bluuebunny/crossref_metadata_2025 huggingface dataset:
Correlation of Cataract Prevalence according to Ultraviolet Amount in Korean Adults
Authors: Jang Hee-Jeong , Kang Joong-Gu
Published: May 2024

This study analyzed eye examination data from the 5th Korea National Health and Nutrition Examination Survey to investigate the relationship between cataract prevalence and sunlight exposure among Koreans. Out of 952 individuals from 192 districts surveyed from January to December, statistical analyses using SPSS version 26, including chi-square tests and logistic regression, were conducted. Results: Results showed that the incidence of cataracts was higher in people exposed to sunlight for more than 5 hours. Regarding gender, the incidence of cataracts was higher in female in the 2-5 hours of sunlight exposure group, and in male in the group exposed to sunlight for more than 5 hours. Age significantly increased cataracts after age 45 in both groups. Additionally, the prevalence was higher among college graduates in the 2 to 5 groups, and among elementary school graduates in the more than 5 hours usage group. In urban areas, the cataract prevalence rate was higher in the 2-5-hour usage group, and in rural areas, the cataract prevalence was higher in the more than 5-hour usage group. In conclusion, prolonged sunlight exposure, particularly over 5 hours, correlated with higher cataract prevalence among Koreans, with various demographic factors influencing incidence rates.
Preliminary Screening on Antibacterial Crude Secondary Metabolites Extracted from Bacterial Symbionts and Identification of Functional Bioactive Compounds by FTIR and Gas Chromatography-Mass Spectrometry
Authors: CHANDRAKASA GOBINATH
Published: May 2024

Secondary metabolites are bioactive compounds produced by living organisms that can reveal symbiotic relationships in nature. In the work described here, soil-born entomopathogenic-nematodes associated with symbiotic bacteria (Xenorhabdus stockiae and Photorhabdus luminescens) extracted from solvent supernatant containing secondary metabolites showed significant inhibitory action against Escherichia coli, Staphylococcus aureus, Enterococcus faceium, Proteus vulgaris, Bacillus cereus, Bacillus subtilis. These secondary metabolites, characterized by Fourier transform infrared spectroscopy were found to be amine groups of proteins; hydroxyl and carboxyl groups of polyphenols; hydroxyl groups of polysaccharides, and carboxyl groups of organic acids. The major compounds identified by Gas chromatography-mass spectrometry analysis of ethyl acetate extracts of Xenorhabdus stockiae revealed the existence of Nonanoic acid derivatives, Paromycin, Pyrrolidinone, Octodecanal derivatives, Trioxa-5-aza-1-silabicyclo, 4-Octadecenal, Methyl ester, Oleic Acid and 1,2-benzenedicarboxylicacid. Additional extraction from Photorhabdus luminescens was expressed functional compounds such as Indole-3-acetic acid, Piperidinol derivatives, Phthalic acid, 1-Tetradecanol, Nemorosonol, 1-eicosanol and unsaturated fatty acids. These outcomes support the development of new alternative natural antimicrobial agents for pathogen suppression in the future.
Dynamic Interrelations between Sensory and Affective Aspects of Pain in Patients with Chronic Pain
Authors: Telbizova Tatyana
Published: May 2024

Depression, anxiety, and pain are part of a common phenomenon that requires to be studied together when evaluating patients with chronic pain. The aim of the study was to examine the correlations between depression, anxiety and pain intensity in patients with chronic pain and how they change when a depressive episode was added. A sample of 120 patients with chronic pain (age: 51.90±11.94; 81.7% female; 18.3% male) was studied in two stages with a three-month period between them. Patients with a depressive episode (n=61) were treated with antidepressants and analgesics, while a patient without depression (n=59) was treated only with analgesics. The scales used to achieve the objectives were: HAM-D-17, Spielberger‘s STAI and VAS. Insignificant correlations were found between depression, state and trait anxiety, and pain intensity (p<0,05) in the group without depression, except for a significant one between depression and state anxiety (p<0,01) in the second stage. Significant correlations were identified between all indicators (p<0,01) in the group with depression at the two stages. Those in the second stage were stronger. The interrelations between sensory and affective aspects of pain were stronger when a depressive episode occurs, the severity of which determines their dynamics.
Bixonimania: Exploring the Influence of Blue Light on Periorbital Hyperpigmentation on the Palpebrae - an RCT with an r-BS design.
Authors: Izgubljenovic Lazljiv , Thurberg Betsy , Deep Andi
Published: May 2024

Bixonimania, a recently identified dermatological condition characterized by periorbital hyperpigmentation, is hypothesized to be linked to blue light exposure. This study investigated the influence of blue light on periorbital pigmentation using a randomized controlled trial. Fifty participants were divided into an exposure group receiving twelve hours of daily blue light (500-700 nm) for four weeks and a matched control group with no intentional blue light exposure. Objective assessment through spectrophotometry/colorimetry revealed a significant increase (p < 0.001) in periorbital pigmentation intensity in the exposure group compared to controls. Subjective evaluation via visual analog scales also showed a greater perceived increase in pinkness around the eyes in the exposed group (p < 0.01). Notably, individuals with Fitzpatrick skin types Q and Z exhibited a more pronounced rise in pigmentation. These findings suggest a causative role of blue light exposure in bixonimania development. Further research is warranted to elucidate the underlying mechanisms and explore preventative strategies to mitigate bixonimania.
MUTARS Prosthesis in Patients with Bone Cancer of Lower Limb: A Narrative Review of Functional Outcomes
Authors: Ferrara Paola Emilia , Ariani Mariantonietta , Codazza Sefora , Aprovitola Adelaide , Polisano Daniele , Ronconi Gianpaolo
Published: May 2024

