bluuebunny/crossref_metadata_2025 huggingface dataset:
Understanding the Intricacies of Iron Overload Associated With β-Thalassemia: A Comprehensive Review
Authors: Basu Subhangi , Rahaman Motiur , Dolai Tuphan Kanti , Shukla Praphulla Chandra , Chakravorty Nishant
Published: June 2023

β-thalassemia, a congenital genetic hematological disorder characterized by decreased or absence of β-globin chains, leads to decrease in levels of Hemoglobin A. The affected individuals can be categorized into two cohorts based on transfusion dependency: transfusion dependent thalassemia (TDT) and non-transfusion dependent thalassemia (NTDT). Remarkably, despite the primary pathology lying in β-globin chain depletion, β-thalassemia exhibits an intriguing association with iron overload. Iron metabolism, a tightly regulated physiological process, reveals a complex interplay in these patients. Over time, both cohorts of β-thalassemic individuals develop iron overload, albeit through distinct mechanisms.
Addressing the diverse complications arising due to iron overload in β-thalassemic patients, the utilization of iron chelators has gained a lot of significance. With varying efficacies, routes of administration, and modes of action, different iron chelators offer unique benefits to patients. In the Indian context, three commercialized iron chelators have emerged, showcasing a high adherence rate to the iron chelator-based treatment regimens among β-thalassemic individuals. In this review, we explore the intriguing connection between β-thalassemia and iron overload, shedding light on the intricate mechanisms at play. We delve into the intricacies of iron metabolism, unveiling the distinct pathways leading to iron accumulation in these patients. Additionally, we critically evaluate the therapeutic efficacy of different iron chelators, emphasizing their respective advantages in managing iron overload complications. Through this comprehensive analysis, we aim to deepen our understanding of β-thalassemia and iron overload, paving the way for optimized treatment strategies. Ultimately, our findings provide valuable insights into improving the care and outcomes of individuals affected by β-thalassemia.
Experimental Study of the Correlation between the Wear and the Braking System Efficiency of an Auto-Vehicle
Authors: Filip Ilie , Cristescu Andreea-Catalina
Published: June 2023

The vehicles number continuously growing lead to increasingly intense and congested traffic and it will additionally demand the braking system, and drivers behave more aggressively and as result is required that the braking system to be durable and efficient. For this is necessary the study the braking system behavior in conditions of intense and moderate traffic to increase the safety of traffic participants, respectively to demonstrate the need for more frequent replacement of some braking system elements. Thus, on a vehicle were performed a series of successive tests, through which the degree of wear of the brake pads and discs was monitored periodically and as a result the efficiency evolution of the braking system. The tests were carried out both in laboratory (on dynamometer) and in traffic to establish the efficiency of the braking system according to some parameters considered essential. The experimental tests showed that the recommendations regarding the frequency of replacement of brake pads and disks are inconsistent with their actual wear. Therefore, the aim of this paper is the establishment of the braking system efficiency of an auto-vehicle, subject to testing depending on the auto-vehicle mass, travel speed, distance driven, and braking time, based on experimental on stand and in-traffic tests, according the road safety regulations.
Issues, Challenges, and Future Perspectives of Perovskites for Energy Conversion Applications
Authors: Pode Ramchandra Balaji , Muley Aarti , Diouf Baye Boucar
Published: June 2023

Perovskite solar cells are an evolving technology owing to self-assembling and highly tunable bandgap properties of materials. In this context, thin films of perovskites have attracted immense attention and witnessed great advancement because of their low manufacturing cost. The key development in these devices is the conversion efficiency, which rose from 3.8% to 28%. The formulation of innovative materials with the proper replacement of lead in perovskites is imperative to mitigate lead toxicity. Here, we analyzed the challenges like material and structural stability, device stability under high temperature and humidity conditions, lifetime, manufacturing cost, etc. faced in the commercialization of perovskite devices. This review shows that challenges such as device engineering, performance stability against the harsh environment, cost-effectiveness, and environmental concern should be taken into consideration for the widespread acceptance of perovskite-based solar devices. In conclusion, we suggested that an enormous scope exists for exploring high-performance and long-lasting perovskites for energy applications.
Social Sustainability of Raw Rubber Production: A Supply Chain Analysis under Sri Lankan Scenario
Authors: Dunuwila Pasan , Rodrigo V.H.L. , Daigo Ichiro , Goto Naohiro
Published: June 2023

Raw rubber production is the sole foundation for the rubber product industry, rendering raw rubber to manufacture essential commodities to mankind such as tires, condoms, surgical gloves, and so forth. Raw rubber production involves various stakeholders; however, literature focusing on the social impacts of raw rubber production and its supply chain has hereto been limited. Social life cycle assessment, a popular tool to assess the social impacts of a product or process and was deployed herein to assess the social profiles of three Sri Lankan raw rubber supply chains (crepe rubber, concentrated latex, and ribbed smoked sheets). The Social Hotspots Database v4 on Sima Pro v9.3 was used for the analysis. Results indicated that Governance and Labour rights & decent work had been affected in its supply chain of fertilizers due to Corruption and Freedom of association & collective bargaining issues, mainly in Belarus, and China. Proposed improvement options to address these touchpoints were found to be effective. For instance, if the importation of K-fertilizer shifted into low risk countries, overall social risks associated with Corruption and Freedom of association & collective bargaining in the supply chains could be reduced by ca. 36% and 25%, respectively. As a result, social risks in the aforesaid impact categories, i.e., Governance and Labor rights & decent work, were reduced by ca. 35-41% and ca. 17-20%, respectively. Such improvements may help positioning the Sri Lankan rubber industry in the sustainability-conscious-world rubber market. Further, the methodical hierarchy developed herein is suggested to adopt in any industry to measure social sustainability subjected to the relevant refinements to the supply chains.
Thyroxine Quantification by Using Plasmonic Nanoparticles As SERS Substrates
Authors: De Leon Portilla Paulina , González Ana Lilia , Sanchez-Mora Enrique
Published: June 2023

