bluuebunny/crossref_metadata_2025 huggingface dataset:
Gabapentin-Induced Adrenal Insufficiency: The HPA Axis—Stress Misresponse and Risk of Infection
Authors: Pechlivanidou Evmorfia , Chatzikyriakos Alexandros , Zisi Maria Anna , Paraskevopoulos Nikolaos , Kaltsa Semeli , Constantas Orestis , Zogakis Panteleimon , Catsouli Aikaterini , Sekouris Nick , Margariti Rodanthi
Published: August 2024

Background/Objectives: This literature review, on occasion of the reported case report, explores the complex interplay between gabapentin (GBP), a gamma-aminobutyric acid (GABA) analog, and the hypothalamic-pituitary-adrenal (HPA) axis in patients undergoing major surgical procedures. It specifically investigates the potential impact of GBP on cortisol levels, stress responses, and infection risk, illustrated by a detailed clinical case. Methods: This review combines a comprehensive literature search with a case report of a 17-year-old male with osteosarcoma who experienced transient adrenal insufficiency and infections while receiving GBP. The case is analyzed in the context of existing literature on GBP and the HPA axis. Results: The findings highlight the intricate relationship between GBP use, adrenal insufficiency, and infection susceptibility. It underscores the need for further research and clinical vigilance when prescribing GBP to patients with underlying medical conditions, particularly in the context of major surgical procedures. The review underscores the need for further research and clinical vigilance when prescribing GBP, particularly in perioperative settings. Conclusions: GBP’s effects on the HPA axis and immune responses are complex and multifaceted. Clinicians should exercise caution when prescribing GBP, especially for patients with underlying conditions undergoing major surgery. Further research is needed to elucidate the mechanisms of GBP's influence on cortisol levels and stress responses.
Autocatalytic Sets And Assembly Theory: A Toy Model Perspective
Authors: Raubitzek Sebastian , Schatten Alexander , König Philip , Marica Edina , Eresheim Sebastian , Mallinger Kevin
Published: August 2024

Assembly theory provides a promising framework to explain the complexity of systems such as molecular structures and the origins of life, with broad applicability across various disciplines. In this study, we explore and consolidate different aspects of assembly theory by introducing a simplified toy model to simulate the autocatalytic formation of complex structures. This model abstracts the molecular formation process, focusing on the probabilistic control of catalysis rather than the intricate interactions found in organic chemistry. We establish a connection between probabilistic catalysis events and key principles of assembly theory, particularly the probability of a possible construction path in the formation of a complex object, and examine how the assembly of complex objects is impacted by the presence of autocatalysis. Our findings suggest that autocatalysis tends to favor longer consecutive construction sequences in environments with low catalysis probability, while this bias diminishes in environments with higher catalysis probabilities, highlighting the significant influence of environmental factors on the assembly of complex structures.
Tightness of Harary Graphs
Authors: Javan Abolfazl , Moeini Ali , Shekaramiz Mohammad
Published: August 2024

In the design of real-world networks, researchers evaluate various structural parameters to assess vulnerability, including connectivity, toughness, and tenacity. Recently, the tightness metric has emerged as a potentially superior vulnerability measure, although many related theorems remain unknown due to its novelty. Harary graphs, known for their maximum connectivity, are an important class of graph models for network design. Prior work has evaluated the vulnerability of three types of Harary graphs using different parameters, but the tightness metric has not been thoroughly explored. This article aims to calculate the tightness values for all three types of Harary graphs. First, it will attempt to calculate the lower bound for the value of the tightness parameter in Harary graphs using existing lemmas and theorems. Then, by presenting new lemmas and theorems, we will try to find the exact value or upper bound for this parameter in Harary graphs. For the first type of Harary graph, the tightness is precisely determined, while for the second and third types, upper bounds are provided due to structural complexity. The lemmas, theorems, and proof methods presented in this research may be used to calculate other graph and network parameters. However, the newness of the tightness parameter means that further research is needed to fully characterize its properties.
Biocompatibility Study of Purified and Low-Temperature Sterilized Injectable Collagen for Soft Tissue Repair: Intramuscular Implantation in Rats
Authors: Koo Tae-Hoon , Lee Jason K , Grogan Shawn P , Ra Ho Jong , D'Lima Darryl D
Published: August 2024

The clinical application of collagen-based biomaterials is expanding rapidly, especially in tissue engineering and cosmetics. While oral supplements and injectable skin boosters are popular for enhancing skin health, clinical evidence supporting their effectiveness remains limited. Injectable products show potential in revitalizing skin, but safety concerns persist due to challenges in sterilization and the risk of biological contamination. Traditional methods of sterilization (heat and irradiation) can denature collagen. This study addresses these issues by introducing a novel technique: double filtration and low-temperature steam sterilization of a collagen gel. In vitro tests document sterility and confirm that the collagen structure remained intact without modification. An in vivo study found no adverse effects in rats or significant lesions at the implantation site over 13 weeks. These results suggest that this novel method to process collagen gels is a safe and effective skin booster. Advanced processing methods are likely to mitigate safety risks associated with injectable collagen products, though further research is needed to validate their biological effectiveness and clinical benefits.
Antioxidant and Antibacterial Activities of Selected Medicinal Plants from Addis Ababa against MDR-Uropathogenic Bacteria
Authors: Eyasu Mebrahtu , Benedí Juana , Romero José Antonio , Martín-Aragón Sagrario
Published: August 2024

