bluuebunny/crossref_metadata_2025 huggingface dataset:
3D Geomechanical Modeling and Application of Upper Clastic Rock Formation in Penglai Gas Field, China
Authors: Xinyu Guo , Ming Tang , Lu Zou , Long Zhang , Yuemiao Zhou , Shiming He , Xianghua Deng
Published: February 2025

The Penglai gas area, with a predicted reserve of 2005 billion cubic meters, is a crucial block for natural gas resources in the Sichuan Basin. In the upper clastic rock formation, drilling accidents such as wellbore expansion, sloughing sticking, tight sticking often occurs due to unstable wellbore conditions. The root cause of these incidents lies in the inaccurate predictions of the geological mechanical in the work area. To achieve safe and efficient drilling, this paper proposes a multi-faceted geological mechanical modeling approach. Firstly, the model utilizes well logging data, rock mechanics experiments, and in-situ stress experiments to finely characterize the rock mechanics parameters and in-situ stress parameters of the upper clastic rock formation in the Penglai gas area. Secondary, a three-dimensional velocity model is employed to establish a three-dimensional geological model of the upper clastic rock formation in the Penglai gas area. By utilizing the preferential sequential Gaussian simulation method, three-dimensional rock mechanics data volumes and three-dimensional in-situ stress data volumes for the work area are obtained. Compared with the logging calculation parameters of the verification well, the error of the three-dimensional model is less than ± 10%. This approach enables the accurate acquisition of rock mechanics parameters and in-situ stress parameters for the target well based on the coordinates and trajectory of the wellbore during drilling design and execution processes. The results of applying the model in 7 wells show high accuracy, with an average reduction of 2–3 bit sticking incidents compared to adjacent wells. The average wellbore expansion rate has decreased from 6.57% in the early stage to 2.71%. The occurrences of complex conditions such as gas influx and wellbore collapse have significantly decreased, and the drilling cycle has been shortened by an average of 24.76%. The results demonstrate that this model is capable of accurately predicting rock mechanics and geomechanics in the upper clastic rock section of the Penglai gas area. This provides a solid theoretical foundation for drilling design and real-time adjustments, offering essential support for the safe and efficient drilling operations in the Penglai gas area.
Abnormal Events Detection During Drilling Based on Knowledge Embedded Real Time Data Analysis
Authors: Shi X. Y. , Ji Y. , Cui M. , Guo W. H. , Tian Y. M. , Wu D. , Jing L. Z. , Yang X. Y.
Published: February 2025

Recognizing the signs of abnormal events during drilling at an earlier time and adopting appropriate action can greatly reduce non-productive time and improve drilling safety. However, due to the complexity of the drilling system and the uncertainty of data measurement, detecting abnormal events accurately and timely is not a trivial task. This paper proposes an early abnormal events detection approach based on real time data mining and knowledge reasoning.

Based on the theoretical analysis, field experience and historical data analysis, main indicators of abnormal events (e.g. kick, mud losses and pipe stuck) under different drilling operations are identified, and this knowledge is represented as logical rules embedded in an event detection model. Various time series analysis and machine learning algorithms are utilized to extract the data characterization, capture the subtle change trends, and recognize the change patterns of multidimensional time series. The proposed model combines both the prior knowledge and data variation characterizations to detect the early signs of the abnormal events. Furthermore, when the events are detected, the model takes the context of the drilling operations, which are automatically calculated in real time, into account to reduce the false alarms.

An early abnormal event detection software tool is built, which is able to detect kick, mud losses and pipe stuck incidents during drilling. The tool used as input both real-time and archived drilling data, and provides alarms when event indicators are detected. More than 50 wells’ historical drill data are used as input to the tool for model verification. The results show that the tool can automatically detect all 25 kick incidents, 4 loss incidents and 21 stuck pipe incidents in the data set. The kick detection time is about 4 mins earlier than the field recorded time by average, the mud losses detection time is about 1 mins earlier by average, and the pipe stuck detection time is about 47 mins earlier by average. The average false alarm rates for kick detection model and stuck pipe detection model is lower than once per 3 hours. The tool was also connected to the real-time drilling data in remote drilling operation support center. During the trail, one kick event and two early stuck pipe signs are detected accurately and timely. The computation time for each real-time data point is less than one second. According to the demonstrated abnormal event detection rate and false alarm rate, the tool is beneficial for detecting kick, mud losses and stuck pipe in early time automatically, which overall improves drilling efficiency and safety.
Comprehensive Assessment on Dynamic Geomechanical Modelling for Fault Re-Active Stress Simulation in Underground Gas Storage
Authors: Chen Dong , Zhou Wei , Wu Yongping , Huang Zhaoting , Li Haiming , Yan Bingxu , Zhu Bo , Feng Xinluo , Huang Xingning , Wu Zangyuan
Published: February 2025

