Items

  • THE VALUE OF FRP PIPE FLEXIBILITY

    This article examines the use of fibre-reinforced polymer (FRP) composites in pipeline transport applications, highlighting the advantages of these materials in terms of mechanical performance and durability. The properties and classification of FRP materials, manufacturing processes, joint types, and above-ground and underground installation solutions are analysed. In addition, reference is made to the ISO 14692 regulatory framework used to assess pipe flexibility, including experimental investigations of mechanical behaviour through tensile and bending tests. The last part of the study presents analytical models and numerical simulations designed to determine maximum stress and displacements, with the results obtained demonstrating compliance with the requirements of relevant international standards.
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  • NUMERICAL MODELING OF THERMAL ENERGY TRANSFER BETWEEN ROCKS AND GROUNDWATER

    Geothermal energy, derived from the Earth's internal heat, stands out as a powerful and consistent renewable resource. Unlike intermittent sources such as solar and wind, it provides a stable, 24/7 baseload power supply suitable for everything from large-scale electricity generation to direct-use heating and climate control. This study investigates the low-enthalpy geothermal potential near the Petroleum-Gas University of Ploiesti, Romania, where the ground maintains a constant temperature of 13-14°C at a 100-meter depth. We developed a numerical model to simulate the heat transfer between rock formations and groundwater to assess the viability of a thermal recovery project.The simulation results point to a stable heat transfer rate of 2-10 kW/m² from the surrounding rock to the groundwater. Our model shows that a four-well system could sustainably produce water at 13.5°C with a flow rate of 30 l/h over a 10-year period, causing a negligible temperature drop of less than 0.5°C in the reservoir. Ultimately, the model confirms that harnessing low-enthalpy geothermal energy in Ploiesti is a viable option. The constant and accessible underground temperature presents a significant opportunity for direct-use applications, such as a district heating system for the university campus. This research demonstrates that even modest thermal gradients can be effectively utilized to develop local and sustainable energy solutions.
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  • RELIABILITY ANALYSIS AND OPERATIONAL RISK MATRIX OF SAFETY VALVES

    This research investigates the application of reliability theory to safety valves, emphasizing fundamental concepts such as the reliability function R(t), failure function F(t), failure rate λ(t), Mean Time To Failure (MTTF), and Mean Time Between Failures (MTBF). A practical case study, based on data collected from a petrochemical operator, illustrates how reliability analysis can identify critical failure modes such as blockage, leaks, early opening, and corrosion, highlighting their severe consequences in safety-related applications. This research applies reliability theory to safety valves, utilizing statistical models like Exponential and Weibull distributions to analyse failure modes such as blockage, leaks, early opening, and corrosion. A key finding is that valve reliability significantly declines after approximately 3,000 operational hours, emphasizing the need for predictive maintenance strategies based on historical and real-time operational data. The study advocates for integrating reliability and maintenance analysis throughout the safety valve lifecycle, shifting from reactive to proactive maintenance to reduce unexpected failures and optimize costs. The study develops an integrated mathematical methodology for failure probability estimation. A case study from a petrochemical operator uses risk assessment tools like risk matrices to prioritize maintenance actions. Data analysis reveals an MTBF of 4250 hours, a CoV of 0.577, and reliability dropping to 49.3% at 3000 hours and 30.8% at 5000 hours. Valve blockage and leaks are critical risks, while premature opening and corrosion are medium risks. Recommendations include using the exponential distribution for reliability analysis, implementing predictive maintenance after 3000 hours, periodic inspections and fluid filtration for valve blockages, and seal replacements and leak-tightness checks for leaks.
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  • AUTOMATIC SYSTEM WITH PLC FOR MONITORING THE PARAMETERS OF A GAS WELL

    Monitoring gas well parameters is essential to ensure the efficient, safe and compliant operation of natural gas extraction and transportation facilities. By monitoring critical values in real time, any anomalies can be quickly detected and corrective measures can be implemented to prevent incidents and optimize production. The monitored parameters typically include: pressure (at the wellhead and in the column), gas flow, temperature, water content or other impurities, sand or solid particle level (if applicable). Modern monitoring systems use digital sensors, data transmission through SCADA networks and analysis algorithms for rapid data interpretation. This provides complete visibility into the performance of each well and contributes to extending the life of the equipment and increasing operational efficiency. The paper presents aspects of the design and implementation of an automatic PLC monitoring system for gas well parameters. Based on the block diagram of the monitoring system, a new configuration of the placement of transducers on the well eruption head is proposed. The system’s electrical diagrams are provided, along with the PLC programming steps and the operating specifications. Additionally, details are included regarding the HMI interface, highlighting how users can easily navigate, set transducer measurement intervals, perform calibrations, or activate alarms.
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  • NUMERICAL MODELING OF THE RISKS OF OIL PLATFORMS