Potentially, traditional medicine is used to manage multidrug resistance (MDR) bacterial infections. This study determined the antioxidant and antibacterial activities of Thymus schimperi (Ts), Rhamnus prinoides (Rp) and Justicia schimperiana (Js) from Addis Ababa against MDR-Uropathogenic Bacteria. Hydromethanolic extracts were prepared. Quantitative determination of phytochemicals and DPPH, ABTS and FRAP assays for antioxidant activities were carried out. In vitro, antibacterial activity and minimum inhibitory concentration (MIC) were performed. Ts had the highest total phenolic (TPC), flavonoid (TFC) and proanthocyanidin content. GC-MS analyses identified 14 bioactive-compounds: in Ts extract, with hexanedioic acid, bis(2-ethylhexyl) ester, thymol, and o-cymen-5-ol being the most predominant, respectively; in Rp extract (6 compounds; hexanedioic acid, bis(2-ethylhexyl) ester, β-D-glucopyranoside, methyl and desulphosinigrin respectively); and in Js extract (5 bioactive-compounds: hexanedioic acid, mono (2-ethylhexyl) ester, debrisoquine, and 8,11,14-heptadecatrienoate, methyl ester) being predominant, respectively. The extracts' TPC showed a strong negative correlation with the DPPH assay (r= -0.999; p=0.023), while its TFC correlated significantly with the ABTS assay (r=0.999; p= 0.032). Ts showed the highest antibacterial activity against clinical isolates of Escherichia coli and Klebsiella pneumoniae ESBL at 1000 mg/mL, and TS had the lowest MIC (4 mg/mL) among evaluated extracts against E. coli (ATCC25922). In conclusion, Ts and Rp showed activity against patient-isolated MDR-uropathogenic E. coli and K. pneumoniae ESBL.
Comparative Analysis of Dietary Habits and Obesity Prediction: Body Mass Index versus Body Fat Percentage Classification using Bioelectrical Impedance Analysis
Authors: Pescari Denisa , Mihuta Monica Simina , Bena Andreea , Stoian Dana
Published: August 2024

Background: Obesity remains a widely debated issue, often criticized for the limitations in its identification and classification. This study aims to compare two distinct systems for classifying obesity: Body Mass Index (BMI) and body fat percentage (BFP) as assessed by bioelectrical impedance analysis (BIA). By examining these measures, the study seeks to clarify how different metrics of body composition influence the identification of obesity-related risk factors. Methods: The study enrolled 1255 adults, comprising 471 males and 784 females, with a mean age of 36 ± 11.90 years. Participants exhibited varying degrees of weight status, including optimal weight, overweight, and obesity. Body composition analysis was conducted using the TANITA Body Composition Analyzer BC-418 MA III device (T5896, Tokyo, Japan), evaluating the following parameters: current weight, basal metabolic rate (BMR), adipose tissue (%), muscle mass (%), and hydration status (%). Results: Age and psychological factors like cravings, fatigue, stress, and compulsive eating were significant predictors of obesity in the BMI model but not in the BFP model. Additionally, having a family history of diabetes was protective in the BMI model (OR: 0.33) but increased risk in the BFP model (OR: 1.66). The BMI model demonstrates exceptional predictive ability (AUC=0.998). In contrast, the BFP model, while still performing well, exhibits a lower AUC (0.975), indicating slightly reduced discriminative power compared to the BMI model. Conclusions:BMI classification demonstrates superior predictive accuracy, specificity, and sensitivity. This suggests that BMI remains a more reliable measure for identifying obesity-related risk factors compared to the BFP model.
Diversity and Anti-infectious Components of Cultivable Rhizosphere Fungi Derived from Three Species of Astragalus Plants in Northwestern Yunnan, China
Authors: Zhou Guo-Jun , Xiong Wei-Jia , Xu Wei , Dou Zheng-Rong , Liu Bo-Chao , Li Xue-Li , Du Hao , Li Hai-Feng , Zhang Yong-Zeng , Jiang Bei , Wang Kai-Ling
Published: August 2024

Astragalus plants belong to the legume family and have obvious rhizosphere effect. The northwestern area of Yunnan China is the main distribution region of Astragalus plants with high application value, but low recognition and resource reserves. The aim of this research is to explore the species diversity of cultivable rhizosphere fungi derived from A. acaulis, A. forrestii, and A. ernestii growing in special high-cold environment of northwest Yunnan, and discover anti-infective components from these fungi. A total of 93 fungal strains belonging to 38 species in 18 genera were isolated and identified. Antibacterial and antimalarial screening yielded 10 target strains. Among them, the ethyl acetate crude extract of the fungus Aspergillus calidoustus AA12 from A. acaulis fermentation substance showed a broad antibacterial spectrum and the best antimalarial activity. Further chemical investigation led to the first discovery of seven compounds from the species of A. calidoustus, including a sesterterpine 6-epi-ophiobolin G (1), two sesquiterpenes penicisochroman A (2), pergillin (3) and 7-methyl-2-(1-methylethylethlidene)-furo[3,2-H]isoquinoline-3-one (4), and three polyketides trypacidin (5), 1,2-seco-trypacidin (6) and questin (7). Compound 1 exhibited moderate to strong antibacterial activity against six Gram-positive pathogens with the minimum inhibitory concentration (MIC) ranging from 25 to 6.25 μg/mL, and prominent inhibitory effect on the biofilm of Streptococcus agalactiae at MIC value of 3.125 μg/mL. This compound also displayed potent antimalarial activity against Plasmodium falciparum strains 3D7 and chloroquine-resistant Dd2 at the half maximal inhibitory concentration (IC50) values of 3.319 and 4.340 µmol/L at 72 h, respectively. This study contributed to our understanding of the cultivable rhizosphere fungi Astragalus-derived in special high-cold environment and further increased the library of fungi available for natural anti-infectious products screening.
Application of ALRW‐DDPG Algorithm on Offshore Oil‐Gas‐Water Separation Control
Authors: He Xiaoyong , Pang Han , Liu Boying , Chen Yuqing
Published: August 2024

