Search Results (22)

Electric submersible pumps (ESPs) are critical for artificial lift operations; however, they are prone to frequent failures, often resulting in high operational costs and production downtime. Traditional ESP failure classifications are limited by lack of standardization and the conflation of failure modes with root causes. To address these limitations, this study proposes a new two-step integrated failure modes and root cause (IFMRC) classification system. The new framework clearly distinguishes between failure modes and root causes, providing a systematic, structured approach that enhances fault diagnosis and failure analysis and can lead to better failure prevention strategies. This methodology was validated using a case study of over 4000 ESP installations. The data came from Egypt’s Western Desert, covering a decade of operational data. The sources included ESP databases, workover records, and detailed failure investigation (DIFA) reports. The failure modes were categorized into electrical, mechanical, hydraulic, chemical, and operational types, while root causes were linked to environmental, design, operational, and equipment factors. Statistical analysis, in this case study, revealed that motor short circuits, low flow conditions, and cable short circuits were the most frequent failure modes, with excessive heat, scale deposition, and electrical grounding faults being the dominant root causes. This study underscores the importance of accurate root cause failure classification, robust data acquisition, and expanded failure diagnostics to improve ESP reliability. The proposed IFMRC framework addresses limitations in conventional taxonomies and facilitates ongoing enhancement of ESP design, operation, and maintenance in complex field conditions. Full article

The application fields of high-speed submersible permanent magnet synchronous motors (PMSM) are constantly expanding. Especially in high-risk and complex environments such as oil exploration, offshore oil exploitation, and deep well operation, the reliability, stability, and efficiency of motor drive systems are more and more prominent. The submersible motor is greatly affected by load disturbance, pressure change, and external oil flow, and the traditional method may not perform well in complex disturbance problems. Therefore, a three-order adaptive nonlinear extended state observer is proposed to collect the input and output information of the system in real time, and estimate the motor speed, position, and total disturbance. A linear feedback control law is designed to eliminate the disturbance. The superiority of the proposed algorithm under complex operating conditions is verified by the Simulink model and experiments, which provide a theoretical basis for the control of submersible motors. Full article

Climate change has driven global awareness of environmental issues, leading to the adoption of clean technologies aimed at reducing Greenhouse Gas (GHG) emissions. An effective method to assess environmental mitigation is the quantification of the Product Carbon Footprint (PCF) in the Life Cycle Assessment (LCA) of production processes. In the oil extraction industry, artificial lift systems use electro submersible pumps (ESPs) that can now incorporate new operating principles based on permanent magnet motors (PMMs) and CanSystem (CS) as an alternative to traditional normal induction motors (NIMs) and can help lower the carbon footprint. This study compares the PCF of ESPs equipped with PMMs and CS versus NIMs, using LCA methodologies in accordance with ISO 14067:2018 for defining the Functional Unit (FU) and ISO 14064-1:2019 to calculate the GHG inventory and the amount of CO₂ equivalent per year. The analysis spans five key stages and 14 related activities. For ESPs with NIMs, this study calculated 999.9 kg of raw materials, 1491.66 kW/h for manufacturing and storage, and 5.77 × 10⁴ kW/h for use. In contrast, ESPs with PMMs and CS required 656 kg of raw materials and consumed 4.44 × 10⁴ kW/h during use, resulting in an 23% reduction in energy consumption. This contributed to an 21.9% decrease in the PCF. The findings suggest that PMMs and CS offer a sustainable solution for reducing GHG emissions in oil extraction processes globally. Full article

