bluuebunny/crossref_metadata_2025_split huggingface dataset:
Offshore LNG and Gas Monetization
Authors: Alabi Femi Adeoye 
Published: August 2021

Objectives/Scope
In recent years, there has exceptional expansion of the liquefied natural gas industry (LNG), which is largely attributed to rising demands in various parts of the world and triggered the emergence of Floating LNG (FLNG) as a faster and more cost-effective strategy for exploitation of gas resources with a huge competitive advantage in the business activities. However, the introduction of new technologies comes with new requirements for tax related issues.

Methods, Procedures, Process
It is a testament to the resilience and adaptableness of the LNG business to check the hypothesis that FLNG provides a method by that stranded gas discoveries will be monetized and essentially within a shorter time, lower fabrication execution risk and the entrepreneurial vibrancy that comes from competitive suppliers and approaches on FLNG. On FLNG plant cost, Brian Songhurst gives a review review of the state of the performance of FLNG after commissioning. The need for the FLNG industry to address both cost base and contractual price formation mechanisms as a viable channel for the delivery of gas is key.

Results, Observations, Conclusions
The impact of Independent Power Projects (IPP) in the third World nations act as game-changer in the monetization, new gas markets discoveries and increasing impact on the global gas economy. FLNG has potentials to transform the phase transition business from technical and business stand points within the economic development of remote offshore oil fields. The opportunity provided by the contractors to lease the FLNG vessel enables the smaller independent energy companies to avoid arranging project finance and carrying the asset on their balance sheet. However, it could also assist the major energy companies where current low oil prices are restricting capital investment to lease their FLNGs. Given the high level of interest in the researcher's two previous papers, this update will prove equally interesting and useful to analysts and participants in the gas sector, as floating technology continues to open new opportunities. Cost Comparison of the FLNG offerings are following a more industry standard design approach based on functional specifications and vendor standard equipment rather than client standards and design methods as used by the energy companies. The reason for the quality style approach is to position the FLNG facilities to be hired and reused by energy company.

Novel/Additive Information
The price of producing LNG from offshore gas reserves through the FLNG ought to be less than from onshore plants thanks to the lower CAPEX, albeit this will be somewhat offset by higher OPEX. This paper provides an update on the floating LNG sector (both floating liquefaction and regas terminals) over the past few years looking into some of the publication of the floating liquefaction (FLNG) contribution from the Oxford Institute for Energy Studies.
Design Considerations for Polyester Construction Stretch Removal and its Impact on Mooring System Design
Authors: Moideen Hisham , Le-Guennec Stephane , Mansour Alaa M. , Peng Cheng , Huntley Mark 
Published: August 2021

Abstract
Polyester based mooring systems offer unique challenges from design, analysis and installation perspective. Non-linear elongation behavior of the fiber is key to these challenges. A good understanding of the fiber elongation characteristics is critical to the design of a robust and efficient mooring system. Mooring systems are one of the primary contributors to the CAPEX of the Floating Production Units (FPU) and the drive to develop cost effective systems has led to improvements/changes to mooring systems. Off-vessel tensioning has been in use for several years, but the option has recently received more in-depth consideration. Off-vessel tensioning is becoming the standard for floating systems with the elimination of on-vessel tensioning systems. The elimination of on-vessel tensioning system brings upon new challenges in terms of mooring line installation and tensioning. A key driver for these systems is the polyester rope pre-load criteria primarily used to remove construction stretch and jump the creep curve that the system may experience. The challenges to each project are unique, however, understanding and assessing the key design impacts will be beneficial to the industry.
This paper focuses on the design of a polyester based mooring system with focus on polyester fiber elongation characteristics and its impact on the design and installation. A polyester test program is established to understand the rope elongation behavior and impact of various pre-load levels. Installation assessment is also performed to understand the installation vessel requirements to achieve various pre-loads. Based on the studies, design updates are made to the mooring system and a novel two tension regime mooring system is proposed. Design impact of the two pre-tension system on various design criterions are evaluated and presented in this paper. The paper also makes recommendations on target pre-load and elongation to be considered in systems that do not plan to re-tension their system post installation. Authors appreciate that recommendations and observations reported may not be applicable for all types of floaters and mooring system.
AI Based Water-in-Oil Emulsions Rheology Model for Value Creation in Deepwater Fields Production Management
Authors: Silva Thiago Geraldo , Miyatake Luis Kin , Barbosa Rafael Madeira , Medeiros Andre Goncalves , Borges Otavio Ciribelli , Oliveira Marcia Cristina , Cardoso Felipe Mauro 
Published: August 2021