    (1) Background: The structural integrity of offshore platforms can be compromised by numerous environmental factors, including wind, waves, ocean currents, seismic activity, or biological accumulations (e.g., vegetation). These elements, acting in concert, generate complex dynamic stresses that must be considered both at the design stage of these structures and subsequently, when assessing their safe operating life. (2) Methods: Based on the research of the international study and the local research study, the authors simulated the effects of the wind and wave equations of the Romanian Offshore Gas Platform Ana. In the context of the above, this paper will focus on describing a method for predicting horizontal displacements for fixed jacket platforms. These displacements are induced by the combined action of the environmental factors mentioned above, and their prediction will be achieved through artificial neural networks. (3) Results: This study presents a new model of ANNs, enabling forecasts of the structural behaviour of a platform deck under various scenarios involving wind, waves, sea currents, and different water depths, and predictions that are particularly valuable in the engineering design process. We introduced in this paper a new Artificial Intelligent Models to prediction environments effects of the Romanian Gas Platform Ana. (4) Conclusions: The design of any element of a fixed structure's analysis function to external forces is determined, and we will analyse exclusively the impact generated by waves, considering that the influence of sea currents is negligible in the specific context of this demonstration, applying the Morison equation.
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  • CONTRIBUTION TO THE STRUCTURAL STUDY AND PETROLEUM INTEREST OF THE NORTHERN PART OF THE TANGANYIKA BASIN OF THE WESTERN BRANCH OF THE EAST AFRICAN RIFT OF D.R. CONGO

    Discoveries are succeeding each other as oil was perceived, a long time ago, as a rather rare resource in sub-Saharan Africa. Paradoxically, it is found everywhere, from Angola to Guinea-Bissau, then along the entire western coast, notably in Ghana, Ivory Coast, and other countries. In addition, for East Africa, interest is not only focused on offshore oil from the Indian Ocean (Mozambique, Tanzania), but also within the continent in the geological structures formed by the East African rifts. In our work, we consider the Tanganyika basin in the East African rifts. Indeed, in certain parts of the Tanganyika basin, oil seepages are visible, with a significant proportion on the side of the D.R.C. (Cap Kalamba), indicating the maturation of the source rock in this area. Thus, the Tanganyika basin has been the subject of hydrocarbon research by several companies, universities, and organizations. However, a problem arises; in 1987, former oil company AMOCO conducted a drilling campaign in the Ruzizi plain during which two wells were drilled, Buringa-1 and Ruzizi-1. Neither of these wells produced oil, and subsequently, AMOCO abandoned all its concessions in the rift region in 1989. This work consists of contributing to the reinterpretation of seismic data conducted by Duke University in 1983-1984 as part of the project PROBE (Proto-Rifts and Oceanic Basin Evolution) in the northern part of the Tanganyika basin, with a view to clarifying its structural model and its oil potential. Indeed, with the advancement of technology, the reinterpretation of these old data can prove important in that we may be able to highlight certain previously unnoticed information due to the limitations of interpretation tools.
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  • A REGRESSION MODELS OF THE GAS DRILLING WELL ERUPTION

    During drilling operations carried out to explore or exploit oil and/or natural gas deposits, uncontrolled eruptions (technical accidents) have also occurred, which have led to damage to the well and, above all, have affected the capacity of the productive layers to continue producing under the initial conditions provided for in the exploitation projects. Also, the explosion of the Deepwater Horizon platform has brought the creation of numerical models (based on numerical regression or artificial intelligence) to avoid such accidents back into the discussion. We developed AI-based numerical regression models to prevent uncontrolled eruptions during Black Sea drilling.
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  • OPTIMIZATION OF AI-COORDINATED INTEGRATED THERMAL-ELECTRIC SYSTEMS FOR GEOTHERMAL WATER VALORIZATION: A CASE STUDY FROM CĂCIULATA REGION, ROMANIA

