bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Fast Adaptive Integral Method for Estimating Stress Distribution and Failure in Large Natural Fracture Networks
Authors: Cao Meng , Sharma Mukul M. 
Published: October 2023

Abstract
The displacement discontinuity method (DDM) is a powerful method for hydraulic fracturing simulations. However, the computational time for this method increases exponentially as the number of fracture elements increases. This occurs primarily because the method involves the multiplication of a large dense matrix with a vector. In this study, a fast adaptive integral method (AIM) is used to reduce the computational time significantly when solving for the displacement field in a large complex fracture network.
The key to the fast Fourier transform (FFT)-based adaptive integral method is the fast matrix-vector multiplication algorithm. The large dense matrix is decomposed into far-field and near-field components. The far-field component is computed by using the uniformly spaced Cartesian grids, and this component provides the foundation to perform discrete fast Fourier transform. The sparse near-field component is calculated by using the grids for fracture elements. Based on the split of dense matrix into far-field and near-field components, FFT is applied to accelerate the multiplication of matrix and vector since no dense matrices are used.
A large fracture network is used to compare AIM with the standard DDM method. It is shown that the fast matrix-vector multiplication algorithm provides a very good approximation of the dense matrix. The accuracy of the fracture displacements is computed for different fracture orientation patterns. It is shown that the displacement calculated by AIM matches the displacement calculated by DDM very well. A comparison of the computational time for both the extended FFT-based AIM and DDM indicates that for small-scale problems, DDM performs as well or even better than AIM because extra computational time is needed for the correction between near neighbors and propagation on a regular grid. However, for large fracture networks with a large number of elements, the computational time needed by AIM is orders of magnitude less than that needed by DDM. The advantages of fast Fourier transform are then fully utilized to compute matrix and vector multiplication.
The new algorithm (extending FFT-based AIM) provides a novel method for solving stresses and displacements in large-scale fracture networks. It is capable of drastically reducing the computational time for such problems with very little loss in accuracy.
Physics-Based Machine Learning Models for Real-Time Prediction of Rheological and Filtration Properties for KCl Polymer Mud
Authors: Abdulwarith Abdulrahman , Dindoruk Birol , Livescu Silviu 
Published: October 2023

Abstract
The rheology of drilling fluid is a crucial component during drilling operations to achieve optimum performance and avoid non-productive time resulting from drilling problems. In field operations, measuring the rheological and filtration properties of drilling fluids necessitates a significant amount of preparation time and experimental work. Often, such data analysis is not conducted on a footage basis. However, some surface parameters, such as mud weight using the mud balance, marsh funnel viscosity using the Marsh funnel, and mud flow line temperature, can be measured in real-time. This study introduces physics-based machine learning models for real-time prediction of both rheological and filtration properties. The machine learning algorithms used include support vector machines (SVM), extreme gradient boosting (XGB), random forests (RF), and multilayer perceptron networks (MLP). These models predict the rheological and filtration properties based on collected field experimental data. The model inputs are mud weight, marsh funnel viscosity, and flow line temperature, while the targets are apparent viscosity (AV), yield point (YP), plastic viscosity (PV), shear stress based on Fann readings at 600, 300, 200, 100, 6, and 3 shear rates in terms of revolutions per minute (RPM), and filtration loss volume. The developed machine learning models underwent hyperparameter tuning based on cross-validation to select the optimum model for each algorithm using the coefficient of determination (R2) and absolute average relative error (AAPRE). Furthermore, all machine learning model predictions were tested and validated using various datasets. The SVM models' performance ranged from 0.85 to 0.97 in terms of R2, with most AAPRE values less than 2%, reaching a maximum of 6%. The developed RF models ranged from 0.94 to 0.97 in terms of R^2, with AAPRE values between 2 and 3%. XGB models ranged between 0.95 and 0.98 in terms of R^2, with AAPRE values from 1 to 2%. The MLP models ranged from 0.991 to 0.99 in terms of R^2, with AAPRE values less than 6%. The developed machine learning models exhibited high accuracy in predicting the mud's rheological properties in terms of PV, YP, and n, with AAPRE values less than 1.94%, 1.77%, and 4%, respectively.
Subsurface Injection Monitoring in Complex Geologic Media Using Pathline, Source Cloud and Time Cloud
Authors: Li Ao , Chen Hongquan , Jalali Ridwan , Al-Darrab Abdulaziz 
Published: October 2023

