bluuebunny/crossref_metadata_2025 huggingface dataset:
Factors influencing the transition of China's economic growth momentum
Authors: Wang Jinhong , Xu Yanting
Published: April 2024

Driven by factors such as structural economic shifts, technological breakthroughs, policy changes, and global economic transformations, China's economic growth drivers have continuously evolved. We constructed a panel dataset encompassing 31 provinces in China from 2002 to 2021 and utilized both panel data models and panel quantile models to delve into the underlying factors driving this transition. We further investigated the varying impacts of these factors across different temporal and geographical contexts based on the stage analysis and spatial cluster analysis. The findings revealed that capital accumulation, digital economy, and technological innovation were the major drivers shaping China's economic growth momentum transition, exhibiting significant heterogeneity across different quantile levels. Additionally, we observed heterogeneity in the influencing factors across temporal periods and regions.
Semiconductor Process Technology and Advances in Image Sensors
Authors: LEE Yongjei , KIM Youngchan , JANG Sujin
Published: April 2024

The main factor in popularization of camera is that the core component, the image sensor, can be made using a semiconductor process. Since Si absorbs the entire visible light and converts the incident light to the signal electrons, image sensor could be made of the Si. So image sensors have been able to develop along with semiconductor processes. This article reviewed two types of image sensors, the structure and operating principle of pixels, pixel performance items and the relation of these items. The initial digital camera almost used a CCD sensor, but the background to why CIS is now the main focus was explained.
Cruces entre lo literario y lo plástico. La relación directa entre las diversas manifestaciones artísticas de María Franciska Dapena sobre su etapa carcelaria
Authors: Iratzagorria Gancedo Enara
Published: April 2024

La artista María Franciska Dapena escribió durante su encarcelamiento (1962-1964) un diario que finalmente fue publicado en el año 1978. El libro titulado ¡Sr. Juez! (Soy presa de Franco…) resulta ser una herramienta imprescindible para comprender a la artista en todo su conjunto. En el presente artículo se evidencian los diferentes factores que invisibilizaron tanto su creación literaria como plástica y se propone reivindicar a Dapena como una artista multidisciplinar, alejándose de las lecturas tradicionales de la historia del arte que la han posicionado únicamente como una artista grabadora. El análisis de su libro ha evidenciado una relación directa entre ambas disciplinas y ha conllevado a una profundización en las cuestiones particulares del encarcelamiento femenino, comprendiendo la nueva mirada que fue desarrollando la artista sobre la opresión de género y de clase.
De la céramique à la chronologie : datation radiocarbone sur composés lipidiques individuels préservés dans les céramiques archéologiques
Authors: Casanova Emmanuelle
Published: April 2024

Cet article présente la méthode de datation par le radiocarbone des céramiques archéologiques via leurs résidus de nourriture préservés dans la matrice argileuse. Cette nouvelle approche est basée sur la datation radiocarbone de composés individuels, deux acides gras d’origine animale. Elle permet de (i) dater des sites non-datables par la méthode du radiocarbone en absence de matériaux classiques, (ii) dater la période d’utilisation des céramiques, (iii) dater directement les ressources alimentaires spécifiques et leur introduction dans les régimes alimentaires et (iv) raffiner les typochronologies relatives. Les développements méthodologiques réalisés pour obtenir une méthode reproductible et des âges fiables, ainsi que les premières applications sont présentés dans cet article.
Assessing the firing of ceramic materials: a seriation-based approach
Authors: Frerebeau Nicolas
Published: April 2024

The study of the firing of archaeological ceramics is a key factor in interpreting ancient techniques and related social practices. This study proposes a new method based on the correspondence analysis of powder X-ray diffraction data (XRD), aiming to provide an alternative to the so-called Equivalent Firing Temperature framework. The properties of correspondence analysis and its application for matrix seriation enable the description of the firing of a ceramic assemblage. The application of correspondence analysis to XRD data of Iron Age ceramics revealed the significant potential of this statistical method in the technological analysis of ancient pottery. This allows to order a large number of samples according to a firing gradient and to track mineralogical transformations occurring during firing. This method should let to more precise comparisons than those based on estimating the equivalent firing temperature.
Le travail émotionnel dans les recherches sur les violences de genre. Regards croisés sur un impensé au sein du monde académique
Authors: Boué Margaux , Mazuy Magali , Mullner Pauline , Wicky Lucie
Published: April 2024

