bluuebunny/crossref_metadata_2025_split huggingface dataset:
Innovative Solutions for Enhancing ESP Performance: Addressing Gas Lock Issues Through Flowback Loop Technology and Packer Removal
Authors: Al Manthari M. , Ali A. , Ferdiansyah E. , Al Mahrouqi A. , Al Hashli M. , Al Zaabi A. , Al Gheilani H. , Ji P. 
Published: November 2024

Abstract
This paper aims to address and mitigate the exacerbated ESP gas lock issues in packer completion operations, in Microporous reservoirs in North West Oman, that hinder fluid lifting, reduce production rates, and cause frequent ESP trips. By introducing an innovative solution for packer removal, it seeks to enhance ESP performance, prolong run life, and significantly reduce deferment, particularly in microporous/tight reservoirs with limited water injection support. Packer removal is considered justified under the company's well integrity management practices if a well cannot flow naturally within three days. To evaluate this, flowback tests were conducted in the field to assess natural well flowing capability within this timeframe. Multiple campaigns successfully demonstrated free-flow capability under ambient conditions. Additionally, Dynamic Transient Simulation analysis was used to predict natural flow following ESP shut-ins under atmospheric backpressure conditions. Model validation and sensitivity analyses were performed to evaluate ESP shut-ins and restarts without activating the ESP. The correlation between simulation results and flowback test findings reinforced the reliability of the conclusions. The implementation of flowback loop technology has shown substantial practical benefits. Based on flowback loop and dynamic transient modeling, the inaugural campaign of packer removal from four wells significantly reduced ESP trips, improved operational efficiency, and decreased oil deferment. In 2023, packer removal where feasible led to a net oil deferment reduction of approximately 22,000 barrels. By 2024, extending packer removal to 18 wells further reduced deferment by around 750 bbl/d. This technology not only improves production by allowing gas to escape, preventing gas lock conditions, but also ensures well integrity compliance without the adverse effects of traditional packer use. This dual benefit showcases a forward-thinking approach to managing ESP gas lock issues. The adoption of flowback loop technology combined with dynamic modeling represents a significant strategic advancement. This solution enables real-time evaluation of a well's natural flow capacity within the critical initial 72-hour period post-installation. This approach aligns with well integrity management standards, providing a proactive solution to prevent future gas lock issues and enhancing overall operational efficiency.
Concept of Inverted Jacket for Brown Field Extension of Offshore Platforms in Shallow Water
Authors: Chatterjee Prabir Kumar 
Published: November 2024

Abstract
This paper proposes a new concept of installing an inverted jacket with battered legs to connect with an existing fixed offshore structure for brown-field projects that require significant amount of additional deck space for new facilities. Use of an inverted jacket will allow more spacing between legs at the top of the jacket implying a larger deck space to accommodate more equipment. However, piles are separated from the legs to avoid convergence of the piles within the seabed. Piles will be driven through separate long sleeves and the annulus between the pile and the sleeve will be grouted before installation of the deck. Rigid/welded connections between the new and the existing deck structure helps in reducing the number and diameter of the new piles.
Numerical studies demonstrate the cases of two real-life structures with inverted jacket extensions at 28m and 35m water depths. Results show that a 2-level deck of size 30mx30m can be safely connected to the existing structure to withstand all gravity and environmental loads applicable for the two sites. The extended deck space can accommodate up to 700 MT of equipment and other facilities. The extended structure has adequate strength and the required minimum reserve strength. The proposed design requires considerably less structural steel compared to the conventional jackets to create the same amount of deck space.
AI-Driven Solar-Powered Digital Fencing for Enhanced Oil & Gas Field Security
Authors: Yousef Ahmed , Bukhamseen Raid 
Published: November 2024

