bluuebunny/crossref_metadata_2025 huggingface dataset:
Hospital Admissions and Mortality in Adults With Congenital Heart Disease in Bahia: a Temporal Analysis
Authors: Freitas Yhana Karoline Silva , Jesus Ana Paula Santos de , Cardoso Monneglesia Santana Lopes , Silva Filho Aloisio Machado da , Nascimento Patricia Veiga , Barbara Josele de Farias Rodrigues Santa , Militão Thayná Oliveira , Freitas Katia Santana
Published: February 2025

Objective: to analyze cases and deaths due to congenital heart disease in adults in the State of Bahia, and estimate the temporal trend
 
Theoretical Framework: congenital heart diseases are changes in the cardiac anatomy that affect the individual since birth. Monitoring these pathologies is necessary, due to complications that compromise the health status and quality of life of the affected population.
 
Method: ecological time series study. Records from the SUS Hospital Information System (SIH/SUS) from 2011 to 2021, and the Mortality Information System (SIM) from 2011 to 2020 for congenital heart disease were used. The sociodemographic and statistical analysis was carried out using the R language.
 
Results and Discussion: the majority of hospitalizations were women (58.7%), adults between 20 and 39 years old (39.54%), self-declared mixed race/color (42%). The observed underreporting of race/color was significant (45.46%). The prevalence of deaths among younger people was higher (42.5%), as well as in the mixed race group (55.1%), single people (43.1%) and those with less than four years of study (38.3%). The research identified a temporal trend of increasing prevalence of congenital heart diseases in adults and greater mortality in young, mixed-race and male adult patients.
 
Research Implications: importance of planning health interventions for the most vulnerable groups, as the variables found are dependent on health outcomes.
 
Originality/Value: this study contributes to the literature by highlighting the influence of sociodemographic factors on health outcomes, even when it is a condition inherent to birth.
The conservatism concept in accounting: Evolution and the present time
Authors: IL'INA Zhanna E.
Published: February 2025

Subject. This article deals with theoretical and methodological issues of the principle of conservatism in accounting, including its concept and history of development, criticism, psychological aspects, as well as the main approaches to assessing the impact of conservatism in reporting on the investment attractiveness of companies.
Objectives. The article aims to study the historical development of the principle of conservatism in international and national accounting practices, analyze the main concepts proposed by the authors of studies on the influence of the principle of conservatism in the formation of financial statements on some economic indicators, conduct a comparative analysis of existing methods for assessing the extent of conservatism of corporate reporting, as well as identify the main disadvantages and advantages of application the principle of conservatism in the preparation of financial statements from the point of view of the informativeness of its content for stakeholders.
Methods. For the study, I used the historical method, analysis, synthesis, and comparison.
Results. The article finds that the exclusion of the principle of conservatism from the conceptual framework of accounting could be due to the current need of reporting users for more objective accounting information, prioritization of the verification function of standard financial reporting, as well as the development of modern technologies and the ability of users to independently conduct a more in-depth analysis of financial reporting data. The evolution of the principle of conservatism has led to changes in approaches to the valuation of assets and liabilities of companies, increasing the transparency and comparability of reporting.
Conclusions. The article concludes that it is necessary to further reduce the subjectivity of value judgments on the financial performance of reporting companies. The use of modern technologies in the process of informing stakeholders about the activities of companies, as well as the improvement of the methodological and regulatory framework will help improve the quality of financial reporting, better meet the information needs of stakeholders, as well as improve the comparability of corporate reporting data.
Industrial policy of import substitution and support of the Russian metal goods market: Analysis of problems and ways to solve them
Authors: YASHALOVA Natal’ya N. , TAVRIKOV Denis M.
Published: February 2025

Subject. This article discusses the issues of import substitution policy and applied research potential.
Objectives. The article aims to classify and find ways to solve problems related to the development of the domestic hardware products market.
Methods. For the study, we used the methods of systems analysis.
Results. The article reveals the problems that are of fundamental importance for the implementation of the import substitution policy in the metal goods industry.
Relevance. The results of the study can be taken into account when developing programmes for the development of the domestic market of industrial products.
Implementation and Evaluation of a Long-Term Care at Home (Home LTC) Service in a Rural Community Pharmacy Setting
Authors: Ditzman Megan , Veach Stevie , Schaefer Jessie , Luett Kaitlin , Kendall Bryan , Witry Matthew
Published: February 2025

