bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of Non-Technical Risks on Project Schedule Overrun: The Perspective of Upstream Gas Projects in Australia
Authors: Basak Munmun , Coffey Vaughan , Perrons Robert K. 
Published: April 2019

Abstract
The complexities of non-technical risks (NTRs) continue to pose serious threats throughout the lifecycle of hydrocarbon projects. Existing studies emphasise mainly internal organisational and operational issues, with a limited focus on factors in the external environment (where NTRs are frequently found). To shine light on this increasingly important topic, this paper provides insight into the complex relationship between NTRs and schedule overruns, and puts forward a ranked list identifying the NTRs that have had the most significant impact on delays in upstream gas projects in Australia.
Data was gathered through an extensive literature review, interviews with industry experts, and a survey to identify relevant NTRs. From these data sources, a predictive model was developed for assessing the impact of NTRs on upstream gas project delays. The survey was circulated among participants directly involved in offshore and onshore (particularly the upstream stage) gas projects, who were requested to indicate via five-point Likert scale the frequency of occurrence and severity of each NTR.
We identified 18 NTRs categorised into the political and regulatory risks, economic/financial risks, social risks, and environmental risks that cause severe challenges in upstream gas projects. The findings reveal that, overall, 78% of participants believed that NTRs cause more severe delays in the upstream stage than in the mid- and downstream stages of gas projects in Australia. Roughly 39% of respondents from the offshore group mentioned that environmental issues were more significant, whereas for onshore projects, social risks were considered dominant. Our analysis shows the relative criticality of NTRs. The top five critical NTRs causing major delays were found to be ‘fluctuations in oil prices’, ‘difficulty in obtaining land/access right’, ‘delay in approval from regulatory bodies’, ‘socio-cultural issues’, and ‘environmental restrictions’. Spearman’s rank correlation test was used to show a high degree of agreement between offshore and onshore project participants in their perceptions about the relative criticality of different NTRs. Factor analysis was applied to examine the clustering effects among NTRs, and multivariate regression modelling assisted in deriving a predictive model to forecast the influence of NTRs on project delays.
Identifying and prioritising critical NTRs that interplay within the project environment, and thereby delay project execution, will increase stakeholder confidence, build trust and integrity, and improve transparency. In this way, this study will help practitioners and decision-makers to anticipate potential delays, and enable them to plan accordingly to minimise their effects on capital project delivery.
Experimental and Numerical Studies on the Drift Velocity of Two-Phase Gas and High-Viscosity-Liquid Slug Flow in Pipelines
Authors: Eghorieta Raymond A. , Pugliese Victor , Panacharoensawad Ekarit 
Published: April 2019

Abstract

Objectives/Scope
Drift velocity for two-phase air and high viscosity oil has been studies in depth, in this research. The drift velocity is one of the key parameters used in the prediction of gas-liquid two-phase flow hydrodynamic behavior. Improvement on the drift velocity closure relationship allows a better design for pipelines and wellbores system that experience two-phase flow phenomena.

Methods, Procedures, Process
Researchers have relied on empirical correlations as a means to predict the drift velocity. These empirical correlations have been limited to the flow of gas and low viscosity (20 cp and lower) liquid. In this study, the effect of drift velocity on gas and high viscosity two-phase flow in pipelines have been investigated. Drift velocity experiments and numerical calculation were carefully performed. A well-designed 1.5-in internal diameter flow loop facility with the capability of pressure drop and liquid holdup measurement was used for this drift flux velocity measurement. Various computational intensive simulations for drift velocities have been performed.

Results, Observations, Conclusions
A new empirical correlation was developed for the prediction of the drift velocity in horizontal and near horizontal pipelines. The effects of inclination and pipe diameters have been accounted for in the new correlation which increase its range of applicability.

Novel/Additive Information
The correlation was validated and compared with other existing drift velocity correlations and experimental data. The new closure relationship allows a significant improvement on the pressure drop prediction for the cases of two-phase gas and high-viscosity-liquid flow in pipe. This enable the transient calculation for subsea pipeline transporting gas and high-viscosity oil by using a drift flux model.
Developing Industry Guidelines for the CFD-Based Evaluation of Wind Load on Offshore Floating Facilities
Authors: Kim Jang Whan , Jang Hyunchul , Shen Zhi-Rong , Yeon Seongmo 
Published: April 2019

