bluuebunny/crossref_metadata_2025 huggingface dataset:
A Novel Approach Utilizing Dual String with ESP System to Enable Gas Separator Configuration with Downhole Packers
Authors: Fardan Ali A , Alsayedali Adnan , Marri Bader Al , Aseef Serag Al , Nasiri Faisal Al
Published: October 2024

The utilization of electrical submersible pumps (ESP) in oil production has been established in the energy industry. Many factors play major roles in selecting the optimum ESP design to maximize oil production and prolong the system run life. One of these factors is the percentage of free gas present at the pump intake while ESP is operating. Oil wells with a high gas-oil ratio (GOR) percentage could experience challenges while operating the ESP and would frequently trip due to unstable production. Furthermore, introducing free gas into the pump could significantly deteriorate ESP pump performance and can lead to mechanical damage due to degradation or electrical damage due to significant overheating. A conventional mixed-flow ESP system can handle up to 20% free gas at the pump intake, while ESPs with axial-flow gas handlers with ESP packer applications could manage up to 50% free gas. Both options were proven inefficient while operating in a higher GOR environment. One of the available solutions is to utilize a gas separator and gas handler with the ESP system to separate the free gas and flow it to the surface through tubing casing annuals (TCA). This technology is commonly used with packerless completion to enable flow through TCA. A novel approach is required to use gas separators with downhole packers.

This study introduces a novel approach by employing a dual-string configuration with ESP systems and downhole packers. This configuration facilitates the utilization of gas separators and handlers, effectively mitigating the adverse effects of free gas on ESP performance. The main string accommodates the ESP and gas separator, while the secondary string remains accessory-free, ensuring efficient cable deployment and system integrity. Moreover, modifications to packers, hangers, and clamps facilitate safe installation and operation.

Simulations analysis indicates significant improvement to ESP performance after following the indicated novel approach. The ESP is able to operate with higher free gas volume fractions (GVFs) at the pump intake while sustaining higher flow rates. This can help in reviving several high GOR wells that could not flow with the conventional ESP system and gas handlers. furthermore, ESP run life is expected to improve significantly due to the reduction of ESP trips caused by flow instability.

The deployment of ESPs with gas separators and handlers is proven to be an excellent success in wells without downhole packers for significantly enhancing the production of high GOR oil producers requiring artificial lift. This study presents a novel approach to safely deploy gas separators and gas handlers with ESP systems while utilizing downhole packer in order to increase well deliverability and confirms the advancement of the emerging technology as opposed to the conventional ESPs that cannot withstand high gas fractions.
Geothermal ESP Remote Monitoring Principles and Case Studies
Authors: Atencia J. , Valero A. , McPhail A. G. , Pereda M. , Corredor F. , Sjerps H. , Nuñez X.
Published: October 2024

Geothermal Electric Submersible Pumps (GeoESP® pump) seamlessly integrate into geothermal projects due to high flow rate capabilities. High downhole temperatures can result in scale, plugging, downhole gauge anomalies, high power consumption, and limited run life challenges. To mitigate these challenges, a novel optimization guideline was created for abnormal event diagnosis based on lessons learned, action plans, and best practices from 12 applications and more than 1700 days of runtime.

The goal of this project is to provide a comprehensive technical guideline of geothermal well events lifted with GeoESP pumps, including real cases and action plans taken. The advanced monitoring features were enabled using a real-time Well Manager System and Remote Terminal Units (RTU) installed at the well site. These included high-resolution data capture and processing, real- time event detection, collaboration dashboards, visualization tools, and Machine Learning (ML) algorithms. The monitoring guideline contributed to the following:

Creating an operation manual with detailed instructions on geothermal ESP units’ best practices and field procedures. Reducing remote troubleshooting, event detection, and action plan times for increased pump uptime. Systematizing proven geothermal events to actionable operational plans. Develop human capital resources that specialize engineers in geothermal applications. Improving the advanced features of the SCADA system through new tools for geothermal assets. Enabling ML applications for real-time pump deterioration tracking and scale detection. Identifying power optimization opportunities using real-time indicators. Tracking the CO2 mitigation effect on the system and scale performance.

This paper will share the operational experience from remote monitoring services that can extend to all types of geothermal plants with ESPs as the main lifting method and can contribute to extending their run life.
Performance Evaluation and Comparative Analysis of Advanced Gas Separator with Three Downhole Gas Separator Systems in Sucker Rod Pumps: A Case Study in Carbonate Reservoirs, Oman
Authors: Al Abri Ahmed T. , Al Badi Said S. , Al Hinai Nasser , Al Abri Ahmed N. , AL Busaidi Khalfan
Published: October 2024

The primary objective of this SPE paper is to conduct comprehensive analysis on four distinct downhole gas separation systems in sucker rod pumps in high GOR light oil wells in carbonate reservoirs in the northern region of Oman. Gas interference is considered one of the main challenges in rod pump operation causing lost in production and equipment reliability. The paper aims to present the results of these trials and perform a detailed analysis of the performance exhibited by each gas separation system. By evaluating their effectiveness and efficiency, this study intends to provide valuable insights into gas separation techniques in similar reservoir conditions. Also to identify the optimum operating conditions for each systems. The ultimate goal is to contribute to the advancement of knowledge in this field and facilitate informed decision-making for gas separation operations.