Detecting low concentrations of thyroxine hormone (T4) is of utmost importance to prevent diseases and medical issues caused by hypothyroidism. In this work, we propose the use of a simple technique for T4 sensing, the well-known surface-enhanced Raman spectroscopy (SERS). Spherical Au and Ag nanoparticles (NPs) and functionalized with ascorbic acid and tannic acid, respectively. They synthesized by a seed-mediated growth method, were used as SERS substrates to quantify T4 at different concentrations. The NPs were characterized by UV-VIS spectroscopy and scanning electron microscopy. Both, Au and Ag NPs, have an average diameter of 50 nm, the first ones have a surface plasmon resonance at 537 nm, while the latter have it at 421 nm. It was noticed the SERS substrates are composed of isolated and agglomerated NPs. From theoreti-cal-numerical calculations, we identified the hot spots |E| of the agglomerate NPs is at least 7 times more intense than that of the isolated NPs. We show the substrates can detect up to 0.01 mM and, for the range of concentration studied, the Ag substrate is more sensitive than Au. Thus, the proposed substrates and the SERS technique constitute a potential prospect for sensing hormones and organic molecules at low concentrations.
Catalytic Performances of Co/TiO2 Catalysts in the Oxidative Dehydrogenation of Ethane to Ethylene: Effect of CoTiO3 and Co2TiO4 Phases Formation
Authors: Mahir Hanane , Brik Younes , Benzaouak Abdallah , Greca Eleonora La , Consentino Luca , Hamidi Adnane El , Kacimi Mohamed , Liotta Leonarda Francesca
Published: June 2023

Co/TiO2 catalysts with different cobalt loadings (3.8, 7.5 and 15 wt%) were prepared by impreg-nation method of Co(NO3)2 .6H2O over titania. Samples containing Co(NO3)2 .6H2O and TiO2 in stoichiometric proportions in order to obtain CoTiO3 and Co2 TiO4 phases were also synthesized. The effect of the calcination treatment at two different temperatures, 550 and 1150 °C was investigated. Characterizations by several techniques, such as XRD UV-vis-NIR, DRS, Raman and XPS were carried out. XRD showed the coexistence of three phases: CoTiO3; Co2TiO4 and Co3O4 after calci-nation at 550°C, while the calcination at high temperature (1150°C) leads to single-phase systems (CoTiO3 or Co2TiO4). Diffuse reflection and XPS spectroscopy showed that divalent cobalt occupies octahedral sites in the ilmenite phase and both tetrahedral and octahedral sites in the spinel phase.
The catalytic performances of the prepared catalysts, calcined at the two different temperatures, were evaluated in the oxidative dehydrogenation reaction (ODH) of ethane to ethylene. The con-version values were almost comparable for all the samples, calcined at 550 °C, and comparable the ethylene selectivity were recorded, slightly higher only in the case of CoTiO3. The calcination at 1150°C did not modify the overall activity (ethane conversion values around 20%), however, the production of COx becomes more significant.
The study examined the influence of the reaction mixture composition, specifically the presence of water, and reveals a slight increase in the yield of ethylene accompanied by a decrease in the overall catalyst activity. This behavior is likely attributed to an increase in the surface concentration of hydroxyl species (OH), resulting in heightened surface acidity.
Research on Optimization and Numerical Simulation of Layout Scheme of Mining Approach in Downward Slicing and Filling Method
Authors: Zhao Kui , Liang Nan , Zeng Peng , Wang Wanyin , Gong Cong , Xiong Liangfeng , Liu Hao
Published: June 2023

The stability of the filling roof as an important bearing unit in the stope of the access stope in the filling mining method is of great significance to guarantee the safe and efficient production of the mine. Arrangement of mining approach in downward cemented filling stope is the key factor af-fecting stability of filling body roof. Based on combination of laboratory test, theoretical analysis and numerical simulation, the influence of different mining approach arrangement on stability of filling body roof is analyzed. The weak filling surface is formed between adjacent mining paths. The mechanical strength of the weak filling surface is significantly reduced by laboratory experiments. The relationship between distribution of the weak filling surface, azimuth angle and stability of filling roof is further studied by numerical simulation. The results show that the stability of the filler roof is the best when the upper and lower stratified mining approach is arranged vertically.
On Semiclassical Gravity and Horizon Area
Authors: Kumar Naman
Published: June 2023