À partir d'un regard croisé entre doctorantes et leur directrice de thèse, les autrices proposent une réflexion théorique et empirique sur la question éthique du travail émotionnel que sous-tendent les recherches sur les violences de genre. Celles-ci ont des coûts qui font partie intégrante de chacune des étapes mises en œuvre dans la recherche. Or, ce travail émotionnel est très peu pensé et a fortiori pris en charge par les institutions. Après avoir défini le travail émotionnel, l’article s'intéresse aux différents coûts portés par les chercheur∙es à chaque étape de l’enquête. Il montre ensuite que le travail émotionnel amène les autrices à redéfinir les rapports interpersonnels, lesquels prennent une place d’autant plus importante quand les dispositifs académiques sont (quasi) inexistants. À partir des expériences de recherche et d’encadrement des autrices, de leurs réflexions personnelles comme collectives, l’article donne à penser ce travail émotionnel, contribue à le rendre visible, propose des pistes de supports, outils et dispositifs institutionnalisés qui pourraient être mis en place. In fine, l’article conclut avec l’idée que malgré ses différents coûts, le travail émotionnel est heuristique et implique des dimensions politiques fortes qui contribuent à la production de savoirs.
The Role of Language in Social Media During the COVID-19 Pandemic
Authors: James Billy , Wilfred Wilfred W.
Published: April 2024

The COVID-19 pandemic brought about unprecedented challenges to societies worldwide, compelling individuals and institutions to adapt rapidly to a new reality dominated by digital communication. Social media platforms emerged as essential channels for information dissemination, community building, and emotional expression during this global crisis. Language played a pivotal role in shaping these interactions, influencing the spread of information, the formation of online communities, and the impact of public health campaigns. This chapter explores the multifaceted role of language in social media during the COVID-19 pandemic. Firstly, it highlights the significance of language as a medium for facilitating real-time updates and news dissemination. Governments, health organizations, and news outlets utilized language to convey critical information, ranging from infection rates and safety measures to vaccination updates, reaching a diverse and vast audience worldwide. This chapter will examine how language served as a crucial tool in combating misinformation.
Public Health Communication and Language Policy at Rhodes University During the COVID-19 Pandemic
Authors: Mamase Zikhona , Aiseng Kealeboga
Published: April 2024

The COVID-19 pandemic offered unprecedented obstacles to public health communication worldwide. Pandemic revealed disparities and significant gaps in access to public health information for those not proficient in English, potentially leading to the exclusion of indigenous language speakers and minority communities from issues of national interest, including vital COVID-19 updates. This chapter examines the case study of Rhodes University in the Eastern Cape, South Africa and explores the institution's language policies and practices during the pandemic. The institution grapples with linguistic diversity, where English is the primary language of teaching and administration. The study explores language, public health communication, and inclusion at Rhodes University. It seeks to find linguistic and cultural contestations during this time by evaluating the university's response to the pandemic through language. The study uses document analysis to understand how Rhodes University's language practices impacted public health communication during the pandemic.
Audience Perception of COVID-19 Vaccination and Its Effect on the Behavioural Responses of Respondents in Oyo West Local Government
Authors: Okeya-Olayinka Adenike Omotayo
Published: April 2024

The COVID-19 disease presents an imminent danger that requires immediate action as it could be deadly. Vaccines against COVID-19 are considered to be of great importance to prevent and also to control, but there are challenges, one of which is uncertainty about public acceptance of the vaccine. The study looked at audience perception of COVID-19 vaccination and its effect on the behavioural responses of respondents in Oyo West Local Government. The study was anchored on the perception theory and the behaviour theory. The multistage probability sampling technique was adopted. The study found out that the COVID-19 vaccination awareness was not enough, thereby making the social media to have the upper hand by passing false rumours about the vaccine in order to get the people discouraged thereby leading to their non-challan behaviour and superstitious beliefs. The study concluded that the masses should be educated on the need to get vaccinated and therefore recommended that there should be more awareness on the COVID-19 vaccination to prevent future infections and deaths.
About Time
Authors: Tijani-Adenle Ganiyat , Fadipe Israel Ayinla , Salawu Abiodun
Published: April 2024

Fact-checking and media literacy promoting organisations are now more committed than ever to combatting misinformation in Africa. The challenge, however, is that they have been publishing the bulk of their contents in colonial legacy languages of the African countries, thereby losing the opportunity to enlighten a significant part of the population that are not on the internet nor conversant with those global languages, particularly as it relates to misinformation about public health. Interestingly, a few Nigerian fact-checking organisations have commenced publishing contents in the three major indigenous Nigerian languages. This chapter reviews the efforts of three purposively selected Nigerian fact-checking organisations in reaching media publics who are not likely to be English-literate nor on the internet. Key findings are that indigenous speaking publics prefer audio-visual contents to texts, and the efforts of the media literacy organisations in reaching indigenous publics is significantly impacted by funds.
Transportation and Installation (T&I) Recommendation for a Semi-Submersible Floating Offshore HVAC Substation
Authors: Song Hongbiao , Tang Zhaoxiang , Collins Clar
Published: April 2024

GE has worked with Genesis to develop a semi-submersible Floating Offshore Substation (FOSS) solution (810MW, HVAC) for USA west coast with 1100-mter water depth. This concept design is based on the metocean data in Morro Bay Area, California (CA). The 1100-meter water depth and swell metocean (long period wave) give rise to extra technical challenges for floating OSS design, especially for the dynamic cable design.