    This study presents an innovative AI-coordinated approach for integrated thermal-electric systems applied to geothermal water valorization in the Căciulata region, Romania. The research combines advanced thermodynamic analysis with electrochemical extraction techniques and artificial intelligence for autonomous optimization. Based on comprehensive analysis of geothermal water characteristics following validated Romanian mineral water standards [1] and advanced AI modeling, results demonstrate significant optimization potential with estimated electricity generation of 1,262,665 kWh annually from 317,706 cubic meters of geothermal water processing. The AI system incorporates optimal mineral composition parameters with bicarbonate concentrations >20mEq% and Kurlow formula adaptations for maximum thermal conductivity. The AI-coordinated system shows enhanced economic viability with efficiency improvements of 15-25% and a payback period of 1.95 years. Environmental benefits include 838 tonnes annual CO₂ reduction and sustainable mineral recovery of 640,484 kg annually. The study contributes to advancing AI-integrated geothermal energy utilization and provides a scalable model for Industry 4.0 thermal facilities.
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  • END-TO-END SECURE WIRELESS SENSOR NETWORK USING PKI INFRASTRUCTURE AND RASPBERRY PI PICO W

    Industry 5.0 is the evolution of the industrial revolution that goes beyond automation and smart systems (Industry 4.0). It focuses on human-machine collaboration, sustainability, resilience, and security. The proposed security system also aligns with the vision of Industry 5.0, which emphasizes not only automation and efficiency but also cyber-resilience, sustainability, and human-centric design. By employing a Public Key Infrastructure (PKI) combined with JWT-based authentication and lightweight cryptographic techniques, the proposed system enhances the trustworthiness and adaptability of Wireless Sensor Networks (WSNs). These features are critical for Industry 5.0 environments, where secure collaboration between humans and intelligent devices is expected to be seamless, scalable, and resilient against emerging cybersecurity threats. This paper proposes a secure, lightweight, end-to-end architecture for WSNs using a Raspberry Pi Pico W microcontroller, digital certificates and a Public Key Infrastructure (PKI) server. The system uses AES and RSA cryptography, JWT-based authentication, and HTTPS communication to protect data from MITM, replay, spoofing, and injection attacks. Data collected from sensors is encrypted and sent via a REST API to a secure server with MySQL integration. The paper details the implementation, testing, and performance of this model and discusses its limitations and future improvements, including extended sensor coverage and blockchain-based trust models.
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  • A REVIEW OF HYDROGEN STORAGE IN GEOLOGICAL FORMATIONS

    This review presents a thorough analysis of the technical, geological, and economic aspects of Underground Hydrogen Storage (UHS), positioning it as a key enabler for large-scale deployment of clean hydrogen supply chains. As global hydrogen demand increases particularly in traditional sectors such as refining and ammonia production the development of safe, seasonal, and scalable storage systems becomes essential to support renewable-based energy infrastructures. Geological hydrogen storage is identified as the most viable solution due to its advantages in volumetric energy density, intrinsic safety, and the availability of suitable subsurface structures such as salt caverns, depleted hydrocarbon reservoirs, and deep aquifers. Techno-economic analyses show that UHS is considerably more cost-effective and technically feasible for large volumes compared to surface-based storage methods. The review synthesizes real-world experiences from the UK, USA, and Austria, where field-scale pilot projects demonstrated up to 82% recovery of injected hydrogen with no significant degradation in reservoir integrity. The paper also highlights challenges related to microbial activity, particularly in porous formations with residual hydrocarbons or brine, where biological methanation or hydrogen loss could occur. A comparative analysis of hydrogen’s physical properties versus methane is included, focusing on density, viscosity, interfacial tension, solubility, and diffusivity, and how these influence hydrogen behavior in porous geologic media. Additionally, the role of cushion gas (e.g., CO₂, N₂, CH₄) is evaluated for its contribution to maintaining reservoir pressure and enhancing extraction performance. The gas selection is shown to significantly impact chemical compatibility, environmental risk, and operational efficiency. In conclusion, this review underscores that the successful deployment of UHS requires a multi-scale understanding of hydrogen dynamics in subsurface formations, supported by robust experimental validation and numerical modeling, to ensure safe, efficient, and climate-resilient storage operations over the long term.
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  • CONTRIBUTION TO THE GRAVIMETRIC AND MAGNETOMETRIC STUDY FOR THE IDENTIFICATION OF ZONES WITH OIL POTENTIAL IN THE CENTRAL BASIN: CASE OF BLOCKS 1 AND 24 IN THE DRC