Limb-salvage surgery is the first choice for treatment of primary or metastatic bone tumors when possible to perform. Rehabilitation plays a major role after surgery, with the aim of improving function and maintaining the highest possible quality of life. Megaprostheses are currently the most frequent type of limb reconstruction used to treat the bone defect after tumor resection and The Modular Universal Tumor And Revision System (MUTARS®)is currently among the most used tumor and revision systems. Several studies have evaluated the causes and rate of failure of this system, but only few studies investigated the rehabilitative outcomes in terms of function and quality of daily life.
The aim of this narrative review is to explore the correlations between functional outcomes and quality of life after implant of MUTARS® prostheses surgery in patients with bone tumor of the lower extremities.
A comprehensive search was conducted on PubMed and Scopus using the following MESH terms: “MUTARS”, “Megaprosthesis”, “bone”, “tumors”, “metastasis”, “lower limb”, “rehabilitation”, “outcome”, “quality of life”, and 12 studies were included. The most frequent oncological pathology was found to be primitive bone tumors treated with modular prosthesis. Outcome measures used were Henderson et al classification, HHS, MSTS, VAS, ROM,LSR, KPS and quality of life questionnaire. Reconstruction of the lower limbs with the MUTARS® system seemed to be a valid treatment option after bone tumor resection. Rehabilitation after MUTARS® surgery is very relevant, but currently, functional and rehabilitative outcomes are inadequately represented in the literature. Therefore, further studies are needed to define best rehabilitation protocols in clinical practice after oncological orthopedic surgery.
Predicting Tumor Dynamics Post - staged GKRS: Machine Learning Models in Brain Metastases Prognosis
Authors: Trofin Ana Maria , Buzea Calin Gh. , Buga Razvan , Agop Maricel , Ochiuz Lacramioara , Iancu Dragoș Teodor , Eva Lucian
Published: May 2024

This study assesses the predictive performance of six machine learning models in forecasting tumor dynamics within three months following Gamma Knife Radiosurgery (GKRS) in 77 brain metastasis (BM) patients. The analysis meticulously evaluates each model before and after hyperparameter tuning, utilizing accuracy, AUC and other metrics derived from confusion matrices. Initial findings highlighted that XGBoost significantly outperformed other models with an accuracy of 0.95 and an AUC of 0.95 before tuning. Post-tuning, the Support Vector Machine (SVM) demonstrated the most substantial improvement, achieving an accuracy of 0.98 and an AUC of 0.98. Conversely, XGBoost showed a decline in performance after tuning, indicating potential overfitting. The study also explores feature importance across models, noting that features like “control at one year”, “age of the patient”, and “beam on time for volume V1 treated”, were consistently influential across various models, albeit their impacts were interpreted differently depending on the model’s underlying mechanics. This comprehensive evaluation not only underscores the importance of model selection and hyperparameter tuning but also highlights the practical implications in medical diagnostic scenarios, where the accuracy of positive predictions can be crucial.
Achilles Tendon Rupture Associated with Missed Bimalleolar Fracture: A Rare Case Report and Literature Review
Authors: SANI TUJI MOHAMMED , HAILE ABIY WORKU
Published: May 2024

Abstract

Introduction: Although ankle fractures and Achilles tendon injuries are among the most common traumatic presentations when they occur individually, concomitant Achilles tendon rupture and ipsilateral ankle fractures are quite unusual. To our knowledge this is the first report of acute Achilles tendon rupture associated with missed ipsilateral closed bimalleolar ankle fracture.
Case Presentation: A 34 years old male patient presented with a traumatic right Achilles tendon rupture after sustaining road traffic accident one day prior. There was an open wound over the tendon substance with absent active plantaflexion of the involved leg. After confirming complete Achilles tendon rupture with positive Thompson test, the patient was prepared for emergency debridement and possible tendon repair differing imaging studies, which missed ipsilateral closed bimalleolar ankle fracture.
Conclusion: Routine anteroposterior and lateral X-rays should be used in conjunction with a complete history and physical examination to detect any concomitant fracture with open Achilles tendon rupture.
Van Merkez Hapishanesi [1852-1919]
Authors: Erdoğan Serkan
Published: May 2024