The electrical submersible pump (ESP) well system is widely used in the oil industry due to its advantages of high displacement and lift capability. However, it is associated with significant energy consumption. In order to conserve electrical energy and enhance the efficiency of petroleum companies, a deep learning-based energy consumption calculation method is proposed and utilized to optimize the most energy-efficient operating regime. The energy consumption of the ESP well system is precisely determined through the application of the Pearson correlation coefficient analysis method, which is utilized to examine the relationship between production parameters and energy usage. This process aids in identifying the input parameters of the model. Following this, an energy consumption prediction model is developed using the dual-stage attention-based recurrent neural network (DA-RNN) algorithm. To evaluate the accuracy of the DA-RNN model, a comparison of its errors is carried out in comparison to three other deep learning algorithms: Gated Recurrent Unit (GRU), Long Short-Term Memory (LSTM), and Transform. Lastly, an orthogonal experiment is executed using the chosen model to pinpoint the most energy-efficient operating regime. Analysis of 325 ESP wells in the Bohai PL oil field indicated that ten parameters, including choke diameter, casing pressure, pump inlet pressure, pump outlet pressure, motor temperature, frequency, oil production, gas production, water production, and GOR significantly impact the energy consumption of the ESP well system. Consequently, these parameters were selected as input variables for the deep learning model. Due to the attention mechanisms employed in the encoding and decoding stages, the DA-RNN algorithm achieved the best performance during model evaluation and was chosen for constructing the energy consumption prediction model. Furthermore, the DA-RNN algorithm demonstrates better model generalization capabilities compared to the other three algorithms. Based on the energy consumption prediction model, the operating regime of the ESP system was optimized to save up to 12% of the maximum energy. The energy consumption of the ESP well system is affected by numerous parameters, and it is difficult to comprehensively evaluate and predict quantitatively. Thus, this work proposes a data-driven model based on the DA-RNN algorithm, which has a dual-stage attention mechanism to rapidly and accurately predict the energy consumption of the ESP well system. Optimization of production parameters using this model can effectively reduce energy consumption. Full article

Submersible tubular pumps are an ideal choice for pump stations that require high flow rates and low lift. These pumps combine the unique features of submersible motors with axial flow pump technology, making them highly efficient and cost-effective. They have found extensive applications in China’s rapidly developing water conservancy industry. In this research, we focus on investigating the pressure pulsation characteristics of the internal bulb body in a specific pump station project in China. To conduct our analysis, we utilize a model of the submersible tubular pump and strategically position 18 monitoring points. These monitoring points cover various sections, including the impeller inlet and outlet, guide vane outlet, as well as the inlet, middle, and outlet sections of the bulb body segment. To calculate the unsteady flow of the system, we employ numerical simulation techniques. By combining the outcomes of model tests, we determine the pressure pulsation characteristics. The comparison of results reveals a remarkable similarity between the efficiency–head curves obtained from the numerical simulation and the model test. While the model test yields slightly higher head results, the numerical simulation indicates slightly higher efficiency values. This finding lends strong support to the reliability of numerical simulation results, which can provide valuable insights for the design and optimization of submersible tubular pumps. Overall, submersible tubular pumps demonstrate their suitability for pump stations with high flow rates and low lift requirements. The study of pressure pulsation characteristics within the bulb body contributes to a better understanding of their performance and facilitates their further application in the field of water conservancy engineering. Full article

A transverse flux linear motor is a special type of linear motor with a high thrust force density, and it has broad application prospects in the field of linear direct-drive systems. In the process of oil production, the vibration of the linear motor poses a significant amount of harm to the system due to its special slender structure. This paper focuses on the electromagnetic vibration of a transverse flux permanent magnet linear submersible motor (TFPMLSM). Firstly, the no-load air gap flux density is calculated based on the field modulation principle. Secondly, the radial electromagnetic force (REF) of the TFPMLSM is calculated, and the finite element method (FEM) is used to analyze the time-space and spectral characteristics of the REF. Then, the influence of secondary eccentricity on the frequency spectrum of the REF is further concluded. Finally, the natural frequencies of each vibration mode are calculated using the modal superposition method and the influence of the REF on the motor vibration is obtained through magnetic-structural coupling analysis. The research results found that the motor does not cause resonance at low speeds, and the fundamental frequency of REF has the greatest impact on electromagnetic vibration. Full article

Deep-sea submersibles carry limited energy sources, so a high efficiency of the equipment is required to improve endurance. In the deep-sea environment, the hydraulic power source is filled with oil, which causes structural deformation of the power source and changes in the physical properties of the medium, leading to unknown changes in the efficiency characteristics of the power source. In order to explore the efficiency characteristics of the deep-sea hydraulic power source composed of a gear pump and a DC (direct current) brushless motor in a variable sea depth environment, we undertook the following. First, considering the effects of seawater pressure and temperature on the physical properties of the medium and the radial clearance deformation of the gear pump, a mathematical model for the total efficiency of the hydraulic power source was established. The results indicate that the deformation of the pump body is mainly determined by the seawater pressure and working pressure. Subsequently, by analyzing the effects of the two factors on the efficiency of the power source, respectively, when the oil temperature range is large enough, the total efficiency of the power source will increase and then decrease under six sea depths; the total efficiency of the power source decreases with the increase in the rotational speed. However, in a land environment, the trend of the efficiency characteristics of the power source is opposite to that of the remaining six deep-sea environments, both in terms of oil temperature and rotational speed. Finally, the efficiency trend of the power source with changes in sea depth under rated conditions was obtained. Under different sea depth ranges, the optimal operating oil temperatures and suitable rotational speed ranges of the power source could be obtained. This paper could provide a certain theoretical basis for the research and development of deep-sea equipment. Full article