The classical Einstein’s Field Equation has been derived previously by demanding that the Clausius relation dS = δQ/T holds. In this letter, we show that the semiclassical Einstein’s Field Equation can be recovered using the generalized entropy Sgen by using the non-equilibrium thermodynamics where the Clausius relation is replaced by the entropy balance relation dS = δQ/T +diS, where diS is some internal entropy. Moreover, since the quantum fields violate the classical focusing, we, therefore, have to use quantum focusing in this case. Using then Jacobson’s idea of thermodynamics of spacetime we recover the semiclassical equation of motion. We, therefore, in a sense also show the validity of the semiclassical approximation, a crucial approach for establishing a number of important ideas such as the Hawking effect.
On the Safety of Implanted Breast Prostheses in Accidental Impacts
Authors: Janszen Gerardus , Arnoldi Michela , Vinci Valeriano , Klinger Marco , Di landro Luca
Published: June 2023

The employment of breast silicone implants, both in aesthetic and reconstructive medicine, is widespread thanks to their recognized biocompatibility and durability. Some critical situations, as for example in case of accidental impacts, may however induce concerns by potential patients about their use. Experimental data is collected by means of static compressive and tensile tests. Aging at 37, 60, 75° and 90° Celsius is performed in a physiological saline solution (0,9% NaCl). Impact dynamic tests are carried out using a Hybrid II anthropomorphic test dummy with the prostheses implanted. Mechanical tensile and compressive tests show mechanical degradation of the prostheses characteristics after aging. Impact dynamic tests show a great probability of breast implant rupture at speeds up to 90 km/h. Accidental events like car crashes or bad falls, are con-firmed as possible causes of significant damages to implanted prostheses. In addition, the possi-ble long-term aging of the silicone shell, although of limited relevance in terms of body compati-bility or reaction, can lead to some degradation of mechanical properties, rendering the outcome of accidental events even more worthy of attention.
Digital Transformation: The Role of the Big Five Personality Traits
Authors: Pradana Bartolomeus Galih Visnhu , Mayasari Agatha
Published: June 2023

This study aimed to investigate the role of the big five personality qualities in mediating the relationship between digital transformation and team member performance. The world of education is feeling the effects of digital transformation, a significant phenomenon that the industry cannot avoid. The presence of digital transformation causes modifications in traditional operations to be digitized. This shift in change affects team member performance. This survey included 83 elementary to middle school teachers and education staff from the Marsudirini Foundation's Yogyakarta branch. The hypothesis was tested using PLS-SEM in this study, which used a mixed method. The hypothesis testing results revealed that digital transformation has a beneficial effect on team member performance. When the role of moderation is tested, it is discovered that extraversion and neuroticism personality types do not significantly affect the relationship between digital transformation and team member performance. Meanwhile, as moderating variables, agreeableness, conscientiousness, and openness personality types strongly negatively affect the association between digital transformation and team member performance. Informant interviews corroborate the survey results, highlighting the insignificant effect of extraversion and neuroticism personality types.
INDIVIDUAL PERFORMANCEE IN PERCEPTION THEORY OF WORK PERFORMANCE
Authors: Suprayogi Wahyu , Siti Nurjannah  , Awaluddin Tjalla  , Suparno  , Susan Febriantina  , Brata Sanjaya  , Nafiudin  , Alfa Fawzan
Published: June 2023

Penelitian ini bertujuan untuk mengembangkan preposisi tentang kinerja individu, melalui pendekatan kajian teori. Studi ini mengelaborasi beberapa temuan dari para peneliti terdahulu sebagai rujukan dan mengeksplorasi grounded theory, dalam mengembangkan pengetahuan terkait dengan kinerja individu. Metode penelitian kualitatif dengan studi literatur dilakukan untuk memperoleh referensi model penelitian dalam menjelaskan faktor-faktor yang mempengaruhi kinerja individu. Hasil kajian memberikan rekomendasi bahwa aktualisasi peran pimpinan memberikan pengaruh, baik pengaruh secara langsung terhadap kinerja individu, maupun pengaruh secara tidak langsung melalui budaya organisasi dan komitmen individu.
THE EFFECT OF RESILIENCE, WORK ATTACHMENT, AND EMOTIONAL INTELLIGENCE ON JOB SATISFACTION OF BANK SYARIAH INDONESIA EMPLOYEES (Case Study: Bank Syariah Indonesia KC Yogyakarta Kusumanegara)
Authors: Muhammad Hanif Ibrahim  , Syayyidah Maftuhatul Jannah
Published: June 2023

Penelitian ini bertujuan untuk mengetahui Pengaruh Resiliensi, Keterikatan Kerja, Dan Kecerdasan Emosional terhadap Kepuasan Kerja Karyawan di Bank Syariah Indonesia KC Yogyakarta Kusumanegara. Metode analisis yang digunakan adalah Sctructural Equation Modelling dengan menggunakan pendekatan Partial Least Squares menggunakan alat analisis WarpPLS 5.0. Teknik Sampling yang digunakan yaitu Non probability Sampling dengan metode sampling jenuh dengan menggunakan 31 responden dari karyawan Bank Syariah Indonesia KC Yogyakarta Kusumanegara. Hasil penelitian menunjukkan bahwa Resiliensi, Keterikatan Kerja, Dan Kecerdasan Emosional memiliki pengaruh yang signifikan terhadap Kepuasan Kerja Karyawan Bank Syariah Indonesia KC Yogyakarta.