The developed semi-submersible Floating Offshore Substation (FOSS) solution (810MW, HVAC) has been further validated and confirmed by one wave basin test performed at Oceanide (South-France) during July 2023.

As one part of one complete FOSS solution, how to transport and install (T&I) FOSS at California west coast site has been investigated. This California site condition brings special challenges for the T&I, such as the port infrastructure limitation, etc.

The main purpose of this paper is to discuss the recommended transportation and installation (T&I) methodology for the FOSS, which includes the load-out, dry transport, discharge, mooring preset, wet tow, mooring hookup and dynamic cable installation.

The recommended T&I methodology is mainly based on the fabrication base case, that the FOSS topside has been integrated onto the hull at the fabrication yard.

Based on the recommended T&I methodology presented in this paper, it can be concluded that the GE FOSS (810MW, HVAC) can be transported from Asian fabrication yard to California west coast, and installed.
Case Study: Space-Industry Robotics Technology Leveraged to Realize Significant Improvements in Offshore Safety and Sustainability
Authors: Beveridge Ivana , Yamokoski John
Published: April 2024

Historically, subsea vehicles were controlled by communications through a tether, which presents several challenges including a limited range of motion, deployment and retrieval, cost and logistics, and environmental impact. These challenges inspired the development of a new generation of robotic solutions seeking to transform the industry into an economically efficient and environmentally sustainable model.

Autonomous systems are increasingly providing economic and environmental value, such as intelligent robots with subsea applications in energy, defense, transportation, and aquaculture. Combined with AI capabilities, these robots can make subsea work more sustainable.

The paper presents findings from a robotics company established in 2014 in Texas by NASA-bred entrepreneurs. Today, the company exports its robotic services and vehicles internationally. Findings offer a first-hand insight into the development of the interconnected, purpose-built ecosystem of surface and subsea robots. The technology leverages autonomous behaviors, acoustic communications, over-the-horizon networking, force/torque controllable electric manipulation, AI and machine learning, and multimodal 3D workspace sensors. It is inspired by NASA's command and control approach for robots in space. When this framework is applied to subsea systems, it removes the need for the tether through the autonomous capabilities onboard the robotic assets. Removing the tether has a cascading effect on support infrastructure and ultimately results in a reduction of on-site human support, thereby making operations safer.

This new subsea robotics approach helps deliver an economically viable and environmentally sustainable model that significantly reduces operational footprints, operating costs, and GHG emissions, while improving offshore health, safety, and environmental exposure. New approaches to subsea technology could help develop complex autonomous ecosystems and serve as proof of concept for developing commercially viable technologies.
Precise Stochastic Fatigue Life Assessment of Umbilicals and Power Cables
Authors: Arnholm C. , Varadhi M.
Published: April 2024

Increasing activity within offshore wind energy and related installations has raised the focus on the integrity and fatigue life of power cables and umbilicals. A limiting factor for assessing fatigue life has been the lack of efficient and precise computational tools that are not overly conservative. This paper presents features of an advanced computational method implemented in a new tool for accurately assessing the integrity and predicting the fatigue service life of dynamic power cables and umbilicals.

Internal friction between components of power cables and umbilicals creates hysteretic stress responses that global finite element analysis (FEA) does not capture. It is widespread practice to assess irregular wave global responses through time-domain FEA and local cross-sectional analysis through specialized FEA tools. The global responses are combined with results from local FEA tools like UFLEX (developed by Sintef Ocean) to obtain accurate stresses capturing local effects, including friction induced hysteresis. Kongsberg Maritime introduced an innovative method in Hoen-Sorteberg et. al 2013 (OTC-24328-MS), employing tension-dependent hysteresis for flexible risers. This methodology has now been expanded to support power cables and Umbilicals.

Fatigue life assessment of unbonded structures like power cables and umbilicals involves analyzing various elements in the cross-section at multiple locations and orientations to accurately identify critical hotspots, considering load sharing and local friction between components like steel tubes, armor wires, and conductor strands exhibiting complex stress hysteresis behavior. Local FEA provides essential data to account for these complex hysteresis effects and linear stress factors like tension and component bending. The improved methodology and its implementation permit comprehensive stochastic fatigue assessment of power cables and umbilicals without imposing an undue computational burden. The outcome leads to more precise and often substantially prolonged fatigue life predictions by mitigating the inherent conservatism found in methods based on regular waves.