With the offshore oil-gas fields entering decline phase, high-efficiency separation of oil-gas-water mixtures becomes a significant challenge. As essential equipment for separation, the three-phase separators play a key role in Offshore Oil-Gas production. However, level control is critical in the operation of three-phase gravity separators on offshore facilities, as it directly affects the efficacy and safety of the separation process. This paper introduces an advanced deep deterministic policy gradient with adaptive learning rate weights (ALRW-DDPG) control algorithm, which improves the convergence and stability of the conventional DDPG algorithm. An adaptive learning rate weight function is meticulously designed, and an ALRW-DDPG algorithm network is constructed for simulating three-phase separator liquid level control. The effectiveness of the ALRW-DDPG algorithm is subsequently validated through simulation experiments. The results show that the ALRW-DDPG algorithm achieves a 15.38% improvement in convergence rate compared to the traditional DDPG algorithm, and the control error is significantly smaller than that of PID and DDPG algorithms.
A Paradigm Shift in Islamic Finance Industry: Value Based Intermediation, Human Development, Ecological Footprint, and Social Impact Financing
Authors: Fahad Shah , Bulut Mehmet
Published: August 2024

This study presents a comprehensive examination of the transformative potential of Islamic finance in advancing sustainable development goals (SDGs). It underscores the unique position of Islamic finance, with its ethical and moral foundations, to contribute significantly to environmental sustainability, social equity, and economic development. The paper highlights innovative financial instruments like Zakat, Waqf, and green Sukuk, which not only align with but also actively promote SDGs. Through a multidisciplinary approach, it advocates for a paradigm shift towards integrating sustainability into the core of financial systems. The analysis includes challenges in harmonizing Human Development Indexes (HDIs) with Ecological Footprints (EFs), proposing strategies for sustainable development, ecological conservation, and educational reforms. This study is pivotal for policymakers, financial institutions, and educators, providing a roadmap for leveraging Islamic finance towards achieving a balanced, sustainable, and inclusive global economy.
Sulfides, Sulfosalts and Sulfates in the Epithermal Au-Ag-Te Emmy Deposit (Khabarovsk Territory), Far East, Russia: Implications for the Mineralization Process
Authors: Yakich Tamara Yu. , Voudouris Panagiotis , Levochskaia Darya V. , Mazurov Alexey K. , Shaldybin Michail V. , Lopushnyak Yuriy M. , Ruban Alexey S. , Erofeev Alexey E. , Minakov Mikhail S. , Maximov Prokopiy N. , Sinkina Ekaterina A. , Bestemianova Ksenia V. , Rudmin Maxim A.
Published: August 2024

This study considers the features of the chemical composition, internal structure, and oscillatory zoning of sulfides, sulfosalts and sulfates in the epithermal high-intermediate sulfidation type Au-Ag-Te Emmy deposit (Khabarovsk Territory), Russia. In this deposit the most widespread sulfide is pyrite occurring in two generations: pre-ore pure pyrite (I) with cubic crystal habit and dimensions from 20 μm to 0.5 mm from the early barren pre-ore hydrothermal stage, and pyrite (II) of the ore stage, which is represented by (a) colloform aggregates (IIa) formed as a result of rapid precipitation from the solution, and (b) crystalline pyrite (IIb), which is precipitated due to continuous decrease in temperature. Both pyrite (II) morphological varieties contain copper (0.06-6.03 wt.%). The crystalline variety of pyrite is associated with goldfieldite, hemusite and kawazulite which were deposited during the early mineralizing event in the deposit.
A Comparison of PROMIS Scores of Metatarsophalangeal Joint Arthrodesis and Polyvinyl Alcohol Hydrogel Implant Hemiarthroplasty for Hallux Rigidus
Authors: El Masry Seif , Boden Allison L. , DiGiovanni Grace M. , Cororaton Agnes D. , Ellis Scott J. ,   on behalf of the HSS Orthopaedic Foot and Ankle Surgery Group
Published: August 2024

Background:

The current literature shows similar clinical outcomes between first metatarsophalangeal (MTP) joint arthrodesis and synthetic cartilage implant (SCI) hemiarthroplasty in the treatment of hallux rigidus; however, prior studies have not reported validated patient-reported outcome measures (PROMs). To our knowledge, this is the first study to compare PROMs using 6 domains of the validated Patient-Reported Outcomes Measurement Information System (PROMIS) in patients treated for hallux rigidus with MTP joint arthrodesis and with SCI hemiarthroplasty. In addition, this novel study provides comparative data on the complication and revision rates for each procedure.

Methods:

A single-center, retrospective registry search identified all patients with preoperative PROMIS scores who underwent MTP joint arthrodesis or SCI hemiarthroplasty for hallux rigidus between February 2016 and June 2021. The study aimed to determine if the 2 procedures showed statistically or clinically equivalent PROMIS scores in 6 domains: physical function, pain interference, pain intensity, global physical health, global mental health, and depression. A multivariable linear regression analysis was performed to compare adjusted 1-year postoperative PROMIS scores between the 2 cohorts. Complication and revision rates were also compared.

Results:

The study included 82 patients who underwent SCI hemiarthroplasty and 101 who underwent MTP joint arthrodesis. Demographic data and preoperative hallux rigidus severity showed no significant differences between the cohorts. PROMIS scores were mostly comparable between the 2 groups, except for the pain intensity domain. The patients who underwent MTP joint arthrodesis exhibited significantly better pain relief at 1 and 2 years postoperatively, which was supported by adjusted postoperative PROMIS scores. At 2 years, the SCI group had worse pain intensity scores and lower global physical health scores. There were no differences between the cohorts in additional PROMIS scores or complication data.

