bluuebunny/crossref_metadata_2025_split huggingface dataset:
Harnessing Ensemble Learning Techniques for Accurate Interfacial Tension Estimation in Aqueous CO2 Systems
Authors: Nsiah Turkson Joshua , Aslam Md Yusof Muhammad , Fjelde Ingebret , Adams Sokama-Neuyam Yen , Darkwah-Owusu Victor , Nii Tackie-Otoo Bennet 
Published: May 2024

Abstract
The interfacial tension (IFT) of aqueous CO2 systems plays a critical role in determining CO2 capillary entry pressure, maximum CO2 storage height, and subsurface storage capacity. Conventional methods for measuring IFT are time-consuming and resource-intensive. This study therefore explores the application of ensemble learning techniques: Gradient Boosting (GradBoost) and Light Gradient-boosting Machine (LightGBM), to predict the IFT of aqueous CO2 systems. A comprehensive dataset of 1570 IFT data points, encompassing six features: pressure (0.1–69.51 MPa), temperature (5.2–196.25℃), monovalent and divalent cation molality (0–5 mol/kg), and methane and nitrogen mole fractions (0–80 mol.%), was compiled from the literature. The data was preprocessed and divided into 70%, 15%, and 15% subsets for model training, testing, and validation. Model performance was optimized through regularization and hyperparameter tuning. Statistical metrics and visualizations were employed for quantitative and qualitative evaluation of the models. The Leverage approach was used to identify potential outliers and ensure model reliability. Sensitivity analysis and feature importance were assessed using permutation importance and the Akaike Information Criterion (AIC). GradBoost and LightGBM exhibited remarkable performance, achieving a coefficient of determination (R2) exceeding 0.98, root mean square error (RMSE) below 2.00 mN/m, mean absolute error (MAE) lower than 1.2 mN/m, and average absolute percentage relative error (AAPRE) less than 1.5% for all data groups. GradBoost surpassed LightGBM in terms of accuracy (higher R2 of 0.99), precision (lower MAE of 0.87 mN/m), consistency (lower RMSE of 1.23 mN/m), and complexity (lower AIC of 53). Furthermore, GradBoost outperformed a committee machine intelligent system, a group method of data handling model, and other robust ensemble models such as random forest and adaptive boosting. Permutation importance and AIC revealed that pressure and monovalent cation molality were the least and most influential features on IFT prediction. Additionally, excluding any of the six input features significantly reduced model performance, with AIC increasing by 6 and 9 folds without temperature and pressure data, respectively. The Leverage approach confirmed the statistical validity and reliability of the GradBoost model, identifying only 3% of the total data points as potential outliers. This study demonstrates the effectiveness of ensemble learning techniques in capturing the complex relationships between variables that govern the IFT of aqueous CO2 systems. The constructed ML models offer a rapid and reliable alternative to conventional methods for IFT evaluation, speeding up workflows, and reducing experimental uncertainties. These advancements hold promise for optimizing CO2 storage strategies and enhancing subsurface CO2 storage capacity.
Numerical Simulation on the Influence of Natural Fractures on the Productivity of Parent and Child Wells Considering Frac Hits
Authors: Liang Yanbo , Cheng Yuanfang , Han Zhongying , Yan Chuanliang 
Published: May 2024

