bluuebunny/crossref_metadata_2025_split huggingface dataset:
Testing the Detection Significance on the Large-scale Structure by a JWST Deep Field Survey
Authors: Zhang Hao , Eisenstein Daniel J. , Garrison Lehman H. , Ferrer Douglas W. 
Published: April 2019

Abstract
In preparation for deep extragalactic imaging with the James Webb Space Telescope, we explore the clustering of massive halos at z = 8 and 10 using a large N-body simulation. We find that halos with masses of 109–1011
h
−1
M
⊙, which are those expected to host galaxies detectable with JWST, are highly clustered with bias factors ranging from 5 to 30 depending strongly on mass, as well as on redshift and scale. This results in correlation lengths of 5–10 h
−1 Mpc, similar to those of today’s galaxies. Our results are based on a simulation of 130 billion particles in a box of size 250 h
−1 Mpc using our new high-accuracy Abacus simulation code, the corrections to cosmological initial conditions of Garrison et al., and the Planck 2015 cosmology. We use variations between sub-volumes to estimate the detectability of the clustering. Because of the very strong interhalo clustering, we find that a medium-sized survey with a transverse size of the order of 25 h
−1 comoving Mpc (about 13′) may be able to detect the clustering of z = 8–10 galaxies with only 500–1000 survey objects if the galaxies indeed occupy the most massive dark matter halos.
Hot Accretion Flow around Neutron Stars
Authors: Bu De-Fu , Qiao Erlin , Yang Xiao-Hong 
Published: April 2019

Abstract
We perform for the first time hydrodynamic simulations to study the properties of hot accretion flow (HAF) around a neutron star (NS). The energy carried by the HAF will eventually be radiated out at the surface of the NS. The emitted photons can propagate inside the HAF and cool the HAF via Comptonization. We find that the Compton cooling can affect the properties of the HAF around an NS significantly. We define the Eddington accretion rate as

, with L
Edd and c being the Eddington luminosity and the speed of light, respectively. We define

as the mass accretion rate at the NS surface in units of

. When

, Compton cooling can effectively cool the HAF and suppress wind. Therefore, the mass accretion rate is almost a constant with radius. The density profile is ρ ∝ r
−1.4. When

, the Compton cooling effects become weaker, wind becomes stronger, and accretion rate is proportional to r
0.3–0.5. Consequently, the density profile becomes flatter,

. When

, the Compton cooling effects can be neglected. We find that with the same accretion rate, the temperature of the HAF around an NS is significantly lower than that of the HAF around a black hole (BH). Also, the Compton y-parameter of the HAF around an NS is significantly smaller than that of the HAF around a BH. This result predicts that the HAF around an NS will produce a softer spectrum compared to the HAF around a BH, which is consistent with observations.
A Novel Approach to Fatigue Life Assessment of Subsea Connectors
Authors: Bennet Derek James , Carmichael Andrew Macdonald , Roberts Simon John 
Published: April 2019

AbstractThe capability to predict fatigue damage continues to be critical for determining the operational life and inspection intervals of connectors and components used in offshore applications. Subsea well intervention systems are subjected to wave induced cyclic bending moments and understanding the fatigue performance of equipment is essential for determining safe operating envelopes.In this paper, a validated fatigue analysis methodology is presented for non-preloaded connectors that are used within subsea well intervention systems. The fatigue analysis methodology addresses limitations in current standards when calculating the fatigue capacities of non-preloaded connectors with different interacting component materials (i.e. low alloy steel and nickel based alloys). The methodology considers the effect on the fatigue life of both non-axisymmetric geometry/loading, FAT loading, as well as the interaction of different connector materials, capturing any potential change in hot spot locations.Three different non-preloaded connections (i.e. consisting of threaded and load shoulder connectors) were analysed using 3-D finite element analysis models, where ΔM-N curves and the associated crack initiation locations were calculated for each connector. Full-scale resonance fatigue tests were successfully performed on the three different connector types, validating the ΔM-N curves calculated using the fatigue analysis methodology. Fatigue failure (i.e. through-wall crack) was achieved in all tests between 100,000 and 5,000,000 cycles matching the predicted crack initiation location from the analysis for each connection. The validated methodology provides accurate calculation of the fatigue life and correct identification of hot spot locations. Using the validated approach described in this paper within the design process can lead to significant improvements in future designs of connectors, enabling safer operational limits and extending the service life of subsea systems.
A Machine Learning Application for Field Planning
Authors: Kumar Amit 
Published: April 2019

