bluuebunny/crossref_metadata_2025_split huggingface dataset:
Slug Induced Vibrations Modelling
Authors: Le Prin Kevin , Minguez Matthieu , Liné Alain 
Published: April 2019

Abstract
In this paper, the authors present an alternative methodology to improve (or at least to reduce) the uncertainty level within the prediction of the life time of subsea structures. The focus is made on rigid spool & jumper (or any piping system) prone to internal intermittent multiphase flow (currently named slug flow) and any potential Flow-Induced Vibrations (FIV) phenomenon. As it will be more exhaustively detailed here below, the proposed modelling aims at recovering at the best both (i) the multiphase flow kinematics (i.e. both gas pocket & liquid slug) to be expected in the flow loop and (ii) the resulting loads seen by the structure. The considered multiphase flow solver is based on the well-known Unit Cell Model (UCM, refer to Nicklin et al. (1962), Wallis (1969)) and coupled with usual commercial Finite Element (FE) solvers to recover the expected vibratory levels within the mechanical system.
With rigorous purpose, a step-by-step validation process is presented within this paper to progressively validate the different step changes in regard to the current Best Practices (as e.g. reminded by Payne (2015) or Ancian (2016)). Both Computational Fluid Dynamics (CFD) model and experimental database, as extracted from the literature, have been considered to assess the ability of the proposed methodology to recover the expected multiphase flow kinematics and the loads induced by a Taylor bubble flowing within a rigid spool. Once validated, the multiphase flow solver has been coupled to a Finite Element (FE) model to properly assess the Flow-Induced Vibrations (FIV) of the spool resulting from such intermittent slugging solicitations. As here below underlined, the presented comparisons with the Industry Standards suggest (i) the need to challenge the recommended practices to ensure safe and reliable design and (ii) to properly manage the safety Design Fatigue Factor (DFF) to be considered within engineering phases.
Upgrading and Conversion Opportunities for Floating Offshore Units
Authors: van Wijngaarden A. Martijn , Daniels Nick 
Published: April 2019

Abstract
Offshore energy market conditions change rapidly, with consequential demand changes for installation equipment, floating units and support vessels. Newbuilding requires a substantial investment and often takes (too) much time to obtain maximum benefit from an emerging opportunity. Upgrading or conversion of an existing unit can be a good alternative.
There are eight different hull types to choose from for floating offshore units. The most common vessel type is the ship-shaped monohull. Within the large pool of existing merchant and offshore vessels, both new and ageing, there are many suitable candidates for upgrades and conversions. Such a new lease of life expands their operational and economical portfolio and serves the offshore industry in reaching spectacular advances in transport, construction and installation performance.
When upgrading or converting existing units multiple tiers of capability increase are distinguished. Each tier brings increasing complexity, risks and re-building costs. Options range from life extension and modernization of an older vessel, temporary conversion, capacity upgrade, adding functions, changing the present function, to ultimately the complete transformation of an older merchant cargo vessel into a brand new offshore unit. Major vessel conversions can be competitive with newbuilding options, provided that such a complex conversion project is prepared and managed well.
New insights into the market drivers for upgrading and conversion of floating offshore assets are provided. The broad range of offshore vessel modifications presented is an industry first. Some remarkable examples of capacity upgrades, double conversions and complete vessel makeovers are presented.
Subsea Long-Distance Tie-Back
Authors: Wiles Douglas Peter , Widjaja Ervina , Davalath Janardhan 
Published: April 2019

Abstract
Subsea deep-water oil and gas developments are characterized by the need for long term planning and large capital allocation with delayed returns. Reduced time to first oil dramatically improves field economics and enables the efficient application of capital. Shorter project durations can be achieved by implementing a phased approach to field development. Phased developments allow for reduced upfront Capital Expenditure (CAPEX) and moderate returns, followed by the future investment from earned revenues to expand the field. The result can be dramatically improved capital efficiency, substantially reduced financial exposure and maximized utilization of common production facilities across the life of the field. Each subsequent phase can become technically more challenging, as offsets become longer, and reservoir properties begin to differ from those of the initial production fluids. This paper provides an overview of the technologies that can be deployed for such a phased development approach, ultimately enabling the economic exploitation of long tie-backs and discusses the status of the required technologies.
The Potential for Offshore Industry to Enable Discovery of Paleo-Landscapes and Evidence for Early People: Past Present and an Optimistic Future
Authors: Faught Michael Kent , Joy Shawn 
Published: April 2019