This paper demonstrates the practicality of the methodology and robustness through real-world implementation. The local-global approach yields precise stress levels comparable to direct local model analysis but with markedly enhanced computational efficiency. Previous similar methods suffered from limitations in both stress accuracy and computational speed, limiting their practical utility. A significant advantage is that this computational tool operates independently without needing specific FEA software integration, allowing users to utilize data from various sources.
Taming a Giant: Reservoir Management Strategies to Deal with the Initial Uncertainties in Búzios Field
Authors: Almeida Marcelo , Bukahi Lilia , Carneiro João Paulo , Pires Paulo Roberto , Pitchon Tatiana , Sant'ana Thiago , Vale Pedro Andre
Published: April 2024

The design and development of pre-salt projects prioritized a set of resources and tools for field management, providing greater flexibility in reservoir management strategies. Among these design facilities, the alternating injection of water and gas (WAG) and intelligent completion using interval control valve (ICV) stand out. For the Búzios field, and in specific for Module 4, operated by Floating Production Storage and Offloading (FPSO) P-77, the application of these resources has allowed the unit to maintain high levels of oil production, even in challenging scenarios of delays and low water injection efficiencies and of gas exports, in addition to premature failures observed in equipment and wells. The present work brings a discussion about the use of these flexible resources (WAG, ICV) in Búzios as support for information acquisition, and for the Reservoir Management decision-making process, focusing on the case study regarding the control of Gas-Oil Ratio (GOR) in P-77. Working in a multidisciplinary and integrated way, the results and gains obtained through the conversion of injectors and the performance of ICVs will be presented, which contribute to maintaining the platform's production potential.
A Spatiotemporal Machine Learning Framework for the Prediction of Metocean Conditions in the Gulf of Mexico
Authors: Steele Edward , Chen Jiaxin , Ashton Ian , Pillai Ajit , Jaramillo Sergio , Leung Pak , Zarate Luz
Published: April 2024

Machine learning techniques offer the potential to revolutionize the provision of metocean forecasts critical to the safe and successful operation of offshore infrastructure, leveraging the asset-level accuracy of point-based observations in conjunction with the benefits of the extended coverage (both temporally and spatially) of numerical modelling and satellite remote sensing data. Here, we adapt and apply a promising framework – originally proposed by the present authors for the prediction of wave conditions on the European North West Shelf – to the waters of the Gulf of Mexico. The approach consists of using an attention-based long short-term memory recurrent neural network to learn the temporal patterns from a network of available buoy observations, that is then combined with a random forest based spatial nowcasting model, trained on reanalysis data, to develop a complete framework for spatiotemporal prediction for the basin. By way of demonstration, the new method is applied for the short-range prediction of wave conditions up to 12 hours ahead, using in-situ wave observations from the sparse network of National Data Buoy Center locations as an input, with the corresponding spatial mapping learned from the physics-based Met Office WAVEWATCH III global wave hindcast. The full spatiotemporal forecast system is assessed using independent measurements in the vicinity of the Louisiana Offshore Oil Port, previously unseen by the machine learning model. Results show that accurate real-time, rapidly updating wave predictions are possible, available at a fraction of the computational cost of traditional physics-based methods. The success of the approach, combined with the flexibility of the framework, further suggest its utility in related metocean challenges. While still at an early stage of development into a fully relocatable capability, it is intended that this contribution provides a foundation to stimulate a series of subsequent efforts to help support improved offshore planning and workability – including (but not limited to) applications linked with better resolving spatial variability across renewable energy sites, predicting ocean current regimes in the proximity of oil & gas platforms, as well as informing adaptive sampling strategies conducted by autonomous vessels – where the adoption of such a machine learning approach, that can be run on a laptop computer, having the potential to revolutionize data-driven decision-making by the industry.
Bonga FPSO: Brownfield CSU: Delivering First Time Right SURU
Authors: Gafar Rasheed , Adeniyi Ajibola , Igurube Erhieyovwe , Balogun Kareem
Published: April 2024

The Bonga is Shell’s flagship Floating Production Storage and Offloading (FPSO) facility situated in deep water Nigeria. The facility commenced production in November 2005. As a producing asset, there is statutory requirement to carry out Turnaround Maintenance (TAM) periodically to ensure continued asset integrity.

Facility startups, especially after a prolonged period of shutdown, have always been a source of concern to facility managers. There is always the risk of start-up issues which can delay ramp up to steady state operations with the attendant loss in revenue and reputation. This value erosion has also been witnessed on Bonga FPSO after previous TAMs. The TAM team therefore sought an improvement in this area to complement the already well-established successful areas of Safety and schedule optimization.

