bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparación de dos tratamientos pasivos para disminuir la concentración de metales pesados en drenaje ácido de minas: cálcico-magnésico y alofánico-magnésico
Authors: Collahuazo Luis , Hermosa Paola , Buitrón Diana , Rojas Cynthia , Guzmán-Martínez Fredy
Published: February 2025

El drenaje ácido de mina (DAM) es un desafío ambiental de la actividad minera que debe atenderse en el corto plazo. Este estudio compara a escala laboratorio la utilización de dos sistemas de tratamiento pasivo para DAM, con el objetivo de disminuir la concentración de elementos potencialmente tóxicos (EPT). El muestreo del DAM fue realizado en la microcuenca del río Santa Rosa, Ecuador. El tratamiento se llevó a cabo en dos sistemas con lechos combinado: un sistema cálcico-magnésico y un sistema alofánico-magnésico. El DAM fluyó a través de cada sistema durante 50 días. Durante el tratamiento se registró el pH, la conductividad eléctrica y el potencial redox; se cuantificaron los EPT mediante espectrometría de masas de plasma (ICP-MS) y se determinaron los sulfatos mediante espectrofotometría ultravioleta (UV). Inicialmente, el DAM tenía un pH de 2.4 y la concentración de As(0.7), Cu(2.5), Ni(0.4), Zn(10.2) (en mg/L) sobrepasaba los valores de referencia establecidos en la legislación ambiental ecuatoriana. Una vez tratado el DAM, en ambos sistemas se disminuyó la concentración de los EPT hasta abajo de los valores de referencia [As(0.05), Cu(0.02), Ni(0.02), Zn(0.18) (en mg/L)]. Asimismo, los resultados mostraron que no hay diferencias estadísticamente significativas entre ambos sistemas, lo que redituaría en la disminución de costos en el tratamiento del DAM debido a la disponibilidad de alófano en Ecuador. Finalmente, se encontró un incremento en la concentración de sulfatos en ambos tratamientos, lo que representa una desventaja y, al mismo tiempo, una futura línea de investigación de este trabajo.
Place of dairy products in the structure of a healthy diet
Authors:   Federal Research Centre of Nutrition, Biotechnology and Food Safety, Moscow, Russian Federation, Pilipenko V.I.
Published: February 2025

Dairy consumption is an important part of a healthy diet and affects the essential health indicators: body weight, glucose and cholesterol levels, blood pressure, and bone density. However, the presence of microRNA exosomes in milk has dysregulatory epigenetic effects on the transcription activity of the fat mass and obesity-associated protein (FTO), key metabolic regulation genes (INS, IGF1, CAV1, GLUT1, LCT), intestinal and systemic immune control transcription factors (NRF2, SREBP1, FOXP3, NR4A3). Loss of epigenetic control of transcription of these genes leads to excess food intake, rapid weight gain, and increased risk of diseases of civilization. Since avoiding the consumption of dairy products is undesirable due to their irreplaceability as a source of readily available calcium and several other nutrients, replacing whole milk with fermented dairy products with a spectrum of additional health benefits may address this problem.
Key words: milk, fermented dairy products, microbiome, exosomal RNAs
Opportunities for diet optimization in women during pregnancy and lactation
Authors:   Federal Research Centre of Nutrition, Biotechnology and Food Safety, Moscow, Russian Federation, Gmoshinskaya M.V. , Gordeeva E.A. ,   BIBICALL RUS, LLC, Moscow, Russian Federation
Published: February 2025

It has now been proven that diets consisting only of natural (traditional) foods cannot fully meet the nutrient requirements of the human body, especially in women during pregnancy and lactation. This article considers the issues of fortification of food products and the possibility of their use in creating the diet for pregnant and lactating women on the example of a drink based on goat’s milk.
Key words: pregnant and lactating women, goat’s milk
Familial cases of microvillus inclusion disease – management experience with home parenteral nutrition
Authors:   N.F.Filatov Children’s City Clinical Hospital, Moscow, Russian Federation, Chubarova A.I. ,   N.I.Pirogov Russian National Research Medical University, Moscow, Russian Federation, Kostomarova E.A. ,   N.F.Filatov Children’s City Clinical Hospital, Moscow, Russian Federation, Korchagina N.S. ,   N.F.Filatov Children’s City Clinical Hospital, Moscow, Russian Federation,   N.I.Pirogov Russian National Research Medical University, Moscow, Russian Federation, Smolyannikova A.B. ,   N.I.Pirogov Russian National Research Medical University, Moscow, Russian Federation, Shumilov P.V. ,   N.I.Pirogov Russian National Research Medical University, Moscow, Russian Federation
Published: February 2025