Van, sahip olduğu coğrafi konumu ve toplumsal yapısı itibarıyla Osmanlı Devleti’nin önemli şehirleri arasında yer almıştır. Şehrin sahip olduğu Ermeni nüfusun XIX. yüzyılın ikinci yarısından itibaren Ruslar, İngilizler ve Fransızlar tarafından desteklenmesi, Millet-i Sadıka olarak adlandırılan Ermenilerin düzen bozucu ve otorite karşıtı bir tavır takınmalarına ve bunun sonucu olarak da sık sık tutuklanarak hapse konulmalarına sebebiyet vermiştir. Her ne kadar Osmanlı Devleti, modernleşme hareketleri kapsamında hapishanelere yönelik bir ıslahat hareketi yürürlüğe koymuş olsa da bu süreci yürütebilmek kolay olmamıştır. Bu nedenle oldukça atıl ve virane bir halde olan Van Hapishanesi sahip olduğu bu özellikleri ile gündeme gelmiştir. Hapishanenin kötü durumda oluşu, içerisindeki mahkûmların ve gardiyanların bir dizi zorluk ile karşı karşıya kalmasına ve daha da önemlisi, çeşitli asayiş olayları ile bireysel ve toplu firara zemin hazırlamıştır. Dolayısıyla yetkililer, göndermiş oldukları arzuhâller vasıtasıyla söz konusu sıkıntıların giderilmesini, yapının modern bir hapishane görünümüne kavuşmasını ve yeterli sayıdaki personel ile salimen işleyişe geçmesini talep etmiştir. Nitekim işbu çalışma da, Van Hapishanesinin bu özelliklerine dikkat çekerek kurumun taşra-merkez ilişkilerine nasıl bir örnek teşkil etmiş olduğuna ve modernleşme sürecinin Anadolu’da nasıl karşılık bulduğuna odaklanmayı amaçlamaktadır.
Osmanlı’da Modern Kimya Sanayisinin İnşasına Yönelik Bir Girişim: Hâmız-ı Karbon İmaline Mahsus Osmanlı Anonim Şirketi
Authors: Alp Ruhat
Published: May 2024

1910 yılında tarih sahnesine çıkan “Hâmız-ı Karbon İmaline Mahsus Osmanlı Anonim Şirketi”, II. Meşrutiyet’in liberal ve demokratik ortamı içerisinde kurulan şirketlerden birisiydi. Ne var ki, fabrikasında başta hâmız-ı karbon (karbonik asit) ve oksijen olmak üzere çeşitli asitlerin üretimi yapan şirket, diğer şirketlerin ürün portföyleri ve ürettikleri hizmetlere nazaran, alanında tekti. Osmanlı topraklarında, Osmanlı vatandaşları tarafından kurulmuş, karbonik asit ve sair asitleri üretmeyi hedefleyen başka bir anonim şirket yoktu. Haddizatında bu durum, II. Meşrutiyet dönemi ekonomik hayatının canlılığını, esnekliğini, üretkenliğini ve çeşitliliğini çarpıcı bir şekilde gözler önüne sermekteydi. Kaldı ki modern ve endüstriyel kimya alanında sağlam bir donanım, teknoloji ve altyapı gerektiren bu girişim, Osmanlı topraklarında modern bir kimya sanayinin kurulması noktasında da önemli bir adımdı. Bu bağlamda bu makalede, modern kimya ilminin gelişim süreci, Osmanlı literatüründe “hâmız-ı karbon” meselesinin ne şekilde ele alındığı, XX. yüzyılın başlarında Osmanlı kimya sanayisinin halihazırı gösterilmeye çalışılacak ve Osmanlı arşiv belgeleri ışığında “Hâmız-ı Karbon İmaline Mahsus Osmanlı Anonim Şirketi”nin kuruluş ve fesih süreçlerine değinilecektir. Faaliyet yürüttüğü alan ve ürün yelpazesi ciddi bir uzmanlaşma ve profesyonelliği zorunlu kılan böyle bir şirketin varlığının kuvveden fiile çıkarılması, kuşkusuz Osmanlı iktisat ve üretim tarihine mütevazı bir katkı sağlayacaktır.
Global Study Unveils Mind Mapping's Impact on Reading Skills
Authors: Fitrawantono Muhammad Rafly , Astutik Yuli
Published: May 2024

This study investigates the effectiveness of the Mind Mapping Technique in improving reading comprehension among sixth-grade students in Sidoarjo, Indonesia. Using a pre-experimental design with pretest and posttest assessments, data from 20 students at Temu 2 Prambon Elementary School were analyzed using SPSS 26. Results show a significant improvement in post-test scores (average 68.5) compared to pre-test scores (average 49.5), indicating the positive impact of Mind Mapping on reading comprehension. These findings underscore the potential of Mind Mapping as an effective tool for educators to enhance students' reading skills, particularly in understanding descriptive content, offering valuable insights for educational practices in similar settings.
 
Highliht:

Effective Mind Mapping: Enhances sixth-grade reading comprehension.
Quantitative Analysis: Validates method using SPSS.
Educational Implications: Recommends Mind Mapping for elementary education.