Abstract
This paper introduces an AI-driven digital fencing system, designed to revolutionize security in oil & gas fields. The main objectives are to improve security and safety of oil & gas facilities while addressing the limitations of legacy physical barriers, reduce false alarms, and eliminate the dependability on the grid to renewable energy for continuous, reliable monitoring of operational information like temperature, wind speed, and humidity as well as the continuous monitoring to all security and safety aspects.
As per a PwC report (AI, 2018)1, The Middle East, particularly Saudi Arabia and the UAE, is poised to benefit significantly from AI, with an estimated economic impact of $320 billion by 2030. AI technologies are expected to contribute over $135.2 billion to Saudi Arabia's economy, equivalent to 12.4% of its GDP, about 14% of the UAE's GDP and close to 8% of Egypt GDP with contribution expected to reach $42.7 billion. The adoption of AI in the region is driven by substantial investments in technology and innovation, positioning these economies as leaders in the global AI landscape.
In this paper, we cover the integration of AI-driven Solar-powered fencing cameras, highlighting their potential to enhance security resilience and reliability in the oil & gas industry.
Advances in Underwater Robotic Inspection
Authors: Bancroft Jonathan 
Published: November 2024

Advanced Non-Destructive Testing (NDT) technologies are the most effective tool in our ongoing fight to ensure the integrity of our offshore assets and subsea infrastructure against corrosion and other damage mechanisms. Over fifty years have passed since the first rigs appeared off the coast of California, in the North Sea, across the Gulf of Mexico, and around the globe. Much of the original structures and associated infrastructure remain in use today.
Operating far beyond their intended lifespans, these structures, pipelines, and other subsea equipment are increasingly vulnerable to aging-related issues, with corrosion being the primary threat among various potential failure modes, including weld cracking. Since the early days, we have witnessed continuous, steady advancements. New materials have been introduced, pipeline designs now better account for the seabed terrain, and the construction, operation, and maintenance of structures and pipelines have become significantly more efficient.
Despite improvements in corrosion protection, mitigation, and inspection technologies, the reality is that the longer a subsea asset has been in service, the more time corrosion or other defects have to develop. This is especially true for older assets installed before the availability of these advanced construction methods. Additionally, the marine environment is harsh and unforgiving, making the monitoring and maintenance of subsea assets integrity crucial, regardless of their age.
Application of Multi Objective Whale Optimization Algorithm for Solving Lift Gas Allocation Problem and Production Enhancement in Oil & Gas Industry
Authors: Kenoth Sasidharan Adiyodi , Paul Samuel Henry , Menon Biju , Kottappuram John , Nair Ajay , Maryam Dashtebayaz 
Published: November 2024

Abstract
Gas lift is one of the most commonly used artificial lift method in oil producing wells. The technique requires constant Optimization of injection gas quantity in the well to maximize oil production. High pressure Lift Gas allocation is an important step in optimization process to reduce the investment on costly and scarce lift gas and maximize oil recovery. In this work, an attempt is made to optimize a group of wells with application of an innovative metaheuristic algorithm. The objective function can be either the generated profit or total produced oil as a function of injected gas.
To achieve maximum recovery from gas-lifted wells, it's essential to identify the optimum injection rate for specific facility constraints, including gas availability, maximum injection depth, and compression capabilities. Normally, these parameters are unchangeable because of prior selection and installation, except when optimization techniques are implemented in the design phase. The Gas Lift Performance Curves (GLPC) are the main design element used for optimized gas injection. These curves are generated by modelling wells in a multiphase steady-state simulator. After building model, sensitivity analysis is run, and the curves are generated. In this work, the common workflow to generate GLPC is followed. Then, a new correlation for GLPC is suggested with help of a bio-inspired meta heuristic Whale Optimization Algorithm (WOA). The correlation is then used to formulate a case study for few wells located in Caspian Sea. R-score and Root Mean Square Error (RMSE) values compared. Wells and PVT models are used to create a simulation. The optimization problem is mathematically formulated using stochastic optimization techniques. The new correlation is used to fit the GLPC with WOA. A set of Pareto Optimal solutions are derived. Results of WOA is compared with other two potential algorithms such as Particle Swarm Optimization (PSO) and Genetic Algorithm (GA) to obtain the global optimum of the distribution of a limited gas lift quantity. The advantages of WOA over PSO and GA is discussed, and the optimum gas allocation is obtained. The correlation outperforms all other models and also bring an injection gas saving of 10-15% and improved oil production to the extent of 5-10% with an automated WOA algorithm application. Compared to the traditionally applied numerical methods for gas allocation and optimization, AI meta-heuristic algorithms are considered as revolutionary methods, offering more solutions to gas allocation problems, which can solve non-linear multi-objective optimization problems quickly and more accurately with fast convergence. WOA is simpler, faster and outperforms PSO and GA and yield maximum production at minimum cost.
Application of Self-Supervised Autonomous Agent Framework for Digital Transformation of Elder Well Potentials Discovery
Authors: Chen H. , Zhao Q. , Lu W. , Gu S. , Jin W. , Liu G. , Lin X. 
Published: November 2024