Conclusions:

While outcomes in most of the domains were similar, MTP joint arthrodesis was more effective at mitigating pain intensity compared with SCI hemiarthroplasty. This information can guide patient counseling and decision-making when considering surgical intervention for hallux rigidus.

Level of Evidence:

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.
Studying the Effect of Temperature on the Electrical Properties of Poly (methyl methacrylate) Doped with Lithium chloride
Authors: Rasheed Laith M. , Sabbar Ali N.
Published: August 2024

تهدف هذه المقالة الى تحليل الخصائص الكهربائية لمادة ال بولي مثيل ميثا اكريلات (PMMA) المشوبة بكلوريد الليثيوم (LiCl). بسبب توصيليتها الكهربائية الرديئة تستخدم المواد البوليمرية بصورة شائعة كعوازل. يعتبر بولي مثيل ميثا اكرالايت من البوليمرات التي كثر استخدامها في التطبيقات الكهربائية والعازلة وذلك بسب امتلاكها خواص كهربائية وعازليه وبصرية متميزة وخاصة بعد تشوبها ببعض المواد. في هذه الدراسة، تم تشويب البوليمر PMMA بنسبة وزنية 0.2% من كلوريد الليثيوم (LiCl). تم تحضير عينات بشكل اغشية رقيقة باستخدام طريقة الصب في الظروف الاعتيادية للمختبر، ثم معالجة العينات حراريا ولمدى من درجات الحرارة. تم قياس كل من مقاومة التوازي وسعة التوازي والمانعة الكلية بالإضافة الى قياس ثابت العزل بجزيئة الحقيقي والخيالي ومقارنتها بخواص البوليمر النقي. تم استخدام  دائرة تحميلية عند ترددات واطئة حيث تم تضمين العينات البوليمرية المعالجة حراريا بدائرة حمل RCL مربوطة على التوازي. اضهرت النتائج تغيراً في هذه البارامترات وخاصة في خزن الشحنات في درجات حرارة معينة وبالتالي زيادة في تحسين خواصها الكهربائية مما يؤهلها  في استخدامها في كثير من الأجهزة الإلكترونية ضمن نطاق درجات الحرارة المستخدمة.
Biosynthesis of silver nanoparticles by extracellular metabolites of marine Kocuria flava and investigated its role in enhancing of antibacterial activity of ciprofloxacin
Authors: Farhan Fadhil Jabbar , Shareef Ali Aboud
Published: August 2024

تهدف الدراسة الحالية إلى تصنيع دقائق الفضة النانوية (AgNPs) حيوياً باستخدام الأيوض الخارج خلوية للبكتيريا البحرية Kocuria flava (F57)، وأستخدامها لتعزيز فعّالية المضاد الحيوي السيبروفلوكساسين تجاه البكتيريا المرضية ذات المقاومة المتعددة للمضادات الحيوية (MDR). جُمعت عينّات المياه البحرية من المياه البحرية العراقية خلال شهر كانون الثاني/2022. تم تشخيص العزلةF57  من خلال الصفات المجهرية، وبعض الاختبارات الكيموحيوية، والتشخيص الجزيئي بتضخيم الجين 16S rDNA، وظهر من خلال رصف تسلسلات القواعد النايتروجينية للجين 16S rDNA مع تلك العائدة للسلالات المسجّلة في بنك الجينات NCBI، وشجرة النشوء والتطور، وجود تطابق نسبته 99.93% مع السلالة K. flava AUMC B-459. أظهرت نتائج قياس الطيف الكتلي GC/MS لمستخلص العزلة F57 وجود ثلاثين مركباً. أُستخدمت الأيوض الخارج خلوية للعزلة F57 لتصنيع دقائق الفضة النانوية، وتم التأكد من نجاح عملية تصنيع الحيوي عن طريق التحليل الطيفي للضوء المرئي- الأشعة فوق البنفسجية وطيف الأشعة تحت الحمراء وحيود الأشعة السينية والمجهر الإلكتروني الماسح وطاقة تشتت طاقة الأشعة السينية. أظهرت دقائق الفضة النانوية فعّالية تجاه خمس عزلات من البكتيريا المرضية ذات المقاومة المتعددة للمضادات الحيوية وهي كلٌ من:Klebsiella pneumoniae ، Pseudomonas aeruginosa ، Staphylococcus haemolyticus ، وعزلتان من البكتيريا Escherichia coli (1&2)، تم تحديد التركيز المثبّط الأدنى لدقائق الفضة النانوية والمضاد الحيوي Ciprofloxacin ومزيجهما معاً ضد العزلات البكتيرية المرضية أعلاه، وكانت العزلة P. aeruginosa هي الأكثر حساسية لدقائق الفضة النانوية، إذ كان التركيز المثبطّ الأدنى تجاهها 7.81 مايكروغرام/مل، وكانت جميع العزلات البكتيّرية المرضية مقاومة للمضاد الحيوي Ciprofloxacin، وأظهرت نتائج مزج المضاد الحيوي Ciprofloxacin مع دقائق الفضة النانوية وجود تأثير تآزري تجاه العزلات المرضية P. aeruginosa و S. haemolyticus وE. coli (2) ، وأصبحت العزلتين E. coli (1&2) حساسة لهذا المضاد الحيوي بعد عملية المزج. لذا فإن دقائق الفضة النانوية المخلّقة حيوياً بإستخدام الأيوض الخارج خلوية للبكتيريا البحرية K. flava (F57) ذات خصائص مضادة للبكتيريا المرضية، وقد أسهمت في تعزيز فعّالية المضاد الحيوي Ciprofloxacin.
Treatment of Contaminated Soil with NORM of Oilfields by Chemical Extraction Method
Authors: Ibrahim Zaidoon H. , Al-Mashhadani Asia H.
Published: August 2024