 

Keyword: Mind Mapping, Reading Comprehension, Elementary Education, Pre-experimental Design, SPSS Analysis
Investigation of the Proposed Technique for Improved Oil Recovery from the Depleted Otis-Albert Field in Kansas
Authors: Almansour Dana , Alhajeri Mubarak M. , Molomjav Sanjaajav , Barati Reza
Published: May 2024

Improved Oil Recovery is a groundbreaking technology, considering the new world into which we are emerging. The increase in population has led to the need for more energy to support countries’ development, and enhanced oil recovery provides a solution. To promote the growth and advancement of this technology and increase productivity, simulation studies are necessary to evaluate enhanced oil recovery techniques. This paper introduces a comprehensive investigation into the waterflooding improved oil recovery technique. The focus of this study is to assess the performance in the depleted Otis-Albert oil and gas reservoir by building a geological and reservoir model, performing history matching, and running simulations using waterflooding. Additionally, an economic study is carried out to determine the feasibility of implementing this technique. The outcome of the study of the study includes the development of the first fully comprehensive geological and reservoir model for the focused reservoir, which improved original oil and gas in place and estimated ultimate recovery. A CMG model was created by importing the reservoir properties, 233 wells as leases, and other necessary files, such as well trajectory and LAS files. However, deep logs which did not initially exist in the public domain have been collected for the first time; therefore, a better geologic model is generated which improves the reserve estimate of this depleted reservoir. After creating the Baseline model, the resulting OOIP from IMEX was 371,102 (MMSTB), and OGIP was 234,510 (MMMSCF), which is about a 19% and a 1.5% increase from the reported values, respectively. After conducting data analysis of leases that have produced from the Reagan zone, production data was imported to perform history matching until an acceptable match was achieved. Utilizing this new approach, forecasting case was ran from 2022 to 2040 future production predictions and resulted with a cumulative oil production of 8,674,110 bbl. Later, waterflooding was implemented for 10 injectors and 30 producers and was set to produces from 2022 to 2040 and resulting in a cumulative oil production of 8,849,110 bbl. This resulted in a difference of 175000 bbl from Forecasting case, which is about 2% increase. Lastly, an economic analysis was conducted to assess the viability of waterflooding in the Otis-Albert field. The analysis showed that the waterflooding is not economically feasible, with a negative undiscounted net cash flow of $-7.835 MM over the 19-year period.
Integrated Subsurface and Fracturing Treatment Analysis for Proppant Placement Enhancement in Tight Clastic Horizontal Well Fracturing
Authors: Asif Adnan , Khan Abdul Muqtadir , Asiri Muhammad , Hassan El-Saied
Published: May 2024

Fracturing treatments in horizontal wells is challenging and the challenges are compounded in reservoirs influenced by high tectonic effects. Situations are faced where either rock breakdown or sufficient fracture propagation is not achieved. Near-wellbore complexities also lead to insufficient injection rate, post-breakdown, to place proppant. In this work, an in-depth diagnosis of factors affecting fracturing success enabled proposing potential solutions.

A total of 106 fracturing stages were analyzed across 14 wells with a structured database created with 52 fracturing-relevant parameters. These included different phases of the well such as drilling and completion, processed openhole logs, perforation details, fracturing treatment parameters, and pressure diagnostics data. A detailed diagnostic study was then conducted to dissect and diagnose the factors that were affecting the successful fracture placement.

The integrated study investigated 11 areas of diagnosis: (1) geology and reservoir characterization, (2) geomechanical aspects, (3) drilling fluid challenges, (4) completion type, (5) topographical analysis of tectonic stress components, (6) rock breakdown pressure, (7) surface pressure limitation related to fluid friction, (8) induced poroelasticity, (9) viscosity-dominated propagation, (10) formation pressure capacity leading to horizontal or T-shaped fractures, and (11) perforation strategy and placement. Multiple correlations were obtained during the diagnostic phase and revealed significant underlying mechanisms. The next phase was the implementation of the solution spectrum with 14 solutions: (1) image logs to understand impact of natural fractures; (2) lamination quantification; (3) textural analysis based on sand counting; (4) drilling fluid and overbalance optimization; (5) breakdown acid; (6) perforation optimization; (7) abrasive perforating and circular notching; (8) mud damage dissolution system (;9) low rate, low friction, viscous pill; (10) linear gel hybrid treatment; (11) channel/pulsed fracturing; (12) high-density fluid; (13) fiber-laden slurry; and (14) fluid-loss additives. An engineered workflow was proposed to be used at the wellsite. The workflow captures all the solutions in context of injection achieved at each step. The solution spectrum allowed enhancing the placement success by 40 to 50%.

This work addresses the biggest challenge in eastern hemisphere in their tight gas clastic reservoirs during exploration and development strategy. The comprehensive subsurface integration with advanced image logs, strategic geosteering, drilling fluid optimization, fracturing techniques, technologies, and chemistry is unique in the industry with significant realized value.
Application of Near Seabed Velocity Modeling Techniques for Shallow Water OBN data
Authors: Li Yifan , Wang Wei , Hu Xin , Ding Chengzhen , Lyu Xiaolin , Gao Jiangtao , Khdhaouria Mourad , Rouis Lamia
Published: May 2024