This paper proposed a simplified modeling approach for a power quality (PQ) assessment of Electric Submersible Pumps (ESP) systems supplied by the two-level, the neutral-point-clamped three-level, and the cascaded H-bridge (CHB) multilevel inverter VFD topologies. The VFD switching function models and their analytical expressions are proposed to understand how they can create high-frequency components that might excite the resonance mode in a transmission cable or a rotating shaft system. Voltage, current, and motor airgap torque harmonics induced by each VFD topology in a balanced operation mode are derived and correlated to the PWM carrier and motor operating frequencies. The motor airgap harmonics are calculated based on Concordia’s transformation of voltages and currents in αβ-plan. These harmonic components are represented in the form of Campbell diagrams. An analysis of harmonics under unbalanced conditions was also conducted in a CHB VFD topology-powered ESP system with failed and bypassed cells. The investigated modulation technique is a neutral-shift PWM method that enables the system to operate balanced line-line voltages even if the line-neutral voltages are unbalanced. The effects of modifying the electrical spectrum using the neutral-shift PWM method on electrical and mechanical spectra are analyzed. The results of the Matlab/Simulink-based simulation show that the proposed full ESP system model is highly accurate in both normal and failure modes. The results are consistent with theoretical predictions and are graphically shown in the time and frequency domains for easy analysis. Hybrid experimental–numerical results on a reduced-scale laboratory setup are also discussed to confirm the correctness of the suggested developments. Full article

This paper focuses on the application of a cross-flow fan (CFF) to generate propulsion for a submersible aircraft with a flying wing configuration. A numerical method is established to simulate the CFF operating both in the air and underwater. This paper then investigates the fluid dynamic characteristics of the CFF, including the velocity field, the pressure field, the cavitation distribution, the lift, and the thrust. It is concluded that proper lifts and thrusts can be obtained when the rotating speed and the angle of attack are reasonably designed. This work provides a valuable numerical methodology for studying the fluid dynamic characteristics of the CFF operating in different media and offers a technical basis for the selection of a motor system for submersible aircraft. Full article

In this paper, the electrical submersible pump (ESP) is combined with information and communication technologies (ICT) to diagnose the operation status and soundness of the ESP. The ICT convergence provides users with maintenance and repair information through history management and remote control in case of failure. The proposed system includes a monitoring unit (MU) that senses the operating state of the ESP, a monitoring control unit (MCU) that transmits the sensed information to internal and external databases, and a monitoring system that allows users to check the status information. The server and embedded system can monitor the operation status of the submersible pump by storing sensor values in the database and displaying them on the screen. The embedded system retrieves the sensor values stored in the database and performs individual and complex diagnoses. The diagnosis results are sent to the server and status information to the monitoring control unit. The diagnosis of the submersible pump was divided into 23 individual sensor classifications, and a multilayer perceptron was implemented. Weights were set through learning and testing. The proposed ICT-converged Smart ESP is considered to be competitive as it greatly improves the existing system in terms of status and maintenance. Full article

As a submersible permanent magnet synchronous motor (SPMSM) must function in downhole high temperature crude oil for long periods of time, the accurate prediction of its temperature rise is crucial to improve the stability of the motor. However, the analysis of its temperature field involves multiple physical fields, such as the electric field, the magnetic field, the fluid field and so on, and it is difficult to calculate accurately. Motor loss is usually loaded as a fixed value when calculating the temperature field, while in reality, the loss always changes with temperature. Therefore, the calculation of temperature is inaccurate using this one-way coupled method. In this paper, the relationship between loss and temperature is investigated and an electromagnetic-thermal fluid multi-physics two-way coupled analysis method suitable for SPMSM is proposed. The loss can be loaded as a variable by this new two-way coupled method, which significantly improves the temperature calculation accuracy. In order to prove the feasibility of the two-way coupled method, experiments based of a prototype of high torque and low speed SPMSM and cavity pump are conducted with the fiber Bragg grating (FBG) sensor measuring SPMSM temperature. Finally, the multi-physics two-way coupled method proposed in this paper is proven to be rational and feasible in the analysis of the SPMSM temperature rise. Full article