AbstractThe commercial extraction of shale gas has led to frequent fracture hits, significantly affecting the ultimate recovery rate of the reservoirs. The objective is to analyze how natural fractures impact the production of parent and child wells considering fracture hits through a more comprehensive fluid-solid coupling productivity model, providing a reference for adjusting construction parameters during the production process.Firstly, a multi-scale quadruple-medium model considering organic matter, inorganic matter, natural fractures, and artificial fractures is established based on the theory of poroelasticity and fluid-solid coupling. This model integrates shale gas multiple flow regimes, gas adsorption/desorption, and stress sensitivity. The COMSOL is utilized to numerically solve the model and its accuracy is verified with field production data. Subsequently, a dual-well numerical model is established to analyze how the characteristics of natural fractures, including length, aperture, density, roughness, and dominant orientation, impact the productivity of parent and child wells during shale gas development.In scenarios involving frac hits, the production rate of the parent well initially experiences a temporary increase followed by a decline, which is higher than in scenarios without frac hits. Over time, however, the production rates under both conditions-frac hits and no frac hits-tend to converge. In the early stage of child well production, due to frac hits, its rate is lower than the production rate of the parent well, and the cumulative production decreases. The length, density, and aperture of natural fractures are positively correlated with the degree of interference, while the dip and roughness of natural fractures are negatively correlated with the degree of interference. The impact of natural fracture occurrence on the degree of interwell interference is ranked as density&gt;length&gt;dip&gt;opening&gt;roughness. Among them, the impact of natural fracture roughness on production is minimal. When the roughness coefficient changes by 20%, the change rate of production in the parent and child well are only 0.003%, which can be basically ignored.A more comprehensive and accurate quadruple-medium fluid-solid coupling productivity model for shale reservoir is establised. The effect laws of natural fracture occurrences on the productivity variation of parent and child wells considering fracture hits are analyzed. The research findings can guide the prediction of shale gas productivity and the dynamic adjustment of production parameters.
Joint-Domain Full Waveform Inversion and Its Applications to Ultra-Shallow Water OBN Data
Authors: Yang Y. , Yin H. , Duan L. , Lyu Xiaolin , Zhang Yu , Han Weishan , Song Jiawen , Khdhaouria Mourad 
Published: May 2024

AbstractFull Waveform Inversion (FWI) is nowadays commonly used for high-resolution velocity model building. Conventional FWI with least-squares objective function often suffers from cycle-skipping problem. This issue becomes prominent in subsurface structures with high complexity, significant deviations between the initial and true models, or a lack of low-frequency content in the data. To address the cycle-skipping problem, we present a novel Joint-Domain Full Waveform Inversion (JDFWI) framework optimizing travel time accuracy in both data and model domains. The model domain uses delay time common image gathers (DTCIGs) for travel time measurement. In the data domain, travel time misfit is extracted without amplitude information. Thus, integrating a time-lag-based misfit function efficiently overcomes the cycle-skipping problem. We first validated our JDFWI with a controlled synthetic test and then applied our proposed JDFWI workflow to a challenging ultra-shallow water ocean-bottom node (OBN) dataset from the South Caspian Basin. While conventional FWI suffers from cycle-skipping problem, JDFWI delivers high-resolution and accurate velocity models.
Case Study: Innovative Applications of Friction Reduction Tools to Solve Drilling Problems in Tough Environment Multilateral Wells
Authors: Silva Paul , Hammad Abdullah , Khurshid Imran , Elimam Hossam , Ruzhnikov Alexey , El-Toum Ahmed , Al Saihati Mohammad , Al-Khalifah Ahmed 
Published: May 2024

Abstract
In an onshore field, horizontal wells are drilled in a complex geological environment. Starting from the fact the surface formations are very unstable, a casing design strategy has been put in place to isolate the easily collapsible formations away from Aquifers and highly water-sensitive shales. In addition to the formation characteristics, multiple loss zones are present not only in the top holes but also in the reservoir section. The fluid column hydrostatic support while drilling is lost, which ends up in exhaustive non-productive time stuck pipe situations. The objective of the study is to systematically propose and describe the engineering strategy, which resulted in a safe and flawless recovery from stuck pipe scenarios taking advantage of friction reduction tools.
This study evaluates the experiences while implementing innovative applications of friction reduction tools to solve drilling problems in these tough environments in multilateral wells – the "out of the box" mindset. After a project evaluation using statistical methods, the main problems identified for this application are summarized into how to increase the probability of freeing stuck pipes in top sections with innovative tools.
The detailed strategy and implementation have been divided into sections to tackle the main problem and the different engineering analysis, risk evaluation, prevention, and mitigation measures. After engineering analysis was performed, the continuous vibration friction reducer tools were installed at the surface in one of the wells with a severe stuck pipe event that lasted over 2 days with zero progress. After 17 hours of the instillation of the continuous vibration friction reducer tools working together carefully with the planned pills strategy stuck pipe was released in record time compared with other events in the area resulting in the avoidance of cutting string and sidetracking the wellbore, saving the cost of the drill string, operational time following the fishing economics.
The paper provides proper technical steps and details to be replicated in similar situations, such as case studies where the stuck pipe needs an unconventional way of treatment.
Successful Cement Job Execution Through Real Time Pressure Match and Control of Equivalent Circulating Density in Losses and Narrow Pressure Margins – A Pakistan Case Study
Authors: Fazal Muhammad Adnan , Tashfeen Muhammad , Rashid Muhammad , Malik Asad Ali , Jan Usman Ahmed , Hussain Abdul , ul Haq Rizwan 
Published: May 2024