Abstract
Recently, machine learning methods have enjoyed resurgence in the oil and gas industry and provide applications to a wide variety of problems (Noshi et al. 2018). However, few address the important problem of field planning, which is the area of focus of this paper.
This paper introduces a machine learning-based framework for field planning and specifically addresses the problem of well location planning. Unsupervised learning is used to understand characteristics of the data, followed by the creation of a regression model trained on available data in a marginal oilfield to develop a prediction tool for well productivity. This data-based prediction tool is used in a workflow to optimize well locations under uncertainty, and then in another workflow, using an adaptation from modern portfolio theory (MPT) (Markowitz 1952), to evaluate recommended well locations. The latter workflow enables the operator to select a portfolio of wells to maximize returns at a given risk tolerance.
Both workflows are applicable to plays where drainage areas for wells are small; consequently, a well can be assumed to produce independently of other wells. This assumption is true for both early-stage shale plays and conventional fields in tight rocks.
As compared to traditional reservoirs, a very large number of wells are drilled in shale plays, generating a very large amount of data that existing productivity prediction tools, such as reservoir simulators, find difficult to consume and use in practical timeframes. The presented framework is attractive for shales because it can easily handle large datasets.
The framework accounts explicitly for risk resulting from uncertainty in well productivity and uses data typically acquired in the field, but not used currently for field planning.
Digital Twin Technology in the Field Reclaims Offshore Resources
Authors: Brewer Thornton , Knight Darrell , Noiray Gautier , Naik Harit 
Published: April 2019

Abstract
For decades, upstream personnel have struggled to efficiently gather offshore data and effectively analyze it to make better business decisions. One internal audit conducted by an oil and gas company found its upstream employees spent up to 80 percent of their time just looking for, then converting the data because the data historically has not been housed in one place within one platform. Traditionally, employees must collect large volumes of information from multiple data sources, including spreadsheets, data streams or tacit knowledge. Alone, the Internet of Things (IoT) sensors connected to equipment in the field can send 1,000 readings a minute to engineers, resulting in an insurmountable data for engineers to assess critically. All of this effort results in underutilized time and loss of money.
The paper's topic addresses the digital twin technology solution which solves energy company's Big Data problems and recoups the wasted time and associated costs of field workers looking for data. Specifically, FutureOn's FieldTwin technology offers a cloud-based, comprehensive and secure platform with the ability to break up the barriers of the data silos built by legacy systems, creating accessible data across the company. Employees spend less time searching for data, and more time identifying trends and innovative ways to exploit the data, i.e., smarter drilling, greater field automation or improved safety.
FieldTwin technology also provides a real-time, data-driven visual representation of the field that creates actionable data, whether it is an operator using the visualization of its subsea assets for field expansions or a renewable company utilizing the digitalization of its offshore wind projects for more effective planning. Studies show humans respond to and process visual data better than any other type of data. The human brain processing images 60,000 times faster than text, and 90 percent of information transmitted to the brain is visual. FieldTwin exploits this reality to enhance data processing and organizational effectiveness spanning project management to risk management in the field.
Success Path: The Secret Methodology to Priority and Probability Assessment for High Reliability Offshore Operation
Authors: Hamedifar Hamed , Kusinski Greg 
Published: April 2019

Abstract
Proper risk assessment involves prioritization and probability, which are themselves a form of uncertainty evaluation. This paper illustrates development of a methodology where a powerful multiple-criteria decision analysis technique known as "Success Path" could further improved the risk assessment of complex offshore operation in a high risk & high rewards environment.
Traditional probability of failure analysis forces decision-maker to converge vague judgment to single numeric preferences in order to estimate high reliability offshore operation. The final resultant of alternatives cannot be tested for statistical significance of and it lacks systematic approach to capture all categories of uncertainties. To overcome the above limitation, this paper demonstrates a modified analytical process, which incorporated uncertainty dealing with human and organizational factors. The proposed method in this work can offer improved assessment for generating mutually exclusive path sets that assure the system's successful operation.
The "Success Path" method have been applied in a variety of situation involving risk and uncertainty in different aspects of offshore oil and gas operation. It is generally useful in such cases to carry out the evaluation over a period of time as project evolves and pass certain phase of the operation. The proposed approach (Success Path), used in the present paper could be used as one of the techniques for making concept maintenance or modification evaluations. This technique is enhancing the capability of taking into consideration different categories of uncertainties both qualitatively, and quantitatively.
This paper will present novel method that can be of benefit to the petroleum industry in the following areas:
Facilitates consensus, generate new insights and provide more confidence in making decision during the critical phases of offshore oil and gas operation Provides a systematic approach that can test the alternative paths for statistical significance. Incorporate extrinsic uncertainties such as human and organizational factors.
Effective Corrosion Mitigation Exploiting Glass Reinforced Epoxy Lined Tubulars in Offshore Producing & Injection Wells
Authors: Duthie Laurie , Almarri Hamad , Saiood Hussain , Lata Ashwani , Radhakrishnan Gokul 
Published: April 2019