The Tarim Basin, a vast sedimentary basin located in Northwast China. The internal topography of the basin predominantly features uplifted areas to the north, northeast, southeast, and southwest, a gentle slope to the west, and a significant depression in the central region. Cenozoic sedimentary rocks in the Tarim Basin have a cumulative thickness exceeding 6000 meters, with Cretaceous deposits being particularly thick and widespread. The basin's geologic structure is complex and heavily faulted, enriched with geothermal, solar, and mineral resources, hence presenting a favourable environment for inducing seismic activity. Therefore, assessing the stress characteristics and susceptibility to sliding of geological structures in the Tairm Basin holds paramount importance for earthquake mitigation and disaster prevention. This study involved statistical analysis of data from 19 boreholes, 65 hydraulic fracturing experiments, and 44 stress relief measurements from the basin and adjacent areas. The study also discusses fault slip potential and seismic hazards based on fault mechanical theories such as the Byerlee-Anderson theory. Results indicate a shift from compressive (thrust) to transcurrent (strike-slip) stress regimes, aligning with the distribution of high-angle right-lateral NNE-trending reverse faults within the region. The dominant orientation of the maximum horizontal principal stress ranges between N45° and E60°. Preliminary inversion results suggest a primary compressive stress regime with localized strike-slip characteristics, which corroborates the inversion results from focal mechanism studies. The average friction coefficient of the faults in the region is calculated at 0.41, indicating a state of stability and low susceptibility to fault slipping. Additional analyses, interpolating lateral pressure coefficients and stress accumulation indicators, uniformly suggest a low general predisposition for fault slipping, although localized higher levels of stress accumulation are observed in shallow fault zones. Our comprehensive analysis infers that faults are more likely to slip in a NW-SE orientation.
A Systematic Approach to Prevent Casing Deformation in Deep Shale Gas Wells- A Case Study From China
Authors: Zhang Huali , Wang Lei , Shao Yinan , Zhang Ning , Xiong Likun
Published: February 2025

In the Luzhou region of the Sichuan Basin, deep shale gas horizontal wells at depths over 3,500 meters have experienced casing deformation issues during staged fracturing operations. This problem has significantly constrained the development efficiency of deep shale gas in this area. A multi-factor analysis was conducted on typical deep shale gas horizontal wells in the Luzhou block, further clarifying the main characteristics and causes of casing deformation.

Physical simulation analysis of casing deformation during shale gas well fracturing revealed the mechanism behind the casing deformation, providing a theoretical basis for prediction and prevention. It was found that casing deformation in deep horizontal wells in the Luzhou block is primarily influenced by geological and engineering factors. During fracturing, large volumes of fracturing fluid are injected into the formation, and after connecting with natural fractures, the formation exerts shear stress on the wellbore, leading to casing damage.

The results show that in the presence of natural fractures, varying stress conditions can alter the direction of hydraulic fracture propagation. Under strike-slip fault stress conditions, hydraulic fractures are prone to deflection, causing shear failure. The stress state and the inclination of natural fractures are the primary factors influencing the slip and movement of the fracture surfaces. Under strike-slip fault stress conditions, natural fractures are more likely to experience slip and shear, leading to casing deformation. The closer the natural fractures are to the Coulomb failure surface, the more likely they are to slip and displace, causing casing deformation. Further analysis of field wells confirmed the factors contributing to casing deformation, providing technical guidance and experience for the prediction and prevention of casing deformation.
Optimization of Shut-In Time Based on Oil Saturation Rebalancing in Post-Fracturing for Horizontal Wells
Authors: Li Xiang , Zhou Wei , Pu Wei , Xie Lei , Fu Lei , Ji Baoqiang , Li Junfei , Yang Xiao , Huang Xingning , Wu Zangyuan
Published: February 2025

Based on the shut-in imbibition process in low-permeability reservoirs, this paper illustrates the saturation rebalancing principle of post-fracturing well shut-in. It establishes an optimization method for shut-in time aimed at shortening the oil production initiation period and achieving quick oil breakthrough. The study analyzes the effects of permeability, porosity, fracture half-length, and fracturing fluid hydraulic on shut-in time. The results show that during the well shut-in period following hydraulic fracturing, oil and water in the matrix and fractures undergo imbibition displacement. If the shut-in time is too short, the oil-water displacement will be insufficient, leading to a longer oil breakthrough time after production. Conversely, if the shut-in time is too long, despite sufficient oil-water displacement, significant dissipation of formation energy near the wellbore may occur, resulting in a shorter natural flow period and lower production rate. Appropriate shut-in times can reduce the oil breakthrough period, extend the natural flow period, and increase well production. The optimal shut-in time is influenced by factors such as permeability, porosity, fracture half-length, and fracturing fluid hydraulic. The minimum and maximum shut-in times are negatively correlated with porosity, permeability, and fracture half-length, and positively correlated with the hydraulic of fracturing fluid. Practical applications in low-permeability reservoirs in the Junggar Basin confirm that the shut-in time optimization method can effectively enhance the development efficiency of hydraulic fracturing.
Critical Techno-Economical Assessment of Coiled Tubing Gas Lift for Revival of Dead Oil and Gas Wells
Authors: K K. Chanchlani
Published: February 2025