Microvillus inclusion disease or microvillus atrophy (MVID) is a genetic disorder caused by mutations in the MYO5B gene. It is characterized by intractable diarrhea and dependence on parenteral nutrition. This article presents three cases of MVID in children from two families. In case 1, the child was found to have the c.1705A>T mutation (Chr18: 47479677, NM_001080467.2) in homozygote, with both parents being heterozygous carriers. In case 2, both parents were heterozygous carriers of previously undescribed mutations (mother – 782T>C (GRCh37 – 47516865, NM_001080467.2), father – 664A>T (GRCh37 – 47518750, NM_001080467.2)), both heterozygous mutations were inherited by the eldest child (case 2), the maternal heterozygous
mutation was inherited by the youngest child (case 3). In all three children, the disease manifested during the first 10 days of life with dehydration, metabolic acidosis, respiratory failure, and oliguria. In case 2, the child died at the age of 5 months. The other two children were followed-up until 4.5 years of age (case 1) and 1 year of age (case 2). Common manifestations included diarrhea of 100 to 300 mL/kg/day, dependence on parenteral nutrition, delay in physical development despite hyperalimentation, frequent episodes of metabolic acidosis, and a tendency to venous thrombosis. In case 1, the child developed secondary Fanconi syndrome at the age of 2.5 years. In all children, the diagnosis was confirmed histologically by the detection of PASpositive material and CD10 marker in the cytoplasm of enterocytes. The article presents the differential diagnosis and therapeutic options for MVID. The observed cases demonstrate the possibility of a typical clinical and morphological presentation
of MVID in both homozygous mutation and compound heterozygous mutation and one heterozygous mutation.
Key words: microvillus inclusion disease, congenital diarrhea, microvillus atrophy, malabsorption, children, infancy, mucosal atrophy
The Quality of Yogurt Drink with Guar Gum and Cornstarch as Stabilizer
Authors: Rahayu Premy Puspitawati , Unur Desi , Fathimah Fathimah , Nursafitri Elsa , Asadel Bintang , Yunita Citra Nur , Purwadi Purwadi , Tohari Imam , Jaya Firman
Published: February 2025

Objective: This study aims to determine the effect of using guar gum and cornstarch as stabilizers in Yoghurt drinks and to determine the stability of Yoghurt drinks.

Methods: The method used 2 stages of research. Stage 1 of the research used a completely randomized design (CRD) with 6 treatments and 3 replicates, T0 (Control); T1 (0.4% Guar gum); T2 (0.3% Guar gum and 0.1% cornstarch), T3 (0.2% Guar gum and 0.2% cornstarch), T4 (0.1% Guar gum and 0.3% cornstarch), and T5 (0.4% Cornstarch). Stage 2 of the study used a completely randomized design (CRD) nested pattern related to different storage periods, H1 (7 days), H2 (14 days), H3 (21 days), H4 (28 days), H5 (35 days) with the same treatment and replication. Data were analyzed using the Analysis of Variance.

Results: The results of stage 1 showed that guar gum and cornstarch as stabilizers had a significant effect (P<0.01) on viscosity, syneresis, and water holding capacity, significant effect (P<0.05) on pH, protein, lactose, and showed that no significant effect (P>0.05) on fat, moisture, total titratable acidity, and LAB content. The results of stage 2 showed that different storage periods had a very significant effect (P<0.01) on viscosity and pH. There was no significant effect (P>0.01) on LAB content.

Conclusions: It was concluded that guar gum and cornstarch can maintain the quality of the Yoghurt drink for 6 weeks of storage.
A case study at Sumber Market on factors influencing beef demand among housewife consumers
Authors: Perwitasari Fitri Dian , Setiani Desi , Bastoni Bastoni , Arisandi Bayu
Published: February 2025

Objective: Beef demand has not been met by beef production household customers are among the many types of beef consumers. Household customers are one type of beef consumer among many others.  The objectives of this study are 1. to analyze the factors influencing beef demand, 2. to determine what factors influence beef demand in Cirebon Regency Traditional Source Market, and 3. to analyze income elasticity, beef price demand, and cross elasticity.

Methods: The research method is a case study located in Sumber's traditional market. Respondents totaled 68 respondents housewives. Data analysis using multiple linear regression was conducted using SPSS version 25.

Results: The results of this study test simultaneously variable X, which has a real influence on variable Y. Factors that affect the demand for beef in the Sumber market are income and family size. The elasticity of demand for beef prices on weekdays is inelastic. While the price elasticity of demand for beef on the five days before Eid al-Adha and Eid fitri is positive if the price increases by 1%, the demand for beef will increase by 0.591 kg and 0.864 kg. The income elasticity is 0.343, which means that if there is a 1% increase in income, beef demand will increase by 0.343 kg. The positive income elasticity value indicates that people's income is directly proportional to beef consumption around the Sumber Sub-district area and beef is a normal good. Cross-elasticity is inelastic where if broiler meat prices increase by 1%, the demand for beef will increase by 0.319 kg.