In the trials conducted, four different gas separator systems were tested separately in sucker rod completions. These systems are the conventional gas separator, collar size gas separator, tandem gas separator, and advanced gas separator. The performance of each system was evaluated based on various factors, with a focus on gross production improvement and pump parameters such as pump fillage, dynacard, and other relevant parameters. The trials were conducted under similar well conditions and completion configurations.

Based on the results of the trials, it was observed that the conventional gas separator and tandem gas separator exhibited similar performance under the tested conditions. On the other hand, the collar size gas and advanced gas separator demonstrated the best performance, exhibiting increased oil production, improved pump fillage, and enhanced equipment quality. Oil production increased by more than 20% in some cases. The study concluded with a thorough comparison of the four systems, providing a comprehensive analysis.

The unique concept behind these trials is to showcase the performance of the different gas separation systems. Additionally, the study aims to identify the optimal well conditions for each system.
Reduction in BP Failure Rate by Introducing Molded Guide Rod Technology
Authors: Al Fulaiti Yaqoob , Al Faraji Omran , Al Naabi Ahmed , Al Shuelly Mohamed , Al Mandhri Abdulladhim , Al Abri Ahmed , Al Jabri Hamed , Al Busaidi Khalfan , Al Rahbi Fahad , Al Qasmi Hamed , Khemnar Atul
Published: October 2024

Daleel Petroleum Company is operating in block 5 in north of Oman producing light oil from relatively tight carbonate reservoir. Beam Pump (BP) and Electrical Submersible Pumps (ESP) are the two used primary artificial lifting systems with around 450 beam pumps contributing about 56% of the company's net oil production.

Rod and tubing failures are two of the main challenges faced in the beam pump performance especially that caused by metal to metal contact which contributed with around 15% of total failures. When the pump is running and during the pumping cycle up and down stroke, it is possible that sucker rods and tubing to have wear and erosion on rod couplings or/and tubing especially in deviated section. This erosion between rod and tubing will lead to parted rod or mechanical tubing leak situation. Therefore, run life of beam pump completion is affected, which increases operation cost and also increases loss production due to downtime. The well then need to be attended by a workover unit to replace a beam pump downhole completion.

In order to mitigate such failure issue, few proactive options were considered and implemented in Daleel. Rod centralizers was initially used, but did not show a good improvement. The molded guided rod was then introduced to Daleel in 2016 as another solut ion to minimize the failure rate. The sucker rod string is equipped with rod guides that help to stabilize the sucker rod string and to prevent the contact between rods and tubing. Promising results were seen after application of guided rods and it was decided to use guided rods in all upcoming new wells and in old wells during replacement. From 2022 Daleel has started installing downhole pump deeper in m ore deviated tangent sections more than 60 degrees and relatively high dogleg severity. The guided rod has helped in successful implementation of deeper beam pump installations and open the door for further production enhancement in block 5.

As a result of guided rod implementation, a significant reduction in rod/tubing failure rate from 15 % to < 7% was observed. Application of guided sucker rods also has helped to improve beam pump run life performance.
First Successful Use of an Electrical Submersible Progressive Pump with a Y-Tool Implementation
Authors: Al-Shatri Mohammad , Kaipov Yermek , Qoqandi Abdulrahman , Alawagi Ahmed
Published: October 2024

This paper presents a unique case study on offshore exploration to prove the commercial potential of oil reserves in the Gulf. It describes the design of a downhole testing platform with a new type of pump. An operating company drilled new appraisal wells to evaluate the presence of multizone reservoirs with heavy oil. The objectives were to confirm the presence of oil reservoirs and well deliverability and prove the field development concept. The well test included the production of heavy oil with an electrical submersible progressive cavity pump (ESPCP) under different regimes, followed by the build-up. The surface testing system was used to manage the fluid at the surface and measure the flow rates. The downhole testing system (DST) was integrated with ESPCP to lift the fluid and to use wireless real-time telemetry to measure the pressure and temperature at different depths.

The reservoir testing was highly successful in proving the commercial potential of the new reserves. The ESPCP was a key element in ensuring continuous reservoir fluid flowing to the surface to achieve flow stability for accurate estimation of the productivity index. Moreover, the progressive nature of the pumping minimized the effect of asphaltene and wax deposition, which could have solidified the fluid in the wellbore during the shut-in period, requiring intervention with coiled tubing.

The ESPCP system is designed for large range of flow rates and features a specialized Y-tool to address potential contingencies. This solution represents a global pioneering implementation aimed at mitigating the risks associated with electrical generation from the permanent magnet motor (PMM) during well completion and retrieval processes. Additionally, the novel well schematic architecture facilitates well interventions using coiled tubing (CT) and sand screen control, enhancing operational efficiency and safety. The stimulation system was designed to improve reservoir productivity by respecting the pump limitations in terms of pH. It also required that the pump material be upgraded to be able to lift corrosive fluid such as acid.