The recompletion of oil wells with an artificial lift system requires a large capital investment in addition to intervention through workover rig with additional issue of liquid fallback increasing with the depth. Coiled Tubing Gas Lift (CTGL) is method to inject gas through coiled tubing with coiled tubing hanger connected to gas injection line. Gas is injected down continuously through a single point (in case of gas wells) or multi-point (in case of oil wells where unloading gas lift valves are desired for proper flowback in case of hydraulically fractured wells) in the coiled tubing which is mixed with oil in production tubing-coiled tubing annulus and helps in lifting oil to the surface. To hang off the coiled tubing in Christmas tree and connect to gas line, tubing hanger and an additional flow tee must be installed above existing flow tee. The objective of this technology is to define the deepest possible injection depth with the available surface gas injection pressure. The critical velocity for continuously removing the liquids by gas lift through coiled tubing and pressure distribution along with annulus for gas-liquid two phase flow are the conditions based on which the CTGL is designed. For reviving the dead oil wells, coiled tubing strings are cut at required depths and connectors are made to accommodate side pocket mandrels on both sides of cut coiled tubing section. Influx problem, hydraulic fractured oil wells, monobore hydraulically fractured wells, liquid loaded wells and wells with casing integrity issues are the candidates for CTGL. Single size CT allows reuse of CT and wellhead equipment in additional wells. The paper will screen out the applicability of this technology in ceased oil and gas wells.
Enhancing Reliability and Emissions Reduction: The Impact of Compact Wide Range Electrical Submersible Pumps
Authors: Saputra M. N. , Rahmanto B. A. , Anggaraini H. , Ryanta A.
Published: February 2025

S-Field stands out as one of Indonesia's largest mature oil fields, boasting a history dating back to its development in 1952. Over the past four years, an average of 450 rig activities annually has been dedicated to repairing and resizing the 1000 Electric Submersible Pumps (ESPs) employed for artificial lift operations. These pumps are crucial for achieving optimal flowrate production, with production targets ranging from 100 to 15,000 Barrels of Fluid per Day (BFPD). However, the extensive rig activity presents significant challenges in managing artificial lift performance, inventory, and energy consumption efficiently.

To address these challenges, the introduction of Compact Wide Range Electric Submersible Pump (CWR ESP) Technology offers a breakthrough solution. This innovative technology enables pumps to operate within an exceptionally wide flowrate range, from 500 to 3000 BFPD. Achieving this remarkable range is made possible through the utilization of high rotational pump speeds, driven by permanent magnet motors, ensuring energy efficiency throughout operation.

In October 2021, a set of CWR ESP D2000HS pumps were deployed, marking a significant milestone. These pumps seamlessly transitioned from conventional speeds of 3000 rpm to an impressive 7000 rpm without encountering any reliability issues. Notably, the CWR ESP demonstrated its capability to produce a flowrate ranging from 600 to 2400 BFPD through periodic speed adjustments alone, eliminating the need for rig intervention. This saved valuable time, preventing three days of potential production loss, and eliminating rig fuel consumption. Impressively, the CWR ESP exhibited reliable performance for over 700 days before proactive replacement was deemed necessary. Comparatively, the tested CWR pump surpassed the median ESP run life at Sinam Field by 104 days and outperformed four conventional ESP types. Additionally, it recorded 8.7% reduction in power consumption compared to conventional ESPs with identical flowrates.

The demonstrated technical prowess and reliability of CWR ESPs present a compelling alternative for artificial lift operations. Beyond enhancing operational efficiency and reducing carbon emissions through rig optimization and energy-efficient operations, the CWR's benefits extend to inventory rationalization, particularly in large, mature field operations.
Overcoming Dysfunctions from Drilling Interbedded and Hard Rocks and Improving Drilling Efficiency
Authors: Centala P. , Suleiman A.
Published: February 2025

This paper shares the learnings from laboratory testing and field testing of a multi-faceted polycrystalline diamond compact (PCD) cutter that can enhance the impact load resistance and toughness significantly up to 60% when compared to a conventional round cutter. Another concept presented is a secondary cutting element's placement to support the primary cutting structure in overcoming shock loads while drilling interbedded formations. Both technologies help overcome shock load dysfunctions in drilling interbedded applications and nodular chert lithologies while maintaining cutting structure integrity, resulting in improved drilling efficiency.

A systematic study was conducted to understand how to enhance the underlying cutter strength by varying the geometry of the diamond table. Different loading methods were used to simulate static, dynamic, and impact loads on the various designed shaped cutter geometries. The laboratory-winning design was then tested on several bit designs for hard rock and geothermal applications where fixed cutter bits could not drill for long intervals.

The lab-simulated drilling tests suggested that the sensitivity of these cutter placements on sections of the bit profile and field trial bit designs in both vertical and lateral sections demonstrated performance improvements in the range of 20% to 40%. Bit durability, footage, and rate of penetration (ROP) were assessed systematically. Multi-faceted cutters provided the benefits of supporting the overall cutting structure integrity while drilling very hard formations and interbedded lithologies. The multi-faceted cutter has an intricate rock interacting geometry capable of withstanding high reactive drilling forces. These niche shaped rock removal elements avoid premature failure and mitigate the onset of bit dysfunctions.