يعد تلوث التربة بالمواد المشعة التي تحدث بشكل طبيعي (NORM) مشكلة شائعة في حقول النفط مما يؤدي إلى برامج مكلفة للمعالجة والتخلص النهائي (الطمر), حيث ان أهم النويدات المشعة في هي 226Ra  و228Ra  . تركز هذه الدراسة على معالجة التربة الملوثة  ب NORM لتقليل النشاط الاشعاعي ضمن الحدود المسموح بها والذي ينعكس على تقليل مخاطر الإشعاع على العمال والجمهور والبيئة. تناولت الدراسة المعالجة الكيميائية لعينتين من التربة عن طريق اختبار الترشيح باستخدام التنقنيات المنفردة والمتتابعة بمذيبات كيميائية مخففة عضوية وغير عضوية (مثل HNO3 وHCl وC₆H₈O₇ وC2H4O2 وEDTA وH2SO4 )، حيث تم قياس تراكيز النشاط الأولي لـ 226Ra  و228Ra  باستخدام محلل مطيافية كاما بكاشف الجرمانيوم عالي النقاوة (HPGe) ، حيث كانت 59674.7 ± 2731.2 و 7058.2 ± 451.07Bq.kg-1 على التوالي للعينة الأولى، في حين كانت 7666.6 ± 615.4 و 826.36 ± 143.4 Bq.kg-1 للعينة الثانية. الاستخلاص المتسلسل انجز في ثلاث خطوات متتالية (تعديل الحامضية وتبادل الأيونات والترشيح بالمذيب النهائي). أن الترشيح المنفرد أعطى نتائج ضعيفة في استخراج نظائر الراديوم من التربة بواسطة المحاليل المخففة, بينما الترشيح المتسلسل كان أفضل ، وجد أن المذيبات الأكثر فعالية هي حمض الأسيتيك (M (C2H4O22 مع نسبة سائل إلى صلب L:S قدرها 5 mL/g عند درجة حرارة  40 ˚C للعينة الأولى، حيث 78.4% و80.6% من 226Ra  و228Ra  تم ازالتها وتحويلها إلى الطور المائي، بينما تمت إزالة 87.9% و91% باستخدام 2M HNO3 للعينة الثانية وبنفس الظروف.
Characterization of Wormhole Growth and Propagation Dynamics during CHOPS Processes by Integrating Rate Transient Analysis and a Pressure-Gradient-Based Sand Failure Criterion in the Presence of Foamy Oil Behavior
Authors: Jiang Liwu , Liu Jinju , Liu Tongjing , Yang Daoyong
Published: August 2024

Characterization of wormhole growth and propagation dynamics has been made possible with the semi-analytical models developed in this work by integrating both rate transient analysis (RTA) and a pressure-gradient-based (PGB) sand failure criterion in the presence of foamy oil behavior. The nonlinearity caused by the foamy oil properties is linearized using pseudofunctions, while the source function and finite difference methods are applied to obtain the solutions for the linearized models in the matrix and wormhole subsystems, respectively. A sequential method is adopted to solve the coupling fluid-solid problem, where new wormhole segments can be generated once the PGB sand failure criterion has been achieved, while their updated petrophysical properties can be sent back to obtain the solutions for the fluid flow in the next time interval. Furthermore, the influence of sand failure/fluidizing and foamy oil properties on the dynamic wormhole network can be investigated with the generated type curves. Both wormhole growth and foamy oil flow dictate an upward fluid production at the early times, while the production-induced pressure depletion dominates the declining production at the late times. The fractal wormhole networks can be dynamically characterized by history matching the field fluid and sand production profiles. Both the sand failure degree and foamy oil properties dictate the effective wormhole coverage and intensity. Sand production is found to be influenced by both the breakdown pressure gradient and wormhole conductivities, while oil production rate can be dominated by the wormhole coverage and intensity. Foamy oil flow can increase the oil production rate and increase the wormhole coverage compared with the conventional oil. The newly developed method in this work has been validated and then applied at field scale to dynamically characterize the wormhole growth and propagation by considering both the sand failure phenomenon and foamy oil properties within a unified, consistent, and accurate framework. Compared to the conventional numerical simulations, the novelty of such a semi-analytical method can not only allow us to characterize the growth and propagation dynamics of the fractal-like wormholes without the need for grid refinement near the wormhole grids but also take the complex sand failure and foamy oil behavior into account. In addition, it can minimize the impact of grid orientation effects in numerical simulations, enabling the growth and propagation of the wormholes in arbitrary directions rather than orthogonal directions conditioned to the largest pressure gradient.
A CO2-Modified Surfactant for Chemical Flooding
Authors: Chen Shaohua , Huang Tianping , Wang Jinxun , AlOtaibi Mohammad B.
Published: August 2024