The downhole testing system allowed us to record the build-up with downhole shut-in, obtain reservoir fluid samples without intervention, and record the data in real time for pressure transient interpretation. Real-time monitoring allowed us to interpret the data in real time and optimize the test duration. Combining multiple gauges at different depths allowed us to evaluate friction losses in completion during high viscous fluid production.

For the first time, the ESPCP was integrated with conventional downhole testing to lift heavy oil reservoirs offshore for production evaluation. In this paper, we provide details about the unique workflow, the lessons learned, and recommendations to the industry based on nine production tests at three wells.
The Discrete-Imitational Modeling of the Pump-Well-Reservior System with a Intermittent Sucker-Rod Pumping
Authors: Jamalbayov Mahammad , Valiyev Nazim
Published: October 2024

The work is devoted to the problem of modeling the filtration processes of light and non-volatile oils in compressible reservoirs with low reservoir pressure, inflow to the well and intermittent pumping of oil from the well by a sucker-rod pump in a integrated system.

The system under study is considered in the context of discrete simulation modeling. It consists of the following objects: Pump, well and reservoir (well-drained zone). An algorithm has been developed for determining the pump idle time based on the criterion of the minimum cost of oil extracted during a full pump cycle.

For the first time, a computer model of the pump-well-reservoir system was created on the base of the discrete-imitational modeling concept taking into account the PVT properties of reservoir fluids and the compressibility of the reservoir rocks. The sucker-rod pumping process in a intermittent mode has been studied, the nature of the influence of the pump idle time on the efficiency of the pumping at various reservoir permeabilities has been established. The developed algorithms can be used to create smart wells.
Ultra Slim ESP - Extending ESP Application
Authors: Nesterov Sergei , Zamesin Evgenii , Repin Vitaly , Stolbov Alexander , Mollaev Aslanbek , Nambiar V.
Published: October 2024

Electrical Submersible Pump (ESP) application is challenged by wells with 4-1/2", 5", 5-1/2" casings and 7" liner/casings with Y-tools. The standard approach was limited to use of conventional 3.75" ESP system with Induction motor, only suitable for 5-1/2" and 7" casings without Y-tool. The Ultra Slim 319 series (3.19" OD) ESP with use of Permanent Magnet Motor (РММ) illustrates the benefits of slim line ESP application under such challenging conditions. The paper discusses 3 successful cases for both Oil and Gas wells. The Ultra Slim 319 ESP with РММ was used:

To increase the flow rate and provide higher reliability from а well that was recompleted with 5" liner. The production achieved was 4000 BPD For gas well unloading from а well completed with 4-1/2" liner or frac tubing Deployed inside а 7" #29 liner with Y-tool having bypass of 2-3/8". The bypass allows standard slick line/WL tools to access the reservoir. The use of Ultra Slim ESP enabled the operator for deeper installation for stable production.

The use of РММ increased the reliability of the entire system by lowering the internal motor temperature rise and in addition lowering the current per barrel produced. The run life achieved is 1300 days in the case of the 5" liner application. The gas well unloading has been successful, however the Operator decided to shut down the project due to macro-economic reasons. The cases of 7" liner with Y-tool are currently under operation and stable. Ultra Slim ESP with Permanent Magnet Motor extends the ESP applications to completions that are out of reach for standard ESP with induction motors. The Ultra Slim ESP with РММ can provide:

Higher production rates Wider ESP application range Longer run life where there is а risk of static pressure depletion Reduced per-barrel production cost due to the use of PPM, which decreases current amperage requirements and enhances efficiency СО2 footprint due to lower energy per barrel produced.

This paper illustrates the versatility of Ultra Slim ESPs, which can address various challenging well scenarios and achieve target performance parameters. This information will be valuable for global ESP applications facing similar issues where solutions have not yet been identified.
Optimizing ESPs in Minutes: Automating Workflows with a THP vs. Surface Rate Approach
Authors: Gioria Gian Marco , Prada Williams , AlIbraheem Abdullah , Alshawi Uday , M. Safaa , Abdulkareem _
Published: October 2024

Optimizing the operating conditions for an ESP (Electrical Submersible Pump) does not need to be a complicated process. The Petroleum Engineers typically analyse the wells using the charts provided by the vendors, where the pump performance is expressed in terms of Head vs In-Situ Rate. However, field engineers and operators usually control the wells by adjusting choke opening - thus the THP (Tubing Head Pressure) - and Frequency. This logical gap can often cause delays and difficulties in performing a continuous optimization.

The paper presents a tool to close that gap, based on automated workflows; it enabled the direct use of familiar variables so that all teams involved can interact smoothly. The tool generates clear visualizations, combining all the system constraints and operating limits, so that the engineers can visualize the Operating Envelope for each ESP well. This approach drastically decreased the time spent analysing the operability of the ESP and consequently improved the actions implementation speed. The primary benefit is the time saved by engineers, especially important for a giant oilfield where relatively few engineers oversee up to 100 wells each. Additionally, it helped junior and senior engineers alike to quickly identify problematic ESPs, elaborate remedial actions, and propose new optimized setpoints.