Abstract

Objectives/Scope
The manuscript presents an innovative agent-based framework aimed at enhancing the reassessment of elder oil and gas wells. By integrating diverse generative artificial intelligence (AIGC) models, this framework harnesses self-supervised feedback mechanisms to continually enhance the reasoning prowess of large-scale models, thereby facilitating curve reconstruction, horizon forecasting, and potential layer interpretation for existing wells. Notably, this approach demonstrates the feasibility of agent-driven AI-native applications in bridging various oil and gas industry contexts without necessitating extensive fine-tuning.

Methods, Procedures, Process
The proposed methodology introduces a novel Explainable Self-Supervised Agent Group Framework (ESSA), which constructs an agent cluster to facilitate seamless interaction among business systems, AIGC models, and scenario-specific models. The ESSA's three-tiered agent system operates within a closed-loop configuration, leveraging continuous feedback and self-supervision agent frame as its core mechanism for aiding reinforced learning to deal with the complex task. This architecture encourages iterative refinement of AIGC models, mitigating issues such as inaccuracies, fabrications, and misleading information, while facilitating precise model selection, content generation, and refined evaluations of aged wells.

Originality
The manuscript underscores the novelty of its platform architecture through two primary contributions: (1) The synergy between the agent ensemble and AIGC models yields an AI-native solution capable of tackling multi-faceted, scenario-spanning challenges in the oil and gas sector. (2) The multi-agent framework fosters a closed-loop ensemble that promotes collective intelligence through self-learning and optimisation, selecting optimal models to continually refine well reassessment processes, significantly curbing operational costs in practical deployments.

Reuslts
To validate the framework's efficacy, we analysed a dataset comprising 50+25 elderly wells, all exceeding 30 years in age, located across two distinct geological blocks. Our evaluation encompassed model selection accuracy, logging curve reconstruction fidelity, horizon classification (encompassing oil, water, gas, sandstone, mudstone, and oil-water coexistence zones), and the capacity to recommend potential horizons. The outcomes underscore the framework's robust agent ensemble organisation, enabling AIGC models to unlock their full potential through self-supervised prompting engineered within the proposed agent framework. With human-in-the-loop interactions, the framework achieved horizon classification and potential horizon prediction accuracies ranging from 50% to 80% for the mature wells under assessment.
Nitrogen level determines arbuscular mycorrhizal fungi nitrogen uptake rate of Stipa purpurea in alpine steppe
Authors: Sun Jiahui , Tang Yu , Chen Keyu , Ren Shijie , Shi Hailan , Dong Qiang , Dong Junfu , Zhang Lin , Cui Xiaoyong , Wang Yanfeng , Ji Baoming , Zhang Jing 
Published: November 2024

Abstract

Background and aims Roots and mycorrhizal fungi, especially the Root-pathway and Myc-pathway, represent two alternative strategies for plants in the process of soil nutrient foraging. However, the concurrent carbon (C) economy associated with resource acquisition through root and mycorrhizal pathways remains unclear, particularly across the nitrogen (N) enrichment gradient.
Methods Using experimental microcosms with a dominant plant of alpine steppe, Stipa purpurea, and inoculated with native arbuscular mycorrhizal fungi (AMF) in combination with 15N and 13C dual-labeling, we quantified the direct N transfer to the host plant through both pathways, as well as the C allocated to the fungi and roots by the same plant, across three N addition treatments (control (0 kg·N ha-1 yr-1), low N (50 kg·N ha-1 yr-1) and high N (150 kg·N ha-1 yr-1)).
Results We found that, under the low N treatment, extraradical hyphae of AMF proliferated extensively, and the plant exhibited significantly positive mycorrhizal responses in terms of biomass and nutrient foraging. The contributions of N foraging through the Myc-pathway to S. purpurea were 13.85%、48.28%、30.59% across the N addition gradient, respectively. Especially under the low N addition, plants preferred the Myc-N pathway over the Root-N pathway. However, the C allocation to AMF by plants under different N levels showed no significant difference.
Conclusion Upon comparing the ratios of N benefit to C cost, we believe that the low N addition can maximize the function of native AMF in N foraging for alpine plants.
Geoelectrical evidence of fluid controlling slow and regular earthquakes along a plate interface
Authors: Nakamura Hayato , Ichihara Hiroshi , Goto Tada-nori , Matsuno Tetsuo , Tada Noriko , Kuroda Manaka , Sato Shinya 
Published: November 2024