Background: The majority of older Americans are expected to need some level of institutional long term care. Community pharmacies are positioned to delay this need by supporting medication management. There are potential mechanisms for pharmacists to deliver long term care at home (Home LTC) services and bill insurers for services that may delay the transition to a higher level of care.
Objectives: This project aims to evaluate the implementation of a community pharmacy delivered Home LTC service in a rural community. The objectives were to: 1) describe implementation and challenges of pharmacy-provided HOME LTC services, 2) attempt billing for Home LTC services, 3) describe pharmacist clinical interventions including drug therapy problems (DTPs) and 4) measure patient/caregiver satisfaction with the service.
Methods: This was a pilot evaluation of a community pharmacist delivered intervention. Patient eligibility requirements include taking 6+ medications, having 3+ chronic conditions, and having 2+ limitations in activities of daily living (ADLs). All participants received a comprehensive medication review. Pharmacy staff prepared medications in monthly adherence packaging and delivery was offered. Home visits were performed by the pharmacist as needed. A post study survey assessed satisfaction and invited suggestions for improvement. Patient characteristics, DTPs, interventions, reimbursement attempts and amounts, and survey responses were documented, and analyzed descriptively.
Results: Fourteen patients were enrolled in the study - 3 living in a group home and 7 were already receiving adherence packaging. All 14 patients received at least 1 clinical intervention, and 4 home visits were conducted. Seven patients (50%) completed the satisfaction survey and reported universally high satisfaction with the service elements.
Conclusion: Overall, implementing a HOME LTC service was successful, however, the pharmacy failed to be reimbursed for service elements, including adherence packaging. Patients were satisfied with the service. Bridging the reimbursement gap is critical to sustainably provide patients with this desired service.
Shape Keepers of Hollow Cylindrical Electrodynamic Tethers for Space Debris Removal
Authors: Hara Yushin , Kuzuno Ryo , Takahashi Hikaru , Sugiyama Yoshihiro , Kikuji Yuki , Ohtani Kiyonobu , Hasegawa Sunao , Makihara Kanjuro
Published: February 2025

Electrodynamic tethers are promising for removing debris but may be severed when they collide with orbital debris. Hollow cylindrical tethers (HCTs) had more severance-resistant designs than conventional solid cylindrical tethers (SCTs) because of their larger diameters for the same weight. However, high survivability could not be achieved if the cross-sectional shape of the HCT deviated from a cylindrical one. In this paper, we propose a novel device called a shape keeper (SK) that maintains the shape of the HCT. We propose three SKs made of different materials: aluminum, nonconductive polyurethane foam, and conductive polyurethane foam. The proposed SKs are evaluated in three aspects. First, the collision damage to a HCT with SKs is evaluated through hypervelocity collision experiments. The introduced SK functions as a bumper and suppresses tether damage depending on the collision point. Second, the debris removal time is investigated by considering the influence of the installed SKs on the debris removal mission. Third, the survivability of the HCT with SKs is assessed according to the two aforementioned evaluations. The results indicate that HCTs with SKs are superior to conventional SCTs in terms of survivability with the same weight.
Minimum Trim Drag for a Three-Surface Supersonic Transport Aircraft
Authors: Seraj Sabet , Martins Joaquim R. R. A.
Published: February 2025

Three-surface configurations offer theoretical drag benefits over two-surface configurations, but the literature is inconclusive on what is the best configuration for a supersonic aircraft. This work uses trim-constrained drag minimization to investigate the impact of different trim surface configurations on supersonic transport design. We first use Reynolds-averaged Navier–Stokes (RANS)-based optimization to compare the trim drag at a supersonic cruise condition for three-surface, canard, and conventional variants of a supersonic transport aircraft. The three-surface configuration has the lowest trim drag at the supersonic condition. We then construct a supersonic buildup model to study the effects of variable trim surface sizing. When the trim surface spans are included as design variables, the design for minimum supersonic drag depends on the desired static margin. Canard configurations are optimal from 0% to 5% static margin, whereas three-surface configurations are optimal from 10% to 25% static margin. We also show that the canard configuration with 5% supersonic static margin is unstable at subsonic conditions. This emphasizes the need to consider subsonic stability and supersonic performance simultaneously for supersonic transport design.
A Practical Approach to Data Digitalization Application for Boosting Production Enhancement Activities in Malaysia's Aging Brown Fields Following the Feasibility Study of Electrical Submersible Pump at the National Level
Authors: Segaran T. Chandra , Sidek M. A. M. , Trjangganung K. , Kamaruddin I. I. , Ahnap M. A. S
Published: February 2025