Conclusions: factors influencing beef demand Case study in traditional markets Sources It can be concluded that the factors influencing beef demand are income, number of family members and consumption. The elasticity of the demand for feeding, the price of beef, and the elasticity of the cross are inelastic.
Research of the Effective Diffusion Coefficient and Activation Energy for the Purpose of Energy Saving during Convection Dryin
Authors: Safarov J. E. , Sultanova Sh. A. , Gunes G. , Ponasenko A. S. , Samandarov D. I. , Pulatov M. M. , Mirkomilov A. M. , Nasirova M. A.
Published: February 2025

In this study, the calculation and mathematical modelling of effective diffusion coefficient and activation energy in convective drying of a product were investigated. The shrinkage coefficient for different temperatures was also calculated. The effective diffusion coefficient was calculated using Fick’s law developed for finite cylindrical geometry. Using the effective diffusion coefficient equation for air temperatures of 45, 55 and 65 °C, the results were obtained as 2.02 ∙ 10–10, 5.05 ∙ 10–10 and 8.08 ∙ 10–10 m2/s, respectively. The activation energy was calculated as 61.1 kJ/mol using the slope of the graph ln(Def)–1/T. The product shrinkage coefficients at drying air temperatures of 45, 55 and 65 °C were found to be approximately 23, 32 and 40 %, respectively. In order to find the most suitable mesh structure of the model, a network independence study was carried out using average moisture content values with an accuracy of 0.001. Nonlinear simultaneous heat and mass transfer equations for 45, 55 and 65 °C dehumidifying air are solved by the finite element method (MATLAB) with initial and boundary conditions. The equations are solved with a tolerance value of 0.001 for thirty minutes time steps. The initial conditions used in the analyses and the thermophysical properties of the product are detailed in tables and graphs. The data obtained from the experimental and numerical solution were compared and it was seen that the results were compatible with each other. According to this result, a mathematical model expressing simultaneous heat and mass transfer can be used to predict the moisture and temperature distribution in the product during drying.
Implementación del sistema web Berezin empleando metodologías ágiles para la gestión de reuniones académicas en entidades educativas 2024, caso IES – UCSUR
Authors:   , Carbajal Moquillaza Alexander German , Silva Yovera Cinthya Maribel
Published: February 2025

La presente investigación tiene como objetivo la implementación del sistema web Berezin, desarrollado bajo metodologías ágiles, para optimizar la gestión de reuniones académicas. El estudio se centró en la problemática de la coordinación ineficiente de horarios entre alumnos y docentes, así como entre los propios docentes, la cual usualmente se gestiona de manera manual, resultando en pérdida de tiempo y conflictos de disponibilidad. El sistema ofrece funcionalidades clave como el registro de disponibilidad de horarios, la creación y gestión de reuniones, y la generación de reportes de actividades. Estas funcionalidades permiten a los usuarios agendar reuniones de manera eficiente y automatizada, mejorando la organización del tiempo y reduciendo conflictos de programación, asimismo, se optimiza el proceso de planificación y ejecución de reuniones académicas. Los resultados sugieren que la adopción de soluciones tecnológicas como Berezin puede mejorar significativamente la eficiencia en la gestión de reuniones en el ámbito educativo, debido a que, en base a una simulación se llega a la conclusión que el proceso de gestionar una reunión entre docentes y con alumnos, con el sistema demora 1 hora y media; mientras que con el método tradicional el tiempo estimado es de hasta 12 horas según indicado por los propios docentes.
Challenging the 30 m Annulus Cement Requirement
Authors: Arild Øystein , Lohne Hans Petter , Ford Eric Patrick
Published: February 2025

The permanent plugging and abandonment of a well requires the establishment of at least two barriers according to the NORSOK D-010 standard. In common practice, a barrier is either a cement plug from formation to formation, which is all cement, or a combination of existing cement behind the annulus, the casing steel itself and a cement plug inside the casing, see Figure 1. The latter case is a cheaper and preferred solution as milling can be avoided and thus reducing cost, environmental footprint and a number of potential operational hazards. The cement between the casing and the formation is called the cement sheath and has typically been in place since the well was constructed. The evaluation of the status of this barrier element after years of production – called verification in many standards – is conducted using different types of logs. Leakage through the cement sheath can happen in three ways; along the interface between the cement sheath and the casing, leakage through the bulk cement itself as the cement has a certain permeability, leakage in cracks or channels present in the cement sheath and finally leakage between the cement sheath and the formation. Significant leakage through the cement sheath prior to permanent P&A typically causes an increased annulus pressure, which is monitored and dealt with if it happens prior to permanent P&A.

In order to qualify the cement sheath when using the NORSOK D-010, 30 m of good bonding is required, i.e. the interface between casing surface and the cement is good in terms of that it most likely will not represent a leakage path along the interface, so called micro annuli. Logs are best at detecting interface phenomena and good logs means that we have strong indications that there are no micro annuli, but logs may also indicate weaknesses in the bulk cement between the casing and the formation.