Abstract

Shallow subducting plate interfaces, as sites of both destructive and “slow” earthquakes, resulting from rapid and slower fault slips, respectively, present a major scientific and disaster mitigation challenge. Although understanding the different slip mechanisms and their spatial relationships is critical, the role of a key factor, pore fluids, is understudied. Here we present clear observational evidence from Hyuga-nada, southwestern Japan, that the pore-fluid distribution correlates with fault rupture behavior. A 3D electrical resistivity model derived from marine magnetotelluric survey data reveals distinct resistive and conductive anomalies along the plate interface that reflect areas of scarce pore fluid and high concentration area of pore fluids sourced from subducting seamounts (Kyushu–Palau Ridge), respectively. The wet area corresponds to the slow slip area whereas dry and the transition areas correspond to areas of fast fault slip. These findings highlight the influence of the pore-fluid distribution on fault processes and underscore its importance in earthquake and tsunami risk assessments.
Transcriptome Sequencing Reveals Significant RNA Variation in Human Sperm Samples
Authors: Chen Weiming , Yu Lei , Jia Zhenyu , Zhu Jianguo 
Published: November 2024

Abstract

As spermatocytes mature, they shed substantial cellular material, resulting in sperm cells that primarily contain DNA. Sperm cells variation in RNA has not been addressed in the literature. We analyzed semen samples from 83 males, with normal sperm motility and asthenospermia, a condition characterized by reduced sperm motility. Using the conventional quality criterion for RNA sequencing, 15 samples (set 1) met these standards, 22 samples (set 2) approached these standards, remaining samples failed library construction. We hypothesize the samples that did not pass the conventional RNA quality standards represent the mature and functional sperm with reduced RNA, these samples have been ignored in previous studies. We have made the RNA sequencing data publicly available in the GSA-Human database, under accession numbers HRA006250 and HRA006906, respectively. These datasets will provide insights into the role of RNA in sperm generation and facilitate the development of (1) new RNA quality standards for sequencing the sperm transcriptome and (2) identification of residual RNA in mature sperm cells and genetic role in influencing offspring phenotypes.
Association of premenstrual disorders during preconception with perinatal depression: an analysis of the perinatal clinical database of a single Japanese institution
Authors: Ohsuga Takuma , Egawa Miho , Tsuyuki Kaori , Ueda Akihiko , Komatsu Maya , Chigusa Yoshitsugu , Mogami Haruta , Mandai Masaki 
Published: November 2024

Abstract

Background
Recent studies have identified premenstrual disorders (PMDs) as a risk factor for postpartum depression. However, routine screening for preconception PMDs is not yet common in Japan. This study investigated the association between preconception PMDs and perinatal depression in a single tertiary care setting.
Methods
We analyzed data from pregnant women who delivered at Kyoto University Hospital between April 2020 and October 2023. PMDs during preconception was assessed using the Premenstrual Symptoms Screening Tool, whereas perinatal depression was measured using the Edinburgh Postnatal Depression Scale (EPDS) during pregnancy and at 1 month postpartum. EPDS cutoff values were set at 12/13 during pregnancy and 8/9 at 1 month postpartum.
Results
Of 789 women analyzed, 54 had preconception PMDs. Univariate and multivariate logistic regression analyses revealed that preconception PMDs was associated with an EPDS score of ≥ 13 during pregnancy, with a crude odds ratio (OR) of 5.64 (95% confidence interval [CI]: 2.64–11.5) and an adjusted OR of 3.63 (95% CI: 1.51–8.14). For an EPDS score of ≥ 9 at 1 month postpartum, the crude OR was 3.22 (95% CI: 1.72–5.85) and the adjusted OR was 2.10 (95% CI: 1.01–4.20).
Conclusions
Our findings indicate that preconception PMDs is a significant risk factor for both depression during pregnancy and postpartum depression. These results support the implementation of preconception PMDs screening during antenatal checkups to identify women in need of early mental health care and preventive measures.
Ultra-lightweight carbon nanocomposites as microwave absorber with high absorbing performance derived from flour
Authors: Zhong Yiming , Long Yunchen , Sun Yinuo , Qin Jiachen , Li Yongxin , Liang Gemeng , Zou Jinshuo , Xie Peitao 
Published: November 2024