Key to this success was the utilization of a Project tool in the Commissioning and Start Up (CSU) toolkit, a World Class Start Up and Ramp Up (WC-SURU) assessment. The WC-SURU exercise was aimed at mitigating against the often-experienced value erosion associated with start-up and ramp up resulting in delay in attainment of steady state operations. This paper discusses the implementation of the scenario thinking using the WC SURU methodology for the Bonga TAM of 2022, the successes, the lessons learnt and the opportunities available for further use of different tools.
Hydraulic, Chemical, and Mechanical Response of Sandstone Rocks for CO2 Storage Systems
Authors: Shandilaya Shivesh , Roshankhah Shahrzad
Published: April 2024

Carbon dioxide storage in sandstone formations with desirable permeability represents a viable method for reducing atmospheric CO2 levels and mitigating climate change. In this laboratory study, we investigate the response of a dry Navajo sandstone specimen to constant-rate water injections under vertical loading up to 12 MPa and zero lateral strain conditions. Our measurements and analyses include identifying the heterogeneity features in the internal structure of the rock via X-ray imaging, the geochemical composition of rock minerals via XRD and XRF, the evolution of the axial load and deformations, and fluid pressure upon injection, and the full-field planar deformations on the rock surface through digital image correlation. The initial goal was to understand the fluid flow regimes ranging from diffusive flow to localization of fractures induced by water injection; however, the high permeability of the sandstone would require higher injection rates than the range available in the current pumping system. The results enhance our understanding of fluid flow and damage mechanisms in the near wellbore region, utilizing a multi-phase, multi-scale, and multi-sensor monitoring system to overcome the limitations of traditional single-sensor measurements.
Anchor Project: Strategies and Approach in Managing the Evolving HSE Risks on a Major Capital Project
Authors: Beyer J. , DeKoker T. , Mohile T. , Rankin B.
Published: April 2024

The Anchor floating production unit (FPU) is a Chevron Gulf of Mexico (GOM) facility located in approximately 5,000 feet of water with a nameplate capacity of 75,000 bopd and 28 mmscfd with future expansion capability. The Anchor development plan consists of seven wells tied back to the FPU through dual flowlines from two drill centers with produced oil and gas transported via export pipelines. This paper will provide an overview of the Health, Safety and Environment (HSE) strategies deployed in support of the design and execution of the Anchor project. It will share key successes and lessons for managing and navigating an evolving risk profile from engineering through fabrication to offshore installation. It will also detail the comprehensive approach used to manage key HSE risks.

The Anchor project used several tools and processes to steward HSE. This comprehensive approach included inherently safer designs and HFE, implementing effective programs to prevent serious injury and fatalities, integrating human and organizational performance (HOP) concepts across all phases, implementing lower carbon initiatives, building a genuine care and concern culture, inclusion of craft-led safety organizations in planning and executing the work and partnership with contractors.

During early project phases, the application of HFE allowed for long term HSE success to be built-in well before fabrication or operation of the facility. Early fabricator/contractor engagement allowed for their expertise on constructability and work execution to mitigate risks and reduce rework and out of sequence work. During work execution, multiple fit-for-purpose safeguard validation and verification programs were implemented. These assurance activities helped manage the hazards and risks that were assessed at Anchor's various work sites - ensuring we moved from "I think" to "I know" it is safe to commence work. Anchor partnered with contractors to use their proven HSE management programs and collaborated with them on the HSE journey to address any potential gaps. Multiple elements enabled the development of a strong safety culture. HOP helped build error tolerant systems and guided the response when things did not go as planned. Organizational learning concepts allowed development of stronger safety programs in a psychologically safe way. Involving the craft workforce in all these elements built ownership of HSE programs and a "speak-up" culture.

This paper will provide additive information on HSE initiatives to protect our workforce, the communities we work in, the environment, and our assets.
CCS Opportunity Along the Gulf Coast Corridor
Authors: Grant T. C. , Morgan D. J. , Cunha L. B. , Vactor R. T. , Hoffman H. E.
Published: April 2024

Carbon capture and storage (CCS) activity along the Gulf Coast from Corpus Christi to the Mississippi River and in state waters of the Gulf of Mexico is increasing. ExxonMobil, Chevron, Talos, Denbury, Occidental, Repsol and many other companies are forming partnerships to take advantage of evolving business opportunities or government co-funding of CarbonSAFE projects.

The Gulf Coast corridor, onshore and offshore, from Corpus Christ to the Mississippi River presents a high concentration of CO2 from industrial sources and excellent storage reservoirs in the underlying Cretaceous and Tertiary sands. Analysis of the technical, geologic, economic and social aspects of this CCS opportunity is necessary for successful deployment of CCS technology and eventual attainment of NetZero goals.

To provide analysis of the CCS opportunity along the Gulf Coast Corridor, the National Energy Technology Laboratory (NETL) has developed a CO2 Transport Cost Model and an Onshore CO2 Storage Cost Model. Nearing completion is the Offshore CO2 Saline Storage Cost Model. These models can provide comparative analysis of storage and transport opportunities for multiple CO2 sources to storage locations onshore, offshore or between either.

The Onshore CO2 Storage Cost Model is aligned with EPA’s Class VI regulations which are also applicable in offshore State waters. Carbon dioxide storage regulations for offshore operations in Federal waters are being developed, built upon existing offshore oil & gas operations but are expected to dovetail with onshore Class VI regulations to minimize any conflicting requirements.