Abstract
This work aims to present a new paradigm in the Exploration & Production (E&P) segment using Artificial Intelligence for rheological mapping of produced fluids and forecasting their properties throughout the production life cycle. The expected gain is to accelerate the process of prioritizing target fields for application of flow improvers and, as a consequence, to generate anticipation of revenue and value creation.
Rheological data from laboratory analyses of water-in-oil emulsions from different production fields collected over the years are used in a machine learning framework, which enables a modeling based on supervised learning. The Artificial Intelligence infers the emulsion viscosity as a function of input parameters, such as API gravity, water cut and dehydrated oil viscosity.
The modeling of emulsified fluids uses correlations that, in general, do not represent the viscosity emulsion suitably. Currently, an improvement over empirical correlations can be achieved via rheological characterization using tests from onshore laboratories, which have been generating a database for different Petrobras reservoirs over the years.
The dataset used in the artificial intelligence framework results in a machine learning model with generalization ability, showing a good match between experimental and calculated data in both training and test datasets. This model is tested with a great deal of oils from different reservoirs, in an extensive range of API gravity, presenting a suitable mean absolute percentage error. In addition to that, the result preserves the expected physical behavior for the emulsion viscosity curve. Consequently, this approach eliminates frequent sampling requirements, which means lower logistical costs and faster actions in the decision making process with respect to flow improvers injection. Moreover, by embedding the AI model into a numerical flow simulation software, the overall flow model can estimate more reliably production curves due to better representation of the rheological fluid characteristics.
Water Disposal Wells Injectivity Enhanced by Well Treatment Optimization
Authors: Mei Wenrong , Al-Anazi Ammal F. , Yateem Karam S. 
Published: August 2021

Abstract
Produced water is always an unwanted by-product for any hydrocarbon producing process. Underground disposal of the produced formation water has many benefits such as minimum or no damage to the environment. However, formation damage arising from injection of water containing impurities is usually of great concerns and poses challenges for maintaining good injectivity of disposal wells. Well stimulation is probably one of the most effective treatment to restore the injection of impaired wells. Therefore, well treatment and optimization always play an important role in cost saving and injectivity improvement.
Although many treatments such as acidizing and mutual solvent have been developed as a standard practice and are widely employed in the oil and gas industry, there is no universal treatment recipe which may be used to effectively stimulate a well without doing any well specific studies. To effectively tackle the injection rate decline issue in water disposal wells, understanding the process, quality of injection water and the nature of the in-situ properties of the formation is vitally important. Therefore, analysis of the formation minerals and lithology, produced water, well performance and field stimulation histories had been thoroughly reviewed and examined to understand the root causes and the mechanisms underlying the rate reduction and how to improve the injectivity. Laboratory experiments had then been organized and conducted for evaluating and optimizing the treatment. Fit-for-purpose well treatments were finally designed and executed for field evaluation. Once the field treatment was done, a thorough review and benchmarking of the treatment job had been performed to capture the lessons learned. More laboratory evaluation may be necessarily carried out for further improvement in the next well treatment.
Applying the above process to the treatment of water disposal wells, a new well specific matrix stimulation treatment had been developed and applied to a few water disposal wells over the last few years. When compared with the outcomes of other types of treatment in history, the injection gain from this type of treatment was significant with a maximum 400% injection increase. Moreover, the improved injectivity had longer effective duration up to 26 months so far. Still a few wells have no signs of injection rate drop. The benefits are obviously enormous in terms of cost saving and injection gain.
Effectiveness of a well specific treatment is rooted into the thorough understanding of the physical and chemical interaction between alien fluids and the in-situ formation. Laboratory evaluation is an important key to the development of a successful treatment recipe, which was showcased by the work presented in this paper. This would enrich the expertise of petroleum professionals in the limited stimulation practice of the water disposal wells.
Potential of Synthetic Weather Radar for Squall Identification and Prediction
Authors: Fulton Ryan , Luffman James 
Published: August 2021