The case studies presented clearly demonstrate how these cutters can overcome performance limiters, bring about drilling cost savings, reduce the number of trips, and minimize damage beyond repair (DBR) of bit bodies. Impact test results revealed that the optimized multi-faceted cutter and the secondary element showed clear dominance over conventional cutters.
Monitoring and Quantification of Trapped CO2 in Porous Media: A Low-Field Online NMR Investigation on CO2 Flooding And Sequestration of Low Permeability Reservoir
Authors: Zhang Zheng , Rui Zhenhua , Liu Yueliang , Zhao Yang
Published: February 2025

Low-field online Nuclear Magnetic Resonance (LF-NMR) technology has been extensively used to describe hydrogen content in pores during CO2 injection. However, spatial migration and existence form of injected CO2 in porous media are still unclear. NMR combined with micro-gas measurement was used to quantify CO2 of different states to evaluate the capacity and security of CO2 sequestration. Moreover, fluid-rock interactions and mass transfer were considered to reveal the migration and evolution mechanism of injected CO2. In this work, quantitative CPMG scanning was done and T2 distribution of hydrocarbon in porous media was obtained and CO2 produced was measured to quantify CO2 in free and dissolved state during constant rate CO2 injection. Considering pressure variation from injectors to producers in reservoir condition, pressure-dependent CO2 injection was designed to obtain CO2 migration law and mass transfer in pores of different radius. On the other hand, depressurizing experiment was done to simulate CO2 exsolution from hydrocarbon and determine dissolubility trapped CO2.

For low permeability rock sample, CO2 first occupied medium pores and macropores after injection, and then expanded to micropores with smaller radius. It was shown that injection pressure is the main factor that controls the direction of CO2 migration because pressure condition reflects phase behavior of CO2. For gaseous CO2 (pressure lower than critical point), only large pores were swept. When the system pressure is much higher than supercritical pressure, micropores were activated for CO2 sequestration. More interestingly, the volume of CO2 in free state increased rapidly when gaseous CO2 was transforming to supercritical phase. Compared with free state CO2, dissolved CO2 in liquid phase depends on saturation pressure. When the pressure was much higher than saturation pressure, solubility trapping in porous media showed great stability. As the pressure was decreased to a value lower than saturation pressure of fluid in pores, CO2 started to exsolve from liquid phase in large volume. Moreover, CO2 preferentially exsolve from micropores first. This work proposes a method to quantify the states of CO2 exists in porous media and illustrates that injection pressure was dominant to control migration and evolution of CO2. In this work, equipped with NMR technology, CO2 injection and depressurizing experiments were done to monitor and characterize dynamic dissolution and exsolution of CO2 in different pores.
Analysis of Acoustic Signals Generated by Proppant Slurry Flow Through Perforations-Experimental Study
Authors: Chen Jiayue
Published: February 2025

This study explores the acoustic signal generated when a water-sand slurry flows through perforations in the frequency domain. The goal is to identify the proppant/sand presence on distributed acoustic sensors (DAS), and therefore to allocate sand concentration during a multi-stage fracture treatment using DAS monitoring data. We have studied whether sand-related signals can be distinguished from a water flow signal in the frequency domain, what are the frequency components of the proppant signal, and how proppant concentration or other parameters affect the proppant-related signals.

In limited entry design, water-sand slurry flows through perforations with a high injection rate and a high-pressure drop across the perforations. This high flow velocity generates the acoustic signal. It is believed that when solids (sand) pass the perforation, the frequency domain responds differently than just liquid flow. To prove the concept, we conducted an experimental study simulating this process at the lab scale. The experimental setup consists of a core with a hole drilled in the middle as a perforation. A steel plate placed at the inlet of the core serves as perforated casing. The injection rate of single-phase flow (water only) and two-phase flow (water-sand slurry) was designed to mimic the field condition to generate enough pressure drop from the flow through perforation. A microphone was used to provide acoustic measurements for the experiments. The apparatus used in this research has only one perforation, which allows us to build correlations between acoustic signals with known water flow rates and proppant concentrations.

With acoustic signals collected, signal processing methods including the Fast Fourier transform method and Yule-Walker method were applied to analyze the acoustic amplitude spectrum in the frequency domain. The spectra obtained for slurries with different concentrations were compared. Theoretical modeling started with understanding the acoustic signal generated by the collision of a single solid particle with a metal surface. Starting with the single collision model, signal processing was applied to the superposition of multiple signals in the time domain to explore the effect of sand concentrations on the spectrum function of the acoustic signal. Results from theoretic modeling were used to confirm the experiment data.

Sand-related signals can be distinguished from water flow sounds in the frequency domain. Certain frequency band picks up when sand is introduced to the system. This characteristic of the frequency becomes higher in amplitude when the concentration of sand increases, but the characteristics of the frequency band remain the same. With regression analysis, sand concentration and acoustic signal amplitude were determined to be linearly related.