Financing CCS project development and operations is a primary challenge that is evolving towards a solution. A key component here is the 45Q credit, which in turn will support offtake agreements between a source and storage operations.

Initial industry interest in the Gulf Coast region presents an opportunity to examine business opportunities for deployment of CCS technology in this area, either onshore, offshore of both.
Drilling Automation - An Engine of Change for Risk Prevention Offshore
Authors: Goodkey Brennan , Fabo Andrew , Le Buhan Francois , Cahalane James , Bisht Sameer
Published: April 2024

This paper delves into the evolving landscape of drilling automation, emphasizing the imperative for these systems to go beyond novelty and deliver quantifiable financial value. With drilling automation maturing over time, expectations are rising for tangible benefits in terms of performance and risk reduction and resulting material costs savings. The paper presents a case study centered on several offshore drilling operations that exemplify the successful implementation of a closed-loop drilling automation solution and the positive impact these technologies can have on the bottom line. Encompassing the entire drilling workflow, from tripping and connections to on-bottom drilling automation and trajectory control, a suite of innovative technology spanning domains and systems will be summarized. What sets this case study apart is the specific focus and prioritization of the requirements and challenges inherent in offshore drilling automation compared to its onshore counterpart. The technology deployed in this case study was not only tailored to the specific considerations of offshore drilling, but was also adapted over time to continually maximize the value added. The paper underscores the significance of a focused approach in identifying and managing the unique risks and priorities associated with offshore drilling. The success of the closed-loop drilling automation solution lies in its adaptability and responsiveness to the dynamic offshore environment, showcasing a paradigm shift from mere technology deployment to strategic adaptation that delivers measurable financial benefits.
Appraising Carbon Geological-Storage Potential in Saline Aquifers Using Pressure-Transient Analysis
Authors: Zhang Qiang , Zhang Fengyuan , Rui Zhenhua , Xu Minghao , Lu Ruihan
Published: April 2024

Pressure transient analysis (PTA), as a powerful technique for CO2 injection data analysis, plays an essential role in assessing the CO2 storage performance of saline aquifers. However, the appearance of the two-phase CO2/brine flow together with pressure-dependent properties introduces significant nonlinearity into the governing equation and makes the use of PTA erroneous. Accordingly, we presented a two-phase approach to estimate the storage capacity and spatial distribution of CO2 plumes by analyzing injection data.

The proposed method consists of an analytical two-phase flow model for CO2 injection in saline aquifers and a straight-line analysis approach for estimating the CO2 storage capacity. The PTA model incorporates the two-phase flow of CO2-brine, and the boundary condition of moving CO2 injection front by employing a modified equation of the distance of investigation. To account for the pressure-dependent reservoirs properties, we established new definitions of pseudo-pressure and pseudo-time and reached the analytical solutions. In addition, approximate solutions in straight-line form are obtained to appraise the CO2 storage potential through an iterative workflow.

We assessed the precision of our proposed method by conducting tests with synthetic data. This data was generated from four numerical cases related to CO2 storage in saline aquifers, simulated under constant injection rate and bottom-hole pressure conditions. We presented a two-phase diagnostic plot to identify transient and boundary-dominated flow regimes. A two-phase specialty plot is proposed to calculate essential reservoir parameters and the CO2 storage capacity. The numerical validation confirms the accuracy of the proposed method with an extremely low relative error in estimating CO2 storage capacity. The good match demonstrates the superiority of the proposed method in the quick evaluation of storage potential over the numerical simulation. Additionally, the method offers early detection of leakage through the prediction of the CO2–brine front.

Instead of assuming constant CO2 properties in two-phase PTA, this paper incorporates pressure-dependent fluid properties into a straight-line analysis approach by defining new pseudo-properties. Unlike the prior single-phase model without an injection front, the moving boundary condition of CO2 injection front is considered in the superposition pseudo-time to provide a more accurate estimation of CO2 storage capacity. This study shows that the use of PTA along with a simple CO2 injection model is simple yet rigorous for CO2 storage projects.
Dashboard for Marine Energy Site Assessment and Monitoring
Authors: Flanary C. , Jones C. , Ellenson A. , Nelson T.
Published: April 2024