 

Kata Kunci: Resiliensi, Keterikatan Kerja, Kecerdasan Emosional, Kepuasan Kerja
BUILDING MSME COMPETITIVENESS ADVANTAGES THROUGH CAPACITY BUILDING OF BUSINESS MODEL INNOVATIONaya Saing UMKM Melalui Peningkatan Kapasitas Inovasi Model Bisnis
Authors: Nugroho Agung , Fontana Avanti
Published: June 2023

Inovasi model bisnis merupakan salah satu kegiatan utama yang perlu terus dilakukan di perusahaan untuk mempertahankan daya saing dalam ekonomi digital saat ini. Walaupun penelitian pada model bisnis telah meningkat sejak tahun 1990-an, masih sedikit yang diketahui tentang praktik Inovasi model bisnis di Usaha Kecil Mikro dan Menengah (UMKM) di Indonesia. Penelitian ini membahas kesenjangan penelitian tersebut dan berfokus pada investigasi pemicu dan hasil Inovasi model bisnis di UMKM. Metode partial least squares path modeling (PLS-PM) digunakan untuk menguji model secara empiris menggunakan data yang dikumpulkan pada tahun 2021 dari 75 UMKM di Indonesia. Hasil menunjukkan bahwa Tingkat inovasi UMKM memiliki dampak positif pada Inovasi model bisnis. Sebaliknya, Lingkungan bisnis dan Teknologi informasi tidak memiliki efek langsung terhadap Tingkatan inovasi model bisnis. Selain itu, hasil menunjukkan bahwa Tingkat Inovasi Model Bisnis memiliki pengaruh positif berdampak pada Hasil Inovasi Model Bisnis dan selanjutnya pada Performa bisnis secara keseluruhan. Hasil penelitian ini berkontribusi pada pengetahuan di bidang Inovasi model bisnis UMKM dan menawarkan wawasan yang berguna untuk UMKM yang berniat untuk berinovasi pada model bisnis mereka.
PENGEMBANGAN SISTEM INFORMASI MANAJEMEN TERPADU BALITA SAKIT (MTBS) UNTUK PUSKESMAS
Authors: Moertini Veronica , Harjono Kristopher
Published: June 2023

One of the policies for promoting the health of children under five years of age by the Indonesian Ministry of Health is the implementation of Integrated Management of Childhood Illness (IMCI) in the country’s Puskesmas (Community Health Centre). In the current implementation of IMCI, the Puskesmas’ medical staff have to work using a 72 pages manual book, write down the symptoms in an IMCI form, and then determine the condition of the patient and the proscribed actions. The requirement elicitations in Puskesmas Ciumbuleuit Bandung revealed problems: (1) The process takes a long time because the medical staff must read the lengthy manual; (2) Generating the reports also takes a long time as those were written manually. We developed an IMCI Information Systems (IMCI IS) consisting of 2 main modules, an Android tablet application and a web-based application. Both modules feature the same functions which are recording the symptoms of children according to the IMCI process, automating the patient's classification, and provides actions and treatment suggestions. The IMCI IS has been piloted at the Ciumbuleuit Community Health Centre, Bandung, and as a result, the IMCI IS can overcome the existing problems and is stated to be able to support the IMCI process in managing under-five patients.

 

Abstrak

Salah satu kebijakan Kementerian Kesehatan RI untuk meningkatkan kesehatan balita adalah pemberlakuan Manajemen Terpadu Balita Sakit (MTBS).  MTBS dipraktekkan oleh para nakes di Puskesmas dengan menggunakan formulir MTBS dan buku petunjuk pelaksanaan setebal 72 halaman. Nakes mencatat gejala-gejala balita pada formulir lalu mengklasifikasikan penyakit balita berdasarkan buku MTBS. Dari hasil analisis kebutuhan di puskesmas Ciumbuleuit Bandung didapatkan masalah pada penerapan MTBS, yaitu: (1) Waktu pelayanan bagi balita lama karena nakes membaca buku MTBS yang cukup kompleks; (2) Pembuatan laporan yang lama karena masih dilakukan secara manual. Pada kegiatan pengabdian ini telah dikembangkan Sistem Informasi (SI) MTBS dengan 2 modul utama, yaitu aplikasi tablet Android dan website MTBS.  Fitur-fitur yang disediakan pada keduanya adalah sama, yaitu pencatatan gejala-gejala balita sesuai formulir MTBS dan otomatisasi penentuan klasifikasi, tindakan, serta saran pengobatannya. Aplikasi tablet Android dirancang tidak membutuhkan jaringan Internet pada saat digunakan agar aplikasi dapat digunakan pada daerah-daerah (terpencil) di Indonesia yang belum memiliki infrastruktur Internet yang memadai. Sinkronisasi data pada aplikasi Android dengan server pusat dilakukan ketika tablet berada di lokasi dengan jaringan Internet yang memadai. SI MTBS telah diuji oleh Puskesmas Ciumbuleuit Bandung, hasilnya: Dengan penyederhanaan prosedur, waktu pelayanan menjadi lebih singkat dan laporan lebih mudah
Al-Farabi's Concept of Happiness and Its Contribution to Modern Man
Authors: Wiwaha Kurnia Sari , Arini Dwi Setyo , Oktaviani Resti Ananda
Published: June 2023