Carbon dioxide (CO2) modification of a nonionic surfactant alkyl polyglycoside (C-APG) was conducted based on a commercial APG product under mild synthesis conditions, including a low temperature (50°C) and a low pressure (2.5 bar). Using this method, CO2 was incorporated into APG molecules through the formation of carbonyl structures. The effectiveness and performance of C-APG as a novel surfactant for enhanced oil recovery (EOR) application in carbonate reservoirs were investigated and compared with its precursor—the unmodified APG. The key factors in the chemical structure of C-APG were characterized by Fourier transform infrared spectroscopy (FTIR) to confirm successful CO2 modification. The properties, including compatibility, surface tension, wettability alteration, interfacial tension (IFT), phase behavior, and static and dynamic adsorption of both APG and C-APG, were evaluated by various techniques and methods. Crude oil displacement efficiency of the surfactants was investigated via spontaneous imbibition, visualized micromodel, and coreflooding tests, respectively. Both surfactants were compatible with a high-salinity water (HSW), they exhibited a similar critical micelle concentration (CMC) of 8.5 mg/L and 13.5 mg/L for APG and C-APG, respectively, and had the same contact angle of around 135°. Interestingly, C-APG was found more effective in reducing IFT between oil and water phases. The IFT of oil in the C-APG solution was 0.058 ±0.001 mN/m, one order of magnitude lower than the value of 0.47 ±0.02 mN/m obtained from the solution of original APG, suggesting a better performance of C-APG in chemical flooding for oil displacement. A Winsor Type I microemulsion was formed by APG within the salinity range, while a transition of Type I to Type II microemulsion was observed for C-APG. The static adsorption of APG and C-APG at 2 g/L in carbonate were 0.93 mg/g rock and 1.08 mg/g rock, and the adsorption decreased to 0.11 mg/g rock and 0.13 mg/g rock under dynamic conditions for APG and C-APG, respectively. The spontaneous imbibition test demonstrated a higher oil imbibition recovery of 18.0% from C-APG solution compared to the result of 10.2% obtained from APG solution. A micromodel test showed that more crude oil was displaced by injection of APG or C-APG solution after waterflooding, while C-APG injection exhibited a stronger emulsification. The oil displacement by coreflood test showed that C-APG injection led to a lower differential pressure and a higher cumulative oil production (48%) compared to APG chemical flooding with a cumulative oil production of 41%. The produced fluids containing displaced crude oil from C-APG flooding, and subsequent waterflooding demonstrated very strong emulsification compared to the fluids produced after APG injection. This study demonstrates the significant potential of C-APG in two aspects—CO2 reduction and chemical EOR for the upstream petroleum industry.
Sucker Rod Make Up: All About Displacement, or is it?
Authors: Anderson Jordan , Oliva Esteban , Mogus Steve
Published: August 2024

Although sucker rod connections are more understood now than they have been in the past, they are a surprisingly complex part of sucker rod operations, and we continue to learn about them. This study aims to further understand sucker rod connection make up variables, how those variables could affect operational reliability, and how to achieve optimal make up conditions. The variables considered were connections with and without pin lube, various coupling and rod grades, and sucker rod tong capabilities.

This study was performed using connection make up and break out testing and secondarily rod tong diagnostics in the field. The connection make up and break out testing was performed using specialized sucker rod make up equipment that could measure make up and break out torque, as well as circumferential displacement. All the previous measurements were taken in varying connection conditions and combinations. This data was analyzed to understand how these conditions affect make up and back off torque. Concurrently with this testing, sucker rod tong diagnostic operations (torque/hydraulic pressure measurements) were being carried out in the field to understand the torque accuracy and capability of sucker rod tongs.

The connection make up and break out testing revealed that connection make up without pin thread lubrication or with proper pin thread lubrication practices both yield acceptable back off torque values. Secondarily, the back off testing confirmed that there is considerable variation in torque necessary when varying rod grade, but not coupling grade. The sucker rod tong diagnostics revealed that many rod tongs do not reach manufacturer specifications for max torque and many also have considerable torque variation that could result in improper make up.
Understanding and Expanding the 1 Feet Per Second Rule of Thumb for ESP Motor Heat Transfer
Authors: Scariot V. K. , Pereyra E. , Sarica C.
Published: August 2024

Some practitioners in the industry target a local velocity of 1 ft/s to ensure proper ESP motor heat transfer. According to this rule of thumb, if the local velocity is lower than this threshold, the flowing area should be reduced to increase the fluid velocity above 1 ft/s and improve heat transfer. The main limitation of this rule of thumb is that it ignores fluid properties and does not provide guidance when velocities are already above 1 ft/s. This paper covers a simplified approach to consider the effect of fluid properties and the ESP motor geometry by identifying the main contributing factors to the motor temperature rise using a simplified heat transfer model. For high water cut conditions, a 1 ft/s velocity with a 1-in. hydraulic diameter results in a Reynolds number of 8× 103. In other words, for water-dominated flows for which the rule of thumb is usually applicable, the rule of thumb ensures a Reynolds number is in the turbulent region. A better alternative for the 1 ft/s rule of thumb is to use a Reynolds number cutoff value to ensure the flow around the motor is turbulent. This minimizes the skin temperature rise component and accounts for fluid properties. This paper analyzes the applicability of the widely used 1 ft/s rule of thumb and provides an alternative way for preliminary motor design or selection.
Field Testing of a Novel Gas Processing System for Electric Submersible Pumps
Authors: Rhys-Davies J. , Luna David , Myska J
Published: August 2024

A new gas processing system, called an Integrated Gas Processor was developed to improve the gas management of an ESP system. The IGP is a multi-module gas processing system designed to increase gas handling efficiency by combining multiple technologies into a single unit. The IGP contains three modules threaded together to form one monolithic unit installed below the main production pump. The Operator installed IGPs in three wells for field trials. Three key performance indicators were evaluated during the field trials: total uptime, total fluid production, and intake pressure. These parameters were compared to previous operation in the wells. It was observed that total oil production was increased by 34% on average, gas production increased by 15% on average and water increased by 40% on average. Intake pressure was reduced by 23% on average and uptime was increased on average by 10%. It was further noted that the ESP’s had a lower number of shutdowns (decreased by 59%) compared to the previous run. The drawdown of these wells increased due to the installation of the Integrated Gas Processor (IGP) compared to the previously installed systems.
Sour Fluid Partial Pressure and Electric Submersible Pumping System Survivability Pattern
Authors: Kalu-Ulu Torty C.
Published: August 2024