Abstract
Pre-contact period submerged landscape archaeology in the United States has been driven and improved by the efforts of cultural resource managers (CRM). While academic organizations in the US have conducted submerged landscapes archaeology, the objective of this paper is to show how CRM projects on the Atlantic outer continental shelf (OCS) and in the Gulf of Mexico have expanded our understanding of principles and methods for mapping and evaluating submerged pre-contact period archaeological sites.
Basically, there are two distinct kinds of submerged cultural resources that are considered by US legislation. These are historic shipwrecks or downed aircraft and pre-contact period archaeological sites. The Secretary of the Interior's qualifications for archaeologists conducting required surveys distinguish between these two kinds of archaeologists - historic and pre-contact. Methods and principles for shipwreck archaeology have been developed and practiced since the 1960s. Survey and analysis for drowned pre-contact sites on the other hand, are recent subjects for marine-focused geoarchaeologists. Geoarchaeologists are uniquely qualified to understand details of local antecedent (pre-transgression) geology, local pre-contact archaeology, and dynamic local sea level rise details necessary for predictive modeling of any particular submerged paleolandscape.
This paper will discuss how a survey for submerged pre-contact sites involves acoustic data and paleolandscape reconstruction techniques, determination of what culture group may have occupied those landscapes, and how details of sea-level rise affected that paleolandscape setting. In addition Phase II operations are necessary to test sub-bottom targets. These include coring and diver dredging operations. These methods and novel techniques for perceiving sites and reconstructing past landscapes will be described. We will show the benefits of following Bureau of Ocean and Energy Management (BOEM) guidelines within state waters as well as federal, and in the process of working offshore to reconstruct culture histories, it may come to pass that offshore industries will be a major contributor.
Prediction of the Aqueous Stability Limit of Surfactant EOR Formulations
Authors: Chang Leonard Yujya , Pope Gary Arnold 
Published: April 2019

Abstract
A new structure-property model was developed to predict the aqueous stability limit of chemical EOR formulations from the surfactant and co-solvent structures. The coacervation of aqueous solutions is modeled in a way that is similar to that of phase transitions for microemulsions but excluding the effect of oil. In addition to modeling the effects of surfactant structure, co-solvent partitioning and structure, and the interactions of divalent cations with anionic head groups, the effect of polymer concentration and the interactions of surfactant lipophiles were modeled. A new aqueous stability dataset consisting of 858 aqueous stability experiments with various combinations of 121 surfactants (internal olefin sulfonates, alkylbenzene sulfonates, alcohol alkoxy sulfate, and alcohol alkoxy carboxylate) and 19 co-solvents (alcohols and alcohol alkoxylates) was used for model development and cross validation. The structures of the surfactants and co-solvents in the new dataset include variations in the type of hydrophobe (carbon number, degree of branching, polydispersity, and aromaticity), number of alkoxylate groups (propylene oxide and ethylene oxide), and the type of head group. The structure-property models for the optimum salinity and optimum solubilization ratio (Chang et al., 2019) can be used with the new structure-property model for the aqueous stability limit to provide a useful guide to experimental testing programs for the development of chemical formulations for enhanced oil recovery and other similar applications requiring both low interfacial tension and aqueous stability.
Machine Learning and Quantitative Ground Models for Improving Offshore Wind Site Characterization
Authors: Sauvin Guillaume , Vanneste Maarten , Vardy Mark E. , Klinkvort Rasmus T. , Carl Fredrik Forsberg 
Published: April 2019

Abstract
Quantitative integrated ground models are a requirement for proper cost optimal site characterization, for offshore renewables, coastal activities and O&G projects. Geotechnical analyses and interpretations often rely on isolated 1D boreholes. On the other hand, geophysical data are collected in 2D lines and/or 3D volumes. Geophysical data therefore provides the natural link to re-populate geotechnical properties found in the 1D boreholes onto a larger area and thereby build a consistent and robust ground model. The geophysical data can be used to estimate geotechnical data and, as of today, there are a few methods available that can reliably map the dynamic properties from the seismic data (stratigraphic information, P-wave velocities, amplitudes, and their attributes) into geotechnical or geomechanical properties, particularly for shallow sub-surface depth. Being able to predict soil properties away from boreholes is important, as often the field layout changes during the development phase, and hence, information at the specific foundation locations may not be readily available.
We have developed a workflow to build quantitative ground models following three approaches: (i) a geometric model in which the seismic data interpretations guide the prediction of geotechnical properties; (ii) a geostatistical approach in which in addition to the structural constraints, we used the seismic velocities to guide the prediction; and (iii) a multi-attribute regression using an artificial neural network (ANN). We apply it to a set of publically available data from the Holland Kust Zuid wind farm site in the Dutch sector of the North Sea. The result of the workflow yields maps or sub-volumes of geotechnical or geomechanical properties across the development site that can be used in further planning or engineering design.
In this study, we use the tip resistance from a CPT as an example. The tip resistance derived using all methods generally give good results. Validation against randomly selected CPT shows good correlation between predicted and measured tip resistance. The ANN performs better than the geostatistical approach. However, these two approaches require good data quality and a rather large dataset to be effective. Therefore, using a global dataset not restricted to the Holland Kust Zuid site may improve the prediction. Moreover, using existing empirical correlation and calibration through laboratory testing or by training another ANN model, the geotechnical stiffness/strength parameters such as angle of friction or undrained shear strength could be derived.
The next step is to use the results and their uncertainty into a cost assessment for the given foundation concepts.
Engineering Data Management Using Artificial Intelligence
Authors: Mahasivabhattu Kalicharan , Bandi Deepti , Singh Shubham Kumar , Kumar Pankaj 
Published: April 2019