    In the search for hydrocarbons, geologists, geochemists and geophysicists work together on the scale of a sedimentary basin. They seek to identify a petroleum system in order to maximise the chances of finding an accumulation of hydrocarbons in a specific part of the subsoil. The exploration campaign in the Cuvette Centrale began in the 1950s with geological, geophysical, geochemical and drilling campaigns carried out by several foreign organisations, including the Belgian firm Remina. These campaigns provided key information about the petroleum systems. These include the presence of hydrocarbon showings and geological structures that may favour the formation, migration and trapping of hydrocarbons. The main aim of this work is to highlight the geological structures of major petroleum interest, while identifying the geological structures found in our study area, particularly in Blocks 1 and 24 in the central basin of the Democratic Republic of Congo, and their petroleum interest, based on the processing and interpretation of magnetic and gravity data. To better study our sedimentary basin, we used the method of regional-residual separation and variation of the Magnetic Field, we had to highlight the faults in different directions North-West towards the South-East, the collapse trenches localised in the North-East, the zones of uplift of Socle which today constitute the top of Inongo. As never done before, this study develops a structural reference model by integrating the analysis of Bouguer and magnetic anomalies. It aims to locate zones of source rock maturation, identify possible hydrocarbon migration paths and pinpoint geological structures conducive to hydrocarbon accumulation. The results, presented in map form, are a strategic tool for petroleum exploration and the analysis of regional tectonic dynamics. In particular, it provides an unprecedented and detailed geophysical record for Blocks 1 and 24 of the Cuvette Centrale, enabling a targeted and efficient assessment of petroleum potential.
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  • BASIC WELL LOG INTERPRETATION IN PYTHON PROGRAMMING LANGUAGE

    Python has rapidly become the programming language of petroleum geoscientists during the last decade. It is used widely in development, research and scientific activities and is included in many commercial software as an option for additional scripting purposes. Geophysical well log data interpretation is one of the most useful and important tools available to a petroleum geologist [12]. The results of log analysis and interpretation play an important role in the decision making in oil and gas activities throughout the exploration, development and production stages. The standard log interpretation workflow for petrophysical analysis of the wells includes: data loading, QC and editing (1); borehole environmental corrections (2); calculation of shale volume (3); porosity calculation (4); water saturation calculation (5); identification of lithology type (6); estimation of net and pay thickness (7). In this tutorial it is shown how to use Python programming code to carry out the standard well log interpretation steps. Third-party libraries have been used in the tutorial: Matplotlib was used in the graphical parts of the scripts; Pandas library was used as a data analysis and manipulation tool. In addition, the following specifically designed Python libraries were used for log data reading and calculations: Lasio, a Python package to read and write Log Ascii Standard (LAS) files and petrophysics, which is a library containing a petrophysical collection of formulas written as Python functions.
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  • ANALYSIS OF THE PERFORMANCE OF THE TSHIENDE OIL FIELD DURING WATER INJECTION

    We analysed the efficiency of the production technique used by Perenco in the Tshiende oil field in the Democratic Republic of Congo. Initially, this field produced oil by natural drainage, based on the mechanisms of fluid expansion and rock compressibility. However, in 1986, a drop in reservoir pressure led to a reduction in production, making it necessary to adopt water injection to compensate for this loss and optimize hydrocarbon recovery. This research responds to the imperative of satisfying growing energy demand while preventing the early abandonment of fields. We used a data storage unit, a computer system and specialized software to process and analyses the data collected. The results show that water injection has considerably improved field performance. Oil production increased and the average reservoir pressure remained above the bubble pressure (927). In addition, the volume of water produced (128907050 m3) gradually exceeded the volume of water injected (107348149 m3), demonstrating the effectiveness of the reservoir sweep. However, variations in the injection rate created imbalances between injection and withdrawal. In 2014, the Voidage Replacement Ratio (VRR) was equal to 1, indicating a temporary equilibrium. The relationship between oil production and VRR confirms that the production rate is directly dependent on the amount of water injected, signalling inactivity in the aquifer. Between 1986 and 1991, the production of oil and water was almost equivalent, but currently, the production of water exceeds that of oil, indicating that the water produced is greater than the water injected. Thanks to the injection of water, the recovery rate for the Tshiende field has increased significantly, from 2.6% to 39.8%, due to the improved efficiency with which the oil is displaced. A volume of water corresponding to that of the pores occupied by the hydrocarbons exceeds 0.90, showing that water saturation is greater than that of the oil. In conclusion, water injection has proved to be an effective solution for extending the productive life of the Tshiende field and improving its recovery rate. We recommend that the company continue to investigate the existence of an aquifer in the field and explore other development campaigns, particularly in the Pinda reservoir, where the results promise new production opportunities.
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  • DRILLING OPTIMIZATION IN ROMANIAN GAS FIELDS USING ADVANCED DIGITAL TOOLS