While NORSOK D-010 has a set of plug length requirements, it might not necessary be the same in all countries (see for example [1] for an overview of plug length requirements). No matter what length criterion has been established, there is very little documentation of why the specific number was chosen. One could argue that it has been based on best practices and that there are no indications of reservoir fluid leakage from permanent P&A-ed well on the Norwegian Continental Shelf. It is also worth noting that the 30m requirement is independent of well and reservoir characteristics. This means that the 30 m applies to a high pressure high temperature case as well as to a low pressure low temperature case. There are special cases where deviations have been accepted and Norwegian regulations accept a risk-based approach to barrier construction and thus plug length, but by and large it is the NORSOK D-10 that is driving the construction of barrier elements in a permanent P&A-setting in Norway.
In-Situ Evaluation of Casing-Cement Debonding During Cooling
Authors: Feneuil B. , Larsen I. , Opedal N. , N’gouamba E. , Wiggen E. , Haug J. , Nordhus I. S. , Skorpa R.
Published: February 2025

Cement annulus is essential to prevent the migration of geological fluids along the well. However, temperature and pressure variations in the casing may damage the annulus and create leakage paths, either cracks in the cement or debonding (microannulus) at the interface with the casing or the rock. Understanding when damage occurs, and how severe it is, is essential to ensure safe operations. In this paper, we present experimental results obtained with the small-scale setup described in (Feneuil et al., 2024), and we study microannulus formation and geometry in two different samples. Both samples are prepared in the laboratory, they comprise of a Portland G cement cylinder (diameter 5 cm, height about 4 cm) placed around a 17-mm diameter steel casing. The setup allows for the evaluation of debonding between the casing and the cement by three different techniques: Pulse-Echo acoustic logging, gas-leakage tests and 3D visualization with X-ray Computed Tomography. With the first sample, we evaluate how the casing-cement bond changes during two temperature cycles from 23°C to -20°C. We show with the acoustic logging tests that cooling down the sample by 30°C below the curing temperature did not affect the casing-cement bond. Clear debonding was triggered after cooling down by 40°C, the former microannulus is heterogeneous, and does not provide a leakage path. The second sample contained a large pre-formed microannulus. The CT pictures show that the microannulus thickness reaches locally several 100 µm, however, the leakage tests reveal that the flow is constrained by the regions of smaller debonding, as the effective microannulus size is about 1 µm. In addition, we observe that the microannulus size is affected by the value of the confinement pressure. The setup and method described here will be further used to compare the efficiency of different sealing materials and as input for simulation work.
Dual Approach in Autonomous Directional Drilling: Innovations with Drillbotics 1.5 Inch Automated RSS and Virtual Rig Platforms
Authors: Soilemezidis C. , Mensah J. S. , Hollstein W. , Al Maasarani K. , Alkhawaja A. , Jamali F. , Dörfler G. , Hölzner N. , Jarbouh K. A. , Ustaoglu D. , Alukkal A. T. , Gudhane L. A. Y. , Jaeger P. , Feldmann E. , Carvajal C. A. P. , Yin A. O. , Sinkuu L. , Quayson J. , Amoah F. B. , Yahaya H. S. , Owusu K. A. , Dongoyo C. K. N. , Owusu A. , Amorin R. , Florence F.
Published: February 2025

SPE’s Drilling Systems Automation Technical Section (DSATS) sponsors the Drillbotics® autonomous drilling contest to promote advanced learning at participating universities. Two groups worked separately to drill a directional well hands-free and to connect to a well model to detect/close in a kick. This paper consolidates the efforts of both teams. Team A, the directional drilling team from the University of Mines and Technology (UMaT) in Ghana, developed a virtual model that replicated full-scale directional drilling operations, facilitating the development and testing of innovative control schemes and automation strategies. Leveraging state-of-the-art drilling software, real-time data analytics, and advanced control systems, the project demonstrated the potential of automated drilling technologies across both the planning and execution phases of drilling projects. Team B, from Technical University Clausthal (TUC) in Germany, designed and built a mini-rig that included a working scaled version of a rotary steerable system (RSS) tool to steer a wellbore through a block of sandstone to reach two non-planer targets. The work incorporates machine learning techniques to evaluate downhole sensor data and improve steering signal input. The modular design of the second-generation surface actuation system offers a more compact and efficient solution than its predecessor. The control architecture and network protocols are analyzed, demonstrating network delays of under 2 msec using a refined second-generation translator setup. The achievements of both teams are important to the future of drilling automation, as their approaches could be used to verify and validate third-party app’s communications prior to field release on full-scale rigs.
Remote Operation Support Based on Wearable Augmented Reality: Challenges and Field Deployment
Authors: AlRawi Layth Nabeel , Wang Lei , Socha Troy
Published: February 2025

In response to the evolving demands within the oil and gas (O&G) industry, this paper examines the integration of augmented reality (AR) headsets in remote operation support, focusing specifically on the challenges encountered, field deployment strategies, and considerations for global scalability and ongoing technology development. Four case studies—remote equipment surveys and troubleshooting, tubular thread inspection, field auditing, and rig site operations—are presented to demonstrate how these technologies can enable feasible solutions for remote support and collaboration, which transform traditional operational paradigms. By leveraging AR and related remote technologies, operational efficiency, safety, and cost-effectiveness are enhanced. However, the implementation of AR in harsh and remote environments introduces unique challenges. Key obstacles, including environmental conditions, connectivity limitations, data security, ergonomic constraints, and user adoption barriers, are highlighted and addressed through various mitigation strategies. For example, ruggedized and explosive atmospheres (ATEX)--compliant AR devices were deployed to withstand tough environmental conditions at drilling rigs. To manage connectivity issues in remote locations, private networks, and encryption protocols were implemented to ensure secure, stable communication channels necessary for real-time support. Comprehensive user training programs were introduced to facilitate smooth adoption and to deliver practical benefits to users. In addition to addressing these challenges, the impact of global deployment strategies and continuous technology development on maximizing the effectiveness of AR in the O&G industry is outlined. Significant operational improvements are indicated by the findings from these case studies, including a reduction in travel-related expenses and carbon emissions, enhanced accuracy in remote inspections, improved safety protocols, and decreased maintenance costs. These results underscore the transformative potential of AR when thoughtfully implemented with robust support systems, highlighting its ability to drive productivity and sustainability in O&G operations globally.