Abstract
This paper summarizes an on-going effort by SNAME OC-8 CFD Task Force to provide guidelines on wind-load estimation by CFD simulation. The intention of the guidelines is to help the industry to obtain reliable and accurate estimations of wind load on offshore floating facilities using CFD technology, for the purposes of stability, global-performance and mooring analyses. The starting point of the guidelines is CFD modeling practices collectively developed by ten participants of the Task Force. Blind validation of the wind loads from CFD simulations has been made for a semisubmersible with simplified topsides geometry. Comparison of the wind loads from independent CFD simulations from the participants confirmed that CFD can provide reliable and accurate wind load with fewer uncertainties in the simulation (or test) set up than wind-tunnel testing. A roadmap to develop the guidelines based on the CFD modeling practices is proposed.
Efficient Design and Execution of Site Investigations for Offshore Wind Farms: Learning from Experience
Authors: Pearce Sean Daniel , Kilsby Christopher , King Felix Jonathon , Jones Lewis 
Published: April 2019

Abstract
This paper demonstrates how a phased site investigation approach complements the design process for offshore wind farms. Examples are given showing how three-dimensional (3D) engineering ground models and real-time data analysis have been utilized by integrated project teams to maximize efficiencies, achieve cost and program savings, and reduce risk.
In general, the aim of a site investigation should be to ensure that: Sufficient ground data is obtained for design, certification, and construction;Data collected is fit for purpose and fully integrated; andA comprehensive interpretation can be carried out with consideration of engineering design and construction requirements.
In the authors’ experience, offshore site investigations are most effective when a ‘geoteam’ (an integrated team of ground specialists including geologists, geotechnical engineers, geophysicists, and others) is assembled at an early stage in the project and carries out early optioneering studies followed by scoping, supervision, and interpretation of a phased site investigation program. Crucially, the geoteam must be able to read and communicate the ground from a designer's perspective and appreciate the Client's constraints and requirements. If they do this effectively, the geoteam will be able to scope a more efficient, targeted site investigation, and provide almost live updates to the engineering ground model. The model can in turn be used to inform real-time decisions being made by the developer, their offshore site investigation representative (Client Representative), and the wind farm's designer.
Consideration of the 3D ground conditions is paramount and should always be combined with an appreciation of the site's geological history and earth surface processes to assess how geological variability and ground hazards may affect design. This will provide strong justification for the scope of site investigation works.
While the UK and European wind farm market is maturing, with the first offshore wind farm in the UK constructed in the year 2000, the US market is currently in a period of rapid early development. Drawing on considerable experience gained from work in the UK and Europe, the authors present a designer's perspective of site investigation, describing lessons learnt from the scoping, execution, and interpretation of numerous site investigations for offshore wind farms.
Four Years of Metocean Support to the Shell Stones Field: From Asset Integrity to Collaborative Research
Authors: Ogle Marcus T. , Smith Rosemary , Williams Benjamin , Schiller Rafael , Perry Ruth , Leung Pak , DiMarco Steven F. , Howden Stephan 
Published: April 2019

Abstract
Fugro was contracted in 2014 by Shell to provide a Fugro Wavescan Buoy system to support the life of field of the Stones development in the Gulf of Mexico. The companies have worked together to expand the monitoring system of the Shell Alcyone buoy system from a tool designed to satisfying regulatory compliance into a scientific platform for deep ocean research. In 2018, Fugro was contracted by the National Academies Gulf Research Program to expand the real-time monitoring of currents below the required 1000 meters to the full water depth of 2950 meters. Shell and Fugro invited universities and non-governmental partners to utilize the Alcyone buoy as a platform to make additional measurements varying from marine life monitoring to deep water column temperature readings to characterize thermocline variability.
Fugro's metocean support to the development of the Shell Stones field started with the installation of a moored buoy system prior to the arrival of the FPSO Turritella and has grown to provide an abundance of unique metocean data. The objective of this paper is to discuss the evolution of a metocean buoy originally designed for NTL compliance, into a collaborative platform for research, development and innovation between the Industry, Academia and Research. Among hurricane data, interesting metocean features captured in the data such as the Loop Current activity and Topographical Rossby Waves are presented.
Since its deployment in January 2015, the Shell Alcyone buoy is evolving into a pioneer platform for asset integrity, metocean monitoring and scientific collaboration. Fugro and Shell's partnership is looking to well beyond 2025 and both parties will continue to strive to learn as much as possible utilizing this unique opportunity and platform.
Measuring Flow in Pipelines via FBG and DAS Fiber Optic Sensors
Authors: Alfataierge Ezzedeen , Dyaur Nikolay , Stewart Robert R. 
Published: April 2019