The marine energy (ME) industry presently relies upon fragmented site assessment solutions that require high resource expenditure for deployment at each site and do not leverage the wealth of readily available tools and information. A wave energy resource assessment dashboard, currently in development, will substantially improve siting, permitting, operations, and maintenance of ME projects by providing an integrated solution that is a one-stop-shop for a developer's needs. The Site Energy Assessment and MOnitoring Dashboard (SEAMOD) will be of commercial interest to anyone seeking to deploy an ME project and is easily expandable to include tidal and wind energy site assessments. The integrated dashboard is being developed using state-of-the-art database and cloud computing methods and data-assimilative modeling tools that can be coupled with low-cost, rapidly deployable wave buoys and environmental sensing hardware. The combined software and hardware dashboard will reduce wave energy site characterization and wave climate monitoring costs by more than 60 percent and provide assessments that meet international industry standards. The final integrated dashboard provides a low-cost solution that delivers comprehensive, scalable, industry-standard energy resource assessments and offshore characterizations required for successful ME development. The integrated dashboard offers visibility of the most recent site modeling, measurements, and historical data. The application and integration of consensus-based standards for wave energy resource assessment, as determined by the International Electrotechnical Commission (IEC), are crucial for the impact and value of SEAMOD. SEAMOD includes monthly, seasonal, and yearly statistics, as well as the total 30-year record, offering temporal resolution of the IEC parameters to aid potential developers in determining the available wave energy resources in their area of interest.

To realize a thriving global ME industry, the physical environment at a potential deployment site must be understood, not only for resource characterization, but also for optimization of device and power conversion performance. SEAMOD directly addresses these needs with a commercially marketable product. SEAMOD is a low-cost solution that provides comprehensive ME resource assessments, baseline environmental monitoring, and offshore characterizations required for successful ME development.
Demonstrating the Accuracy of a Novel Modification to Cubic EOS to Predict the JT Effect Using Field Data
Authors: Singh J. , Shirani F. F. , Erickson D.
Published: April 2024

Joule-Thomson (JT) cooling plays an essential role in the flowline's design phase. It is one of the defining factors for pipeline minimum temperature. Therefore, it controls the pipe's alloy selection based on its minimum allowable temperature. Additionally, JT cooling impacts hydrate control. Common design models can overpredict the JT cooling value. This leads to extra CAPEX and OPEX costs. This paper will use data from nine fields to demonstrate the accuracy of cubic EOS's ability to predict JT cooling out of the box and with tuning.

The cubic EOS was modified to shift the enthalpy curve to improve the JT cooling prediction across the choke. For this study, the measured pressures and temperatures before and after the choke for 28 wells located in 9 different fields across the world were analyzed. This data was fed into a thermodynamic simulator to calculate JT cooling for both the original and modified cubic EOS. A comparison between the JT cooling values calculated by both methods with the actual data from the field demonstrated the improved cubic EOS's ability to predict JT cooling accurately.

It was noted that the JT predicted by the modified cubic EOS was much more accurate to the temperature drop across the choke in the field. The reason for inaccuracy in the original cubic EOS is that there are limited terms in the equation to predict the change in enthalpy due to pressure. This inaccuracy can be specially noted at higher pressures where the EOS predicts a lower density this can results in large errors in the JT prediction (typically too low). Using the improved cubic EOS can accurately predict JT cooling value and ultimately leads to improved predictions for online model. It also provides an idea of the margins which should be looked at for the design of areas where JT occurs in the field (choke and topside control valves).
Life Cycle Assessment of Oil and Gas Drilling Activities
Authors: Carvalho B. C. , Souza H. R. A. , Soares S. R. , Fontes M. A. , Gomes E. J. , Marinho L. S. , Junior W. F. C. , Calderari M. R. C. M.
Published: April 2024

A Life Cycle Assessment (LCA) study is presented for the comparative evaluation of environmental performance across different drilling scenarios, in the context of offshore oil and gas well operations. Particular emphasis is placed on offshore and land pathways for treatment and final disposal of drilling fluids and cuttings. The LCA model was developed in accordance with ISO 14040 and 14044 standards, encompassing distinct life cycle stages: fluids manufacturing, inbound logistics, drilling operations, outbound logistics, and end-of-life treatment and disposal. Six scenarios, involving diverse combinations of water-based (WBDF) and non-aqueous (NADF) drilling fluids, and three end-of-life alternatives—offshore disposal, industrial landfill, and incineration—were systematically assessed and compared. The Life Cycle Impact Assessment (LCIA) method employed was ReCiPe (H) Midpoint 2016, and the considered impact categories were climate change, particulate matter formation, freshwater eutrophication, marine eutrophication, freshwater ecotoxicity, and marine ecotoxicity. Among the lifecycle processes, logistic operations were found to have the lowest environmental impacts across all categories. The drilling phase exhibited significant influence, particularly in climate change and particulate matter formation. The fluid formulation phase, specifically in scenarios involving WBDF, prominently affected both freshwater eutrophication, marine eutrophication, and freshwater ecotoxicity. Marine ecotoxicity was mostly influenced by the end-of-life stage in scenarios involving offshore disposal. For five of the six impact categories, the scenario with the best overall environmental performance was drilling with NADF and offshore cuttings disposal, due to the greater performance of this type of fluid in drilling processes and the reduction in environmental impacts associated with avoiding onshore treatment and final disposal. Conversely, the discharge of cuttings into the sea had a pronounced impact on the marine ecotoxicity category due to the potential toxicity of substances such as copper, barium, and zinc. Among terrestrial treatment options, scenarios involving incineration were consistently more environmentally impactful across all impact categories. The findings of this LCA study offer a robust technical-scientific foundation, facilitating informed discussions and aiding decision-making processes regarding the environmental impacts of oil well drilling operations. This pertains particularly to the choice of drilling fluids and the management of drilling waste within this industry sector.
An Experimentally Validated Physics-Based Simulation Approach to Predict the Fracture of Shear Devices Used in Downhole Tools
Authors: Lan Weiming , Gupta Susheel Kumar , Jin Henghua , Hohenberger Travis
Published: April 2024