    The continuous evolution of the energy industry, driven by decarbonization goals and digital transformation imperatives, has led to significant advancements in drilling operations. This article explores the integration of advanced digital tools, real-time monitoring systems, predictive analytics, and automated drilling rigs as key enablers of operational excellence in upstream activities. A comprehensive overview is provided on how closed-loop digital workflows, adaptive control systems, and automation technologies have improved drilling efficiency, reduced non-productive time (NPT), enhanced safety, and supported environmental sustainability efforts. The paper presents an in-depth case study conducted in a Romanian gas field, where targeted drilling optimization initiatives were implemented across multiple well sections. In addition to digital enhancements, the use of Non-Aqueous Drilling Fluids (NADF) was a decisive factor in overcoming geological challenges associated with reactive shales and unstable formations. Compared to conventional Water-Based Muds (WBM), NADF systems delivered superior wellbore stability, reduced filtrate invasion, higher rate of penetration (ROP), and improved compatibility with directional drilling. Through real-time parameter adjustments, connection efficiency improvements, surveying strategy optimization, and dynamic management of critical-path activities, cumulative time savings exceeding five rig days per well were achieved. The study also highlights the benefits of predictive maintenance, adaptive drilling practices, and digital twin simulations as future avenues for further optimization. The findings demonstrate that a strategic approach combining advanced technology, high-performance drilling fluids, real-time operational intelligence, and continuous improvement frameworks can substantially enhance drilling performance, reduce costs, and support sustainable field development. The article concludes by identifying future focus areas such as adaptive drilling systems, machine learning-driven predictive analytics, expanded use of digital twins, and organizational standardization, offering a roadmap for achieving resilient and competitive drilling operations in the context of the global energy transition.
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  • BEARING TYPE – CRITERIA, APPLICATIONS AND TECHNICAL RECOMMENDATIONS

    The choice of the suitable bearing type is a significant step in the mechanical design, which has a direct impact on the system performance, reliability, and efficiency. Bearings are devices that are used to enable rotational or linear movement, while reducing friction and handling stress. Selecting the right bearing entails a multi-objective decision process which considers factors such as the application requirements (e.g. the type and magnitude of the load, the speed, misalignments, the temperature, the lubrication, the environment, spatial constraints). For example, deep-groove ball bearings are widely used in electric motors and other household appliances, they are capable of carrying moderate radial and axial loads simultaneously at high speeds; while tapered roller bearings, used for vehicles' wheel hubs, are capable of carrying combined loads and large loads in one direction. In high-speed spindles or precision instruments angular contact ball bearings are best when greater high-speed capability is required and in also handling axial loads and being able to be positioned and accurate enough for precision mounting, especially in the tightness of the corner that the bearings are being used. However, spherical roller bearings are ideal if the machine component being supported also experiences misalignment and is subjected to shock loads. Various other environmental conditions including dust, moisture, and corrosive substances may require sealed or shielded bearings or alternative materials (e.g., ceramics, polymers). Additionally, maintenance access, expected working life also is an important factor to consider whether a bearing requiring lubrication, is sealed for life or can take tough working cycles. Hence, the selection of a bearing cannot be made simply on the basis of the theoretic or empiric evidence, but requires a comprehensive knowledge of mechanical and tribological fundamentals, combined with experience and taking into account industry standards and the recommendations of the bearing manufacturers. This procedure leads to increased useful life of the devices, reduction in downtimes, and to improved effectiveness of the systems in a vast spectrum of engineering applications.
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  • RESEARCH ON THE OPTIMAL PERFORMANCE OF TASKS UNDER REDUNDANCY CONDITIONS IN THE CASE OF A ROBOT WITH FIVE DEGREES OF FREEDOM