Abstract

Carbon materials, known for their lightweight properties, are widely utilized in electromagnetic wave absorption applications. In order to overcome the limitations of effective absorption of electromagnetic waves by a single carbon material, magnetic cobalt nanoparticles were incorporated into a carbon network derived from flour, resulting in the development of Co/C nanocomposites with a porous structure through fermentation. The research results show that the electromagnetic wave absorbing material prepared in this way has advantages such as being thin (1.80 mm), lightweight, having a wide effective absorption frequency range (8.07 GHz), and high electromagnetic wave absorption capacity (-61.6 dB).The electromagnetic wave absorption capability of the material originates from the multi-level interfaces in Co/C nanocomposites, the porous carbon structure formed during flour fermentation, and the dielectric relaxation generated during the polarization process. The excellent electromagnetic wave absorption performance is mainly attributed to impedance matching and attenuation factor optimization. The presence of a small amount of amorphous carbon in the carbon network reduces the condensation and oxidation of magnetic cobalt nanoparticles, thus enhancing the impedance matching. By adjusting the Co/C ratio inside the nanocomposites, the impedance matching of the Co/C nanocomposites is improved, and the absorption capacity of the CO /C nanocomposites is improved. This article reports the method of determining the ideal content of absorbent in flour based composites and the principle of optimizing the electromagnetic wave absorption capacity of nanocomposites.
Validation of a hand-held Ultrasound device in the evaluation of Aortic Stenosis
Authors: Zubiaur Jon , de Castro Adrián Margarida , Pérez-Barquín Raquel , González Manuel Lozano , Gorria Gonzalo Martin , Guerrero Luis Javier Ruiz , Calderon Andrea Teira , Setien Ignacio Santiago , Lozano David Serrano , Vilchez Francisco González , de Prada Jose Antonio Vázquez 
Published: November 2024

Abstract

Purpose
Hand-held ultrasound devices (HHUD) are increasingly used in routine clinical practice, though they lacked continuous (CW) Doppler capability until recently. There is limited evidence on the utility of HHUD in assessing aortic stenosis (AS) in real-world settings. Our goal is to validate a new HHUD with CW Doppler assessing AS hemodynamic severity.
Methods
An observational, single-center study was conducted with patients diagnosed with AS. Following a reference echocardiographic study in the cardiac imaging laboratory, a HHUD with CW Doppler (Kosmos, EchoNous™) was used by an operator with intermediate echocardiography experience (American Society of Echocardiography, level II). The focus was on measuring aortic transvalvular Doppler velocities. Agreement between the mean trans-aortic gradient (mAG) was assessed using the intraclass correlation coefficient (ICC) test. A total of 101 patients were included.
Results
The reference test obtained a mAG of 29 mmHg (19.8–42.2), while the HHUD test showed 27.2 mmHg (16.2–43.9). A strong correlation was observed (r = 0.89), with an ICC value of 0.87 and no significant bias (1.61 ± 0.9). The HHUD demonstrated excellent ability to identify severe AS (kappa = 0.81, 95% CI 0.68–0.94; global agreement 92.1%). Agreement was lower in patients with obesity, poor acoustic windows, or atrial fibrillation.
Conclusions
The HHUD showed good agreement with standard echocardiography in assessing AS. While it slightly underestimated mAG, it was accurate enough to reliably quantify AS severity.