The behavior and survivability of electric submersible pumping systems (ESPs) used for hydrocarbon production vary from one condition to another. Sour environment is generally known to bring about stress cracking of some sort in well completion assembly. Regrettably, the pattern and correlation of the survivability of ESPs to partial pressure remains unclear. Therefore, this paper sets to assess the contributions of partial pressures to ESP systems durability and survivability in a sour environment. An assessment of the relationships of different ESP systems in such environment with naturally occurring element of varying partial pressure is conducted and discussed in the paper. Weibull two-parameter distribution function approach in addition to extensive literature review were applied to understand and represent the contributions of sour fluid partial pressures on ESP’s durability and survivability that operated in hydrocarbon environments. The partial pressures of naturally occurring element - hydrogen sulphide, was conducted and determined to exhibit varying behavioral patterns, and contributions to the durability and survivability of electric submersible pumps in contact with the well fluid. The results obtained were matched with the Bathtub curve to identify the reliability patterns common to ESP assembly completion strings because of the fluid partial pressures. From the analysis, the varied partial pressures considered had different effects on the survivability of ESP systems operating in the various environments. The patterns of the ESP systems in the sour fluid environment cut across three main regions of Bathtub-curve performance patterns, which defined early survivability pattern, and normal or constant operating survivability pattern, and the wear-out survivability pattern. ESP performance and survivability patterns were observed to vary as the partial pressures increased while normalizing at certain levels partial pressures plateauing at about 200 psi. Finally, the naturally occurring sour fluid’s partial pressure had normalizing effects on ESPs as the run-lives increased. The paper adds to the body of knowledge in the oil and gas industry by bringing to clarity the contributions of partial pressures on ESP systems performance and survivability patterns used in sour hydrocarbon environment.
ESP Testing: A Key Role in Enhancing Reliability
Authors: Foresti B. P. , Viana A. M. , Bacellar F. R. R. , Silva J. A. G. , Neves M. S. , Ribeiro M. P. , Oliveira P. S. , Costa B. M. P. , Cemin D. , Sousa C. F.
Published: August 2024

Electrical Submersible Pumps (ESPs) have been manufactured since 1928 [1], and since then, much has changed regarding the equipment and its application scenarios. When they were first invented, ESPs were used in onshore fields for short tie-backs. Since then, the application scenario has changed significantly. Conversely, for Petrobras, they are mostly used in deep-water offshore fields with wet Christmas trees and long tie-backs, in most cases, inside subsea equipment (such as MoBo [2] or skid-mounted ESP [3]).

For the latter scenario, denominated as critical wells in Petrobras, the resources and costs involved in installing a new ESP and retrieving a faulty one are very different from those in the onshore scenario. Considering the rig costs and deferred production, for a subsea well, one operation might cost more than 30 million dollars. In the case of a premature failure that requires retrieving the faulty equipment and installing a new one, the impact is hence more than 60 million dollars. Once again, this is a very different scenario from the onshore scenario.

The world’s first ESP in a subsea well was installed by Petrobras in RJS-221 (Carapeba field) in 1994, in shallow water. Following that, in deep water, Petrobras installed an ESP in RJS-477 (Albacora Leste field) in 1998 [4]. From 1998 to around 2008, Petrobras experienced numerous premature failures with ESPs. The situation was so dire that there was even consideration given to abandoning the use of ESPs in favor of gas lift. This would result in lower production but also reduced deferred production and decreased workover costs.
A Tubing Anchor Engineered for Rod Pumping Horizontal Wells Improves Production Performance
Authors: Saponja J. , Hari R. , Brignac J. , Jaszan D. , Coyes C. , Chaudhry F.
Published: August 2024

High gas to oil ratio (GOR) producing horizontal wells is now commonplace. This ratio continues to rapidly escalate as reservoirs suffer regional and basin wide pressure depletion. The North Dakota Bakkeni formation is a prime example of a concerning GOR trend and can be seen in Figure 1. Higher GOR's and depleted reservoir pressures lead to increased gas rates and multiphase fluid velocities within horizontal wellbores. Increased multiphase fluid velocities can then transport more damaging solids to a sucker rod pump and increase failure frequencies. Consequently, challenges for controlling failure frequencies and workover costs with sucker rod pumping continues to intensify, especially for improving downhole gas and solids separation.

Sucker rod pumping normally requires the tubing string to be secured or anchored to the casing, downhole near the sucker rod pump. Anchoring of tubing prevents tubing movement during a rod pump's operating cycle. Tubing movement can undesirably reduce downhole pumping efficiency and increase risks for damage to the tubing, casing, pump and sucker rods. A downhole tubing anchor (TA) or a downhole tubing anchor catcher (TAC) are a bottomhole assembly component installed for this purpose, but they can present risks for increasing operating expenses and limiting of a well's production potential.