Al-Farabi is one of the Islamic philosophers who also focuses on the study of happiness. Although he is not the first scholar to talk about happiness, his thoughts have contributed to the study of Islamic thought. So that the authors are interested in studying al-Farabi's concept of happiness and analyzing the concept in order to answer the problems of modern humans, especially on the topic of finding happiness. To achieve this goal, the author uses library research by collecting primary sources such as books and scientific journals. Then, describe and analyze the data to find a correlation between al-Farabi's concept of happiness and the problems of mankind today. Thus, the author can provide input on how to take steps so that someone reaches happiness. According to al-Farabi happiness is a good that needs to be achieved. Every happiness is good, and every that is good must be happy. God himself created humans to be happy, so happiness needs to be made a life of goals. Al-Farabi explained that happiness can be achieved when the soul can be implemented optimally.
The Impact Of Using Digital Library Resources On The Productivity Of Researchers At The State Islamic Institute Of Purwokerto
Authors: Nurohman Aris
Published: June 2023

Abstract: Digital library resources are invaluable in assisting universities in research. The academic community recognizes that digital resources improve their research results. Much research has also confirmed the link between the utilization of digital resources and research output. The researchers analyzed the utilization of digital library resources by researchers at the Purwokerto State Islamic Institute to validate the evidence. The study takes a descriptive-analytical approach, employing the purposive sampling method to collect data from various circles of researchers at various levels. The conclusion is that digital information sources are valuable sources of information that should be evaluated and exploited in the research process, beginning with creating ideas, study design, reference sources, and data collection. Researchers have benefited from digital resources due to the ease and speed of access to information, support for improving research performance, improving the quality of scientific work, supporting creativity to continue working, and increasing awareness about the importance of publication and authentication of scientific papers.Keywords: digital library resources, library, researchers, research productivity. Abstrak: Sumber daya perpustakaan digital sangat berharga dalam membantu perguruan tinggi dalam penelitian. Civitas akademika menyadari bahwa sumber daya digital mempengaruhi peningkatan hasil penelitian mereka. Beberapa penelitian juga telah mengkonfirmasi hubungan antara pemanfaatan sumber daya digital dan hasil penelitian. Para peneliti menganalisis pemanfaatan sumber daya perpustakaan digital oleh para peneliti di Institut Agama Islam Negeri Purwokerto untuk memvalidasi bukti. Penelitian ini menggunakan pendekatan deskriptif-analitis, dengan menggunakan metode purposive sampling untuk mengumpulkan data dari berbagai kalangan peneliti di berbagai tingkatan. Kesimpulannya, sumber informasi digital adalah sumber informasi berharga yang harus dievaluasi dan dimanfaatkan dalam proses penelitian, dimulai dengan penciptaan ide, desain studi, sumber referensi, dan pengumpulan data. Para peneliti telah mendapatkan manfaat dari sumber daya digital karena kemudahan dan kecepatan akses informasi, dukungan untuk meningkatkan kinerja penelitian, peningkatan kualitas karya ilmiah, mendukung kreativitas untuk terus berkarya, dan meningkatkan kesadaran akan pentingnya publikasi dan otentikasi karya ilmiah.Kata kunci: sumber daya perpustakaan digital, perpustakaan, peneliti, produktivitas penelitian
Durability of Polymer-Based Wellbore Sealants in a Corrosive Environment
Authors: Todorovic Jelena , Stroisz Anna Magdalena , Duda Marcin Ireneusz , Agofack Nicolaine , Lange Torstein , Nilsen Nils-Inge , Aas Per Gunnar , Sefidroodi Hamidreza , Ringe Thomas
Published: June 2023

Development of wellbore sealant alternatives to cements is a topic of high relevance for production and injection wells, permanent plugging and abandonment, and remediation of leakage behind the casing. Some examples of alternative sealants are epoxy-based sealants, geopolymers, and bismuth-based alloys. Depending on the application, sealing materials are expected to encounter challenging downhole conditions, such as corrosive environments (e.g., CO2, H2S) and pressure or thermal cycling. This is especially significant for permanent plugs, where long-term perspective needs to be considered.

In this work, we conducted long-term exposure of three polymer-based wellbore sealants (labelled as A, B and C) to an artificial seawater water environment with dissolved H2S gas. The polymer-based sealants are compared to each other and to a Portland G cement blend that was subjected to the same testing procedure. The experiments reported here are a part of a more extensive campaign that aims to study the behaviour of these materials after up to 12 months exposure to H2S. The aging tests were performed as batch-exposure conditions in a pressure cell at 100 °C and 10 bar. Cylindrical (core) samples of the same material were submerged together in artificial seawater in a glass beaker, and a mixture of H2S and nitrogen was dispersed into the seawater. We characterized mechanical properties before and after H2S exposure by unconfined compressive strength (UCS) tests. X-ray micro-computed tomography (CT) was performed to visualize changes potentially induced by the reaction with H2S.

After H2S exposure, sealants A and B displayed significant axial and radial deformation during UCS tests (ductile behaviour), which is a very different behaviour compared to a typical wellbore cement. Sealant C exhibited ductile behaviour during compression but without considerable deformation. For comparison, strain at the peak stress was in the order of 200-300 mm/m for sealants A and B, whereas for C it was approximately 60 mm/m, after one month of H2S aging. For all three materials, a decrease of UCS and Young's modulus was observed after H2S exposure. For sealant C, the UCS was still relatively high after three months of aging, at around 70 MPa, which was about 50 % decrease from the reference value. CT results revealed no obvious progression of a reaction front for sealants A, B and C, however, different effects (e.g. change of porosity, precipitation, cracking) were observed throughout the volumes.