Abstract
Corrosion in offshore well completions can lead to serious well integrity problems and costly workover operations. Although carbon steel is an ideal material for most completions, under certain conditions corrosion can attack and severely damage carbon steel equipment. Corrosion resistant alloys (CRA) are a good option but come with the considerable downside of very high cost. A relatively simple and cost effective approach to protect completion equipment against these corrosive elements is to line carbon steel completion tubulars with a non-metallic Glass Reinforced Epoxy (GRE). The GRE material properties provide excellent protection against a range of conditions including; highly corrosive fluids, erosive granular materials, Carbon dioxide (CO2), Hydrogen Sulfide (H2S) and acid treatments.
The GRE lined Carbon steel is capable of combatting a range of corrosive environments in oil producers, water injectors / supply wells, including water with high concentration of total dissolved solids (TDS), chloride and sulfates and oil with high levels of H2S and CO2. The steel tubing is protected from these unforgiving ecosystems by lining the inside of the tubing with one continuous GRE tube. To secure the GRE lining and to increase the strength, a cement is pumped down the narrow annulus between the GRE lining and tubing internal wall. This procedure is relatively simple with the resultant GRE lined tubing having exactly the same tubing strength properties as the bare tubing.
The primary method for detecting any well integrity problems with water injector wells are from determining high pressures in the tubing casing annulus (TCA). To date, all of the water injector wells installed with 7" GRE lined tubing have remained integral with no indication of any corrosion. Several of the oil producer and water supply wells that were lined with GRE have subsequently been worked over to replace faulty equipment; primarily electrical submersible pumps (ESP's). Encouragingly, the condition of the recovered GRE tubing had suffered no corrosion, scaling or other degradation benefiting from the GRE protection.
The non-metallic GRE material is exceptionally robust with notable longevity and very resistant to any scale build-ups, leading to improved flow assurance. At the same time being tough enough to withstand any routine well intervention for logging, acid stimulation and other applications. The durable qualities and chemical characteristics of these non-metallic materials in downhole completions is likely to expand in the coming years, with increasing applications being found.
Marine Seismic Source Characterization Using Fiber Optic Sensors
Authors: Alfataierge Ezzedeen , Dyaur Nikolay , Chang Li , Stewart Robert R. 
Published: April 2019

Abstract
This laboratory study explores the geophysical imaging applications of a fiber optic sensing system in a marine environment, from fiber installed on pipes or casing to fiber laying on the floor. The most common application with fiber installed on casing is borehole seismic imaging. With fiber laying on the ocean floor, surface seismic imaging is a possible application. This is tested in a laboratory setting using a Distributed Acoustic Sensing "DAS" system, Fiber Bragg Grating "FBG" system, and a conventional geophysical hydrophone system. A setup is made using PVC pipes and a water-filled tank to simulate a marine environment, and the sensing systems were distributed along the pipes and on the tank floor.
Single mode telecommunication fiber was laid out on the tank floor and the pipes, which consist of a vertical pipe segment and a horizontal pipe segment. The pipes are connected to a water reservoir to allow flow from the reservoir through the vertical pipe then the horizontal pipe into the tank. An array of FBG sensors were distributed along the pipes and some were left floating in the water. A hydrophone array was secured to the vertical pipe segment and distributed along the horizontal pipe segment to make conventional geophysical imaging measurements. Seismic sources with different frequencies were used, a piezoelectric transducer was used to introduce higher frequency (ranging from 500 Hz to 25 kHz), and a hammer source was used with different material as broad frequency sources. The measurements made were compared across the sensing systems and the frequency response was used to evaluate the preservation of the source frequency signature on the sensing instruments.
The DAS system was sensitive to low-frequency ambient noise which made it difficult to see the frequency response of the seismic sources, however, it was useful in capturing the higher range of frequencies. The FBG system showed better results in capturing lower frequency signal but was limited by the high frequencies it could capture. Nevertheless, the captured high frequencies exceeded the frequency range of interest for seismic imaging but are useful for applications of wireless communication using fiber and PZT transducers. Therefore, both systems can capture the response of the seismic sources for imaging but with different noise sensitivity.
The results presented in this study indicate that a fiber optic sensing system can be used for seismic imaging in an offshore environment. Further tests are recommended in larger scale environments to confirm the findings of this study. The advantages of using a fiber optic sensing system are highlighted in this study. Finally, further applications to wireless communication via fiber optic sensors and high-frequency transducers are discussed.
Subsea Broadband Using Underwater LASER Telemetry and Remote Access
Authors: Mons Ishan , Veedu Vinod , Pollock Jacob , Nakafuji Glen , Elshahawi Hani , Jim Kevin , Hadmack Michael 
Published: April 2019