Production can be limited if the annular flow path cross-sectional area of a tubing anchor (to the casing's internal diameter) is a flow path restriction. A flow path restriction negatively impacts downhole gas separation performance by causing multiphase flow instabilities. Further, sluggy and inconsistent multiphase flows that commonly emanate from a horizontal wellbore can worsen from a flow restriction, making downhole gas separation even more challenging. Flow restrictions can increase turbulence and then cause undesirable foaming and gas entrainment. Foaming of fluids is generally characterized by smaller gas bubbles in the liquid, which are more difficult to separate from the liquid.
Autonomous ESP Optimization Using Machine Learning Demonstrated in the Permian Basin
Authors: Erickson R. , Ramos R. , Meek J. , Benham D. , Haapanen B. , Hicks B. , Wheeler C. , Vasylyshyn B.
Published: August 2024

Many oil and gas companies rely on natural intelligence, resident knowledge, and rules-based logic to optimize production. This is especially true for fields where electric submersible pumps (ESP) make up a considerable proportion of production. The nature of ESP artificial lift systems makes them well suited for greater remote monitoring, enhanced automation, and implementation of machine learning (ML) for autonomous optimization. Extensive use of electrical surface controls integrated with downhole sensors provides an ideal operating environment to implement Artificial Intelligence (AI) through machine learning to achieve autonomous full self-pumping (FSP) operation. However, most operating companies stop short of using automation and machine learning to its full potential.

This paper will present a case study highlighting the demonstration, refinement, and implementation of a machine learning algorithm to optimize multiple ESP wells in the Permian Basin. The paper will also present a case study for the development, demonstration, and refinement of an autonomous ESP optimization solution driven by this machine learning model. The paper will discuss key learnings from each study to assist operators in their digital journey with considerations for effective field implementation.
Optimizing Gas Lift Design: Unveiling Ideal Wellhead Temperature Across Diverse Reservoirs at Mehsana Oil Fields
Authors: Chanchlani K. , Gogoi R. , Gunwant D. , Rajak H. , Devshali S. , Meena S. , Kote N.
Published: August 2024

The operation of gas lift valves of the gas lift systems at field scale is controlled by the nitrogen pressure charged in the dome. Nitrogen pressure in gas lift systems is influenced by the gas injection temperature and production fluid temperature. In gas lift wells completed in water drive reservoirs, emulsion flowing with high water cut causes an increase in opening pressure of the topmost gas lift valves (GLV). When these wells are shut or provided with low gas injection supply pressure, these wells get loaded with minimal gas injection taking place. In depletion drive reservoirs, lower reservoir temperature causes a decrease in the opening pressure of the bottom-most gas lift valve, causing higher gas injection and lowers the grid pressure. In mixed drive reservoirs, any abrupt wellhead and reservoir temperature gradient will cause an ineffective gas lift operation. Flowing bottom-hole surveys with convection and conduction thermal methods are the prerequisites for the compact thermal model. Through the analysis, it was established that the nitrogen gas temperature in the dome is much more influenced by radial heat transfer along the mandrel-GLV interface than the axial heat transfer along the GLV body. The mathematical correlation for the ideal wellhead temperature was established based on heat transfer coefficients of production fluid and injection gas, and it can be expressed in terms of production fluid and injection gas temperatures. Conventional Gas Lift (CGL) wells experience the phenomenon of loading due to higher temperatures brought by bottom water to the surface and Intermittent Gas Lift (IGL) wells experience the problem of grid pressure drop. Both problems can be tackled by the unveiling of the wellhead temperature during design and can improve the efficiency by reducing downtime. The paper will focus on gas lift valves operating on diverse reservoir drive mechanisms and the calculation of their wellhead temperature using a unique thermal model for conventional gas lift mandrels.
Liquid Management in Gas Wells: Exploring the Impacts of Tubular Restrictions
Authors: Mateus-Rubiano Camilo , Alsanea Maziad , Karami Hamid
Published: August 2024

Liquid accumulation in gas wells impairs their production capabilities and reduces their operational lifespan. Various techniques have been explored to address this issue, yet no optimum solution has been identified for all wells. Operators continue to seek cheap and efficient methods to mitigate liquid loading in gas wells. Previous works have suggested that partial tubing restrictions, or inserts, have the potential to increase interfacial shear and droplet entrainment, thus delaying liquid loading. Due to increases in frictional pressure losses when inserts are present, a challenge remains in finding the operational conditions where their use results in a net positive effect for the well. In this work, experiments are conducted in a flow loop with a 25-ft vertical section, made from 2″ ID clear acrylic pipes, using air and Isopar-L oil at room temperature and near-atmospheric pressures. The accuracy of various two-phase flow models and correlations is evaluated for low superficial liquid velocities. Tests are conducted using insert rings with two internal diameters, 1.5″ and 1.75″. Liquid-gas flow pattern, liquid holdup, and pressure gradient are recorded and analyzed for each test. Results are compared with previous studies to assess the locality of the effects caused by the inserts and identify optimal conditions for their implementation

The combined effects of insert size and spacing are analyzed on well deliquification at various flowrates. Video recordings show the dual mechanism by which inserts enhance liquid lifting, droplet generation promotion and liquid film fallback retention. Results indicate that inserts are particularly effective in modifying flow behavior within the churn flow region. Commonly used models are inadequate to predict pressure gradient and liquid holdup in this flow pattern, particularly at low liquid rates. The use of a single insert shows positive changes in the liquid holdup compared to the tests without inserts. Yet, better outcomes are obtained for both liquid holdup and pressure gradient when two inserts are used. This configuration, with an 18-ft spacing between inserts, closely matches tubular joints length. This suggests that properly designed tubing joints can function similarly to inserts, offering a cost-effective and passive solution to mitigate liquid loading in gas wells. The optimum range to use this technique is for low liquid loading conditions and gas rates of churn flow. The results of the analysis can provide a guideline on the best conditions to apply this technique and significantly reduce the operational costs and improve the revenues.