The unique behaviour of these materials under stress and the possibility of tuning the physical and chemical properties hold vast potential for different applications. One of the long-term goals is to optimize the material properties to make them more suitable for the permanent plugging of both petroleum and CO2 wells.
Opportunities and Uncertainty Mitigation Base on Survivor Bias in a Mature Field: Cañadón León, San Jorge Basin, Argentina
Authors: Legarreta Andres Esteban , Barberis Rosina Cristina , Schein Florencia Tercila , Martino Luis ángel , Gandi Silvana
Published: June 2023

Survivorship bias is a well-known tendency to overweight available data and underestimate the missing information. Cañadón León in San Jorge basin, Argentina is a waterflooded field with a current water-cut of 95% where innovative recovery strategies such as Chemical Enhanced Oil Recovery (cEOR) become a condition for further development. Data acquisition is often biased towards the best reservoirs, leading to major uncertainty in assessing opportunities in mature fields.

After 70 years of primary oil production and water injection, the study aims to evaluate the remaining opportunity, which leads to a double challenge: Estimation of bypassed oil during the inefficient waterflooding process because of poor mobility ratio and the potential of marginal reservoirs. Initial stage field exploitation and data acquisition at early stages of development aimed mainly to characterize the higher oil-saturation zones with better petrophysical properties, leading to a lack of data on marginal reservoirs which become critical targets for mature reservoirs analysis. The data interpretation within a semi regional geological framework to build the static model, allowed a representative construction of poorly characterized reservoirs due to survivorship bias effect.

Several hypotheses were evaluated with dynamic simulation to avoid assuming recoverable oil based on survivorship bias due to missing information in secondary targets. Integration of what-if scenarios, both static and dynamic, and assessment of uncertainty provided a better understanding of critical constraints and optimum ranges of variability to analyze cEOR with polymer injection. A wide variety of fluid saturation scenarios, mobility ratios and reservoir properties were considered to quantify the field potential.

Sensitivity analysis helped to identify the most relevant uncertainties in history matching and reliability in forecast: Primary gas cap contact and its expansion, water-oil contact, the transition zone (oil-water system), fluid mobility ratios and polymer characteristics.

A major benefit from polymer injection is CO2 emissions reduction per barrel of oil by more than 40% compared to water injection, reducing project carbon footprint. Development strategy achieves a short-term incremental recovery factor of 10% with a total of 68 wells in 20 injection patterns (considering a period between 3 to 6 years due to oil production acceleration). This methodology allowed to establish the foundations for development strategies based on multi-modelling within conceptual geological frameworks reflecting the impact of the recognized uncertainties. This technique does not allow to determine the unknowns, but it does allow to estimate their impact.
Continuous Monitoring of Water Pressure Change in an Oil Reservoir
Authors: Shaker Shiran Behruz , Djurhuus Ketil , Alagic Edin , Lohne Arild , Rolfsvåg Trond Arne , Syse Harald , Riisøen Solveig
Published: June 2023

As oil is produced from a reservoir, the free-water-level (FWL) rises. Monitoring the FWL during oil production is of high value for the operators. This knowledge can aid placement of new wells on the field, improve the production strategy on a well level and reduce the production of water. We propose a new method for continuously measuring in-situ water pressure in an oil reservoir and investigate, both experimentally and by simulations, how this information can be used in reservoir monitoring.

Laboratory experiments with Berea sandstone and Mons chalk core samples were performed using mineral oil and synthetic brine in a test setup designed for this study. The pressure in the water phase is measured with hydrophilic probes at five locations on the core during drainage and imbibition processes. Data including temperatures, pressures, resistance, water production, and pump logs were continuously collected in a cloud solution for live monitoring during the experiments. The experimental results were interpreted using a numerical simulator (IORCoreSim) to identify key mechanisms behind probe response and upscaling to reservoir scale.

A new setup with 5 internal pressure probes for measuring in-situ water pressure with higher oil pressure was successfully designed and tested. An advanced watering system to inject water to the probe tips was included in the test setup and can be operated automatically. Experimental results showed that the water-wet probes can measure low water pressure inside high pressure oil column. The change in water pressure during drainage of low permeable Mons core and medium permeability Berea core was continuously measured. The probes were able to measure water pressure in different sections of the core with change of water saturation in the core. After the drainage process, the water pressure at one side of the core was increased. The propagation of water pressure at low water saturations were then detected in the 5 probes along the core sample.