    The fulfillment of programmed tasks by industrial robots in redundant conditions occurs when a robotic system has more degrees of freedom than would be necessary to accomplish the task. From the point of view of mechanical modeling of robotic structures, this translates into the fact that the number of motor coordinates of the robot is greater than would be necessary and sufficient to ensure the position and orientation of the robot's end effector required by the task. In such situations, there is the possibility of optimally performing the programmed task under the conditions of meeting certain criteria that may refer to better accessibility of the robot's workspace in the presence of obstacles, achieving a minimum in terms of movements at the level of the robot's motor axes or obtaining motor coordinate values as far as possible from the edges of their variation ranges. The paper analyzes the case of a robot with five rotation modules whose task is to ensure a trajectory imposed at the origin of the coordinate system attached to its end effector. The redundancy case is analyzed by imposing as an optimization criterion the achievement of a minimum of displacements at the motor axes level of the analyzed robot. Finally, the results obtained for the variation of motor coordinates in the case of a linear interpolation of the end effector movement are presented.
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  • ANALYSIS OF PINDA RESERVOIRS IN THE MOTOBA FIELD: METHODOLOGY, LITHOLOGICAL CHARACTERISTICS, AND POTENTIAL ZONES FOR WATER INJECTION

    The paper presents a comprehensive study of the Pinda reservoirs in the Motoba field, Democratic Republic of Congo (DRC), highlighting the methodology adopted to collect and process geological and petrophysical data. The analysis focuses on the LP1, LP2, and LP3 layers, with the primary objective of locating suitable areas for the establishment of injector and producer wells. The analysis includes data collection and processing, followed by result interpretation to create maps of isobaths and iso-values of hydrocarbons in place. Tools such as Grapher and ArcGIS were used to visualize this information. The history of the Motoba field, discovered in 1975, is also discussed, illustrating the challenges and successes of production, particularly the water injection initiated in 1998 and resumed in 2011. The regional geology and stratigraphy of the Pinda formation are described, emphasizing the lithological complexity and diagenetic processes that have influenced reservoir quality. The study reveals that the Lower Pinda reservoir is divided into sub-units, each exhibiting distinct petrophysical characteristics. Data on porosity, saturation, and clay content were analyzed to establish a dynamic model for evaluating hydrocarbons in place. The results from the isobath maps show significant depth variation, identifying favorable areas for well implantations, particularly in the Northwest, East, and Southeast. Recovery factor analyses and GOR indicate opportunities for resource optimization, with regions identified as suitable for water injection. In conclusion, this paper underscores the importance of a methodical approach in reservoir evaluation and strategic planning of injection operations in the Motoba field.
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  • PICK AND PLACE ROBOTIC CELL SIMULATION USING RoboDK SOFTWARE

    n the era of advanced technology, the automation of industrial processes has become an essential element for improving efficiency and productivity. One of the most relevant aspects of this phenomenon is the development of robotic systems capable of performing repetitive tasks with a precision and speed superior to human ones. The objective of the work is the design and implementation of a robotic arm intended to perform the "pick and place" function, an essential process in numerous industrial fields, from product manufacturing to logistics and assembly. Pick and place involves picking an object from a specific location and placing it in another position. This task, while seemingly simple, is fundamental to the production flow of many industries. For example, in automobile manufacturing, components must be handled with care to ensure the quality and integrity of the final product. In logistics, robotic arms are used to organize goods in warehouses, reducing handling time and human error. The article presents the structure and operating specifications for the Doosan Robotics M1013 robot, as well as the RoboDK software, with its main features and application areas. After defining the specifications and selecting the hardware components, such as servo motors, sensors and control modules of the manufacturing cell, we move on to the design stage, where a 3D model of the robotic arm will be created. This model will allow the simulation of the robot's operation and the anticipation of possible problems, before the physical construction.
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  • RESEARCH ON THE KINEMATICS OF A MECHANISM WITH A TRIAD AS A COMPONENT

    The structural approach to mechanisms from the perspective of component kinematic groups shows that as the class of component groups increases, the complexity of the mechanisms that contain them also increases. From this perspective, it is obvious that solving problems related to the kinematics of these mechanisms also becomes much more difficult to put into practice. In such cases, when mechanisms contain kinematic groups of a class greater than two, determining the analytical expressions of the parameters that establish the configuration of the mechanism during operation is extremely difficult. Therefore, in such cases, the development of some numerical calculation algorithms is indicated. The present paper analyzes the operation of a mechanism that has a triad as a component, in which one of the component kinematic joint is translational. To determine the variation of the position parameters, an iterative numerical calculation algorithm was developed and transposed into a computer program that allows the simulation of the functioning of the analyzed mechanism. Finally, the variation curves of these parameters over a kinematic cycle are presented, for a working configuration of the analyzed mechanism.
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  • MINI-FALL OFF TESTS AS A COST-EFFECTIVE TOOL FOR RESERVOIR CHARACTERIZATION AND DST DECISION-MAKING IN DEEPWATER CONVENTIONAL RESERVOIRS