The necessity of a flow express control of oil dispersed system (ODS) properties, such as crude oil, oil products, water–oil emulsions, and polluted waters, is substantiated. This control is necessary for the production and preparation of oil for transportation through the pipeline and oil refining, oil products, and wastewater treatment systems. A developed automatic measuring complex (AMC) is used to implement the concept of digital oil deposits. The primary measuring device is a relaxometer developed by us based on nuclear (proton) magnetic resonance (PMR). The design and operation algorithm of the AMC and the relaxometer are described. Equations have been developed to determine the ODS characteristics using the measured PMR parameters. This makes it possible to determine the flow rates of crude oil, the concentration of water in the oil, the concentration of asphaltene, resins, and paraffins in the oil, as well as the density, viscosity, and molecular weight of the oil. Additionally, it is possible to determine the dispersed distribution of water droplets in emulsions in oil production and treatment units. Data on this distribution will improve the management of separation processes. It has been established that the implemented control of multiphase ODS using PMR parameters (relaxation times, populations of proton phases, and amplitudes of spin-echo signals) makes it possible, using AMC, to assess the consumption of electricity in technological processes at the digital oil deposits, as well as during the transportation of oil and oil products through pipelines. AMC makes it possible to reduce electrical energy consumption in technological installations and reduce pollution emissions into wastewater. The advantages of using the developed AMC are shown in examples of its application. Such as an assessment of the influence of the gas factor on electricity consumption during oil transportation through pipelines or compensation for the additional moment of resistance on the shaft of the submersible motor, which is caused by surface tension forces at the interface of water droplets in the emulsion. Full article

In order to study the method for reducing the losses in cryogenic permanent magnet motors for LNG pumps, the design of a submersible cryogenic permanent magnet brushless DC motor is presented in this paper. First, the materials used in the motor were tested at room temperature and at a low temperature, and the BH curve and BP curve of the silicon-steel sheet were obtained. Next, DC power supply and PWM power supply were used to analyze the influence of the power-supply mode on the motor loss. Finally, based on the calculation results of the motor loss, the ability of the copper-shielding layer to reduce the motor loss was explored. In the calculation process, the influence of the temperature was considered, and the motor losses at different temperatures were compared and analyzed, which provided a reference for reducing the loss of the cryogenic permanent magnet motor. Full article

Oil production is a complex technological process that requires significant electricity consumption. The main electricity consumers in oil and gas production workshops are artificial lift facilities. Currently, among the objects of mechanized mining, installations of electric submersible pumps are widespread. When planning technological modes, it is necessary to be able to assess the change in the power consumption parameters when changing the technological process parameters. The paper proposes a typical replacement scheme for the electrical complex element. The power consumption calculation of electric submersible pump installations has been carried out. The error in the power consumption modeling results of electric submersible pump installations in comparison with the results of instrumental measurements is no more than 10%. The estimation of additional losses of electric energy caused by the influence of harmonics is carried out. The proposed technique makes it possible to estimate the power consumption of an electric submersible pump installation when changing the parameters of the technological process and equipment. The results of the work can be used for planning material support and optimization of warehouse stocks within the framework of integrated logistics support for the technological process of industrial enterprises. Full article

A speed-sensorless state-feedback controller for induction machines (IMs) with LC filter is proposed. The speed and state estimation is based on a speed-adaptive observer, requiring only the measurement of the filter input currents. The motor currents are controlled by a state-feedback controller with prefilter and integral control action, in order to achieve fast and asymptotic set point tracking. Observer and controller gains are calculated offline using linear quadratic regulator (LQR) theory and updated online (gain-scheduling) in order to attain stability and improve controller performance in the whole operation range. Implementation aspects, such as discretization of the control system and reduction of computational effort, are taken into account as well. The proposed control scheme is validated by simulations and experimental results, even for critical operating conditions such as speed zero-crossings. It is shown that the overall control system performs very well under various load- and speed conditions; while its tuning remains simple which makes it attractive for industrial application such as geothermal electric submersible pumping (ESP) systems. Full article