The novelty of the tool is the ability to simplify an industry-standard process, offering a straightforward alternative. It can be adapted and scaled to any field with ESP installations, while it only requires simple programming skills.
Understanding the Cause of Impeller Breakdown in ESP Gas Handlers
Authors: Boudi A. A. , Pessoa R. F. , Hasanov E. , Saeed M. Y.
Published: October 2024

Electric submersible pumps (ESPs) are a widely used artificial lift method used to support oil production and boost pressure. They perform excellently in liquid applications and fairly well for gassy applications if properly designed and fitted with the right components, such as a reliable gas separator and/or gas handler (GH). This paper deals with the possible failure analysis of an ESP GH, specifically the consequences of mechanical breakdown of impeller blades.

Solids, such as scale, sand and debris upstream of the ESP, can cause mechanical failures or wear of exposed parts. Impellers or augers used in rotating gas separators and gas handlers are at higher risk of damage due to their hydraulic design and frontline facing the incoming abrasive fluid. Root cause analysis based on Dismantle, Inspection and Failure Analysis (DIFA) can identify the failed component and failure mechanism such as the GH with axial type impellers. A more ductile metallurgy with higher yield-strength can be proposed as corrective action and the improvement can be confirmed through Finite Element Analysis (FEA).

Solids found during ESP DIFA are believed to be the primary trigger of gas handler impellers’ failure. The sources of solids can be several and intrinsic to well operations such as little debris remaining after workover job or corrosion byproducts coming from the casing below the ESP. Because of the impellers axial design, thin blades, limited vane support at the impeller hub, tight clearances and brittle material, it is highly possible one or a few blades broke initially with a catastrophic dominoes effect as the released metal debris can be caught between the impellers and diffusers, crushing in smaller pieces can be dragged up by the produced fluid into the upper stages. The observations suggest that all blades shattered in all the 17 GH impellers, leaving just the impellers’ hub that is attached to the shaft. Likewise, multiple dents and broken vanes can be observed in the diffusers of the GH as a result of the metal crushing. The failure mechanism can extend to the pump stages as some fragments of the GH can be dragged further up that could result in shaft overload and leading to failure of the two-piece shaft coupling between the gas handler and the pump.

This paper provides valuable insight about potential inherent design weaknesses of some gas handlers fitted with axial or helical-axial stages. The DIFA results support the proposal for an upgrade of the metallurgy as a quick fix to cope with rig operation commitments. The higher strength of upgraded GH impellers was validated through FEA; however, additional improvements mainly in terms of mechanical design are also proposed and discussed.
Hybrid Artificial Lift System – Gas Driven High-Speed Pump for Wells with a Lack of Reservoir Energy
Authors: Shakirov Anton , Alexeev Yaroslav , Nizetic Tomislav
Published: October 2024

Over time, with intensive field development, well conditions can deteriorate; there is a risk of water and gas breakthrough, reservoir and bottom-hole pressures may decrease if there is no effective reservoir pressure maintenance system in place. Neither Electric Submersible Pumps (ESPs) nor Gas Lift (GL) are capable of effectively maintaining efficient production in certain conditions. To address these issues a new hybrid production method was developed – a hybrid gas lift system with a turbine-driven centrifugal pump.

The Turbine-driven pumping system effectively solves bottlenecks of both standard ESP and Gas Lift artificial lift methods by use of the most advanced high-speed pump with operating speeds up to 15,000 rpm powered by a non-combustion ultrasonic turbine. Downhole components are integrated in a turbine submersible pump (TSP) set having no electric parts. Pressurized gas is injected into the annulus, entering the gas turbine at its setting depth, it expands creating torque on its shaft and driving a centrifugal pump. Having passed the turbine, the injected gas is discharged to the production tubing where it is utilized again for gas lifting.

The implementation of the Gas Lift with the turbine-driven pumping system enables the highest possible production volumes providing optimization beyond the conventional Gas Lift capabilities. The system can be deployed both on tubing and riglessly, either with a slick line or coiled tubing. Total pumping efficiency can be improved up to 39%. The technology enables production optimization and/or achieving target drawdown with minimized gas injection rate and pressure if compared to traditional Gas Lift. Technology avoids the use of electricity in the well resulting in dramatic improvement of reliability and runlife, reducing the number of shut-ins and minimizing non-productive time.

Unlike conventional methods, that often suffer from high energy consumption, mechanical complexity, and limited adaptability to varying well conditions, the turbine-driven pump offers a novel solution that overcomes these limitations. It is suitable for a wide range of well conditions, including high-temperature environments, where conventional methods may struggle to perform. Potential implementation in the geothermal industry further underscores its importance in driving the green transition of the oil and gas sector towards more sustainable practices.
Automated Control Solutions to Enhance Beam Pump Performance and Increase Well Productivity: Block-5 Oman
Authors: Al Badi Said S. , Al Abri Ahmed T. , Al Hinai Nasser , Al Abri Ahmed N. , AL Busaidi Khalfan
Published: October 2024

Producing wells in tight formations and matured fields with high gas to oil ratio is proven to be challenging approach. Although, these wells have good production initially but they experience a sharp production decline resulted in low oil recovery, well instability and pump performance deterioration. That could end up with higher deferment and frequent beam pump failures. Fully automated solutions using different control options could maximize the well productivity and enhance the run life of the beam pumping surface and subsurface equipment.