This study provides a new correlation to interpret proppant placement in individual perforation clusters from high frequency DAS measurements.
Dissolvable Frac Plug with BIP Design for Hydraulic Proppant Fracturing in Unconventional Wells
Authors: Zhu Yunyang , Gao Xiang , Chen Huan , Chen Zhongsiao
Published: February 2025

In the gas and oil industry, efficiency optimization within unconventional reservoirs persists as a crucial and formidable challenge. As the exploration and development of these reservoirs advance, horizontal wells are being drilled to increasingly greater depths. Plug and perf (P&P), serving as the principal approach for reservoir stimulation, entails the execution of multiple stage hydraulic fracturing procedures subsequent to fracturing. A newly engineered dissolvable plug, which disintegrates following the main fracturing operation and thereby obviates the necessity for milling, substantially augments efficiency, curtails costs, and diminishes carbon emissions. Nevertheless, it typically requires 20 to 30 minutes and the pumping of 300 to 400 barrels of water to propel the ball downward and seal the plug inner bore to form isolation.

The modification of the wire line adapter kit (WLAK) to be commensurate with the dissolvable frac plug, along with the alteration of the ball drop method to ball in place (BIP), comprehensively resolves this predicament. It eradicates the ball chasing process for down hole isolation, truncates the operation time by 13% during the overall single stage stimulation, and conserves 300 to 400 barrels of water per stage. Through the assessment of the performance of the dissolvable plug in unconventional reservoirs, and in adherence to the PDCA model, the deployment process is streamlined, and the mechanical stability is fortified to preclude post plug and perf operations for the dissolvable plug, thereby diminishing non-productive time.
Streamlining Horizontal Well Deployment in Unconventional Najmah MFS Formation through the Integration of Spectral Gamma-Ray and High-Resolution Imaging Technologies: North Kuwait
Authors: Al Ajmi Saad , Al-Azmi Mejbel , Al Otaibi Fahad , Joshi Girija , Pattnaik Chinmaya , Issa Dania , Danash Tarek , Vican Kresimir , Abdulkarim Anar
Published: February 2025

The Najmah Marine Flooding Surface (MFS) in northern Kuwait, recognized for its significant organic-rich clay content (2-30% total organic carbon, i.e TOC), offers considerable promise for gas, condensate, and light oil production. Nonetheless, geosteering challenges arise from limited seismic resolution and stratigraphic uncertainties, leading to lateral variations in petrophysical properties and pay-zone thickness. The formation is characterized by porosity levels ranging from 2-6% and permeability values from 0.01-1.5 mD, with the flow behavior dependent on a natural fracture network.

A comprehensive logging operation was conducted utilizing advanced logging-while-drilling (LWD) technology, integrating spectral gamma ray (SGR) measurements and ultra sonic-high-resolution imaging (UHRI). The SGR analysis facilitated a detailed evaluation of the formation's mineralogical composition by breaking down total gamma ray (GR) responses into their key elements—potassium (K), uranium (U), and thorium (Th). This process is essential for accurately distinguishing organic-rich zones from other lithologies, laying the groundwork for effective geosteering in future operations.

The integration of UHRI in the lateral section provided high-resolution imaging, enabling the accurate identification of fractures and other geological features that influence reservoir dynamics. A total of 60 features were identified, including 41 fractures and 19 bedding planes. This vital structural information played a crucial role in refining completion strategies and boosting production efficiency.

These findings offer valuable insights for improving future field development strategies and optimizing drilling operations in the Najmah MFS. This methodology is strongly recommended for application in upcoming well profiles with similar characteristics, contributing to improved resource management in the unconventional reservoirs of northern Kuwait.
Estimating Water-Gas Ratio in Producing Gas Wells Through Multi-Fidelity Data Assimilation by Integrating Wellbore Physics and Data-Driven Reservoir Models
Authors: Sinha Utkarsh , Sankaran Sathish , Sabharwal Varad , Ravuri Meher , Zalavadia Hardikkumar , Li Zhuoran
Published: February 2025

Effective management of conventional gas wells relies on timely detection of water breakthroughs, crucial for optimizing reservoir recovery, production, and pipeline operations. Current gas flowmeters struggle to accurately measure water rates, and while methods like well tests and tracers are effective, they are costly and infrequent. Multiphase flowmeters need frequent calibration, and virtual metering approaches depend on pre-known phase ratios. We propose a hybrid model integrating data-driven and physics-based methods for continuous water-gas ratio (WGR) estimation using routine pressure measurements and sporadic WGR data. Our approach combines an optimization framework for data assimilation with a parameterized model for WGR evolution, utilizing gas rate, wellhead, and bottomhole pressures along with multi-fidelity measurements. A weighted loss function minimizes errors in bottomhole pressure (BHP) and WGR estimates. Applied to an offshore mature gas field, our method demonstrated good accuracy, with an average error in BHP of 23 psia across 40 wells over 7 years of production. Water breakthroughs were detected in 20% of wells, validated by increased water rates at the processing platform. This hybrid approach enables proactive reservoir management by merging engineering principles with data-driven modeling.
Analysis of Seepage Pattern of CO2 Intensified Fracturing-Flooding Water Injection Development in Deep Low-Permeability Heavy Oil Reservoirs
Authors: Luo Chen , Liu Huiqing , Li Xiang , Gai Pingyuan , Zhang Zhaoxiang , Yin Fanghao
Published: February 2025

Fracturing-flooding (FT) is a sophisticated fracture-driven enhancement technology designed to optimize hydrocarbon storage and recovery. Particularly effective in deep low-permeability heavy oil reservoirs, this method revitalizes the reservoir structure, enhances reservoir utilization, and substantially improves the crude oil recovery rate. Additionally, the integration of CO2 injection within the FT process can significantly augment heavy oil recovery efficiency by enhancing the oil-water relative permeability dynamics.