Abstract
Cementing the section/casing without inducing losses has always been challenging in narrow margins of allowable equivalent circulating density (ECD) from fracture gradient. The losses are caused by exceeding the ECD limit. Exceeding the limit results in annulus integrity issues and a leaking casing shoe that leads to sustained casing pressure. When this happens, it requires extensive remedial planning. The conventional and current loss cure tool is addition of loss control fibers, and we must manage the pump rates in pre-job planning. But there is no control or monitoring of the ECDs during the job. Historically, for similar cementing jobs, decisions for future improvement are made only after post-mortem analyses, i.e., remediation plans are formulated for future operations based on what previously went wrong. Significant time is spent on deliberating over several indirect factors that may or may not have affected job outcomes. With the recent emphasis on performance, digitalization, and sustainability, the operator must identify a workable solution based on real-time parameters.
A real-time measurement and simulation solution that addresses the previously listed challenges was deployed to monitor and control a challenging 13 3/8-in. casing cement job in a remote well with extreme health, safety, and environment (HSE) risk. In this well, the permitted ECD margin from mud weight was only 1.3 ppg. A formation integrity test was performed at 15.9 ppg using 12.5-ppg mud. However, because of wellbore stability issues, mud weight was increased to 15.6 ppg, leaving behind a narrow margin of permitted ECD from fracture limit (set at 16.9 ppg based upon offset well data). Accordingly, spacer and cementing fluids were designed to keep the ECD within the fracture limit to avoid losses.
The job was monitored in real time for pumping pressure and calculating downhole ECDs in comparison with planned values. While working remotely, it enabled the customer to make real-time decisions on pumping rate to keep the ECD in check. The job was successfully pumped without any losses and the final ECD was kept within the 16.9-ppg limit.
The monitor/simulation software application enables users to monitor, compare, and evaluate cement job acquisition data with dynamic simulations generated in real time. Customers and experts can monitor the job remotely, diagnose abnormal events, and propose solutions in a timely manner, providing interpretation and support throughout the job execution. The solution eliminates the need to travel to the rig for cement job monitoring, saving staff hours and contributing toward sustainability. It remotely monitors cement jobs, decreases travel time, and decreases the time needed to make decisions, while also assuring preestablished job objectives are met.
Holistic Approach to Overcome High Temperature Challenges by Drilling the Deepest Wells in Colombia
Authors: Marino C. , Campos N. , Jaramillo L. , Cardona J. , Paulin A. , Ariza A. , Bustos C. , Barnett K. , Botero J. , Schadid H. , Perez P. , Munoz J. 
Published: May 2024

Abstract
This study presents the challenges and success of drilling in the Colombia's northeastern fields, where static temperatures reach approximately 315°F. The objective was to complete the drilling operations within a time frame of 85 days, across four distinct sections, using a specialized downhole tool qualified for high temperatures. These tools were not just standard equipment; they underwent local qualification to verify their operation at high temperatures. Strategic bottomhole assembly (BHA) design, aided by simulation, ensured drilling stability. Post-drilling analysis using data analytics improved operational efficiency and progression rates.
The initial well, Well 1, achieved a depth of 22,350 ft measured depth (MD) (22,058 ft true vertical depth, TVD), which is the deepest well in Colombia's onshore drilling history. Subsequent drilling operations, particularly in Well 2, demonstrated notable operational efficiencies. One of the key successes of this project has been the improvement in tool reliability and the optimization of resources. The incidence of BHA failures decreases to zero events, attributed to more stable drilling dynamics. A critical component in managing the high temperatures was a mud cooling strategy, which reduced the downhole temperature by approximately 14°F on average (with a maximum reduction of 20°F) at the surface. This study offers a benchmark addressing the engineering complexity of high-temperature and deep wells, enhancing tool reliability under harsh conditions, leveraging a calibrated temperature model, the efficiency of mud cooling procedures, and the application of data analytics to enhance BHA design and execution.
Dragon Oil's Behavioral Based Safety Process Be Observed, Be Aware, Be Safe (BOAS)
Authors: Gazakbayeva Aygul , Raval Kalpeshkumar 
Published: May 2024