Abstract
High speed wireless communication has proven elusive in subsea environments due to the inherent bandwidth limitations of acoustics and range limitations of other transmission modalities. A truly connected subsea system necessitates a high-speed, resilient architecture that can enable the integration of new sensor technologies and edge analytics and allow closed-loop monitoring and control of subsea operations for integrity monitoring and optimization. Like terrestrial Internet of Things applications, the realization of this "digital subsea" vision requires the application of high speed, point-to-point wireless technologies to complement rather than replace "hard-wired" communications such as optical fiber or acoustic systems. This work addresses the development of ULTRA (Underwater LASER Telemetry and Remote Access), an ultra-long range underwater laser communications system for use in critical points of the subsea communications architecture to increase reliability, operational flexibility, and reduce communication system maintenance associated with physical subsea connections.
To demonstrate the data capacity and range of ULTRA, a subscale laboratory point-to-point wireless laser communication system was constructed with the flexibility to transmit through either air or water. The test system used power and modulation frequencies for air, fresh water, and different qualities of seawater. Optical and RF encoding methodologies were implemented to facilitate and characterize data transmission through the various media. The laboratory experiment used a subscale, filtered, and attenuated 5 mW blue-green laser in a 22-meter folded path configuration to demonstrate real-time data transmission at 312 Megabit per Second (Mbps) data rate using single channel Quadrature Phase Shift Keying (QPSK) modulation. A field prototype ULTRA system will use an unattenuated 5 mW laser that can reach approximately 280-meter range at 312 Mbps in clear conditions, which are typical of deepwater subsea. The selection of laser power and data rate are considered operational tradeoffs in environments where underwater vehicles operate. The extended range of ULTRA can enable various use cases to greatly augment subsea data communications capacity to enable the "Digital Subsea".
Fire Test Facility for Offshore Field Equipment - Success Achieved with Systems Engineering Practice
Authors: Johnson Matthew Ernst 
Published: April 2019

The Advanced Technology Lab has developed a Fire Test Facility that became operational in spring 2015. This paper describes a fresh approach to the systems engineering process path taken during development to capture new capabilities and opportunities for such a system. New functions and safety features are discussed, as compared to the original system that was replaced.
Recent fire incidents on offshore rigs have increased interest in meeting rigorous standards for fire safety. As a result of a needs assessment, a replacement Fire Test Facility (FTF) was developed in order to test offshore equipment. Offshore valves and connectors on rigs must be certified to withstand sustained fire conditions per American Petroleum Institute (API) standards 6FA/B/C. The requirements include surviving fire temperatures up to 1800 F for a period of 30 minutes, while holding internal pressure and even withstanding bending loads.
Updated safety regulations at the company led to a review of the original Fire Test Facility, and it was determined that a new system was necessary to incorporate blast protection, controls automation, and situational awareness. After establishing needs and goals from our internal customer, derived requirements were generated. Using the company’s system engineering "engine", this led to a design that met customer requirements and enhanced safety. Improvements over the original system include a 6-sided bunker structure, passive ventilation, gas safety purges, remote operation to keep workers outside the hot zone, and real-time charting to assess test performance.
After integration of the facility, a verification matrix was used to assess system functionality and performance. The improved system allows for quicker test turnaround, and more refined burn tests at reduced costs compared to using external test facilities. Mock fire tests can be performed to assess "what-if" conditions prior to actual testing of equipment. Several tests were successfully performed to API standards. Results and observations throughout the systems engineering process, including systems integration and checkout of the Fire Test Facility are provided.
Development of Deepwater Natural Gas Hydrates
Authors: Hancock Steven , Boswell Ray , Collett Tim 
Published: April 2019

Abstract
Deepwater natural gas hydrate resources potentially exceed all other conventional and non-conventional hydrocarbon resources on a world-wide basis. However, before these offshore gas hydrate resources can be classified as reserves, it must be demonstrated that gas hydrates can be produced under conditions that make economic sense. The purpose of this paper is to provide an overview of the technical issues that will challenge the development of deepwater natural gas hydrates.