This approach of fully automated solutions is integrating the real-time data from downhole sensor and the pump fillage data to continuously monitor and optimize the beam pumping system. The automated solution can be easily configured and controlled on well basis. Basically, this solution is based on two options which are the intake pressure mode and pump fillage mode which could be alternatively used and can be simply configured with present limits to control the well automatically.

This study examines the use of fully automated control solutions in beam pump operations in Block-5, Oman. Implementing Pump Fillage (PF) and Pump Intake Pressure (PIP) modes has optimized well performance, reducing beam pump failures by 9% and extending operational life by 23% from 2015 to 2023. These automated modes also decreased stuffing box leaks by over 85%, reduced environmental leaks by 70%, and cut power consumption by more than 60%. Additionally, surface motor run life increased by 55%, and reduced human intervention allowed for better resource allocation. These results highlight the effectiveness of applying these solutions across all wells in Block-5, particularly under challenging conditions.

This paper offers practical and applied solutions of fully automated methods to monitor and control the beam pumping system depending on data drawn from over 400 wells in block-5 in north of Oman. These solutions meant to maximize the well productivity while enhancing the run life of beam pump system in very challenging reservoirs that are depleted, tight or have high GOR.
Integration of AI and Domain Expert Knowledge to Improve ESP Efficiency and Performance
Authors: Yin Dakai , Li Qian , Karimi Ali , Mitsakos Nikolaos , El Mahbes Reda , Cox Jacob
Published: October 2024

In the 21st century, the concept of the digital oil field has gained global acceptance and application in gas and oil production. Among the various artificial lift tools, the electrical submersible pump (ESP) stands out as one of the most widely used, with approximately 3,000 installations across Occidental Petroleum Corporation fields. Over the past two decades, enhancements in Occidental in-house-developed ESP surveillance have enabled the company to optimize production and enhance reliability. The surveillance system has also combined extensive real-time operational data, production history, failure analysis, and equipment records.

Over the past few years, machine learning and artificial intelligence have made significant inroads into the energy industry, particularly in oilfield production management. Occidental pioneered the LiftSMART ESP tool system by harnessing these revolutionary technologies alongside its extensive ESP database. This integration promises improved efficiency, reliability, and overall performance in oilfield operations.

The LiftSMART system, with its ongoing development, currently comprises three main modules: Operation Health Check: identifies unusual behaviors in the ESP and detects deviations from expected performance.Auto-Advisory and Optimization: offers suggestions for optimizing ESP operations and provides practical recommendations.Failure Prediction: generates survival curves for each ESP, helping to predict potential failures, enabling proactive maintenance, and minimizing downtime.
Ultrahigh Speed ESP Technology Solution for a 11,400-ft Well: First Successful Deployment with Induction Motor in Ecuador
Authors: Andagoya Kevin I. , Villalobos Jorge L. , León Fernando , Hidalgo. D Mario H. , Vela Nicolás , Sotomayor Alejandro , Orozco Andrés , Ekambaram Raju , Koduru Preethi , Reyes Carlos , Enriquez Luis , Vásquez Hugo
Published: October 2024

The idea of becoming more efficient is in the scope of every industry. Whether we think about the history of chips, computers, cell phones, or medical devices, all of them have successfully developed technologies that can do more as they become smaller. This is not the exception for the oil and gas industry, as demonstrated by this artificial lift development of ultrahigh speed (UHS) electrical submersible pumps (ESPs). This paper covers the challenges, advantages, and the deployment process of this technology in a field in Ecuador. The obtained advantages such as reduction in field assembly time, improved capability to deploy in more aggressive deviated wells, adaptable logistics, and finally successful flow handling. Based on this experience, new candidate wells are currently being studied for this application.
Procedures in Unlocking ESP Full Potential and Extending the Run-Life in High Gas-Oil-Ratio Wells
Authors: Alsayedali A. , Fardan A. , Khamees S.
Published: October 2024

Excessive gas production from high gas-oil-ratio (HGOR) wells imposes multiple challenges on the Electrical Submersible Pump (ESP) systems. The light gassy fluid can compromise both the ESP mechanical and electrical integrity through severe degradation due to operating in upthrust position and through the extreme motor overheating caused by the repetitive gas-locking events. This paper discusses procedures that result in significant improvements in ESP operation in HGOR environments.

The procedures targeted the three main stages of ESP life cycle, namely: ESP design and planning phase, ESP installation and function test phase, and ESP operation phase. The developed procedures are applied for all new and current ESP installations and are continuously updated based on new results obtained through performance and data analysis.