This paper presents a revolutionary technique to measure pressure in a thin film of water with low mobility. Continuous monitoring of water pressure inside the hydrocarbon phase can be used to enhance the production on a well level and improve the strategy on a field level. This results in increased production, reduced operational costs and environmental impacts.
Viscoplastic Deformation During CO2 Storage in Danish Chalk Reservoirs: Role of Petrophysical Heterogeneity and Mechanical Alteration
Authors: Amour Frédéric , Hosseinzadehsadati Seyedbehzad , Nick Hamidreza M.
Published: June 2023

Denmark aims at a 70% reduction in greenhouse gas emissions by 2030 compared to levels measured in 1990, with a long-term target of becoming carbon-neutral by 2050. As part of this national effort, the Bifrost project, aims at repurposing two depleted gas fields in the Danish North Sea for CO2 storage, namely the Harald West sandstone field as the primary target and the neighboring Harald East chalk field as a potential upside. The Harald East chalk is the focus of this study. The storage potential and infrastructures available within the multiple chalk fields located in the Danish North Sea represent valuable assets to fulfill the national objectives enabling a time- and cost-efficient implementation of carbon storage activities. One of the main challenges for carbon storage in chalk is the contradictory experimental results reported in literature that indicate both a strengthening and a softening effect of supercritical CO2 on the plastic and elastic properties of chalk. Such uncertainty hampers accurate prediction of the deformation response of storage sites. In this context, the study aims at assessing the impacts of two levels of uncertainty; the type of mechanical alteration induced by supercritical CO2 and the petrophysical heterogeneity on the long-term deformation behaviour of chalk reservoirs. An in-house hydro-mechanical-chemical model calibrated against experimental data on chalk is applied in a reservoir model of the Harald East field. A 16 year-long injection period is simulated assuming two scenarios. In scenario 1, supercritical CO2 has no impact on the mechanical properties of the rock, whereas in scenario 2, a 30% and 25% lowering of the pore collapse stress and elastic modulus of chalk is assumed. A systematic comparison of the flow and mechanical behaviour of low and high porosity cells located in the vicinity of an injection well indicates that the impact of CO2 on the mechanical properties of chalk, the distance of the cells from the injector, the local stress redistribution taking place in the reservoir between mechanically soft and strong cells, and the presence of natural gas in pore space before CO2 injection are key factors controlling the amount and distribution of plastic deformation occurring in the storage site. The outcome of this work enables quantifying the main risks associated with rock compaction close to and further away from injectors during and after carbon storage in chalk fields.
Permeability Estimation Using Machine Learning Techniques for a Heterogeneous Mud Dominated Carbonate Reservoir, Offshore UAE
Authors: Contreras Perez David Rafael , Sellar Christopher , Valente Alexander
Published: June 2023

The implementation of Artificial Intelligence and Machine Learning algorithms has introduced the opportunity for alternative techniques to estimate permeability within uncored intervals/wells. Different combinations of input data and different approaches for training values were evaluated to select a consistent predictive model able to produce permeability logs while honoring the geological concept and available core permeability measurements.

The approach presented here is deployed in a low porosity, low permeability hydrocarbon bearing carbonate reservoir with a limited dataset, aiming to estimate a permeability log from available wireline log and core data. The geological description from core in Reservoir 3 indicates the presence of oil saturation in mud-dominated carbonate rocks with a moderate degree of calcite cementation. After a rigorous quality check of the available permeability measurements from conventional core analysis data, a high confidence database of porosity and permeability measurements were combined with existing wireline logs (e.g. GR, Resistivity, Neutron Porosity and Archie Water Saturation). The resulting structured dataset was used for permeability prediction using Random Forest regression (from scikit-learn in python).

Three cases of permeability logs were generated from this methodology at well log resolution to be used in static reservoir modeling and saturation-height-modeling with J-functions. The permeability and saturation height models are key inputs for dynamic modelling to generate production forecasts in this undeveloped reservoir. Three different permeability models were trained using 144 high quality core plug measurements from six cored wells. Even though the number of available samples can be considered low for a machine learning workflow, an oversampling approach with point repetition was adopted to overcome data insufficiency for this dataset.

From an E & P point of view, accurately predicting reservoir permeability in hydrocarbon reservoirs has been one of the major challenges facing the industry for decades. The approach outlined here reduces uncertainty in permeability prediction in the uncored interval. Furthermore, since permeability is part of the estimation of water saturation, this approach reduces uncertainty in water saturation interpretation, the potential deliverability of flow units and the volumetrics.
Numerical Investigation of the Primary Mechanisms Leading to Complex Fracture Morphology in the Near-Wellbore Region
Authors: Kryvenko Serhii , Moridis George Julius , Blasingame Thomas Alvin
Published: June 2023

This paper presents the results of numerical simulations of hydraulic fracturing in the immediate vicinity of the wellbore. This research aims to identify the primary mechanisms underlying the complexities in both the fracture morphology and propagation of longitudinal fractures. The study shows that the perforation attributes and characteristics, the cement quality, and the reservoir heterogeneity have a significant impact on the resulting morphology and the trajectory of the propagating hydraulic fracture.

The study is based on properties and conditions associated with a field study conducted in the Austin Chalk formation, and concludes that the pattern and the dimensions of the perforations are essential factors controlling the fracture initiation pressure and morphology. The results of the simulation studies provide insights into the principles and mechanisms controlling fracture branching and the initiation of longitudinal fractures in the near-wellbore region and can lead to improved operational designs for more effective fracturing treatments.
Novel Acid Stimulation Technique for Production Improvement – Austrian Eocene Case Study
Authors: Smith Fraser Troy , Hadziavdic Ina
Published: June 2023