With over 80% of Malaysia's fields relying on gas lift, a late life crisis is evident, prompting secondary and tertiary production enhancements to sustain oil production. Challenges like gas lift gas shortages, aging facilities, and increased water cut possess efficient oil recovery limitations, which fueled the demand for an alternative lift technology in offshore Malaysia brown fields. However, replacing a gas lift system is a tedious task. This study proposes an automated screening method swiftly identify candidates, reducing the time and workforce needed to select from hundreds of wells and streamlining production optimization activities for brown fields selected in offshore Malaysia. This data input and analysis automation system will be tested with data from multiple fields to pre-screen the strings and establish a basket of opportunities before proceeding with screening using well modeling. From the vast number of attributes used in this study, essential parameters that will be used for candidate screening have been identified. The automation of this data for screening enables narrowing down the number of potential candidates for modeling and detailed analysis. Electrical submersible pump (ESP) design and economic analysis will be done once the candidate has been finalized through well modelling. Critical parameters such as remaining reserve, absolute open flow, well angle, dog leg severity, the latest liquid rate, the latest oil rate, the latest water cut, the latest gas oil ratio, sand count and identified integrity issues are essential for a production enhancement activity. By digitalizing this data, automation will ease the path to identify a pool of production enhancement candidates out of hundreds of strings in a field. The identified candidate will proceed to the maturation process where well modeling, design, and economic analysis will be conducted. This process saves time and increases the number of candidates available for production enhancement activities in a field. This automation process is not limited to identifying ESP candidates but can also be used for stimulation candidates, gas lift optimization candidates, and water shut-off candidates as well. This automation of the screening method demonstrates significant time savings by processing and analyzing data efficiently. Therefore, the automation approaches are expected to provide a pool of candidates and identify a basket of opportunities for production enhancement activities, subsequently revolutionizing the well modeling process and improving decision-making during candidate maturation. In conclusion, the system hopes to improve the candidate identification process on a larger scale.
Evaluation of Enhanced Drilling Dynamic Sensor Positioning in Drill String Resulted in Substantial Improvements in Operational Efficiency and Cost Reduction: North Sea Case Study Analysis
Authors: Pourtangestani Mehdi , Alemi Hassan , Maliekkal Harish , My Lien Ta , Khoobyari Hamid
Published: February 2025

Industry has been actively integrating advanced solutions to enhance drilling efficiency and reduce Non-Productive Time (NPT), which are critical to any drilling project. As a result, use of downhole drilling sensors has become increasingly common, from vertical to complex well profiles. These sensors enable real-time monitoring of downhole drilling dynamics, allowing for parameter adjustments that extend bit life, reduce Bottomhole Assembly (BHA) wear, and improve overall operational performance.

This approach aimed to minimize drill string dysfunctions caused by interactions between drill string components and formation layers of varying compressive strengths, which can lead to dynamic vibrations. To determine ideal placement of real-time downhole sensors in the drill string, Finite Element Analysis (FEA) was employed for simulations and modeling, incorporating field operational criteria to evaluate BHA configurations. The simulations produced high-frequency measurements, which were validated using offset data from actual field runs, confirming the accuracy of the results.

The results highlighted that real-time sensor placement near cutting elements in the BHA, particularly above the BHA steering drive and close to the drill bit, could significantly improve drilling performance. This optimized configuration, enriched by real-time downhole data, enhanced the drilling process without compromising the steering efficiency required to meet trajectory goals as demonstrated in the presented case study for the reliability and consistency of this engineering analysis, by early detection of drill string dysfunctions, including shock and vibration, led to higher mitigation capabilities, resolving string hanging issues in rotary mode and improving overall control and effectiveness.

Field results showed a remarkable 50% increase in the rate of penetration (ROP) and a reduction in total bit runs, resulting in enhanced operational productivity and saving over $2 million in overall drilling costs. This study, leveraging case data from the North Sea, United Kingdom, provides valuable insights into optimizing downhole sensor placement in the BHA. By enabling early detection of drilling dynamics and minimizing downhole vibrations, this approach significantly reduces NPT and hidden costs in drilling projects.
The Hydrogeological Modeling for Geological Carbon Storage in the Kanto Plain, Japan
Authors: Ishise Y. , Shimamoto T. , Kobayashi Y. , Yoshioka M. , Ikawa R. , Machida I.
Published: February 2025

Many large-scale geological carbon storage (GCS) projects targeting saline aquifers are ongoing or being planned in various areas of the world, aiming at sufficient carbon offset to suppress global warming. In conducting GCS in saline aquifers, it is important to understand the regional groundwater flow from the viewpoint of long-term safety as well as appropriate evaluation of the storage volume. These issues can be achieved by appropriate boundary conditions considering groundwater flow in the numerical simulation for GCS. In this study, we propose a quantitative workflow to assess the impact of groundwater flow on CO2 plume migration in GCS, through the case study for the Kanto Plain, Japan. In this workflow, we constructed a regional hydrogeological model and performed simulation of CO2 injection into this hydrogeological model.

The regional hydrogeological model for the Kanto Plain was constructed based on the published information including geological information and chemical properties of groundwater. We compiled chemical properties of groundwater, especially Cl- concentration and stable isotope ratio, and evaluated their distribution. Those distributions are summarized in the conceptual model.

To reproduce groundwater flow on the conceptual model and the analytical results of chemical properties distribution, a numerical simulation was conducted. History match for the numerical model was conducted with the distribution of salinity, and good match was obtained by changing permeability distribution. From this hydrogeological model, it was found that the flowing velocity below the saltwater-freshwater interface is very limited, ranging from 0.1 mm/year to several mm/year.