Abstract
Squall event impacts are a long-standing problem offshore, especially in regions where radar imagery and reliable nowcasts are unavailable. Existing methodologies for monitoring and advising of impacts have been near-stagnant for decades. In this paper, initial results of using machine learning tools paired with advancements in weather satellite imagery processing are presented. The approach is based on a novel method of processing satellite, lightning, radar, and numerical weather model datasets trained against observed weather radar as truth to create gridded synthetic radar and short-term forecast. The capability has demonstrated to be an effective system in simulating and predicting the high precipitation rates that are associated with squall activity in real-time. The resulting output provides precipitation rates among other attributes at 1-km resolution, updated every five minutes, and gridded extrapolative nowcasts produced to four hours ahead. Initial results over multiple geographic domains of the system have performed exceptionally well at identifying and tracking strong thunderstorm activity, with and without ground radar, including detection rates over 90% and false alarm rates near 20%. As the technique is improved and deployed more broadly on a global scale, the objective is to provide a consistent, high-fidelity dataset that enables squall risk identification and advisories within a minimum two-hour planning horizon. The primary visualization for situational awareness is a commonly used format: weather radar. New levels of productivity and safety are possible with the global expansion and application of this system. This work was completed as a collaboration between Solcast, WeatherZone, and DTN.
Experimental Investigation of FPSO Roll Motion Response Coupled with Sloshing in a Pair of Two Row Cargo Tanks
Authors: Igbadumhe Jane-Frances , Furth Mirjam , Bonoli Jack , Dzielski John 
Published: August 2021

Abstract
Floating Production Storage and Offloading Units (FPSOs) will continue to be in high demand because of their numerous advantages; such as, their ability to offer early production and operate in ultra-deep water locations, while remaining easy to relocate to meet changing needs. By design, slack cargo tanks are almost always present in FPSOs due to continuous loading and offloading operations; however, the presence of slack cargo impacts the seakeeping stability abilities of FPSOs. There are limited published experimental data on coupled sloshing with seakeeping of stationary vessels, and existing studies on this have focused on single row cargo tanks which is seldom the case in FPSOs. The aim of this paper is to study roll motion coupled with sloshing in partially-filled pair of two-row tanks of a stationary FPSO model exposed to regular beam waves. The model tests was performed in the Davidson Laboratory towing tank at Stevens Institute of Technology. The FPSO model response in roll was measured, and the time histories of sloshing oscillation were measured on the starboard and port side of one of the stern cargo tanks. The results show that varying internal cargo sloshing leads to unpredictable motion response of floating vessels that should be accounted for in the design and offloading operations of FPSO.
Innovation to Reduce Operation Downtime in Sulfate Removal Offshore Applications
Authors: Cuenca Yolanda , Tejero Àngels , Das Supriyo , Brooke-Peig Daniel , Martin Philip , Bechir Flavio 
Published: August 2021

Abstract
Sulfate removal in injection water is standard practice to prevent scaling and souring in subsea oil reservoirs. Nanofiltration membranes have been used to this purpose since 1987, when FilmTec™ SR90-400 elements were installed in an offshore platform in the North Sea. The most pressing concern in this type of systems is membrane fouling, with the associated reduction in effective plant operation time and shorten element lifespan caused by the standard Clean-in-Place (CIP) protocols. The object of this research has been to test the latest developments in biofouling-resistant sulfate removal membranes to achieve oil and gas (O&G) industry requirements. Improved chemistry and improved module engineering have enabled the production of new membrane elements that represent the next-generation in sulfate removal nanofiltration. Next-generation sulfate removal membranes have been trial-tested. In pilot testing, target performance was validated in terms of productivity, permeate quality and fouling resistance. The results of this testing indicate that improvements in membrane chemistry and module engineering have resulted in a 63% decrease in pressure drop and a much slower fouling trend over the total of 6 elements. This significant improvement should allow an important reduction in the number of cleanings, which the authors have estimated to be of 50%. Moreover, sulfate rejection values are in the range of 99.9% (below 1 ppm of sulfate in the permeate), providing great injection- quality water. Full-scale testing in a production site in the Atlantic Ocean was done to validate pilot testing results, showing a continued operation of 100 days without any need for a clean-in-place (CIP) procedure. The results obtained in the extensive testing carried out on these new antifouling elements, show that the improvements implemented in its design have the ability to improve the operation of Sulfate Removal Units (SRU). These improvements are the results of reducing maintenance costs and downtime on offshore platforms, resulting in increased operation and improved productivity.
Offshore Platform Topsides Structural Design: Using Topology Optimization to Generate Novel Design Concept
Authors: Li Zhongwei , Wang Aimin , Wang Jonathan , Dasilva Otto 
Published: August 2021