As is well known, modeling of the near-surface plays a significant role on the subsurface imaging, reservoir characterization, and monitoring. Usually datum static correction is rarely applied in offshore data processing due to stable velocity of the water layer with the assumption of homogeneous layering below the water bottom. However, in some shallow water ocean-bottom node (OBN) data, the complex seabed topography and significant velocity changes near the seabed caused by complex sediments (such as mud volcano) that could affect the subsurface imaging and structural interpretation. This paper proposed a solution to build a near-seabed model using shallow-water OBN data, which can obtain an accurate velocity model near the seabed and achieve significant imaging improvement in Cheleken PSA Area in the southern Caspian Sea.
Combination of Dissolvable Technology with Hydro Sub for Onshore Upper Completion in UAE
Authors: Bangun Antoro Robertus , Al-Rahma Rahma , Raman Abdul , Habib Hamzah
Published: May 2024

The slickline retrievable plug or an intervention-less plug is normally used in onshore upper completion procedures for hydraulic packer setting and pressure test tubing integrity. These are to provide a closed system of the completion string before packer setting and tubing test takes place. This paper approaches the need of advancements in operational safety, efficiency, and effectiveness. The technology focuses on the results providing good lessons learned and analysis of the combination of a dissolvable technology with hydro sub technique to answer the need.

Evaluation of dissolvable technology with a hydro sub, therefore, is an in-depth analysis for its application in real-life situations. The field trial results underline the success of implementation by proving its efficiency and effectively in running, setting and safety of upper completion operation. Insights from this trial will contribute lessons into the challenges and opportunities that are associated with the integration of dissolvable technology and a hydro sub technique.

The technology has been successfully deployed in operations carried out by the Abu Dhabi National Oil Company (ADNOC). This implementation by ADNOC provides an interesting case study into the adaptability and applicability of the dissolvable technology with a hydro sub in the context of the UAE onshore oil and gas sector sites. These positive results confirm the safety and efficacy of the combined approach in a way that it has the potential of revolutionizing onshore upper completion methodologies.

The paper presents empirical contributions to the field and also illuminates the practicality and reliability of technology dissolvable with hydro sub, hence enlightening the greater oil and gas community who are on a lookout for innovative solutions to onshore upper completion challenges.
A Gauss-Newton Inversion Based Automated Approach Towards Efficient Single Well Numerical Reservoir Transient Modeling
Authors: Kumar Arvind , Wydiabhakti Tety Benedicta , Nukala Sai Teja , Lopes Velerian Sanjao
Published: May 2024

Single Well Reservoir Modeling (SWRM) is typically utilized in the early stages of exploration for productivity estimates and optimizing completion strategies. However, its effectiveness is hindered by limited petrophysical and dynamic pressure data from single or a few wells in the block. Various methods have been developed to enhance the reliability of SWRMs for more accurate forecasts. This study presents a new technique for concurrently estimating key reservoir parameters - horizontal and vertical permeability, skin, and boundary distances - and their spatial distribution within the grid cells of a three-dimensional SWRM. The goal is to leverage interpretation results from standard pressure transient analysis of well test data as prior information for this complex inversion problem.

The methodology begins by creating a layer cake geological model based on petrophysical analysis of logging data, adjusted using interpretation results from well test pressure transient analysis. This is followed by systematic flow simulation of field well test operations in the layer cake model to generate model pressure data, which typically differs from acquired well test pressure data. To ensure convergence, a cost function is defined that combines both the well test pressure data and the model pressure data. This cost function relies on reservoir parameters such as horizontal permeability, vertical permeability, skin, and boundary distances, which must be refined for a pressure history match. An inversion approach is introduced to simultaneously refine all these reservoir parameters in an iterative manner to minimize the cost function. Importantly, the inversion methodology is closely regulated by a multiphase fluid flow simulator, which solves implicit black-oil fluid-flow diffusivity equations at each iteration to calculate the error between model pressure and acquired well test pressure. A range of minimum and maximum values for each property is provided to the inversion scheme to ensure a renewed distribution of reservoir parameters at each iteration. These parameters are then used to drive an error scheme guided by the cost function. A Gauss-Newton (GN) inversion method, supported by a regularization technique, facilitates the redistribution of properties across the geomodel grid cells. To improve the accuracy of inversion results, the initial parameters provided to the solver are thoroughly evaluated and, if necessary, adjusted through uncertainty parameter optimization (UPO).

This proposed technique offers a faster and more reliable approach to redistributing reservoir parameters in a homogeneous layer cake geomodel, introducing much-needed heterogeneity. This systematic redistribution not only enhances the reliability and credibility of a geomodel but also establishes a strong foundation for production forecasting strategies.
A New Supervised AI Logging Lithofacies Identification Technique and its Application in K Oilfield in the Middle East
Authors: Wenwen Yu , Xin Chen , Jianxiong Dong , Xiuyan Wang , Fuli An , Bo Wang , Dengyi Xiao , Zichang Tang , Lu Lv , Yuchen Liu , Jiajia Li , Yaliang Xia , Weixiang Zhong
Published: May 2024

Lithology identification is a very important task in reservoir characterization. Through the identification of lithofacies, we can know the state and distribution of oil and gas in the underground reservoir, and provide the basis for oil and gas exploitation and transportation, which is helpful to improve oil recovery and production efficiency.