In this study, we explore the seepage dynamics associated with CO2-intensified fracturing-flooding (FT) water injection strategies in deep low-permeability heavy oil reservoirs. Utilizing a two-dimensional visualization physical simulation apparatus in conjunction with advanced AI-driven image recognition technology, we assess the planar propagation and characteristic behaviors of the CO2-intensified FT water injection. Additionally, we investigate the microscale seepage performance enabled by this technique using micro-nanochip technology. Furthermore, we analyze the enhanced oil recovery effects and the CO2 utilization efficiency to optimize the reservoir's storage capacity.

In low-permeability reservoirs, CO2 injection as part of fracturing-flooding (FT) processes significantly expands the plane wave area and reduces oil saturation when compared to conventional FT water injection alone. The dissolution of CO2 into crude oil reduces its viscosity by swelling the oil phase. Additionally, CO2 mitigates the 'water locking effect', thereby facilitating the transformation of residual oil from clusters into films and droplets, which enhances oil mobilization. Furthermore, CO2 decreases the strength of the oil-water interfacial tension, which helps prevent the coalescence of dispersed-phase droplets upon collision. This action promotes the kinetic stability of the oil-water system and diminishes the flow resistance, thereby improving sweep efficiency. The low-pressure CO2 injection not only enhances the oil displacement efficiency but also increases the utilization rate of CO2 and incrementally elevates the storage capacity within the oil-water system. The proposed development plan for intensified FT water injection with CO2 in deep low-permeability heavy oil reservoirs proved to be effective in improving oil-water seepage capacity and mitigating greenhouse gas emissions.
28in Hybrid Bit Technology Drilling through Complex Offshore Drilling Intervals
Authors: Alvarez O. , Othman M. , Alrowitea M. , Daksuev D.
Published: February 2025

This paper explores the successful application of hybrid bit technology in offshore gas well operations. It details the strategic steps taken to meet the primary objectives, utilizing a 28-Inch hybrid bit technology to tackle the complexities of drilling in challenging offshore intervals. Key aims of the bit design and tool deployment encompassed achieving single-trip completion of the section, enhancing drilling speed and efficiency, and driving cost savings in operations.

Offshore gas drilling presents significant costs and challenges, particularly in large hole sizes. In this specific scenario, the interval comprises highly interbedded formations and a demanding drilling environment, including fluid loss zones, boulders, and hard, abrasive intercalations. The challenging 28-Inch section spans over 4,000 ft of medium to hard dolomites with occasional streaks of anhydrite and interbedded limestone with shales. The conventional approach to drilling such sections involves using two or three roller cone tungsten carbide bits, leading to high drilling costs and instability issues due to prolonged hole exposure.

To address these challenges, multiple wells in the area were meticulously analyzed, examining both time and depth-based logs along with electrical logs. This comprehensive analysis revealed a drilling trend, indicating that hybrid bit cutting structures were best suited for this demanding application. The hybrid bit solution was chosen for its unique capability to shear and crush formations during drilling, combining the durability of roller cone bits with the efficiency of PDC (Polycrystalline Diamond Compact) drill bits. This distinctive drilling mechanism enables hybrid bit technology to efficiently drill through this challenging application compared to traditional drill bits.

In the field-testing phase, the hybrid bit was deployed in two consecutive wells. Although the drilling parameters were controlled to prevent total losses, which impacted the overall average rate of penetration (ROP), the outcomes were remarkable. Both wells successfully completed the section using only the hybrid bit, which was pulled out of the hole in good condition. Furthermore, both wells achieved above-average ROP and saved 3 to 4 days of drilling time compared to the conventional method of using standard roller cone bits.

The 28-Inch hybrid bit technology has proven to be the ideal solution for addressing the demanding offshore gas drilling challenges in this application. It stands out as the only drill bit technology capable of completing this section in a single trip, thereby facilitating the achievement of all performance targets set for the test.
Extending Automated Drilling Capabilities by Enabling Automated Data Aggregation and Drilling Advisory Workflows - Case Study
Authors: Temer Elias , Arabi Hakim , Bisht Sameer , Xu Lina , Casado David , Calligrafi Remy , Rocha Carlos
Published: February 2025