BAPP (Behavioral Accident Prevention Process) technology gives us the mechanism to measure and address At-risk actions before these behaviors result in injuries. Observation and feedback identifies multiple causes for the At-risk behaviors. Some of these issues are addressed immediately while other issues are best addressed by a group of individuals in a facilitated problem-solving session.
Observers are the foundation of the process as they are responsible for recording accurate information about the specific behaviors that are performed safely and At-risk daily. Observers provide a soon, certain and positive consequence to their co-workers as they recognize the safe behaviors that have been made and identify the reasons for any At-risk behaviors that occur. It is critical that Observers accurately identify the specific barriers that prevent their co-workers from working safely and record this information so that the data can be reviewed and the issues addressed in problem solving sessions.
Action Plan leaders play a crucial role in the BAPP approach. Action Plan leaders typically lead groups of employees through the action planning process, using observation data.
Fit-for-Purpose Approach in Selecting Logging-While-Drilling Technologies—Key Enabler for Productive Horizontal Well Drilling: Case Studies Based on Experience in the Caspian Region
Authors: Ospanov D. , Nevzorov R. , Mukanov Y. , Chzhen I. 
Published: May 2024

Abstract
The number of horizontal wells is increasing in the Republic of Kazakhstan. A clear understanding is needed to select the right tools that will enable us to drill horizontal wells with high efficiency. The optimum bottomhole assembly (BHA) and geosteering strategy considering the specifics of the target horizon, and economical and geological goals are integral parts of horizontal well planning. In this paper we highlight the relevant experience needed to select logging-while-drilling (LWD) technologies and geosteering strategy design. This experience was gained during a successful collaboration between SLB and JSC Embamunaigas (the Operator), which in recent years turned the Operator's vector of drilling from vertical to horizontal, as 16 out of 34 underdevelopment oilfield assets undergo implementation of horizontal wells.
Drilling Data Based Approach for Real-Time Rate of Penetration Prediction for Motorized Bottom Hole Assembly Using Artificial Intelligence
Authors: Youssef Amir Shokry , Gowida Ahmed , Elkatatny Salaheldin , Ibrahim Ahmed Farid , Abdulraheem Abdulazeez 
Published: May 2024

AbstractPredicting and optimizing the drilling rate of penetration (ROP) poses a significant challenge due to its dependence on various factors, prompting increased attention towards achieving precise ROP estimations given its direct influence on overall drilling expenses. Among the factors influencing ROP, the driving mechanism of the bottom hole assembly (BHA) plays a pivotal role. Motorized BHAs offer versatile applications beyond directional drilling, including optimization of ROP and mitigation of downhole vibration. While several models have been proposed to forecast ROP for rotary and rotary steerable system BHAs, limited attention has been directed towards motorized BHAs. In this study, a novel artificial intelligence (AI)-based model employing gradient boosting regression (GBR) was developed to predict ROP for motorized BHAs, leveraging surface drilling parameters, mud characteristics, and motor output features. The dataset used for model training, validation, and testing was sourced from six wells spanning two adjacent fields in the Egyptian Western Desert, comprising over 5,800 data points. Mean absolute percentage error (MAPE) served as an evaluation metric for prediction accuracy, while the correlation coefficient (R) quantified the extent of agreement between real and predicted ROP values. Results demonstrated that the GBR model accurately estimated ROP for motorized BHAs, exhibiting a high correlation (R of 0.95) between predicted and real values. The GBR-based model consistently performed well without exhibiting underfitting or overfitting issues. Furthermore, the developed model enables exploration of the impact of different drilling parameters on motorized BHA ROP, thereby facilitating ROP optimization, reduction of open hole exposure duration, and overall drilling cost minimization.
WITHDRAWN: Hybrid Architecture for Secure Data Communication Within the Private Cloud
Authors: Naeem Awad Bin , Senapati Biswaranjan , Sudman Md. Sakiul Islam , Abdel-Rehim Wael M. F. 
Published: May 2024