    This research introduces a methodology employing Mini-Fall Off injection tests to enhance reservoir characterization and inform Drill Stem Testing (DST) decision-making in deepwater conventional reservoirs. The methodology begins with log-driven permeability estimation, which is corrected using mobility data from Wire Formation Tester (WFT) point results. Despite these corrections, uncertainties persisted regarding the dominant permeability, which is crucial for ensuring the minimum required deliverability for DST. To address these uncertainties and flow assurance challenges, the Mini-Fall Off injection test was employed to estimate permeability within the target flow zone unit of the conventional reservoir. This approach allowed for precise permeability assessment in specific zones, thereby enhancing the overall understanding of reservoir quality and well deliverability. The Mini-Fall Off test provided critical Value of Information (VOI) by revealing that the well deliverability did not meet the minimum required flow rates for DST, leading to the cancellation of DST and substantial cost savings. The application of Mini-Fall Off tests demonstrates a significant advancement in reservoir assessment strategies, offering a cost-effective and efficient alternative to traditional methods. By integrating log-driven permeability data with WFT-derived mobility data and employing the Mini-Fall Off test, the methodology provides a comprehensive framework for reducing uncertainties and optimizing resource allocation in the oil and gas industry. Furthermore, this technique underscores the importance of VOI in data acquisition and decision-making processes throughout the asset lifecycle, from exploration to development. The results of this study highlight the potential for Mini-Fall Off tests to become a standard practice in reservoir characterization, particularly in deepwater conventional reservoirs where cost and efficiency are paramount. This work presents a novel, cost-effective approach to obtaining accurate reservoir characterization, thereby demonstrating its potential to optimize operational efficiency and resource management in the oil and gas sector.
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  • THE IMPACT OF FEATURE SELECTION AND DATA PRE-PROCESSING ON ML MODELS

    This research aims to identify issues with datasets that affect the training of machine learning models. The paper demonstrates the impact of feature processing on the model evaluation metrics. Initially, the paper evaluates unprocessed categorical features based on customized rules. The results of the seven evaluated algorithms show very low metric values. The demonstration is conducted on a dataset with 16 features for predicting depression among students. The dataset consists of 7,022 records. The issue of depression was chosen because it involves many features, which facilitate the analysis of the correlations between them. Moreover, the large number of features and records allowed for the analysis of generalization capacity by training on different dataset scenarios for all seven algorithms. The demonstration shows that data pre-processing generates better results when the inputs are exclusively numerical. Subsequently, the research demonstrates the importance of individually analyzing the contribution of each parameter within the model. The study encompasses three categories of tests, which are implemented using the ML.NET framework in the C# programming language.
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  • RESEARCH ON THE GENERATION OF INTERPOLATED MOVEMENTS IN THE CASE OF A ROBOTIC MECHANISM WITH ANTHROPOMORPHIC STRUCTURE

    The implementation of robotic system commands, along with the design of the component mechanisms, contributes to their correct functioning while performing various tasks. In this sense, the precise generation of interpolated movements at the level of the end effectors from the component of robotic mechanisms is particularly important in the optimal performance of tasks in many industrial applications. Compared to the point-to-point commands, the interpolated commands are intended to pilot the robotic mechanisms so that their final effectors follows an imposed trajectory in the operational space of the robot with an imposed hourly law. The paper presents a method for generating interpolated movements in the case of a robotic system whose active mechanism has an anthropomorphic structure. The presented method uses the differential model of the analyzed robotic system. The introduced interpolation is linear, and the hourly law used is in the form of a polynomial of the fifth degree. Within the simulations performed, the four possible configurations of the anthropomorphic robotic mechanism that allow the achievement of the imposed task were highlighted. Finally, for one of these configurations, the variation curves of the coordinates corresponding to the actuation motors for a certain task are established.
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  • CONTRIBUTION TO THE GEOLOGICAL AND PETROLEUM STUDY OF THE WEST-CONGOLIAN BASIN – CASE OF CARBONATES IN THE KITOBOLA REGION IN CENTRAL CONGO, D.R. CONGO