Automation is revolutionizing efficiency in various sectors, notably in oil and gas, by streamlining tasks to enhance speed, safety, and labor reduction. On-target well delivery solution systems integrate automation, advisory systems, and data aggregation, leveraging AI to optimize drilling operations while ensuring compliance with well-construction plans. In drilling edge operations, data aggregation systems collect and manage information from various sources using standardized protocols, addressing challenges such as hardware duplication and network complexity. In this paper we proposed a multi-layered solution through a data aggregation layer and a shared domain service layer, ensuring consistent data management and secure transmission to the cloud using protocols like WITSML, ETP, and Avro for efficient data handling. Using this solution will allow deploying, with less hardware, multiple workflows such as real-time advisory, predictive analytics for risk mitigation, and cross-domain workflow coordination, all aimed at improving operational efficiency and decision-making while maintaining data integrity across diverse workflows.
A New Clean Completion Technology for Soluble Screen Tubes in Ultra-Deep Well with High Temperature and High Pressure
Authors: Liu W. , Gao W. , Zhang H. , Wei B. , Jiang R. , Liang L. , Zhang L. , Xie Y.
Published: February 2025

In response to the problems of insufficient completion fluid replacement and wellbore contamination caused by well killing fluid in the conventional completion process of ultra deep fractured sandstone reservoirs in Tarim Oilfield, a new technology for clean completion with soluble screen tubes has been developed, which includes the configuration of soluble screen tubes and release short joints in the production zone.

Soluble screen tubes, when used as tubing during well completion fluid replacement, can replace high-density well killing fluid in the lower part of the perforation section, ensuring the cleanliness of wellbore for fluid replacement; During reservoir transformation and production, the soluble sieve tube is dissolved in acid and the soluble pore plug is used to reduce fluid flow resistance. The release short section can be repaired and salvaged in sections by shearing the pin under pressure. Through experimental research on tools such as soluble sieve tubes and release short joints under pressure, the reliability of the tools has been verified.

Based on the application research in the laboratory and D304 well site, the effectiveness and feasibility of the new technology of clean completion with soluble screen tubes have been proven. In the perforation section, the soluble screen tube column effectively solves the contradiction between incomplete liquid replacement from the lower part of the column to the middle and upper parts of the perforation section and increased flow resistance from the lower part of the perforation section. Comparing the two types of tubing structures, namely tubing completion and soluble screen clean completion, it is found that the soluble screen clean completion process has significant advantages in fluid replacement, high-pressure gas flow, drainage area, daily production, etc., and the process is simple and easy to operate on site.

This technology has been applied in over 10 high-pressure gas wells in the ultra deep fractured sandstone reservoir in front of Kuche Mountain in Tarim Oilfield, with a success rate of 100%. At the same time, this technology has the advantage of integrating completion fluid replacement with well repair and salvage, providing important reference for the selection of completion technology for similar wells.
Análise do perfil epidemiológico de mulheres submetidas a histerectomia para tratamento de lesões do colo uterino no Estado do Maranhão entre 2018 e 2023
Authors: Bulhão Marjana Pinheiro , Lucena Êmilly Araújo Costa , Serra Mariana Barreto
Published: February 2025

Objetivo: Analisar o perfil epidemiológico das mulheres submetidas à histerectomia para tratamento de lesões do colo uterino no Maranhão entre 2018 e 2023. Métodos: Trata-se de um estudo observacional, transversal e retrospectivo pautado na análise de dados do Sistema de Informação do Câncer (SISCAN). As informações coletadas foram organizadas pelo software Microsoft Office Excel®. Resultados: Foram registradas 933 cirurgias para tratamento de lesões cervicais no estado entre 2018 e 2023. O maior quantitativo ocorreu em 2019 com 190 (20,36%) procedimentos, prevalecendo a faixa etária entre 40 e 44 anos com 149 (15,96%) histerectomias. A raça amarela obteve o maior montante com 472 (50,59%) procedimentos. Quanto às alterações colposcópicas, 373 (39,98%) lesões abordadas eram sugestivas de lesões de alto grau. As lesões com diferenciação moderada foram as mais prevalentes com 202 (21,65%) registros. O tipo histopatológico mais frequente foi a cervicite crônica inespecífica com 396 casos, seguida da neoplasia intraepitelial cervical (NIC) grau III, com 195 ocorrências. Conclusão: Constata-se que há maior prevalência de pacientes da raça amarela com idade entre 40 e 44 anos submetidas à histerectomia para terapêutica de lesões cervicais. A maior parte das cirurgias abordou cervicites crônicas e NIC III, com menor incidência de neoplasias malignas.
Orientações fonoaudiológicas para uso em teleconsultas de crianças com disfagia neurogênica
Authors: Silva Tatiana de Paula Santana da , Martins Wiliane de Souza , Ximenes Coeli Regina Carneiro , Lima Maria Luiza Lopes Timóteo de , Nascimento Cynthia Maria Barboza do , Camelo Evellyn Millene Alves , Cruz Taciana Melo
Published: February 2025