We conducted simulation of CO2 injection on the numerical hydrogeological model. CO2 injected below saltwater-freshwater interface are almost nothing affected by the ground flow because the flowing velocity of groundwater at the layers is very limited.
Re-Imaging of Complex Carbonate and Pre-Rift Geological Setting in Ultra Deep Water, Offshore Sabah
Authors: Do Hoang Lam , Teng Keat Huat , Chan Daniel , Ernst Fabian , Khiong Luk Chee , Ibrahim Abdel Rahman , Light Linibid , Halim Nik Nur , Bt M Zohdi Siti Fahimah , Ghazali Mazlan B
Published: February 2025

Off the coast of Sabah, offshore Malaysia, there are typically imaging issues arising from a complex geological overburden containing carbonate bodies with highly spatially varying velocities that creates structural undulation at the target level. In this study, we demonstrate the application of the latest seismic imaging technology such as Dynamic-Resolution Time-Lag Full Waveform Inversion (DR-TLFWI; Wang et al., 2023) and Q-Reverse Time Migration (Q-RTM) to successfully resolve the challenging imaging issues related to shallow gas, complex carbonate, and volcanic geology setting in a deepwater environment. Dynamic resolution Time-lag Full waveform inversion utilizes both diving waves and reflections for velocity update with optimized low- and high-wavenumber components, to resolve the velocity in the deeper part of the image that lies beyond the reach of diving waves. This Full Waveform Inversion (FWI) algorithm with dynamic weighting applied to different gradient components also enables more effective utilization of the full wavefield. The imaging uplift from this FWI results in less structural undulations in the carbonate structure, potentially reducing uncertainties in the subsequent exploration. The results of re-processing also have provided improved seismic images for reservoir delineation and characterization, and better understanding of the stratigraphy and structures in this complex geological setting.
Identification and Interpretation of a Curved Oil Water Contact in a Carbonate Reservoir: A Case Study from Khasib Limestone, Ah Field, Iraq
Authors: Chen Mingjiang , Zhang Qing , Li Hongxi , Li Xiansheng , Li Sijia
Published: February 2025

The Khasib limestone holds over 60% of the oil reserves in the Ah oil field in Iraq. During production, water has been observed flowing from the structural high while oil is produced from the flank area, a phenomenon that cannot be explained by a simple tilted oil-water contact (OWC). This paper aims to identify the realistic OWC and to uncover the mechanisms responsible for the significant OWC variation.

The Khasib reservoir is divided into seven distinct horizons based on lithofacies and petrophysical properties. For each horizon, a characteristic point was selected on well logs to obtain corresponding resistivity and elevation values. Cross plots of resistivity versus elevation were used to determine the OWCs for each horizon, and the elevations of the oil-down-to (ODT) and water-up-to (WUT) levels were established by analyzing trend lines in the variation. Additionally, seismic techniques were employed to visualize structural evolution, while oil migration history was examined to explain OWC variations.

Findings indicate that differences in pore structure contribute to OWC variations across horizons. Rocks dominated by micropores have smaller pore throats and higher OWCs, while rocks with interparticle pores or selective solution vugs have larger pore throats and lower OWCs. Persistent tectonic activity since approximately 80 million years ago has transformed the structural trap, and multiple phases of oil accumulation have led to lateral variations in oil saturation, resulting in a curved OWC within the Khasib reservoir. The OWC tilts from west to east along the structure's long axis. Along the short axis, the contact level in the northern and southern flanks is lower than at the structural crest, with the lowest contact occurring in the northeastern flank of the field.

The curved OWC is confirmed by production performance data from over 260 horizontal wells and core observations, providing valuable insights for optimizing the field development plan and predicting additional reserves in the eastern area of the field. Furthermore, this study suggests that OWCs in carbonate reservoirs can exhibit curved forms, offering a beneficial perspective for analyzing similar fields.
Research On The Catalytic Role Of Nano-clays On The Pyrolytic Reforming And In-situ Hydrogen Generation Of Heavy Oil
Authors: Luo Chen , Liu Huiqing , Huang Yaowei , Lv Xueying , Liu Renjie
Published: February 2025

In-situ combustion gasification (ISCG) provides a promising pathway for the conversion of petroleum resources into clean hydrogen energy. This is achieved through the in-situ hydrogen generation (ISHG) via hydrothermal cracking reactions during the combustion process. Nano-clays exhibits excellent thermal stability, strong adsorption capacity, and ion exchange capabilities, making it an outstanding acidic catalyst for the thermal decomposition reactions of heavy oil.

