coulomb model to compare the changes of mechanical properties of reservoir during the exploitation and judge whether the hydrate reservoir is disturbed. Consequently, the critical production pressure is determined. Then, the optimal production rate of different types of reservoir can be determined by adjusting production pressure within the critical bottom hole pressure. The work of this paper will provide a certain reference value for the rational and safe production of hydrate in the future.
Compact Modular Manifold – Standardization and Modularization for Low Cost in a Low Volume Market
Authors: Sundt Hans Kristian , Ali Hasan 
Published: April 2019

With increasing volatility in the oil prices, continued focus on low cost solutions is key to maintain a sustainable subsea industry. The industry has and will continue to have a tremendous amount of focus across many standardization initiatives and Joint Industry Programs.
The total number of trees awarded since 1961 is in the range of 7 000 - 8 000 representing an annual average of approximately 140 which in the last 10 years has been closer to 300.
Assuming 2/3 are installed by a manifold with an average of 4.5 trees per manifold, gives roughly 45 manifolds worldwide per year in the entire subsea industry. Take into consideration that the manifold is the largest piece of equipment in the subsea production system acting as system integrator and interface, bridging the trees with the flow line, often having to absorb the field specific requirements and you have the ultimate standardization challenge in a low volume environment.
An important aspect discussed above is that the manifold is indeed part of a bigger system. There are many ways to approach standardization and, in the article, we argue that the optimal approach is to standardize from materials and upwards in the system hierarchy. The approach taken to standardize the manifold was therefore to start with a broad set of system attributes across the subsea production system rather than focusing on the manifold alone. This allows the standardization to be a wholistic approach aiming to optimize the supplier’s operational production strategies, maximize use of lowest cost production processes as well as developing the right standard products.
The modular compact manifold has therefore been developed through extensive use of data analytics due both to the large number of variables and the size of the dataset to find the optimum breakdown of the manifold into modules. The manifold shares components and production process with the subsea tree for valves and branch blocks using standard pressure classes. Standard pipe schedules have been identified to further reduce number of parts required in the portfolio. This has enabled configure to order manifolds with a limited number of pre-defined components that can be held in stock to minimize lead time. The use of compact branch blocks has also the allowed the manifold to significantly reduce footprint and weight further ensuring efficient installation.
Genomic Identification of Low-Density Granulocytes and Analysis of Their Role in the Pathogenesis of Systemic Lupus Erythematosus
Authors: Kegerreis Brian J. , Catalina Michelle D. , Geraci Nicholas S. , Bachali Prathyusha , Lipsky Peter E. , Grammer Amrie C. 
Published: April 2019

Abstract
Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the presence of low-density granulocytes (LDGs) with a heightened capacity for spontaneous NETosis, but the contribution of LDGs to SLE pathogenesis remains unclear. To characterize LDGs in human SLE, gene expression profiles derived from isolated LDGs were characterized by weighted gene coexpression network analysis, and a 92-gene module was identified. The LDG gene signature was enriched in genes related to neutrophil degranulation and cell cycle regulation. This signature was assessed in gene expression datasets from two large-scale SLE clinical trials to study associations between LDG enrichment, SLE manifestations, and treatment regimens. LDG enrichment in the blood was associated with corticosteroid treatment as well as anti-dsDNA, low serum complement, renal manifestations, and vasculitis, but the latter two of these associations were dependent on concomitant corticosteroid treatment. In addition, LDG enrichment was associated with enrichment of gene signatures induced by type I IFN and TNF irrespective of corticosteroid treatment. Notably, LDG enrichment was not found in numerous tissues affected by SLE. Comparison with relevant reference datasets indicated that LDG enrichment is likely reflective of increased granulopoiesis in the bone marrow and not peripheral neutrophil activation. The results have uncovered important determinants of the appearance of LDGs in SLE and have emphasized the likely role of LDGs in specific aspects of lupus pathogenesis.
Blood and cardiovascular health parameters after supplementing with ketone salts for six weeks
Authors: Holland Angelia M. , Qazi Ahmed S. , Beasley Kristen N. , Bennett Hannah R. 
Published: April 2019

Background: Exogenous ketone salts (KS) have been administered as treatment for various health conditions; however, the safety of chronic supplementation in a healthy population has yet to be explored.Aim: This study examined the safety of KS supplementation for 6 weeks in healthy, young adults and determined the effects of KS on blood ketone levels.Setting: Data collection occurred in a laboratory at Augusta University.Methods: Twenty-three men and women (aged 18–35 years old) supplemented with KS or a placebo (PLA) twice per day for 6 weeks in a randomised, double-blinded, PLA-controlled design. Baseline and post-intervention measures included body mass index (BMI), resting blood pressure and heart rate, questionnaires assessing mood and energy, urinalysis, and venous blood measures, including comprehensive metabolic panel (CMP), lipid panel, and complete blood count (CBC). In addition, the participants consumed the assigned supplement during the baseline and post-intervention visits; blood ketone levels were assessed immediately before and after 30 and 60 min post-supplementation.Results: Systolic blood pressure was significantly lower (p 0.05) after supplementing with KS for 6 weeks but not PLA. All other health parameters remained unchanged by KS supplementation, including BMI, resting heart rate, urinalysis, CMP, lipid panel, and CBC. After acute administration of KS but not PLA, blood ketone levels were significantly elevated (p 0.001) 30 and 60 min after supplementation at both baseline and post-intervention visits.Conclusion: Chronic KS supplementation seems safe, significantly elevates blood ketone levels 30 and 60 min after supplementation and may lower blood pressure. Future explorations should determine the success of KS supplementation as a strategy to combat hypertension.