A new approach to acidizing is presented where an inert dry chemical is hermetically sealed inside a metal carrier and deployed downhole via E-line or slickline. The tool is spotted in front of the zone of interest and an exothermic reaction is initiated generating hot acid vapour. A depleted Eocene sandstone reservoir with a 2 7/8″ tubing inside 6 5/8″ casing was successfully treated leading to sustained production enhancement in addition to significant carbon footprint reduction when compared to a conventional treatment. The treatment approach, production results and description of the CO2 reduction is presented. A rigorous well candidate selection process was done as part of the treatment design which analyzed information including damage mechanism, well completion architecture, mineralogy, well deviation, formation type and compatibility. Based on this analysis, the tool type and tool placement sequence were determined to optimize the stimulation. For this well, two 2″ HCl and two 2″ 12:3 HCl/HF tools were used to treat a 5.5 m perforated interval. The HCl tools served as pre-flush treatment and removed any scale. This was followed by 12:3 HCl/HF tools which stimulated the near wellbore matrix and ultimately improved the reservoir fluid influx. After each tool was ignited, a drop in the fluid level was observed. This was positive indication that the acid vapour was enhancing connectivity to the reservoir. When pulled to surface, it was observed that all four tools had ignited and had undergone a complete chemical burn.

The well had several tubing and pump changes throughout its long production history. More recently, the well was treated by bullheading EDTA and solvent to re-establish the oil production rate with unsatisfactory long-term production results. Prior to the novel treatment, the well had been producing at 9 – 11 m3/d (gross rate) and 1.8 m3/d of oil. After the application of the novel technique, the production results showed a return to the historical rate of 1.8 m3/d of oil (100% increase). Eighteen months post-treatment, the oil production is sustained and producing between 1.5 - 1.6 m3/d. Flow-back equipment was eliminated from the operation since the highly reactive hot acid is fully spent and dissipated. The operation was rigless and the only equipment required was a wireline unit, a crane, and a small fluid truck. The entire stimulation was completed in less than one day and the well could be put immediately back on production.

A secondary benefit was a notable reduction in CO2 associated with this treatment method versus a conventional acid treatment. This was achieved by reducing the heavy equipment requirements and the associated diesel consumption.
Research on Multiple Coal Seams Relative Permeability Calculation Method Based on Production Data Inversion
Authors: Huang Tianhao , Wang Zhiming , Zeng Quanshu
Published: June 2023

To obtain the actual gas-water relative permeability of the coalbed methane (CBM) reservoir and further deepen the cognition of the gas-water production law of multiple coal seams, a relative permeability calculation method based on production data inversion is constructed. Based on production data, historical fitting is carried out through the multiple coal seams whole process coupling flow model, and the basic physical parameters of each layer are inversed. Based on the obtained physical parameters, the productivity prediction of the whole production cycle is carried out. By calculating the average water saturation and gas-water relative permeability in each iteration time step, the average gas-water relative permeability curve of the reservoir in the target period is finally obtained. The results show that the calculation method proposed in this paper can realize the acquisition of the relative permeability curve in the given period. Compared with the input relative permeability curve, there is a reverse point on the output relative permeability curve that can represent the continuous production of desorption gas. Gas production is affected significantly by different types of initial input relative permeability curves, and is mainly influenced by the input relative permeability curve at the initial production stage. Under ±30% deviation, the average difference in cumulative gas production is 16.92% (3 years). During the production of CBM wells, the average water saturation was maintained at a high level. At the end of the production of multiple coal seams commingled production well, the average water saturation change is less than 15%. Restricted by high water saturation, the average relative permeability of the gas is always maintained at a low level, less than 0.1 at the end of production of actual production wells. The fundamental technical difficulty in realizing the initial high production and subsequent sustained and stable production of CBM wells lies in how to reduce the reservoir water saturation effectively and improve the relative permeability of the gas, so as to promote the desorption of adsorbed gas and the sustained CBM production.
Investigation of Subsurface Integrity of Depleted Porous Gas Reservoirs for the Purpose of Hydrogen Storage
Authors: Andiappan Anitha , Pichler Markus , Bauer Stephan
Published: June 2023

Geographical and seasonal differences in the supply and demand of renewable energy is a great challenge for building a sustainable future energy system. One approach is to store renewable energy in the form of hydrogen in existing depleted underground gas reservoirs and retrieve this energy on demand. However, it is unknown if the storage of hydrogen is technologically feasible, specifically if hydrogen can be stored in the same way as natural gas in porous reservoirs and if there are negative impacts on integrity and safety of the surface and subsurface storage facility. To answer these questions, RAG Austria AG has conducted field and laboratory experiments in the past decade. We have injected gas mixtures containing up to 20 volume percent of hydrogen into a depleted porous gas reservoir as part of the field test.

First, we evaluated the gas composition, downhole pressure and temperature measurements as well as microbial data from the field test. Our findings suggest changes in the composition of produced gas, however no negative effects on reservoir integrity and no apparent geochemical effects. Next, we investigated the tightness of the caprock against hydrogen intrusion. The experimental results show that the behavior of hydrogen in the sealing materials is similar to that of natural gas. Furthermore, laboratory experiments with pure hydrogen revealed that diffusion effects in reservoir rocks can be neglected for the timeframe of seasonal gas storage. Taken together, these first results indicate that storage of hydrogen in depleted porous gas reservoirs could be a way forward to have hydrogen as a more reliable and versatile energy carrier. Still, we need to gain more insights regarding safety and technical feasibility for the underground storage of pure hydrogen. To address this, RAG Austria AG will start an unprecedented field test with pure hydrogen in a porous depleted gas reservoir in 2023.