Abstract
An investigation is made into the use of a fiber optic sensing system for monitoring and measuring fluid flow in pipes. This is done using two fiber optics sensing systems, a Distributed Acoustic Sensing "DAS" system and a Fiber Bragg Grating "FBG" system. A laboratory setup is used to conduct these tests and the setup is structured to simulate an offshore environment. The laboratory setup consists of a water reservoir that flows water through PVC pipes into a tank, fibers are attached to the pipes, and a flow meter is used to measure the flow rates. From the conducted flow experiments, a relationship between flow rates, DAS amplitudes, and FBG wavelength shifts is built.
This paper presents the response of fiber optic sensing systems to flow experiments that were conducted with various flow rates, and simulated leak tests with and without flow. The results are used to establish a relationship between the fiber optic response and flow variation, to develop a method of measuring flow rates via the fiber optic systems. Such that any pipes equipped with fiber optics could be used to measure approximate flow rates.
This study finds a strong correlation between the fiber optic sensing systems measurements and measured flow rates. In the FBG system, flow was found to have two influences on the FBG measurement; an increase in flow shows an increase in the FBG sensor wavelength, also, the turbulence of flow was found to be proportional to the amount of fluctuations in the FBG measurements. Such that wavelength shifts of up to 120 picometers are visible for an average flow rate of 27±0.1 Gal/min. With the DAS system, the amplitude response shows a stronger relationship to the turbulence of flow rather than the average flow rate. Such that the highest amplitude response during a flow test would always correspond to the flow valve being half open (which was found to be the most turbulent flow).
In conclusion, this study indicates that fiber optic sensing systems can be used on pipelines and well casing to monitor and measure flow. Additionally, it demonstrates that taping the sensors on the pipe is enough to capture the signal produced by fluid flow in a pipe. The relationship provided between the FBG measurements and flow rates can be used to compute approximated flow rates when using an FBG sensing system to monitor flow.
Experimental Measurement of Touchdown Zone Stiffness for SCR in Gulf of Mexico Clay
Authors: Al-Janabi Husham A. , Aubeny Charles P. , Chen Jinbo , Luo Meng 
Published: April 2019

The location near the touchdown zone (TDZ) of a Steel Catenary Riser (SCR) onto the seabed is a primary "hot spot" for fatigue-assessment, with seabed stiffness having a major influence on the predicted fatigue life. This paper presents the results of laboratory model tests evaluating the effects of cyclic loading, loading rate, load amplitude, riser embedment depth and consolidation on the vertical stiffness of the soil supporting the riser in the TDZ.
Monotonic and cyclic model tests using single gravity, displacement-controlled laboratory model tests of soil stiffness were conducted. All tests used high plasticity Gulf of Mexico clay with undrained shear strength corresponding to typical normally consolidated conditions. A test program was developed to evaluate: (1) rate effects for monotonic and cyclic loading, (2) vertical stiffness for displacement amplitudes ranging from 0.02-0.05 D (where D = riser outer diameter), (3) soil stiffness degradation with increasing in the number of cycles, (4) stiffness recovery during rest periods, and (5) stiffness recovery under prolonged cyclic loading.
The results show that the cyclic resistance during a shallow embedment, 0.5 D, and large amplitude-cycles, 0.05 D, drops significantly during the first few cycles in the displacement-controlled cyclic loading. The resistance will continue to drop and approaches zero after about one hundred cycles for both the penetration and the extraction resistance. By contrast, for small amplitude-cycles, 2% D, soil resistance degrades during the first few cycles, but reaches an apparent steady state at larger cycles. After the pause periods, ranging from 1 to 13 hours, and after each series of 100 cycle parcels, the vertical displacements occurring during consolidation were recorded. Consolidation following rest periods leads to a short-term increase in the soil secant stiffness, which quickly declines to pre-rest period levels after the resumption of cyclic loading. However, under prolonged cyclic loading the soil stiffness gradually trends upward.
The test program adds to the database evaluating the influence of the major variables (displacement magnitude, embedment depth, etc.) affecting soil stiffness for SCR fatigue-assessment. Additionally, it presents new results on stiffness recovery during rest periods, stiffness reduction after resumed cyclic loading, and gradual gains in stiffness under prolonged cyclic loading. The findings on stiffness recovery are particularly important, as this has been a major source of uncertainty in prior investigations.
Research on Ocean Wave Spectrum and Parameter Statistics in the Northern South China Sea
Authors: Xie Botao , Ren Xuhe , Jia Xu , Li Zhigang 
Published: April 2019