These procedures can have a major positive impact on the ESP mechanical and electrical health. Gas-locking related trips are some of the most challenging trips as they require extensive troubleshooting and analysis to prevent re-occurrence. They also require keeping the ESP and well shut-in for pressure build-up. All of this tremendously affects the field production strategy and hence the reduction of gas-locking trips through these procedures not only improves the ESP health but also ensures the field production is maintained. Through the aid of such procedures, the run-life of failed ESP can exhibit a significant increase. In addition, gas-locking related trips per well can be significantly reduced after successful implementation of these procedures. The reduction in ESP downtime is key in aiding companies achieve their production strategy.

Implementation of the procedures that are discussed in this paper can be utilized for all HGOR fields where ESP installations are planned as the main artificial lift method to reduce gas-locking related trips and improve the run-life.
Role of Plasticity in Induced Seismicity Risk Mitigation: A Case of the Groningen Gas Field
Authors: Zhao Xiaoxi , Jha Birendra
Published: October 2024

Earthquakes induced by fluid extraction from deep underground reservoirs are not well understood in rocks that are deforming plastically. The problem grows in importance when seismicity risk mitigation strategies, such as gas injection into a depleting hydrocarbon reservoir, attempt to reverse the declining pressure trend of a poromechanical system deforming irreversibly. This is the case at the Groningen gas field and similar fields worldwide. Poroplasticity associated with half a century of seasonally fluctuating gas production makes it challenging to predict Groningen’s state, especially with hundreds of faults compartmentalizing the reservoir. We provide new insights into the role of plasticity in depletion-induced seismicity and its mitigation via injection. The irreversibility of plastic deformation is key to predicting stress and fault stability when the pressure trend is reversed by fluid injection. The elastic deformation assumption predicts unrealistically high Coulomb failure stresses on the faults, implying a higher risk of induced seismicity than possible under plastic deformation. The inaccuracy in the elastic model’s predicted stress cannot be discerned from the reservoir pressure or subsidence measurements in the field. Therefore, rock’s plasticity must be considered in assessing and mitigating the risk of induced seismicity. The probability distribution of the change in Coulomb failure stress over 115 faults in the field reveals a multimodal shape that emerges from the stabilization and destabilization of different faults depending on the fault’s geometry and position relative to the wells.
A New Methodology for Quantitative Risk Assessment of CO2 Leakage in CCS Projects
Authors: Sorgi Claudia , De Gennaro Vincenzo , Mandiuc Andreia
Published: October 2024

Assessing risks during carbon dioxide (CO2) sequestration involves a systematic process to identify them (risk assessment), analyze, prioritize, score them (risk analysis), develop mitigation strategies, and plan for measurement, monitoring, and verification (MMV) activities. In this context, risk assessment and analysis are often conducted involving qualitative approaches and/or subjective evaluations based on experts judgments. In this paper, we propose to use numerical results of dynamic subsurface modeling to assess risks in a more precise, less subjective, and quantitative manner, enabling a comprehensive definition of effective MMV plans. In this context, MMV evolves into modeling, measurements, monitoring, and verification [(M)MMV]. The conceptual model used for this study integrates flow and geomechanical-coupled behavior to assess caprock integrity, faults reactivation, and ultimately the risk of CO2 leakage. Uncertainty analysis and a 4D probabilistic workflow are used to quantify the likelihood and consequences of CO2 leakage and to score risks.

The proposed approach offers a general framework to enable subsurface-modeling-based quantitative risk assessment (QRA) for the definition of successful (M)MMV plans. In this study, we have focused on the QRA of leakage risks through the fault and intact caprock. Other applications are possible, such as: (1) leakage risks through the caprock resulting from caprock failure; (2) lateral CO2 migration leading to permit limits violation or inducing interferences with neighboring activities; (3) leakage risks resulting from loss of well integrity; (4) risks of faults reactivation; (5) risks of surface heave; and (6) risks of induced seismicity. All these results can be used to formulate effective (M)MMV strategies for an optimized and cost-effective risk mitigation.
Applications of Machine Learning in Sweet-Spots Identification: A Review
Authors: Khanjar Hasan
Published: October 2024

The identification of sweet spots, areas within a reservoir with the highest production potential, has been revolutionized by the integration of machine learning (ML) algorithms. This review explores the advancements in sweet-spot identification techniques driven by ML, analyzing 122 research papers published in OnePetro, Elsevier, ScienceDirect, SpringerLink, GeoScienceWorld, and MDPI databases within the last 10 years. The review provides a comprehensive analysis of ML applications in sweet-spot identification and highlights best practices in data collection, preprocessing, feature engineering, model selection, training, validation, optimization, and evaluation. The paper categorizes and discusses the different data types used in ML algorithms into six groups, analyzes the combinations of frequently used data types for training and validation, and visualizes the distribution of input parameters and features within each of the six main categories. It also examines the frequency of target variables used in these models. In addition, it discusses various supervised and unsupervised ML algorithms and highlights key studies offering valuable insights for researchers.
Distributed direct air capture of carbon dioxide by synergistic water harvesting
Authors: Li Gang , Wang Yongqiang , Qu Longbing , Ding Hui , Webley Paul
Published: October 2024