    Previous studies carried out in the West-Congolian basin have highlighted potential formations that could play a major role in a petroleum system. In order to complete and enrich the geological and petroleum dossier of the said basin, a field trip to the Kitobola locality in the province of Central Congo was necessary to sample, analyze and describe the carbonate formations that outcrop there, in order to detect their importance from a petroleum point of view by describing and analyzing their mineralogical characteristics, and geochemical characteristics of these rocks, as well as evaluating their basic petrophysical parameters, notably porosity and permeability, in order to determine the role they might play in a petroleum system. Samples were sent to CRGM laboratories for petrographic, petrophysical and geochemical analyses, which revealed the presence of limestones (mudstones, wackestones and pelmicrite) with low porosity ranging from 1.18 to 1.49% and near-zero permeability between 0.2 and 0.5 mD. Geochemical analyses revealed a TOC ranging from 0.9 to 1.3 and high proportions of calcium oxide CaO associated with the limestones. As a result, these formations cannot be used as reservoirs, but rather as blankets, given their low porosity and near-zero permeability. On the other hand, they would make excellent source rocks in a petroleum system, given their very satisfactory TOC values. This article provides new information on the intrinsic characteristics (petrographic, petrophysical and geochemical) of the carbonate formations outcropping in the Kitobola region of the West Congolian Basin, while also highlighting potential source rocks or blankets.
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  • A CONCRETE DROPOUT NEURAL NETWORK FOR SHEAR SONIC LOG PREDICTION

    Assessing the risk associated with drilling and wellbore stability studies requires the shear sonic log. These logs apart from distinguishing formation fluid from lithology are needed to obtain geo-mechanical rock parameters required for the safe design of rock fracturing. Although sonic logs are of great importance, they are usually not obtained due to the limiting cost of acquisition. Neural networks have been used to generate these logs to save cost, but these networks are prone to overfitting. The dropout rate has been proposed to tackle this problem, however selecting the optimum dropout probability rate can be challenging manually or expensive computation wise. This research therefore investigated concrete dropout, a dynamic technique for adapting the dropout rate of a neural network to the data. The concrete dropout technique was applied to an artificial neural network (ANN) and a convolutional neural network (CNN) model to predict the shear sonic log with Monte Carlo simulation. Comparison was also made with the deterministic ANN and CNN models which had no dropout layers added and a Bayesian-optimized multilayer perceptron (MLP) model. These models were trained and validated with four (4) wells from the Volve field, using features with the highest correlation. The Concrete dropout ANN was found to outperform both the deterministic versions and the MLP model with R2, RMSE, MSE and MAE scores of 0.9548, 3.6415, 2.4433 and 0.0179 respectively. The neural networks built in this study showed an enhanced predictive performance with concrete dropout addition over the networks with no dropout added, showing that the technique was able to adapt the dropout rate to fit the nature of data and improve performance, which finds great application in real time deployment. The findings of this study also proposed a cost-effective way of sampling and averaging multiple outputs from a single neural network model, leading to enhanced predictive performance as the addition of concrete dropout allowed the network output distributions rather than point predictions.
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  • DETERMINATION OF AREAS SUITABLE FOR THE DETECTION OF GEOLOGICAL STRUCTURES IN THE LOKORO SUB-BASIN USING THE MAGNETIC METHOD

    This work focuses on identifying potential areas in the Lokoro sub-basin, a strategic region located in the south-western part of the central Congolese basin. Covering an area of 51,759 km², this sub-basin encompasses the Mai-Ndombe province. Mapping the geological structures of this area is essential for highlighting hydrocarbon potential, a crucial aspect for future tenders. The study is based on the processing and analysis of magnetic data collected in the Lokoro sub-basin. The magnetic method, which evaluates the distortions of rocks buried in the earth's crust, enables the interpretation of magnetic anomalies linked to subsoil susceptibility. This approach provides clues to geological formations likely to accumulate hydrocarbons, offering valuable insight to prospectors. The anomalies detected may indicate the presence of geological structures favorable for hydrocarbon accumulation. By deepening our understanding of the geological structures of the Lokoro sub-basin, this research facilitates the exploration and exploitation of petroleum resources in this promising region. In sum, this study is a crucial step in revealing the hidden potential of the Lokoro sub-basin and in guiding petroleum exploration efforts in this resource-rich area.
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