Abstract

The full text of this preprint has been withdrawn by the authors due to author disagreement with the posting of the preprint. Therefore, the authors do not wish this work to be cited as a reference. Questions should be directed to the corresponding author.
Assessing Permissive Hypercapnia's Role in Cerebral Oxygenation and Recovery Quality in Elderly Cerebrovascular Patients During Thoracoscopic Procedures: A Research Framework
Authors: Ni Chenlu , Qiu Yuwei , Zou Yuanyuan , Zhang Yunyun , Zhu Yin , Wu Jingxiang 
Published: May 2024

Abstract

Background
One-lung ventilation (OLV) can disrupt the respiratory cycle and lead to changes in oxygenation and local cerebral oxygen saturation (rSO2), which may predispose elderly patients to an imbalance in the ventilation/perfusion ratio and an increased risk of hypoxemia. Permissive hypercapnia has been gradually recommended as a lung-protective mechanical ventilation strategy in recent years, in theory could enhance cerebral blood perfusion and oxygen supply. However, the actual clinical benefits of this physiological response remain uncertain. Our study hypothesizes that permissive hypercapnia during OLV may have a beneficial effect on the cerebral oxygen supply and demand balance in elderly patients with a history of cerebrovascular disease undergoing thoracoscopic lung surgery.
Methods
This is a prospective, single-center, randomized controlled, double-blind clinical study. 270 participants(≥65years) scheduled for thoracoscopic surgery will be included in this study. Participants in the treatment group will use protective lung ventilation strategy during operation, maintain end-tidal partial pressure of carbon dioxide at 50-65mmHg; Participants in the placebo group will not use protective lung ventilation strategy during operation, maintain end-tidal partial pressure of carbon dioxide at 35-45mmHg.
Discussion
The primary hypothesis of the forthcoming study is that permissive hypercapnia during OLV might have a beneficial effect on the cerebral oxygen supply-demand balance in elderly patients with a history of cerebrovascular disease who are undergoing thoracoscopic lung surgery, in term of reducing the incidence of event rate of cerebral desaturation.
Trial registration: This trial is registered at www.chictr.org.cn with a registration number of ChiCTR2200064832.
Fatigue resistance of concrete – Influence of time-dependent scattering of compressive strength
Authors: Voß Sören , Schmidt Boso , Oettel Vincent 
Published: May 2024

Abstract

In terms of sustainability and resource efficiency, concrete structures such as bridges and wind turbines should be used as long as possible and – in the case of new constructions (as a replacement) – the cross-sections should be as slender and thin-walled as possible using high-performance or ultra-high performance concrete. A further development of the fatigue design would be useful both for the verification of a possible longer remaining service life and for a safe, but also for economical and sustainable design of these engineering structures, which are particularly exposed to fatigue. The verifications of structural safety for non-static loading of concrete in the national and international design codes and standards provide for high safety margins, particularly for concretes with high strengths. These result, among other things, from the large scatter of the number of cycles to failure in experimental fatigue tests. In this article, current verifications of structural safety for non-static loading of concrete are presented, results of compressive tests on concrete specimens of different strengths, geometries and test boundary conditions are summarised in a database and the scatter of the experimentally determined number of cycles to failure is statistically evaluated. In addition, the compressive strength of concrete, which significantly influence the scatter of the numbers of cycles to failure, are statistically analysed for concretes of different ages. From this, a continuous description of the strength development and its scatter is derived. Finally, the compressive stress levels of the previously analysed fatigue tests are adjusted using a stochastic approach in order to take into account the scatter of the compressive strength of concrete as a function of the concrete age. By applying the time-dependent scatter of the compressive strength of concrete, a significant reduction in the scatter bandwidth of the analysed numbers of cycles to failure in the S-N curve is achieved.