Adsorption-based direct air capture (DAC) of carbon dioxide, using chemisorbents like solid amines, has been widely recognized as a sustainable measure to contain atmospheric CO2 concentrations. However, the productivity and economic viability of DAC have been compromised by the high energy consumption for regenerating the adsorbents. Here, we show that by synergistically harvesting water and carbon dioxide from the atmosphere, we can regenerate the unit using in situ vapor purge at low energy and capital cost. The desorption of CO2 is substantially enhanced in the presence of concentrated water vapors at around 100°C, concurrently producing 97.7% purity CO2 and fresh water without the use of vacuum pumps and steam boilers. Moreover, we demonstrate that the DAC prototype can also be powered by sunlight, which recovers 98% of the adsorbed CO2, with 20% less energy demand, enabling sustainable carbon capture from air in a real distributed manner.
Body processes that influence self-care: Validation of an instrument for long-term care
Authors: Lourenço Marisa , Peixoto Maria José , Encarnação Paula , Martins Teresa
Published: October 2024

Objectives
This study aimed to develop a multidimensional assessment instrument focused on bodily processes that influence self-care and validate an instrument in long-term care (BIP@self-care). Methods: A methodological study was conducted with 149 elderly people with functional impairment to develop self-care activities. Generalised Linear Models and cluster analysis were used to analyse the data. Results: Balance and muscular strength were crucial factors in the recovery of autonomy. Sitting balance, dynamic balance, lower limb muscle strength and upper limb muscle strength significantly discriminated between the two identified groups. Conclusion: The BIP@self-care proves to be a comprehensive tool for assessing self-care deficits after a health event within the context of long-term care. These findings have significant implications for nursing practice and the development of targeted interventions aimed at improving these individuals’ autonomy and quality of life.
Functional Group Analysis for Screening Biochars for Nitrogen Recovery from Human Urine
Authors: Nelson Kara , Fusi Soliver , Wang Monong , Qi Yarong , Lammers Laura
Published: October 2024

Applying biochar enriched with total ammonia nitrogen (TAN) recovered from human urine to soils offers a promising approach to improve global sanitation, agricultural productivity, and close the nitrogen cycle. Despite its potential, biochar's capacity to sorb nitrogen varies significantly, with few studies conducted considering the complex solutions and high total TAN concentrations in urine. We provide evidence for a direct relationship between TAN sorption capacity and biochar functional groups, assessed via bulk oxygen-to-carbon ratio (O:C), surface O:C, and proton density (δσH). These measures serve as screening tools to identify effective biochars for TAN recovery. Biochars with bulk O:C of 0.13–0.31, surface O:C of 0.15–0.35, or δσH of 0.01–0.25 mmol c/g exhibited TAN sorption capacities of 0.2–2.5 mmol TAN/g. We observed an unanticipated behavior; as equilibrium TAN activity approached full-strength synthetic urine, the TAN sorption capacity increased dramatically to previously unreported values, warranting further investigation. To contextualize our findings, we estimate around 3% of TAN from human urine across African countries could be recovered by select biochars. This work strengthens evidence for biochar's TAN sorption potential and presents screening methods to identify optimal biochars for low-resource settings.
Maternal Night Blindness and Microphthalmos, Anophthalmos, and Coloboma (MAC) Disorders – Is there an Association?
Authors: Nischal Ken , Subhedar Ketaki , Tibrewal Shailja , Shah Chintan , Ratna Ria , Majumdar Atanu , Bhattacharya Subhajit , Sen Pradhnya , Bhaduria Madhu , Ganesh Suma
Published: October 2024

OBJECTIVES
Microphthalmos, Anophthalmos, and Coloboma (MAC) are common causes of childhood blindness. In 1996, World Health Organisation (WHO) proposed night blindness (NB) as a functional indicator of Vitamin A deficiency (VAD). We aimed to investigate the association of maternal antenatal NB, environmental risk factors and socioeconomic determinants with MAC.
METHODS
A case-control study was conducted between 2018 to 2021 comparing risk factors between MAC and control cases. Data regarding maternal antenatal NB, birth order, consanguinity, family history, maternal dietary habits during pregnancy, history of spontaneous abortions, and father’s income were collected retrospectively and through telephonic interviews with mothers. Bilateral anophthalmos, severe microphthalmos or a combination defined a severe MAC phenotype.
RESULTS
220 children with MAC and 219 normal controls aged 0–3 years were included. Antenatal maternal NB was observed in 33.2% of MAC and 3.2% of controls (p < 0.001). A higher birth order (2nd or more), parental consanguinity, and a history of prior spontaneous abortions were also more common in MAC. A history of antenatal maternal NB was more common in severe MAC (67.3%) as compared to the less severe MAC (22.6%) (p < 0.001).
CONCLUSIONS
The study identified antenatal maternal NB, higher birth order, parental consanguinity, and history of spontaneous abortions as significant risk factors for MAC disorders, highlighting the influence of maternal nutrition and genetics. To the best of our knowledge, this is the largest case-control study to show an association of maternal NB and MAC. Maternal NB has been used as a functional indicator of VAD.
Melatonin-Pretreated Mesenchymal Stem Cell-Derived Exosomes Alleviate Cavernous Fibrosis in a Rat Model of Nerve Injury-induced Erectile Dysfunction via miR-145-5p/TGF-β/Smad Axis
Authors: Zhang Xiaolin , Yang Mengbo , Chen Xinda , Zhang Ming , Peng Yiliang , Lu Mujun
Published: October 2024