Our findings suggest that AR, paired with comprehensive challenge mitigation strategies, offers a valuable model for future applications across the industry. With continued advancements in wearable technology, remote support can further evolve to meet the industry’s demands for operational efficiency, safety, and environmental sustainability.
Qualification of Two-Part Granite-Based Geopolymers for Field Testing
Authors: Khalifeh M. , Kamali M. , Taheri A.
Published: February 2025

A two-part granite-based geopolymer alternative to ordinary Portland cement (OPC) was designed and tested, progressing from laboratory scale to yard scale. The mix design was proposed and evaluated based on API laboratory standards. Further, the hydraulic sealing performance was assessed using a 5-inch tubular in the lab. The recipe was scaled up to mix 450 liters of geopolymer slurry, intended to fill an 8-meter, 9 5/8-inch pipe. During the yard-scale mixing, samples were taken periodically, and the properties were compared with lab-scale data. The geopolymer mixing process met expectations for field application. Additionally, the results from rheology measurements and strength development fell within the range of lab data. Hydraulic sealability tests, both in the lab and in yard trials, depicted that the granite-based geopolymer can provide hydraulic sealability up to 20 bar of differential pressure across the testing pipe.
Assessing a Novel Glass-Based Fluid for Annular Barrier Remediation in Cemented Well Sections
Authors: Taheri Amir , Wolterbeek Tim , Olsen Max , Hatlebakk Ragni , Gardner Dave , Kragset Steinar
Published: February 2025

This study investigates a novel glass-based fluid for sealing microannuli in cemented well sections, aiming to enhance well integrity. The research focuses on assessing the material's sealing efficiency, permeability changes before and after remediation, and performance under pressure and drying conditions. Tests were performed on a vertically-oriented, 50 cm-long cemented annulus section, constructed using 7-inch inside 9-⅝ inch diameter casing pipe. After inducing a microannulus, baseline permeability was measured using gas and water at 80°C. Subsequently, glass-based fluid was injected using a modified hesitation squeeze method. Post-remediation tests showed a significant reduction in water permeability, from 4.8 mD to 10 µd, demonstrating successful sealing. Durability was further evaluated through pressure loading, drying, and self-sealing tests, confirming the material's effectiveness under various conditions.

The study revealed that the fluid's sealing properties and water-like rheology enable it to address microannuli where traditional squeeze cementing operations struggle, particularly in low-injectivity scenarios. Although some challenges remain, such as performance in larger defects and long-term durability, the findings indicate that glass-based fluids have significant potential for sealing defects in cement. The study also recommends further research to optimize operational procedures for field application of the glass-based fluid in well environments.
Quantifying the Impact of Cuttings and Fluid Properties on Friction Coefficient in Torque & Drag Analysis
Authors: Baldino S. , Ozbayoglu E.
Published: February 2025

This paper aims to enhance the accuracy of torque and drag (T&D) predictions by quantitatively analyzing the impact of cuttings bed and fluid properties on the friction coefficient (FC). The study focuses on directional and horizontal drilling operations where these factors significantly influence drilling performance. A large-scale testing facility was employed to investigate the effects of cuttings bed height and fluid properties on T&D. Torque measurements were taken under various RPMs, at on and off bottom conditions, with different water-based fluids and cuttings concentrations. By varying those conditions, the study measured the resulting torque and used these data to accurately determine the friction coefficient. An LSTM machine learning model was also utilized to predict and detect downhole anomalies in real-time, providing a surface-torque based data-driven tool able to recognize excessive friction in hole and thus estimate the stuck pipe risk during drilling operations. For unweighted water-based fluids, friction coefficients were quantified as 0.31 for no cuttings, 0.45 for low/medium cuttings bed, and 0.52 for high cuttings bed. In the absence of cuttings, polymers-based fluids showed lower torque due to high lubricity (lowest FC of 0.28), while weighted fluids were affected by barite's abrasiveness leading to the highest average FC of 0.34. Additionally, the study observed that the presence of cuttings disrupted the lubricating effect of polymers, leading to a friction coefficient of 0.48, approaching the one observed for water and high cuttings bed. Due to abrasiveness, weighted fluids peaked at 0.55. Trained, tested and validated with the collected experimental data, the LSTM model accurately predicted surface torque under varying RPM and weight on bit conditions, effectively detecting anomalies caused by poor hole-cleaning. These findings offer a comprehensive quantification of the impact of cuttings and fluid properties on the friction coefficient and introduce a surface-torque based real-time tool for stuck-pipe risk evaluation. This can lead to better management of drilling operations and reduce risks associated with poor hole-cleaning and high friction. This study presents a systematic effort to quantify the effects of cuttings and fluid properties on friction coefficients under controlled conditions and on a large-scale facility. The integration of machine learning for real-time anomaly detection and the detailed quantification of FCs offers enhanced predictive tools and valuable insights for improved T&D analysis. These contributions can benefit well engineers by providing a more accurate and reliable basis for both the design and operational drilling phases.
A Study of Instabilities Observed When Heave Compensating Deepsea Risers
Authors: Kyllingstad A.
Published: February 2025