This study investigates the catalytic role of different nano-clays on cracking and upgrading of heavy oil, as well as ISHG through gasification. Experimental trials were conducted using nano-clays and various oil samples, employing isothermal pyrolysis experiments to analyze the influence of nano-clays on the composition and properties of both gas-phase and liquid-phase products via chromatographic analysis. Furthermore, thermal gravimetric-mass spectrometry (TG-MS) was employed to study the catalytic role of nano-clays on the thermal decomposition and gasification of heavy oil for hydrogen production. The hydrogen gas yield and hydrogen generation efficiency (HGE) were determined using equivalent carbon spectra analysis (ECSA).

Due to the strong adsorption capabilities of nano-clays, polar components within heavy oil are thoroughly adsorbed, facilitating more comprehensive thermal cracking reactions under high-temperature conditions. Chromatographic analysis indicates a significant increase in the content of light hydrocarbon fractions in the oil phase after the addition of nano-clays. Thermal in-situ gasification becomes more thorough, resulting in a notable elevation in the content of light hydrocarbons in the gas phase and a greater generation of hydrogen. TG-MS and ECSA demonstrate that the catalytic action of nano-clays, particularly at their strong Lewis and Brønsted acid sites, accelerates the onset of hydrogen generation during thermal decomposition and gasification of crude oil. The ECSA reveals that nano-clays can increase hydrogen production and enhance HGE. The acidic catalytic and ion exchange properties of nano-clays facilitate the occurrence of ISHG primarily before the stage of fuel deposition, while also being influenced by the composition and moisture content of the oil sample. Hydrogen, as a clean and green energy source, boasts high energy density and generates no pollution during combustion. Nano-clays provide an economically efficient method and pathway for catalyzing in-situ gasification of heavy oil to produce hydrogen, while also enhancing the effectiveness of thermal cracking and reforming of heavy oil.
Revolutionising Pad Trajectory Design: An Innovative Algorithm for Enhanced Design Efficiency and Quality
Authors: Jin Peng , Liu Qing , Jiang Lu , Li Wei , Yu Tao
Published: February 2025

A key challenge in the planning stage of pad drilling is the close proximity of well placements, making the anti-collision escape strategy very challenging. Well designers need to spend long hours adjusting the trajectories. This paper proposes a new workflow to automate the multiple trajectory design for pad drilling to improve efficiency and alleviate human labor. It only requires the surface locations and targets with preferred trajectory profile configuration input to generate feasible trajectories on a pad.

Data analytics were performed to reveal the principal features of pad wells and classify pads into a finite list of pad patterns. Commonly employed collision avoidance strategies were identified from the data and embedded into the templates. An algorithm based on the minimum curvature method was designed to generate the layout and geometry of all the trajectories on the same pad, which spreads out the vertical section by auto-adjusting nudge azimuth and direction for collision avoidance and builds up, preferring single curve for ease of operation. Trajectories can be visualized and adjusted on the pad level and further fine-tuned interactively.

It was tested with numerical experiments using several pads of different scales. Drillable trajectories for each pad can be generated in less than 1 second. The algorithm can either mimic the profiles of the manual designs or propose completely different designs based on different pattern configurations. To compare the output with the original designs, we define an evaluation table for each output set of pad trajectories, with key geometry information and estimated engineering analysis, including anti-collision, T&D, etc. This KPI table can also be used to evaluate the existing pad designs and assist users in decision-making.

A usability test with user interviews was conducted for this new algorithm, which proved its value in the conceptual design stage for the whole pad design. The workflow provides immediate interactive visualization and comprehensive information on the overall KPIs and makes it easy to compare different plans. The interview also reveals specific user needs and habits in different basins and scenarios, guiding the direction for further algorithm improvement.

With this fast multiple trajectory generation algorithm, pad design and optimization efficiency can be boosted, laying the foundation for safe, efficient operation while maximizing the return of investment.
Optimization of Inflow Control Device Completion Design Using Metaheuristic Algorithms and Supervised Machine Learning Surrogate
Authors: Tan C. , Chua A. , Muniandy S. , Lee H. , Chai P.
Published: February 2025

Inflow control device (ICD) completion design optimization is crucial for maximizing hydrocarbon recovery and net present value (NPV) in horizontal wells with heterogeneous reservoirs properties. However, conventional workflows often suffer from high computational costs and limited exploration of the vast solution space. This study presents an innovative approach that integrates machine learning surrogate modeling with the African Buffalo Optimization (ABO) algorithm to address these challenges.