Objetivo: Apresentar orientações fonoaudiológicas que podem ser direcionadas por teleconsulta a cuidadores e pais de crianças com disfagia neurogênica. Métodos: Revisão sistemática de acordo com o modelo PRISMA e estratégia PCC, a partir da pergunta norteadora: “Quais orientações fonoaudiológicas podem ser direcionadas durante teleconsulta a cuidadores e pais de crianças com disfagia neurogênica?”. Os artigos foram buscados nas bases de dados LILACS, MEDLINE, Pubmed, SciELO e Cochrane Library. Foram achados 3.033 artigos foram identificados e 15 foram incluídos em definitivo para compor a revisão. Resultados: Sobre o perfil a maioria das pesquisas foi desenvolvida em países sul-americanos. As orientações possíveis a serem ofertadas por teleconsulta incluíram sugestões sobre a oferta da dieta por meio de utensílios, a necessidade de adaptações da consistência alimentar e o conhecimento sobre a postura e a realização de manobras auxiliares na deglutição durante a alimentação. Considerações finais: As evidências encontradas são de baixa qualidade metodológica, porém apresentam aspectos importantes no cenário de teleconsulta, que de forma geral relacionam-se a adaptações na dinâmica de alimentação do paciente, incluindo a aprendizagem de estratégicas de postura e de promoção da segurança alimentar.
ИНСТИТУЦИОНАЛЬНЫЙ ПОДХОД К ИССЛЕДОВАНИЮ КАТЕГОРИИ «НАЛОГОВЫЙ ПОТЕНЦИАЛ»
Authors: Шемякина М.С.
Published: February 2025

Обосновано, что налоговый потенциал является одним из видов налоговых институтов. Автором разработана институциональная модель налогового потенциала, раскрыта её структура. Доказано, что в основе формирования налогового потенциала лежит институт собственности, характеризующий трансформацию налогооблагаемых ресурсов при воздействии налогового механизма в налоговые доходы. С позиции институционализма дано авторское определение категории налоговый потенциал. Выделены формальные и неформальные институты, на которых базируется институт налогового потенциала .

Introduction. Economic development of regions and municipalities is impossible without an adequate assessment of fiscal capacities. In this regard, the study of a kind of safety bag - fiscal capacity, on which the sustainable development of public-law entity depends, seems to be highly relevant. The goal of the study is to develop the theoretical positions in terms of determining the nature of tax capacity through the use of an institutional approach. To achieve this goal, the following tasks are defined: to analyze the totality of dissertation (PhD) researches, monographs, and periodical materials devoted to the problem of determining the nature of tax capacity and assessing the tax capacity in order to classify the approaches to reveal the essence of the category of tax capacity from the standpoint of the institutional approach to determine its structure to develop an institutional model of tax capacity. Results. Institutionalization of the category of tax capacity is analyzed, four stages in its development are revealed, and their brief description is given. A detailed analysis of the literature allowed to classify the approaches to the interpretation of tax capacity and to identify resource, reproduction, effective, and institutional approaches. It is substantiated that tax capacity is one of the types of tax institutions. The author has developed an institutional model of tax capacity and justified its structure. It is proved that the basis of formation of tax capacity is the institution of property, which characterizes the transformation of taxable resources when tax mechanism is exposed to tax revenues. From the standpoint of institutionalism, the authors definition of the category of tax capacity is given. Formal and informal institutions on which tax capacity institution is based on are identified. Conclusion. The results of the study show that the use of the institutional approach to determine the nature of the category of tax capacity is much broader and allows to synthesize the approaches already known, and also opens up new directions for further research.
Pleiotropic effects of netakimab in patients with psoriatic arthritis, spondylitis and comorbid metabolic syndrome or a new opportunity for weight control? Case report
Authors: Karibova Alida K. , Akhmedkhanov Seypula Sh. , Kudaev Magomed T. , Azizova Ekaterina A.
Published: February 2025

The article presents the results of studying the efficacy of netakimab (Efleira) in the complex treatment of patients with psoriasis, psoriatic arthritis, spondylitis and concomitant metabolic syndrome. The study included observations of clinical manifestations of diseases and changes after the use of netakimab. As a result of treatment, there was an improvement not only in clinical symptoms, but also in the metabolic syndrome parameters. In all 3 patients treated with netakimab, there was a decrease in the activity of sacroileitis, accompanied by weight loss, which indicates pleiotropic effect of this drug. The described clinical cases are of interest to rheumatologists, dermatologists, endocrinologists, therapists, general practitioners, and illustrate the successful use of netakimab as an interleukin-17 inhibitor.
Efficacy of combination chondroitin sulfate plus glucosamine hydrochloride in osteoarthritis: A systematic review
Authors: Naumov Anton V. , Khovasova Natalia O. , Unkovskiy Aleksey V.
Published: February 2025

Osteoarthritis is the most common musculoskeletal disorder, leading to reduced mobility and disability. Currently, in OA, basic therapy with slow-acting symptomatic drugs for the treatment of osteoarthritis (SYSADOA) is recommended, among which chondroitin sulfate (CS) and glucosamine hydrochloride (HS), as well as their combinations, have the most convincing evidence of effectiveness. The combined drugs of CS and HS include the drug ARTRA®. The purpose of this article was to provide a systematic review of the efficacy studies of the combination drug CS and HS (ARTRA®). Of the 20 publications on the study of the efficacy of ARTRA®, 6 articles with a total of 3683 patients met the inclusion criteria. In patients treated with ARTRA, both Visual Analogue Scale and Western Ontario and McMaster University Osteoarthritis Index pain relief was observed at all time points (3, 4, and 6 months). Functional capacity of patients also had positive dynamics in the intervention groups in all presented studies.