This paper discusses an instability phenomenon sometimes observed on drillships when latching or unlatching a long riser to the well head while the drawworks is operating in the active heave compensation (AHC) mode. The paper starts with presenting field data clearly showing an incident of instability. Next, it focuses on the physical causes or conditions for instabilities to occur. The root cause is identified to be an inherent and poorly dampened bending mode of the entire drillship. This mode has a natural frequency equal to the vibration frequency observed during the instability event. Two additional causes are also discussed in some details: the complex dynamics of the riser and the dynamics of the drawworks and its control system when run in the AHC mode. The dynamics of all 3 systems are coupled to give an analytic formula for the decay rate of the ship vibration mode. This formula is used for predicting the conditions when the decay rate is negative, and instability can occur. The paper also includes results from an advanced simulation model.

The results from this model confirm the predictions from the analytic analysis. Finally, various proposals for solving the instability problem are briefly discussed.
A Quantitative Drilling Fluids Advisor
Authors: Whyte J. M.
Published: February 2025

The management of drilling fluid properties has, in most cases and continues to be a highly manual process. A combination of infrequent measurements of insufficient accuracy, fluids data not being stored as a time series, limited understanding of the interactions between critical components and low levels of mixing system automation has made the creation of a system to advise on fluid treatment a considerable challenge. Our solution is to create a fluids advisor - a system of inter-connected algorithms, which work together to give quantitative recommendations of fluid treatment and management. We achieve this by combining field data collection and analysis with an in-depth physicochemical understanding to enable automated treatment advice. This advisory system was tested successfully during the drilling of two oil-based and one water-based sections in the UK North Sea.

The advisor's self-learning framework creates a workflow that encompasses the automated detection of critical fluid treatment decisions points, calculates the exact quantities of treatments required to achieve an objective and can autonomously decide if a treatment action should be taken. In addition, the advisor automatically detects the presence of contaminants in the fluid and any operation on the rig that affects the fluid system (Fluid States). This is achieved using a hybrid data-physics model created using sequential design of experiment (DoE), combined with extensive experimental work on fluid formulation and incorporation of contaminants and low-gravity solids. This allows the determination of fluid properties resulting from any treatment made to the fluid system and to prescribe quantitative treatments to fluid engineers. A self-learning data framework enables treatment recommendations from the model to be modified during and after each operation to improve advice and predictions for future operations.

Advice provided to the offshore engineers consisted of qualitative advice on different treatment and operational decision points and quantitative recommendations on what treatments were required to achieve a particular objective. 100% of qualitative recommendations were accepted by the offshore engineers with 75% being implemented immediately. Changes to properties due to treatments were predicted accurately with a MAPE of ∼5% across an API fluids check, indicating the excellent agreement between measurements and prediction. The rig's fluids engineers used the advisor (via remote operations) to optimise treatments to the fluid system. Overall, use of the advisor used 15.4% less chemical additives than offset sections.

Our approach combines both physics and data with innovative work on clay exfoliation to enable truly accurate, quantitative fluid treatment recommendations. For the first time, the process of recommending, calculating and implementing fluid treatments is automated fully.
Gulf of Mexico Deep Open Water Drilling; A Salty Evolution
Authors: D'Ambrosio P. , Perez J. Patino , Franco C.
Published: February 2025

As an industry we could say that the Gulf of Mexico (GOM) salt drilling challenge has been conquered. No longer do well trajectories avoid drilling through salt, no longer salt sections are limited to be vertical only, nor is salt creep common a cause of Bottom-Hole-Assemblies (BHA) lost in hole. However, over the last decade the increased complexity on deepwater fields in the Gulf of Mexico, such as increased step-out, production platform optimization, multiple geological objectives as well as Authorization for Expenditure (AFE) optimization has led to more challenging conditions for planning and executing open water work; including drilling longer riserless salt sections with more aggressive directional work, avoiding collision risks and Water-Based Mud (WBM) volume constraints due to limited volume capability despite the use of 6th and 7th generation dual activity drilling rigs. Salt drilling challenges in ultra-large diameter open water GOM continue to exist, they have evolved.