Backgrounds: Cavernous nerve injury-induced erectile dysfunction (CNI-ED) is a common complication after radical prostatectomy. As a consequence of the concomitant severe fibrosis of the corpus cavernosum, conventional treatment approaches have had little success. Methods: Pre-treatment of adipose-derived stem cells with melatonin allows for the extraction of active exosomes (MT-hASC-EVs) from the conditioned medium. The therapeutic effects of MT-hASC-EVs were assessed in a rat model of CNI-ED, and the anti-fibrotic properties were evaluated. MicroRNA sequencing was used to identify specific microRNAs highly expressed in MT-hASC-EVs, and differential microRNAs were screened for regulatory pathways through target gene enrichment analysis. Finally, the conclusions from bioinformatics analysis were validated through in vitro experiments. Results: Intracavernous injection of MT-hASC-EVs significantly restored erectile function and reduced the extent of corpus cavernosum fibrosis in the CNI-ED rat model. MT-hASC-EVs promoted the proliferation and anti-apoptotic effects of CCSMCs in vitro. Mechanistically, MT-hASC-EVs inhibit fibrosis by delivering miR-145-5p, which targets TGF-β2/Smad3 axis. Conclusions: MT-hASCs-EVs can inhibit cavernous fibrosis and improve erectile function in a rat model of CNI-ED by targeting the miR-145-5p/TGF-β/Smad axis.
A case of prone position combined with iNO therapy under EIT monitoring in the treatment of refractory hypoxemia after lung transplantation
Authors: Dong Yan , Xu Zhongping , Tian Jing , Wang Dapeng , Chen Jingyu , Xu Hongyang
Published: October 2024

We report a case of severe primary graft dysfunction (PGD) and refractory hypoxemia after bilateral lung transplantation in our center. The effect of conventional therapy of the patient was inadequate, and the patient was unable to be weaned off extracorporeal membrane oxygenation (ECMO). Employing electrical impedance tomography (EIT) monitoring technology, we implemented a series of interventions including prone position, inhaled nitric oxide (iNO) therapy, tracheotomy and other treatment methods. After undergoing a rigorous treatment process, the patient was successfully transitioned out of intensive care unit (ICU) on the 24th day after operation. In conclusion, the utilization of EIT for visual respiratory management, in conjunction with a multifaceted therapeutic approach, substantially contributed to the improved prognosis of lung transplant recipients.
Antepartum maternal weight indices, Maternal Serum Leptin and Birth Weight: A cross-sectional comparative study
Authors: Mbachu Ikechukwu , Umeononihu Osita , Mbachu Chioma , Okechukwu Zeblon , Udigwe Gerald , Okpara Henry , Aniebue Uzo
Published: October 2024

Background: Obesity has adverse effects on pregnancy outcomes, including macrosomia. Both have adverse synergistic effects on each other.
Aim and Objectives: To determine the association between Maternal weight, BMI, and birth weight.
Methods: This was a cross-sectional comparative study carried out over months. The case (experiment) group included neonates with macrosomia and their mothers. The control group was neonates with normal birth weight and their mothers. The maternal weight, height and body mass index were measured at booking and before delivery and categorized using the WHO obesity classification. The Data was analyzed using Stata statistical package version 14. Continuous variables, including age, birth weight, and mean leptin levels, were summarized by mean± standard deviation. There was a test of associations between variables to determine a significant relationship at a p-value of < 0.05. A total of 45 mother-neonate pairs that completed the study were used in the analysis. The study participants include 23 mother -neonate pair with normal weight and 22 mother-neonate pair with macrosomia. The mean birth weight was 3.78±0.05. The mean age of the women was 29.93±5.32, with the 25-29 age group being the modal age group. Only 2(9.09%) out of the 22 women with macrosomia had normal BMI at booking. There was a significant relationship between WHO Obesity class at booking and macrosomia (p-value=0.03). The mean maternal weight at delivery was 88.93±15.28. There was a significant association between the mean maternal weight before delivery and birth weight (83.17 for normal weight and 94.95±12.42 for macrosomia) p-value=0.004. The mean maternal serum leptin was 4.90±1.82. The value was higher but not statistically significant in women that gave birth to macrosomic babies.
Conclusion: Maternal prenatal weight indices showed a significant association with macrosomia. As recommended by the World Health Organisation, pregnant women should be counselled on the need for proper weight gain during pregnancy and interventions should be instituted to make sure they achieve appropriate weight gain. Early booking should also be encouraged for proper counselling, dietary interventions and follow up.