Abstract
Environmental processes are random in nature and represent a necessary input for evaluation of environmental loads. Accurate estimates of wave parameters are becoming increasingly important for the floating platform design in South China Sea (SCS). This paper is organized as follows. To begin with, we provided a brief introduction on the measuring instrument and field data. Then, seven types of ocean wave spectrum models were compared by with the observed data. The result of calculation showed that the JONSWAP spectrum had a good precision and a wide suitability under various sea states in SCS. Next, the peak enhancement factors of JONSWAP were calculated. In order to evaluate the evolution of peak enhancement factor under typhoon condition, the observed data at different water depths were analyzed. Subsequently, the non-dimensional wave spectrums spectra under the specific wind grade were proposed and the results can provide reference for offshore operations. The ratios between maximum wave height (Hmax) and significant wave height (Hs) were determined finally. The research results about for the characteristics of a wave had been used in the engineering design for several projects in China.
Internal Ketone Sulfonate : A New Bio-Sourced Surfactant for Chemical EOR in Sea Water
Authors: Company Roberto , Tay Astrid , Mouret Aurelie , Mascle Matthieu 
Published: April 2019

Abstract
Surfactant Chemical EOR is a proven technology to increase oil recovery with several successful field trials. Offshore trials are less frequent due to the complexity of operations and also because of the limited availability of suitable chemicals adapted to sea water. For using classic anionic surfactants offshore, pretreatment of the water for reducing salinity or the use of alkali are required. In either case an additional unit has to be added to the platform, raising the price of oil production. The structure of the surfactant can be modified for sea water, using ethylene/propylene/butylene and their derivatives to prepare surfactants that are branched and sometimes extended. However sourcing can be an issue due to limitations on production sites. Internal Ketone Sulfonates (IKS) are new bio-sourced surfactants particularly suitable for chemical EOR in sea water. They are a good alternative to petro-derived chemicals with improved raw material availability and carbon footprint. Solubility is proved for TDS higher than 48g/L TDS in synthetic sea water. Phase behavior and low interfacial tensions were evaluated with classical Winsor analysis. Interfacial tension of 3.5*10−4 mN/m between the IKS formulation and dodecane was reached at the optimal salinity of 31 g/L TDS (R+=0.13) for a temperature of 60°C. The formulation was tested for oil recovery under dynamic porous media conditions and allowed to recover RF = 99% (+/-1.7%) after water flood.
Polymer Mooring Component for Offshore Renewable Energy
Authors: McEvoy Paul , Johnston Eve 
Published: April 2019

Abstract
The paper presents a cost benefit analysis of using polymer mooring components in the mooring system design of the Maine Aqua Ventus I (MAV1) floating offshore wind turbine (FOWT) project. Polymer components in mooring lines can offer new mooring system responses, which can be tailored to the needs of challenging mooring systems. For FOWT deployments these can deliver mooring system responsiveness at the thrust loads of the turbine, despite the high background mooring loads. MAV1 will deploy two 6MW floating offshore wind turbines off the coast of Maine and this paper compares the existing mooring system design against a polymer mooring component solution, undertaking dynamic analysis of the mooring systems across multiple sea states (including ultimate limit states, fatigue limit states and accidental limit states). The Aqua Ventus platform is modelled in Orcaflex, with multiple mooring system designs containing different polymer component responses modelled and contrasted. Results are analyzed and load analysis data used to undertake a cost benefit analysis. Cost reductions are shown across the mooring system (anchors, lines, connectors), as well as the platform and tower structures. Fatigue analysis is undertaken using a Rainflow analysis of the sea states to be experienced by the platform over its life, for both the existing and the polymer mooring configurations.
Polymer mooring components which can be used throughout the renewable energy and offshore industries to manage mooring loads, and are capable of mooring any sized platform, in any challenging conditions. While the specific components modelled in this work are targeted at FOWT or tidal platforms with novel stress-strain response curves designed to suit the high background thrust load conditions, other component responses are available to deliver design load and fatigue reductions on existing catenary or TLP moored platforms. Components can be easily retrofitted into existing mooring lines or deployed in new lines.
Using polymer mooring components can dramatically reduce the peak loads experienced by the platform. Previous work has looked at an OC4 FOWT model in hypothetic conditions, whereas the current paper presents new work related to a real US FOWT deployment. The paper demonstrates that &gt;50% reductions in design loads are possible. Cyclic loads are also substantially reduced, resulting in &gt;60% reduction in wave induced fatigue in extreme sea states. This results in operational and maintenance cost savings.
The patented mooring components have been developed initially for aquaculture and wave energy applications and have now been scaled to the MN loads required by the FOWT and offshore industries. Components are certified to relevant standards and delivered to projects globally.