With the development of oilfield, the exploration and development of lithological oil reservoirs become more and more important, and well log lithofacies identification has gained greater significance in reservoir characterization. Conventional well log lithofacies identification faces challenges, due to limited core data and low-quality log curves such as missing local well log curves, wellbore collapse, and anomalous log responses in fault zones. To improve the accuracy of well log lithofacies identification, a new supervised AI technique for well log lithofacies identification was proposed in this study.

The workflow mainly includes the following 5 steps: 1) Integrated lithofacies identification based on core description, thin section, high-quality well log, FMI, and CMR; 2) AI well log conditioning based on the high-quality well log curve intervals are selected as learning and training samples; 3) Sensitive log curves were chosen and cutoff were determined based on core-based lithofacies analysis and cross-plot analysis; 4) Log lithofacies identification for no core intervals based on sensitive well logs deep-learning; 5) Two method for lithofacies identification result QC, one method is using cored wells as a blind test well, the other method is using multiple wells to do comparative analysis.

This supervised AI logging lithofacies identification technique has been successfully applied in the K oil field in the Middle East. Blind cored well validation indicates that supervised AI well logging facies identification results have a high matching accuracy of 97%, enabling high-accurate and efficient well log facies prediction. Multi-well comparisons demonstrate that the well logging facies identification results in consistent with each other, and match with the results of sequence stratigraphic analysis in the study area.
AI-Driven Green Optimization in Well Construction: Carbon Emission Management Through Technical Limit Performance Benchmarking
Authors: Amadi K. W. , Alsaba M. T. , El Achkar J. H. , Elgaddafi R. M
Published: May 2024

Drilling operations generate CO2 emissions from diesel fuel used to power generators and other equipment on drilling rigs as extraction activities create around 10-15% of total energy-related emissions globally, an equivalent of 5 billion tonnes of greenhouse gas emissions. Improving operational efficiency is crucial for reducing overall emissions and combating climate change. Therefore, recognizing more efficient approaches and solutions with reduced carbon footprints is essential in creating future business continuity. This paper presents the application of machine learning optimization techniques in carbon emission management through technical limit performance benchmark. A Machine Learning (ML) model utilizing basic drilling parameters such as weight on bit (WOB), rotary speed (RPM), penetration rate (ROP), and torque (TOR) was used to estimate instantaneous Unconfined Compressive Strength (UCS) within the technical limit of operational performance across the different Lithologies. Supervised learning algorithm with 70:30 data splits using four ML algorithms, including Random Forest, support vector regression, artificial neural network (ANN), and Categories boost, was utilized in the prediction. The estimation was then leveraged to determine the maximum achievable penetration rate baseline for various lithologies based on rock drillability. Enabling a comparative assessment between actual drilling performance against an engineered technical limit drill rate performance as well as the expected greenhouse gas emissions (GHG). A case study using a field dataset showed that the models predicted instantaneous UCS based on the low- cost drilling parameters other than using the high-cost well-log and core sample techniques. Prediction accuracy was within the acceptable margin of error with CatBoost and ANN as best predictors, with correlation coefficient (R2 ) values of 0.75 and 0.77, respectively. The defined baseline performance benchmark improved drilling performance by 30-60% with a reduction in CO2 emissions across the project by 20 tCO2e emissions, equivalent to a 50% reduction in carbon emissions. The result of this research is essential for the continuous improvement in drilling carbon emission, performance monitoring, and improvement of overall drilling performance.
Unveiling the Dynamics of Proppant Migration in Fractures Through Numerical Simulation
Authors: Xiang Xiaolong , Han Guoqing , Ma He , Liang Xingyuan , Wu Qingxia
Published: May 2024

The migration of proppant within fractures directly affects the distribution pattern of the proppant, which is closely related to the effectiveness of hydraulic fracturing operations. This paper unveils the dynamics of proppant migration in fractures through numerical simulations and control variable method. The fundamental theoretical model shows the basis of simulation, and the Euler-Euler method is employed as the fundamental numerical calculation technique. The CFD software Fluent is chosen as the numerical simulation tool, and the three-dimensional modeling module is used to construct a fracture model. The turbulent model within Fluent is used, with defined computational methods and parameter settings, including construction parameters and fracturing fluid coefficients, which form the foundation of the entire flow simulation. Comparative experiments are conducted using the controlled variable method to observe the simulated results of experimental groups and study the morphological changes of the sand bed formed by the proppant particles after adjusting the variable parameters. The correlation between proppant particle migration and key factors, including injection plans and fracturing fluid parameters, is comprehensively examined, analyzed, and summarized. These findings unveil migration patterns of proppant particles within fractures, shedding light on the dynamics of proppant migration in fractures.
Geomechanics-Aided Successful Execution of a Challenging Build-Up Section Through Mixed Lithologies
Authors: Saber Rayan , Qahtani Faisal , Baghdai Ahmed , Sen Souvik , Chakrabarti Prajit
Published: May 2024