Abstract
The paper presents topology optimization performed for the concept study of a semi-submersible platform topsides structure. The topsides truss system consisting of I beams carries the equipment payload and the environment loads. The structural weight needs to be reduced in order to maximize the allowable equipment weight, and the structural strength criterion must be satisfied for the harsh ocean environment. Topology optimization is a powerful tool to generate designs that optimally distribute the structural material for the balance between structural weight and strength. A finite-element-based topology optimization method assigns a density value to each structural element and updates this density value using topology optimization algorithms during each design iteration. Elements in the load-transferring path retain high density value at the end cycle and form an efficient structural shape under the given design load conditions and constraints. The topology optimization generated novel and optimal geometric arrangements for the topsides structure. Two corresponding innovative topsides truss concepts were developed. The new topsides designs were compared with an existing benchmark design for the structural weight and strength to demonstrates the advantages of topology optimization over conventional empirical approach for offshore platform topsides structural design. At the same strength level, the novel designs reduced the structural weight significantly. One novel design was selected for practical semi-submersible designs at Exmar Offshore Company.
Near-Wellbore Hydraulic Fracture Non-Planar Propagation and Torturous Morphology in Tight Sandstone Formation
Authors: Zhang Ruxin , Shan Qinglin , Cheng Wan 
Published: August 2021

Abstract
In this paper, a 3D near-wellbore fracture propagation model is established, integrating five parts: formation stress balance, drilling, casing and cementing, perforating, and fracturing, in order to investigate fracture initiation characteristics, near-wellbore fracture non-planar propagation behavior, and torturous hydraulic fracture morphology for cased and perforated horizontal wellbores in tight sandstone formation.
The method is based on the combination of finite element method and post-failure damage mechanism. Finite element method is used to determine the coupling behavior between the pore fluid seepage and rock stress distribution. Post-failure damage mechanism is adopted to test the evolution of hydraulic fractures through simulating rock damage process. Moreover, a user subroutine is introduced to establish the relation between rock strength, permeability, and damage, in order to solve the model. This model could simulate the interaction between fractures during their propagation process because of the stress shadow.
The simulation results indicate that each operation could cause redistribution and reorientation of near-wellbore stress. Therefore, it is important to know the real near-wellbore stress distribution that affects near-wellbore fracture initiation and propagation. Initially, hydraulic fractures initiate independently from each perforation and propagate along the direction of maximum horizontal stress. However, hydraulic fractures divert from original direction gradually to interconnect and overlap with each other, because of stress shadow, resulting in non-planar propagation behavior. Individual fractures coalesce into a spiral-shaped fracture morphology. In addition, a longitudinal fracture could be observed because of wellbore effect, which is a result of weak cementing strength or near-wellbore weak plane. Finally, the complex and torturous fracture morphologies are created near the wellbore, incorporating Multi-spiral shaped fracture and horizontal-vertical crossing shaped fracture. However, the propagation behavior of fracture far away from wellbore is controlled by in-situ stress, forming a planar fracture.
The highlights of this 3D near-wellbore fracture propagation model are following: 1) it considers near-wellbore stress change caused by each construction to ensure the accuracy of near-wellbore stress distribution; 2) it achieves 3D simulation of fracture initiation and near-wellbore propagation from perforations; 3) the interaction between fractures is involved, resulting in complex and torturous morphology. This model provides the theoretical basis for fracture initiation and propagation, which also could be applied into heterogenous formations considering the effect of discontinuities.
Automatic Detection and Tracking of Marker Seeds Implanted in Prostate Cancer Patients using a Deep Learning Algorithm
Authors: Amarsee Keya , Ramachandran Prabhakar , Fielding Andrew , Lehman Margot , Noble Christopher , Perrett Ben , Ning Daryl 
Published: August 2021

Purpose:
Fiducial marker seeds are often used as a surrogate to identify and track the positioning of prostate volume in the treatment of prostate cancer. Tracking the movement of prostate seeds aids in minimizing the prescription dose spillage outside the target volume to reduce normal tissue complications. In this study, You Only Look Once (YOLO) v2™ (MathWorks™) convolutional neural network was employed to train ground truth datasets and develop a program in MATLAB that can visualize and detect the seeds on projection images obtained from kilovoltage (kV) X-ray volume imaging (XVI) panel (Elekta™).

Methods:
As a proof of concept, a wax phantom containing three gold marker seeds was imaged, and kV XVI seed images were labeled and used as ground truth to train the model. The projection images were corrected for any panel shift using flex map data. Upon successful testing, labeled marker seeds and projection images of three patients were used to train a model to detect fiducial marker seeds. A software program was developed to display the projection images in real-time and predict the seeds using YOLO v2 and determine the centers of the marker seeds on each image.

Results:
The fiducial marker seeds were successfully detected in 98% of images from all gantry angles; the variation in the position of the seed center was within ± 1 mm. The percentage difference between the ground truth and the detected seeds was within 3%.

Conclusion:
Our study shows that deep learning can be used to detect fiducial marker seeds in kV images in real time. This is an ongoing study, and work is underway to extend it to other sites for tracking moving structures with minimal effort.