A case study on a synthetic reservoir model based on the Gullfaks oil field demonstrates the effectiveness of this approach. Latin Hypercube Sampling was initially used to generate training data for surrogate models, but the bias towards low-NPV cases limited their predictive accuracy. Incorporating high-quality training data with more high-NPV examples significantly improved performance, with LightGBM consistently outperforming other algorithms. The enhanced ABO-LGBM optimizer achieved a 29.77% increase in NPV compared to the open hole (OH) case, showcasing the superior capability of the integrated workflow. While computationally more intensive than simpler models, the improved accuracy of LightGBM justified the trade-off. The study also revealed the complex interaction of fluid flow dynamics and reservoir heterogeneity, emphasizing the need for further research in ICD optimization. The proposed workflow significantly reduced computational time and SME man-hours for up to 75%, offering a promising pathway for enhancing the efficiency and effectiveness of ICD completion design in the oil and gas industry. Future work could explore advanced sampling techniques, alternative machine learning (ML) algorithms, hybrid optimization approaches, uncertainty quantification, real-field validation and incorporation of operational constraints to further advance this field.
Optimizing Mature Gas Fields with Hybrid Models – Case Study and Value Analysis
Authors: Sabharwal Varad , Singh Chauhan Prithvi , Guo Zhenyu , Ravuri Meher , Sankaran Sathish , Shrivastava Rahul , Sanchez-Ocana David Marques , Nguyen Thi
Published: February 2025

Production optimization in mature gas fields is a complex and challenging task that requires reservoir knowledge captured over several years of production and long-term data management strategies. Traditional surveillance methods for well and reservoir performance are manual, interpretive and do not scale over several wells with high data volumes to make timely decisions. Hybrid models that blend physics and data-driven methods prove to be useful in automatic performance tracking, early detection of anomalous events, classifying actionable opportunities, and help in continuous system optimization.

An automated solution was designed, consisting of 14 reservoir and production workflows to improve asset operational efficiency for a mature gas basin in Australia. The solution involves workflows that enable continuous optimization through evergreen reservoir, well and network models to maximize reservoir performance, field production capacity, opportunity generation, and exception-based surveillance. Each workflow solves specific problems from bottomhole pressure calculation to network optimization. These workflows are interlinked and together are responsible for production optimization and opportunity generation. In this paper, we discuss the application of our integrated surveillance and optimization system deployed in the Cooper Basin of Australia, and operated by Santos Ltd. The system allowed operators to quickly evaluate and identify several opportunities to improve well productivity within a short span of deployment. The system has captured 5 MM USD generated from automated production opportunity identification and classification. Self-calibrating models, integrated with reservoir and surface networks, provide improved scenario optimization for integrated asset management with a potential 14 MMscf/d uplift in field production. Several improvements in model quality were noted, as well as frequency of model calibration increased from manual updates twice a year to once every week with the automated system. The integrated system has been augmented into existing company processes of capacity determination and business planning.

The solution demonstrates the effectiveness of a hybrid modeling system for automatic fields and wells performance tracking, early anomaly detection, actionable opportunity identification, and promotes continuous system optimization. Our focus is to improve asset operational efficiency, optimize production and enhance surveillance processes. The solution utilizes a new generation of hybrid modeling tools that enable continuous asset optimization. Furthermore, the solution augments the capability of engineers by providing a practical way of combining data-driven methods with our understanding of physics.
Unlocking Potential: Multidisciplinary Integrated Surveillance and Recovery Strategies to Monetize a Thin Oil Rim in Minor Reservoir at G Field
Authors: Bt Kosnon Nur Khairina , Bt Ayub Nur Afiqah , B M Zulkifli Nik M Qusyairi , Harris Lee Hazreen Bt , Kumar Sanjeev , Kumar Suman , Ramli Zuhairi B
Published: February 2025

Oil production from G field is in declining trend where major reservoirs have been monetized through stages of development with good recovery factor. Considering infill development campaign for the field is currently shelved due to commercial challenges, minor reservoirs are being evaluated to sustain the field production. This paper deals with multidisciplinary integrated surveillance efforts carried out in evaluating thin oil reservoir characterized by fluid type uncertainty, flow sustainability and limited connectivity.

A thin oil rim reservoir with approximately 1 meter thickness and 100md permeability has been identified for production as the reservoir has never been tapped before. Promising oil zone characteristic is observed upon evaluating the open hole logs and mud logs from existing wells producing from nearby reservoirs. All candidates have been assessed for reservoir quality alongside well intervention complexity to compare the economics results. The selected well has the most competent commercial value as this well will not require to have cement packer prior to additional perforation operation, on top of good reservoir quality.

An additional perforation job was completed in 2019, targeting to drain oil production from the identified minor reservoir. However, the well was unable to flow as expected due to unforeseen reason in which prompted the team to conduct static gradient survey. The interpreted survey result shows presence of oil from the gradient and the reservoir pressure is still close to original reservoir pressure, which verified that there is no communication between the well to existing wells which are currently producing gas from the gas cap of the same reservoir. On top of that, sand production was observed thus hindering the team from conducting planned pressure build up survey. Eventually, the well was idle for 4 years. With increasing demand in oil, the reservoir was recently reperforated with bigger gun size for deeper penetration. Besides, gas lift valve changeout was done to improve the well lifting efficiency. While the team is striving to bring the well to its expected performance, the well is currently flowing at low THP thus proving the oil presence from the reservoir.