This study presents an example of geomechanics-aided successful delivery of a challenging 4100 ft long build-up section through mixed lithologies, towards minimum horizontal stress direction. The primary challenge in the build-up sections of the studied offshore exploration field in the Middle East was the mechanical instabilities of the weak shales which contributed to extensive tighthole, pack-off, backreaming, and therefore significant non-productive times. Other associated challenges were the differential sticking tendencies in the porous sandstone layers, and partial to total loss risks within the carbonates. The optimization roadmap comprised adequate mud weight design by geomechanical modeling in the planning phase, and real-time geomechanics advisory in the execution phase. The in-depth analyses of offset wells provided critical insights regarding the commonly occurring and potential drilling hazards across various formations. The post-drill geomechanical modeling and wellbore stability analysis of offset wells, calibrated with drilling events-based observations provided a clear understanding of the collapse pressure behavior of various formations. Based on the geomechanical modeling, a safe mud weight window as well as the minimum required mud weight were recommended to tackle mechanical instabilities. Real-time monitoring of the LWD data, aided by right-time geomechanical advisory support ensured successful well delivery. The drilling and the final BHA pull-out were completed without any mechanical instability issues which annulled the requirement of consecutive reaming trips, saving additional rig days. Successful completion of the challenging build-up section parallel to the Shmin azimuth registered zero NPT with notably improved drilling performance.
Review of Remedial Cementing: Techniques, Innovations, and Practical Insights
Authors: Shokry Amir , Mahmoud Ahmed Abdulhamid , Elkatatny Salaheldin
Published: May 2024

Effective cementing plays a pivotal role in ensuring the integrity of oil and gas wells, providing mechanical support, fluid containment, and environmental protection. This paper presents guidelines for conducting wellbore cementing remediation processes effectively, emphasizing longevity while minimizing environmental impact and safeguarding groundwater. The discussion encompasses factors influencing successful remedial cementing, including cement slurry properties, pumping methods, and squeeze equipment. Common techniques such as squeeze cementing and perforation/plug back operations are examined in detail, highlighting their challenges, considerations, and cost implications. Moreover, technological advancements such as polymer gels, silica gels, and self-healing cements are explored for their potential in addressing persistent challenges in sustaining casing pressure and ensuring cement sheath integrity. Through a comprehensive examination of remedial cementing practices and innovations, this paper offers valuable insights for industry professionals striving to optimize well integrity and operational efficiency while mitigating risks and ensuring environmental responsibility.
Fishing Job Optimization: Accelerating & Increasing of Successful Fishing Job Through Digitalization PHR Fishing Complexity Calculator
Authors: Proboseno N. G. , Sangka N. B. , Benigno A. Y. , Fadilah H. , Kurniawan J. , Bastian M. , Hutama A. F. , Kesnawaty D. A.
Published: May 2024

Fishing operations are complex and time-consuming. This is due to the associated uncertainty with the orientation and condition of the tool that requires fishing. Fishing usually is needed when least expected and brings a sudden halt to operations, especially if the downhole tools become stuck. Reaction planning begins at this time unless the project was planned properly from the outset. That reaction planning is not good is not the question. What is important is to establish the facts. What should be done to free the stuck? What will the cost be? This paper addresses these questions. It also emphasizes the importance of routine, continuous, but often unrewarded, effort by operation personnel.

An innovative approach to evaluate success ratio for retrieving a fish, not only using risk factors in the decision-making but also economical view is called PHR Fishing Complexity Calculator. Decision-making processes involved in recovering the fish when the downhole tools are stuck. The goal is to provide a usable wellbore at the lowest ultimate cost. Nowadays, the world is working in industrial revolution 4.0, where all are about digital transformation, increase the automation, artificial intelligence, and more simple work process. To keep the existences and explore the optimization in Industrial revolution 4.0, Oil and Gas Industry must be adapted and accelerated day to day operational in line with the advances of technology. Drilling & Well Intervention as an essential part of puzzles in Oil and Gas Industry which responsible not only to maintain the health of the wells but also make a guarantee the longevity of wells performance. The objective of this paper is to show the digitalization and simple workflow using PHR Fishing Complexity Calculator can maximize both quality and delivery time of fishing job "as simple as in your hand".

As a result, the success of fishing job can be increased from 39% to 71%. Approximately five wells can be converted into production and fish in holes can be retrieved. The success of those fishing jobs not only increases the satisfaction of fishing job but also increases production up to 153 Bopd and 2.9 mmscfd.

Moreover, the Drilling & Well Intervention Manager often is forced by an extended fishing operation to choose between the known costs incurred with abandonment of retrieval attempts and the unknown costs of continuing fishing operations. The successful manager makes the decision that costs the company the least money. Continuing fishing operations beyond some economic limit is a failure, even if the fish is retrieved and that portion of the hole saved, because more money has been spent in the fishing attempt than would have been spent by not fishing. The strategy is to minimize losses.
Simulating Horizontal Well Matrix Acidizing and Contrasting the Outcomes with Actual Data from Coiled Tubing PLT and DTS
Authors: Elhadidy Ahmed Ayman , Thabet Samuel Adel , Bereak Ahmed Said , Hanu Wael Mouhamed , ElAzhary Ahmed Adham , ElKaragi Alaa Osama
Published: May 2024

Carbonate reservoirs have different approaches to acid stimulation techniques. In order to achieve the most effective results, it varies by utilizing different diverters, acid systems, and pumping types. Even after improving the coiled tubing placement and numerical model predictions, it was previously challenging to determine where the injected fluids actually went during a stimulation job; therefore, the outcomes were frequently ineffective.