Abstract
A lot of data in the engineering world exists in the form of paper drawings and documents. Technically, these are considered as "unstructured data [1]"as it is difficult to extract content from the drawings using traditional programs as compared to data stored in databases. These drawings are often used for design and maintenance activities in both greenfield and brownfield projects. Today, digital is a key enabler in oil and gas to increase workforce efficiency. Hence there is a growing need to get the dumb drawings digitized. However, the only means of converting these drawings into digital format is to manually re-draw them.
With the emergence of technologies like Computer Vision, Optical Character Recognition(OCR) and Natural Language Processing(NLP), we no longer need to depend on human cognitive capabilities to process information from a drawing. Artificial Intelligence(AI) systems can be trained to recognize the visual content in drawings and provide a simplified context. AI based algorithms can read a scanned Process and Instrumentation Diagram (P&ID) to recognize the graphical content of the drawing like instruments, tags, pipelines, text etc. The information extract that AI generates from a dumb drawing can later be passed to an automation script to create a new digital version.
This paper emphasizes the use of Artificial Intelligence in processing a scanned drawing and automatically redraw it on a digital platform. Adapting this approach can bring considerable advantage in the pursuit of going digital.
Maximizing Tax Incentives for Offshore Exploration and Production Efforts Following the Tax Cuts and Jobs Act of 2017
Authors: Riebe Craig S , Sanchez Amanda R , Windhorst J Blake 
Published: April 2019

Abstract
The tax changes introduced under the newly-enacted Tax Cuts and Jobs Act (the "Act") are complex, but various provisions can be leveraged to produce direct financial benefits for innovative companies in the energy industry. Cutting edge technologies and innovations related to offshore renewable energy, robotics, automation, oilfield digitalization, geotechnical engineering, and other technical areas are critical to the growth of the energy industry. Understanding how the new provisions interrelate is essential to maximizing the Act's valuable tax incentives for offshore exploration and production companies in the United States.
The Act maintains the permanency of the Research and Development Tax Credit in § 41 of the Internal Revenue Code ("IRC"), reduces the corporate tax rate from 35% to 21%, eliminates the alternative minimum tax for certain entities, limits the net operating loss deduction to 80% of taxable income, and repeals the existing carryback and carryforward provisions under IRC § 172. This paper will discuss the legal implications of the new Act and provide methods and tax strategies that will directly impact energy companies’ return on investment and strengthen offshore exploration and production efforts.
Perhaps most notably, since the Research and Development Tax Credit ("RTC") remains permanent, companies in the industry may recover qualified research expenditures related to the development of new or improved products, processes, formulas, inventions, techniques, and software. The RTC is a highly valuable incentive that directly impacts a company's tax liability both at the federal level and in certain states. Because of the reduced corporate tax rate, the changes related to net operating losses, and the elimination of the alternative minimum tax for certain entities, this credit provides a powerful incentive for many energy companies. In addition, since the Act will soon require taxpayers to capitalize and amortize expenditures related to qualified research conducted outside of the United States over a period of 15 years, companies performing critical research in the United States may soon be able to realize an additional current year deduction if certain expenditures are characterized differently under IRC § 162. Creating a tax strategy that incorporates the RTC and related provisions in the Act may result in a valuable benefit to energy clients creating and utilizing intellectual property throughout the world.
Kinetic Behavior of CH-Hydrate Formation in a Sandy Medium Induced by a Multi-Stage Cooling Process
Authors: Yin Zhenyuan , Moridis George , Chong Zheng Rong , Linga Praveen 
Published: April 2019