Torsional instability that leads to high levels of shocks & vibrations and over-torqued connections is the most common open water salt drilling challenge. Someone could say that this challenge lightly affects the instantaneous salt drilling performance as we keep drilling faster. However, it highly affects the overall well construction performance. Costly BHA damage equipment as well as excessive Non-Productive-Time (NPT) and Invisible-Loss-Time (ILT) time laying down BHA components that present Over-Torqued Connections (OVTC) not only affects well construction times but it's also a safety concern. OVTC requires keeping personnel exposed to red zones for extended periods of time until such connections are broken down or removed unbroken from the rig floor, causing also challenges while backloading and transporting these components.

This paper will concentrate on the drilling efficiency of the ultra-large diameter (24" – 26") riserless / open water salt drilling sections in the Gulf of Mexico. Prior SPE papers and data from 27 riserless salt drilling runs will be examined and analyzed, describing the engineering, planning and risk assessment process to optimize the BHA design on a well-by-well basis to drill safely and efficiently and to achieve the objectives established for the section. Other factors such as drilling fluid density and rig capabilities will also be discussed as an integral part of the drilling system.
Advancing Downhole Vibration Analysis Through Automated Analytics in Rotary-Steerable Applications
Authors: Brock R. J. , Wilson J. K. , Price D. B. , Prince R. B.
Published: February 2025

While drilling automation typically focuses on rig control systems and performance optimization, this study broadens the scope to include the evaluation of overall drilling performance and the identification of operational issues. The automation of routine analyses frees engineers from time-consuming data processing tasks, allowing them to focus their expertise on critical problem-solving and optimization opportunities. This work examines the implementation of multiple algorithms: one for identifying various downhole vibration modes, another for evaluating the directional response of a push-the-bit Rotary-Steerable System (RSS), automated connection break down analysis, and measure-while-drilling (MWD) recycling attempts analysis. These automated systems enable quicker operational responses with appropriate corrective actions.

The study begins with an assessment of data quality, emphasizing the importance of a robust cloud-based architecture for data collection, cleaning, and storage. From there, a systematic approach is taken to translate the thought process of experienced engineers into logical programmatic steps for data evaluation. The validated algorithms are deployed within cloud-based infrastructures for large-scale implementation, providing real-time access to key performance indicators and analysis results.

Detailed heat maps showing the effects of operating parameters better visualize and understand vibration trends, while automated steering interval evaluation provides insights into RSS directional performance. Connection break down analysis examines time components of drill pipe connections, and recycling analysis tracks the efficiency of MWD survey data transmission. Building these automated tools has reduced the time requirement for understanding operational data, which drastically shortens the time between identifying issues and implementing solutions.

This study introduces innovative methods for quick evaluation of drilling operations data. By ensuring consistency in identifying drilling dysfunction across teams and aiding in the professional development of less experienced engineers, these automated algorithms contribute to knowledge sharing and operational efficiency at scale.
Laboratory Setups for Evaluation of Annulus Barrier Materials
Authors: Opedal N. , Ngouamba E. , Feneuil B. , Wiggen E. , Skorpa R. , Taghipour A.
Published: February 2025

Barrier materials are essential to avoid uncontrolled migration of fluids in wells. In this paper we review laboratory setups developed over the past decade, focusing on the challenges and the main results. Cement systems based on Portland G cement are still widely used, but new materials are constantly developed to adapt to increasingly demanding field conditions. Laboratory tests provide a cost-effective way to develop and test new barrier materials, specifically for the annulus. Several independent groups have built down-scale setups to study annular barrier materials. Each setup aims to test the barrier material in conditions as close as possible to field conditions. We first describe and compare the different setups, focusing on their features, advantages, limitations and give examples of the results, and compare them with similar setups from the literature. The interactions between a formation, an annular material and the casing opt for many different outcomes regarding sealability. Casing eccentricity or the presence of drilling fluid at the formation wall are some examples of situations where the annular material might exhibit lower performance. However, another important parameter is the ratio between the rock/cement mechanical properties. Large ratios of Unconfined Compressive strength (UCS) and Youngs Modulus leads to higher propensity for creation of flow paths in the annulus. Flow (permeability) testing of these samples illustrate the dynamic behavior of the flow path(s) and how the micro annulus sizes are influenced by the level of the applied confinement pressure around the casing, and by the level of the pressure inside the casing. The evaluation of the flow path geometries using X-ray CT show how complex these geometries appear in "real" systems. This finding further highlights the importance of proper validation/calibration of any flow rate model or calculator. The evaluation also shows that the typical flow paths develop from existing defects. The work presented shows the development of various down-scale setups made with the objective of understanding the behavior of annular barrier materials upon effects such as temperature and pressure cyclic changes. The results illustrate the importance of continuing development of testing facilities to ensure that wells are constructed using optimized barrier materials.
Improved Drill Bit Forensics Through a Hybrid Analysis of Smartphone-Captured Videos and Operational Time Series Data
Authors: Safarov A. , Ashok P. , van Oort E.
Published: February 2025

Drill bit photos/videos can be used as primary data sources for bit forensics. However, photos/videos only provide the final state of the drill bit, and there is still uncertainty with respect to how the damaged state was reached. The purpose of this work is to automate drill bit damage forensics using a video recording of the bit with time series data of drilling operation, thereby providing better generalization of bit forensics and a timeline of damage progression. Through the combination of 3D mesh building and custom-trained damage classification models, the algorithm was able to accurately classify drill bit damage, with the 3D mesh precisely capturing the cutter's shape and the object recognition model consistently recognizing the cutter's position throughout frames. This is then combined with damage evaluation models based on time series data to arrive at the damage timeline.