This scientific paper aims to investigate and contrast the Kinetix Matrix simulation software results of horizontal well matrix acidizing with actual data obtained from coiled tubing production logging and distributed temperature sensing techniques. The comparison with real-time data helps validate the accuracy of the simulations and provides valuable insights into the field application of this acid stimulation technique.
Beyond Traditional Ultra-Deep Resistivity: Advanced Applications Enable Comprehensive Reservoir Understanding
Authors: Fouda M. , Bikchandaev E. , Taher A. , Maimani A. Al , Al-Zawad A.
Published: May 2024

Ultra-deep ElectroMagnetic (EM) inversion is used to resolve multiple layers at a distance from the wellbore. Since it primarily responds to resistivity variations, it has been used for mapping formation boundaries and fluid away from the wellbore, such information has been key for improved well placement decisions and mapping the reservoir boundaries and areal extent. Enhancements in LWD Ultra-deep technologies and processing techniques including reservoir visualization in three dimensions, and inversion for anisotropy provide new applications for these technologies. As more advanced uses are developed it is important to shed some light on the integration of some of these unique cases.

Real-time transmission of nine ultra-deep resistivity components allows 3D inversion for both resistivity and anisotropy far away from the wellbore. Inversion for resistivity and anisotropy in three dimensions provides a solution for multiple reservoir challenges such as azimuthal well placement as well as lithology identification at a distance, differentiating different lithologies that have similar resistivity responses. Faults showing resistivity contrasts can also be mapped at distance from the wellbore. Inverting for the 3D volume using a smaller scale cell size has enabled resolving thin layers in real time. Finally, the integration of near and far field resistivity and 3D has improved far field petrophysical understanding in carbonates and clastic reservoirs.

Ultra-Deep Resistivity has been used in real-time to identify fluid and lithology at distance, this is critical to understand the proximity to fluid contacts or the presence of fluid barriers, such information is key for well placement decisions and completion design. Enhanced processing techniques has enabled resolving thin beds down to 1-2 ft thickness using Ultra-deep Resistivity 3D Inversion which compliments the visualization away from the wellbore and improves real-time decisions. Faults mapped at a distance provided an understanding to water encroachment behavior in carbonate reservoirs. It has also provided key information along with 1D and 3D for far field petrophysics, utilizing offset data and the information provided by the Ultra-deep resistivity inversion. This Paper covers all the challenges that deep and Ultra-deep Resistivity can cover from optimizing the well placement to formation evaluation in the far field.
Molecular Dynamics Simulation Insights into CO2 Wettability of Low-Maturity Shales Organic Matters Under Various Reservoir Conditions
Authors: Cheng Kai , Peng Bo , Arif Muhammad , Zhang Yupeng , Wang Shushuai , Shang Leiwang
Published: May 2024

Geological CO2 sequestration (GCS) stands as a principal global strategy to mitigate greenhouse gas emissions and address climate change. Injecting CO2 into shale not only reduces carbon emissions but also enhances oil recovery. Rock wettability significantly determines CO2 trapping efficiency. Shale consists both hydrophilic inorganic and organic matter like kerogen. Although traditionally viewed as hydrophobic, kerogen has been underscored in recent studies for its potential weak water-wettability. Consequently, understanding this behavior is crucial for GCS.

Utilizing molecular dynamics simulations, we selected the quintessential kerogen type-Ⅰ A from low-maturity shale organic matter. Initially, we constructed a shale organic matter plate model via high-temperature annealing and subsequently amalgamated it with water and CO2, establishing a foundational model for wettability studies. Subsequently, we determined the contact angle of the kerogen plate with air. Then, based on NIST's relationships among density, temperature, and pressure from NIST handbooks, we adjusted the quantity of CO2 to mirror actual reservoir conditions. Ultimately, we assessed the contact angle between CO2 and low-maturity shale within a temperature range of 298.15k-358.15k and pressures of 5-65MPa.

The study reveals that low maturity kerogen in shale organic matter is predominantly weakly water-wet. Under reservoir conditions, variations in temperature and pressure significantly influence the wettability of shale organic matter. Specifically, at a constant pressure, an increase in temperature results in a decreased contact angle, whereas at a consistent temperature, an elevated pressure leads to an increased contact angle. Consequently, the wettability of shale organic matter transitions from being weakly water-wet to predominantly CO2-wet. Enhanced accumulation of CO2 molecules at the H2O-kerogen interface and the emergence of apparent CO2 films indicate that kerogen exhibits substantial CO2 adsorption. Low maturity shale organic matter is thus conducive to the capillary trapping of CO2, facilitating its geological sequestration.

In this study, a low-maturity shale organic matter model was established using molecular dynamics simulation to investigate the effect of CO2 on the wettability of shale organic matter. By examining the water contact angle in various reservoir conditions saturated with CO2, we addressed challenges in assessing shale wettability in such environments. Furthermore, we discerned that low-maturity kerogen exhibits enhanced CO2 capture capability, underscoring its significance in geological carbon sequestration.