Abstract
Methane hydrates (MHs) have been considered as the future clean energy resource because of the vast resource volume and the capability to store methane effectively. To synthesize MH-bearing samples in laboratory for analysis of the thermophysical/geomechanical properties and the formation/dissociation behavior is important because of the scarcity of obtaining naturally-occurring MH cores. With the aim to achieve maximum uniformity in the MH-bearing samples, we designed experiment involving a three- stage cooling process to induce MH formation in the sandy medium under an excess-water condition. The experimental measured P and T were used to estimate the phase saturations of all phases (aqueous, gas and hydrate) over time based on a pore-volume balance method. In the absence of direct visualization capability, we further analyzed the experimental results through numerical simulation to derive the spatial distributions of all phases in the sample. Heterogeneity was identified because of the heat inflow from the surrounding resulting from the imperfect insulation of the reactor. We reached the conclusion that creating homogeneous MH-bearing samples in laboratory is extremely challenging and may not be possible. Our results offer explanations for MH formation at preferential locations and shed light on alternative innovative designs of experimental apparatus or cooling processes (with increased number of cooling steps and longer duration) to create uniform MH-bearing core samples.
Prediction and Monitoring of Installation of Offshore Foundation Monopiles for Windfarms
Authors: Van Dorp Rob , Moscoso Nicolas , Bielefeld Marcel , Verbeek Gerald 
Published: April 2019

Abstract
Upon recently, most offshore foundations were based on a number of driven piles that were installed with an impact hammer. With the increase in offshore windfarms two major developments have occurred: the shift from jackets to monopiles, leading to increase of the diameter of the foundation piles, and a shift from impact hammers to vibro hammers.
As the use of vibratory hammers is becoming more and more common practice, the need for accurate vibro-driving simulation software has increased, which requires that the soil modelling is enhanced to address soil fatigue during pile driving and to predict reliably the soil behavior and resistance during pile driving. In addition pile driving monitoring, which is routine for piles driven with an impact hammer, needs to become common practice.
This paper addresses advances in soil modelling that allows more accurate pile driving simulation as well as the application of Vibro Driving Analysis (VDA) or Monitoring (VDM) to validate the simulation results. This is illustrated by a case study of the test pile for the Delft Offshore Turbine project, a 28 m long monopile with a diameter of 4 m that was driven 15 m into dense sand layers using a vibro hammer. After some 6 months the pile was extracted, and pile driving simulations and VDA were done both for the installation and extraction phase.
Experimental Investigation on Generation and Development of Shallow Water Flow in Overpressured Sand Formation
Authors: Shi Can , Lin Botao , Jin Yan , Shentu Junjie 
Published: April 2019

Abstract
Shallow water flow (SWF) is a common type of geological hazard in deep-water drilling. It usually occurs in a relatively shallow stratum below mud line (about 450-2500m). When encroached by a drill bit, the substantially over-pressured sand body can generate SWF that may dramatically impair the integrity of the drill string and the associated equipment. However, the mechanism that triggers SWF is lack of detailed understanding, leaving a safe design of drilling through SWF prone strata in suspense. In this paper, through the independent design and development of the shallow water flow simulation device, the damage, and flow mechanism of the sandstone occurred during the SWF events. It can be found through the experiment that in the occurrence of shallow water flow event, there is much sand accumulation around the pressure relief port. The sand body below the pressure relief port is lifted upwards as a whole, and the sand layer above the pressure relief port has a specific amplitude decrease. The findings could not only help understand the SWF process but also build a foundation for subsequent research on prevention and control of SWF incident. In addition, it provides theoretical guidance for improving drilling equipment to ensure that the SWF hazard is adequately controlled.
Performance Characteristics of the NoiseSpotter: An Acoustic Monitoring and Localization System
Authors: Raghukumar Kaustubha , Chang Grace , Spada Frank W. , Jones Craig A. 
Published: April 2019

Abstract
In support of monitoring technologies to evaluate the potential environmental effects of offshore energy devices, this project attempts to ultimately improve upon traditional acoustic sensing techniques by developing a cost-effective compact array of acoustic vector sensors that characterizes, classifies, and provides accurate location information for anthropogenic and natural sounds. The NoiseSpotter consists of three acoustic vector sensors arranged in a three-dimensional array deployed as a seafloor mooring. Each vector sensor measures acoustic pressure and the three-dimensional particle velocity vector associated with the propagation of an acoustic wave, thereby inherently providing bearing information to an underwater source of sound. Here, performance characteristics of the NoiseSpotter are presented, along with an analysis of its abilities as an operational passive acoustic monitoring system to characterize sources of sound. Data are presented from controlled acoustic transmissions in a quiet environment and an energetic tidal channel in the presence of non-acoustic flow noise. NoiseSpotter performance is demonstrated through its modular design, ease of deployment/recovery, ability to remove signal contamination by flow noise and the ability to geolocate acoustic sources of interest.