Despite the challenges encountered, the team has taken all the lesson learnt from the well intervention complexity and well performance as baseline to further assess and develop the remaining minor reservoirs at G field.
Study of Cellulose Nanomaterials and Solid Particles Synergistically Stabilising Foam Drilling Fluids
Authors: Dai Liyao , Li Mei-Chun , Sun Jinsheng , Lv Kaihe , Bai Yingrui , Yang Jingbin , Yang Dongqing
Published: February 2025

As a renewable clean energy, geothermal resources have the advantages of large reserves, wide distribution and sustainable development. However, due to the high temperature of geothermal reservoir, high salinity of bottom hole fluid, low pressure coefficient and serious fracture development, the use of traditional drilling fluid drilling is easy to cause complex accidents such as lost circulation and wellbore collapse, which seriously limits the efficient development of geothermal resources. In response to the above problems, this work develops a temperature-resistant and salt-resistant foam drilling fluid suitable for geothermal drilling, which provides a new idea for the safe and efficient development of geothermal resources. The performance of various blowing agents was evaluated, resulting in the identification of a blowing agent with exceptional temperature and salt resistance, along with its corresponding compounding system (0.1 wt% AOS+0.3 wt% BS-12). In order to enhance the stability of foams in high-temperature and high-salt environments, cellulose nanofibrils (CNFs) and Laponite were employed in a synergistic manner as solid particle stabilisers in the foam drilling fluid. The findings of the study indicated that an increase in solid particles concentration resulted in a reduction in foaming ability, while the half-life time was observed to be prolonged. The introduction of solid particles not only diminished the size and surface tension of the foam particles at the gas-liquid interface, but also elevated the viscosity of the system, thereby enhancing the stability of the foam.
Overcoming Challenges of Well Intervention During Simultaneous Production Operations and Hook-Up Commissioning to Restore Production of Big Bore Gas Producers
Authors: Yeow M. L. , Khaidzir K. Mohd , Abu-Jafar F. , Nordin H. , Choo D. , Nor S. M. , Wahab M. B.
Published: February 2025

Challenges of Slickline and Coiled Tubing fishing and milling operations was resolved without HSE incident in Simultaneous Production Operations mode with Hook Up Commissioning and Production Operations to restore production from a big bore gas producer, thus adding 150 MMSCF/D production. The well has 7″ Completion tubing with partially open downhole isolation valve and difficult downhole fish (deep set plug + Toolstring).

Challenges include correct tools, equipment, job design, procedures, weather, limited deck space, personnel movement control and ensuring each well intervention step are carried out with high chances of success. Solutions to resolve the challenges with multiple ongoing works from Well Intervention, HUC and Production were integrated and optimised to ensure all teams meet their work objectives safely within time, cost and without HSE incident. Engineering analysis, risk management and reliable well intervention equipment with good communication and decision making among work teams were implemented in planning, preparations and execution to overcome the challenges.

The well intervention works were successfully completed without HSE incidents demonstrating simultaneous operations involving HUC, Production Operations and Well Intervention can be carried out successfully. Insights include correct equipment design and procedures, working instruction to communicate effectively with personnel, good safety awareness, improving work integration between HUC, Production Operations, Well Intervention and Logistic teams, managing crew with extended shifts and improving equipment reliability. Lessons learnt on the following: running large 0.16″ Slickline wire & 2″ Coiled Tubing including depth calibration, techniques to fish wire and overcoming buckling in big bore completion.milling of ball valve with Coiled Tubing i.e. types of mills, operating downhole milling motors, milling steps, weight on mill, indications of successful milling.hot-work (welding and cutting) with habitat, thus avoiding production shut-downSimultaneous Slickline, Coiled Tubing and Well Testing well intervention with HUC on a producing platform including steps to avoid triggering flame and gas detectors on a producing platform.

The successful campaign increases confidence for multi-disciplinary surface, facilities, HUC, Production Operations and Well Intervention teams to carry out such simultaneous operations in future.

Successfully integrating simultaneous operations between Well Intervention, HUC and Production Operations on an offshore field development is a demonstration of creating real value through technical and operational expertise thus helping reduce development and production cost and time. Insights from this successful work will contribute to realising the aim of the industry to improve efficiency and costs.
A Novel Upscaling Method for the Arrhenius Kinetic Model in Fracture Simulations, with Application to the In-Situ Conversion Process
Authors: Tan Qizhi , Liu Shuyang , Li Hangyu , Wang Yanji , Liu Junrong , Sun Wenyue
Published: February 2025