Shear devices are used in the energy industry to control the actuations of downhole equipment. These devices must shear reliably at desired forces. The failure to do so leads to substantial non-productive time and workover. Due to design and environmental sensitivities, achieving reliable fracture of the shear devices is challenging. Design of Experiment (DOE) method with a numerical damage model was used to understand design sensitivities which enable reliable performance of shear devices. In doing so, a temperature-dependent elastoplastic ductile damage model was constructed and calibrated for a metal material. The maximum shear stress (MSS) damage model, calibrated with a single uniaxial tension test, demonstrated good performance in capturing the complex variation in critical failure strain. Implementation of the MSS damage model in FEA facilitated accurate prediction of crack initiation and propagation in shear devices. The numerical DOE studies on shear devices were conducted by changing various critical parameters, including shear plane, contact angle, engagement length, boundary conditions, and cross-sectional diameter. The results were validated through a series of experimental tests. The simulated shears closely matched testing results, usually within 10%, and the predicted fracture surface profiles and fragments aligned well with experimental observations. The modeling technique was extended to case studies on actual shear devices, and experimental results were replicated accurately.
The Energy Reducing and Safety Concept for CO2 Injection Platform
Authors: Lee J. , Kim S. , Lim S. , Kim M. , Park S. , Kim K. , Ahn S. , Nam J.
Published: April 2024

The global warming has been focused as severe problem due to climate change, thus a large number of countries endeavor to reduce global warming gas. CCS technology is an inevitable option as long as the renewable energy sources cannot supply energy demand. The development of economical technology regarding CO2 injection is crucial for establishing a presence in the CO2 injection market. Therefore, we need to identify effective pathways to lower the cost of CO2 injection. This study's purposes constructing offshore fixed or floating type platform for CO2 injection with economical option. We conducted several case studies for CO2 injection system with additional process via process simulation, and the results indicated that high efficiency system can reduce electric power consumption by more than half. For the safety of CO2 injection system, we conducted risk assessment of solidification such as dry ice and CO2 hydrate via process simulation and lab scale experiments. The results indicated the risk of dry ice is affected from circumstance and phase of CO2. The CO2 hydrate risk is assessed by conducting a matching experimental data of batch reactor with experimental data of flow reactor. In addition, we conducted pilot-scale CO2 injection experiment to verify process simulation results and find consideration for design philosophy and operation philosophy. The results of pilot-scale experiment presented that various factors can be reflected in operation philosophy such as start-up, emergency stop. Furthermore, multi-phase flow was also considered during make up of designing pressure and temperature, which was also verified via fluid simulation. The overall results can be utilized to economical CO2 injection platform design. The results of this paper can introduce options to reduce electrical power consumption of CO2 injection system. In addition, the essential consideration can be conducted for designing CO2 injection platform especially in CO2 solidification and multi-phase flow.
Digital Twin of Polyester Mooring Lines for a Deepwater Field in Hurricane Environment Using Motion Sensors – Lessons Learned
Authors: Jaeger B. W. , Lobo D. M. , Pereira L.
Published: April 2024

A mooring monitoring campaign has been conducted to investigate dynamic behavior in the mooring system of a deepwater Floating Production System (FPS) in a hurricane environment, to investigate the risk of polyester rope contact with the seabed, which, based on the prevailing understanding of rope characteristics and modelling, should not occur. In total 12 subsea motion sensors have been deployed in the campaign, covering 3 different locations (depths) on 1 off mooring line in each of the 4 mooring clusters. The mooring sensor data is combined with onboard vessel motion data and environmental data to feed a standalone digital twin. The purpose of the digital twin is initially to aid the understanding of the dynamic behavior and characteristics of the polyester mooring lines but could later be expanded to cover additional purposes such as operational decision support. The monitoring campaign is ongoing for the second year and the results reported here are based on data from the first hurricane season (2022-2023). Results for the first season did not include any extreme storms which means that direct seabed impact or other direct evidence of unexpected behavior in extreme conditions have not been observed. Instead, a range of results, including moderately severe sea states related to a hurricane, are used to establish and verify the digital twin, and explore sensitivities and variations in the mooring system modelling and polyester rope characteristics. Key results from this work are presented and the potential for further development is discussed.