This study introduces two different techniques of conducting drill bit forensics, one using videos and the other using operational time-series data. The video analysis provides a visual evaluation of cutter damage, whereas the analysis of time series data helps to understand the mechanism of cutter damage using trends indicating drill bit vibrations. The integration of the time series analysis can improve forensics by providing a timeline for damage evolution. The hybrid approach using time series provides a parallel analysis of cutter damage, allowing an improved understanding of the damage progression to be obtained. It is also expected to significantly accelerate dull grade assessment, leading to quicker operational responsiveness and improved drilling performance.
A Case Study on Setting Up an Auto-Driller to Prevent Instability
Authors: Chhantyal K. , Padir A. G.
Published: February 2025

Auto-drillers are widely used in the drilling industry to regulate the process by maintaining key drilling parameters such as Weight On Bit (WOB) and Rate Of Penetration (ROP). A lack of understanding of an auto-driller and its control parameters can result in drilling dysfunctions and process instability. This paper is a case study on how to properly setup and apply an auto-driller presented with offshore drilling data. Most common auto-drillers have two main modes namely WOB and ROP. An operator can select the desired mode of operation, or in some auto-drillers, the mode switches automatically based on setpoints or limits. Inappropriate setpoint(s) and/or controller gains for the given formation coupled with the process limits can result in instabilities. This paper highlights the importance of understanding the auto-driller's functionality, setup, and its application for achieving good regulation. In the event of varying formation or the presence of heave, it is difficult to achieve good WOB regulation using an auto-driller in ROP mode. The case study shows that ROP is highly influenced by the rig heave and WOB oscillates with the heave motion when ROP mode is applied. In WOB mode, an auto-driller adjusts block speed to regulate WOB. If the resulting block speed is limited by the operator set process limits, WOB regulation is lost. Therefore, an operator needs to understand the interrelation between WOB setpoint, resulting block speed, process limits, and controller gains. An auto-driller with extreme controller gains against a formation and/or in combination with a heave can also result in irregular WOB regulations. Non optimal controller gains can sometimes be suitable for given conditions and still give satisfactory regulation. The study highlights different scenarios where an auto-driller can be limited due to improper settings resulting in instability, inefficient drilling, increasing probability of bit damage, axial vibrations, and thereby stick-slips. The paper suggests the correct practice of using an auto-driller.
Understand and Apply PDC Bit-Rock Interaction Model Towards Directional Response of Drill Bit
Authors: Valbuena F. , Savage M. , Belloso A. , Bomidi J.
Published: February 2025

Performing directional work with Polycrystalline Diamond Compact (PDC) bits have been a constant challenge since their introduction. As well trajectories continuously get more complex, more scrutiny is placed upon the drill bit design than ever before. Historically, there have been successful design philosophies that can be employed to improve PDC bit responses to steering inputs. How those philosophies can be tailored to meet the needs of particular applications, has proven a challenge. Computational models allow the engineer to better understand the effect of forces (rock-bit interaction) and responses of a given PDC bit, accelerate the iteration of concepts, and improve the cutting structure to promote bit response to directional assembly requirements.

This paper will discuss the method used to tune the directional response of a PDC bit based on the concept of bit imbalance force through advanced computational simulation as well as the validation process, through in lab testing and field cases. Drilling environments ranging from vertical versus build drilling, with specific deflection parameters, in addition to general drilling parameters such as Revolutions Per Minute (RPM), Weight On Bit (WOB), Rate of Penetration (ROP), can be prescribed in the model. The model calculates the forces from both the PDC cutting structure and bit body-rock interaction for that prescribed situation and allow the engineer to evaluate the imbalance force present in that situation.

A PDC drill bit's total imbalance force can significantly impact its responsiveness to inputs from a given steering assembly. This force changes with the bit design as well as the environment in which the bit is currently in; vertical versus a build, for example, but also in the amount of deflection that the steering assembly is applied to the drill bit. The ability of the simulation program to take these various factors into consideration and deliver insight into how this force changes in these environments, allows for more accurate assessment of what the steerability is within a given drill bit design. This is shown to be particularly important on Rotary Steerable System (RSS) assemblies, where it has been found that design steps taken to engineer the total imbalance force of a drill bit design can lead to improved steering responses.

The novelty of this paper will be providing insight into how the computational model for bit-rock interaction can be utilized to assess the forces of different bit design iterations in various operating environments. This includes varying operating scenarios such as while being deflected by a directional assembly and while operating at different parameter sets. These varying conditions generate varying forces. Visualizing the responses in these different conditions allows for more accurate assessment and ability to apply design concepts proven over the years to arrive at a drill bit design that is more responsive to directional assembly inputs.