The in-situ conversion process (ICP) involves complex thermal-reactive-compositional flow processes. To accurately represent the production performance of ICP, computationally intensive small-scale grid-blocks are entailed for numerical simulation. The presence of natural or hydraulic fractures in many oil shale reservoirs further complicates and increases the computational cost of these simulations. Accurate modeling of pyrolysis reactions of solid organics in fractures is critical for production outcomes. To address these challenges, this work introduces a highly accurate upscaling method tailored for ICP simulations involving fractures modeled by the Embedded Discrete Fracture Modeling (EDFM) method. The upscaling method is compatible with both open-source and proprietary reservoir modelling software, highlighting its broad applicability. The method employs simplified models and a temperature adjustment procedure to approximate the temperature evolutions of the grid-blocks in non-simplified models. Based on these approximated temperature evolutions, the Arrhenius kinetic parameters of fine-scale grids are upscaled to coarse-scale grids to enhance computational efficiency. The method's effectiveness is demonstrated through 3D ICP models, where it accurately upscaled the pyrolysis reactions in both matrix and fracture blocks. Additionally, the method accelerates fine-scale ICP simulations by approximately 400 times while maintaining the accuracy of fine-scale production dynamics, making it well-suited for ICP simulations in complex geological settings.
Breakthrough Horizontal Water Shut-Off Using Nano Technology; Field Trial and Optimized Treatment Recipe
Authors: Sulaiman Ahmed A. Al , Jacob Suresh , Almohsin Ayman , Salem Ibrahim
Published: February 2025

This paper discusses a successful rigless chemical water shut-off (WSO) application utilizing Nano-Silica fluid technology in a horizontal oil well completed with passive Inflow Control Devices (ICDs). An extensive downhole monitoring system, consisting of production logging tools (PLT), noise logging, and memory gauges, was implemented pre and post treatment to optimize job performance. A customized coil tubing (CT) bottom hole assembly (BHA) enabled real-time monitoring and precise control over sealant placement into the target zone.

The treatment aimed to use Nano-Silica technology to isolate an ICD compartment experiencing excessive water production caused by fractures in the wellbore. By sealing off this water entry point, the goal was to delay water diversion into adjacent compartments, thereby treating deeper into the formation. Candidate selection relied on PLT to characterize water flow profiles and identify the optimal treatment interval. Diagnostic tools included noise logs, post-job PLTs, and injectivity tests to refine gelation timing.

Treatment design focused on injecting the Nano-Silica fluid through ICD ports, leveraging its low initial viscosity. Once reaching the designated gelation time, controlled by reservoir temperature and concentration of sodium silicate (Na2SiO3)/NaCl (activator), the treatment solution formed an in-situ plug. Real-time monitoring via live CT BHA ensured safe treatment execution within predetermined operational limits, preventing damage to open-hole packers. Enhanced BHA configurations incorporated memory pressure and temperature gauges for comprehensive interference testing between compartments.

Post-treatment analysis showed remarkable improvements. Optimization of gelation time and recipe increased plugging strength from 25% to 100%, yielding a 36% decrease in water cut without impacting oil production rates. Initial post-job rate tests confirmed these gains. Furthermore, PLT oil flow profiling indicated a fourfold enhancement. Insights gained from interference tests validated the efficacy of the WSO procedure.
Integrated Approach to Proactive Sand Management: Subsurface and Surface Control Strategies
Authors: Zainal S. , Shafie N. A. , Salehuddin M. T. M. , Ramli N. A. , Hendraningrat L. , Riyanto L.
Published: February 2025

Sand production is a well-known issue in oil and gas fields. It can lead to other sand-related issues such as well plugging, erosion, production downtime, etc. The issues can be more serious, not only to the loss of wells and production facilities but also to safety and the environment. Therefore, sand management is a critical aspect of oil and gas production, ensuring operational efficiency, equipment integrity, and environmental protection. This paper presents an integrated solution project for proactive sand management, encompassing both subsurface and surface control strategies.

The paper describes strategies for integrating control techniques, empathizing with their role in mitigating sand-related issues. The sand-related issues from the fields were observed and mapped. The active sand control methods were selected: mechanical and chemical agglomeration. The concept of a chemical solution is to provide a larger agglomerate of grains sands and stronger bond strength between particles, resulting in longer agglomerated sand particle longevity.

The chemical agglomeration was comprehensively tested in the laboratory with actual downhole and surface sand samples, and it is agglomerating them into much larger particles that promote the performance and integrity of the sand screen and production separator/desander at downhole and surface facilities, respectively. In the downhole control, the sand screen was installed, and injection was done simply with a bullheading method. This technology has proved to improve production in the field with rapid payback period. Meanwhile, surface control can be applied to separator/desander facilities and shows immediate agglomeration with the chemical and enlarged sand grain agglomerates and settled at the bottom. Both strategies can increase oil and gas production and improve operational efficiency and equipment integrity.

The findings and recommendations from this paper contribute to enhancing sand management practices in the oil and gas industry, promoting cost-effectiveness, asset reliability, and environmental stewardship.