Abstract
Monitoring of subsurface fluid motion is critical for optimizing hydrocarbon production and CO2 sequestration. Streamlines are frequently employed to visualize fluid flow; however, they provide only an instantaneous snapshot of the velocity field and do not offer an exact representation of fluid movement under varying field conditions. In contrast, pathlines are constructed by tracking individual particles within the fluid, enabling us to trace the movement of these particles as they traverse through changing velocity fields. This paper presents the development and application of pathlines for flow visualization in complex geologic media. The flow visualization is further aided by source cloud (streak lines) and time cloud (isochrones representing moving fluid fronts). We demonstrate the power and utility of the developed tool in fractured media using Embedded Discrete Fracture Model (EDFM).
Pathlines track the history of flowing particles in the reservoir. Pathlines can be spliced from streamline segments over time, tracing the trajectory of a particle under changing velocity fields. For each interval, a pathline’s end is extended with a streamline segement whose elapsed time of flight (TOF) equals the time interval. Based on the pathlines, streaklines and timelines can also be visualized. Streakline is formed by all fluid particles emitted at the same location. Timeline is the contour formed by all fluid particles emitted at the same instant and represents the fluid front movement. In 3D, these two concepts are more generally visualized in groups of points rather than lines, so we refer to them as source cloud and time cloud.
The proposed injection monitoring methods - Pathline, Source Cloud and Time Cloud - are tested using a 3D field-scale model with complex geologic features to demonstrate its power and utility. The pathlines were compared with streamlines, time of flight and the water saturation distribution. Three scenarios are tested: a constant well schedule, a changing well schedule with shut-ins, and a changing well schedule with fully injection cease. Results indicate that the pathline provides more accurate swept volume, consistent with saturation distribution. The robustness of our algorithm and implementation is demonstrated with a complex Embedded Discrete Fracature Model (EDFM) with non-neighbor connections to visualize flow patterns in discrete facture network. Pathlines display the fluid flow across fractures and are subsequently used to examine the sweep efficiency and the well connectivity.
A Dynamic Assessment for Maximization of Synergy Through Integration of Two Operations. Case Study
Authors: Cagliero G. J. , Cavallin S. , Ventocilla S. 
Published: October 2023

Resume
When two businesses decide to integrate, they can generate synergy. An effect that causes the value of the whole to be greater than the sum of the parts.
The additional value generated can be identified through an economic model that, based on the behavior of key variables (input), estimates not only the benefit for each party, but also the synergy.
With such a model, through scenario simulation, sensitivity and data analysis, an equilibrium point can be found where the value of synergy is equitably distributed between the parties.
This economic model can be simplified through an equation based on a multivariate regression with the following objectives:
Simplify the behavior of variables and understanding of cash flows, so that the parties can negotiate commercial, technical, legal and contractual conditions. Distribute equally the value generated even when conditions change. Estimate a margin of error acceptable to all parties.
Controlled CO2 Injection into Storage Reservoirs to Minimize Geomechanical Risks Under Geologic Uncertainty
Authors: Zheng F. , Jha B. , Jafarpour B. 
Published: October 2023

Abstract
Carbon Capture and Storage (CCS) has gained recognition as a mitigation strategy for reducing the accumulation of atmospheric CO2. However, the injection of CO2 into storage reservoirs can lead to increased pore pressure, which in turn induces stress changes in and around the injection site. These stress changes may give rise to several geomechanical hazards, including caprock failure, ground surface uplifting, and induced seismic activity. To address this concern, we have developed a novel optimization approach aimed at maintaining the caprock integrity during the storage of CO2 in geologic formations under geological uncertainty. The developed workflow integrates advanced numerical optimization algorithms with coupled multiphase flow-geomechanics-fracturing models for simulating the response of the storage reservoir to CO2 injection. Using the geomechanical response of the simulation, we define and quantify the potential caprock failure and CO2 leakage risks. An optimization formulation is used to minimize the risk of caprock fracturing and CO2 leakage by finding the optimal distribution of dynamically changing CO2 injection rates across several wells throughout the injection period. The results are extended to incorporate the uncertainty in the simulation model through ensemble-based optimization. The proposed optimization approach identifies the well injection schedule (flow rate vs. time profile) to minimize the risk of caprock fracturing by distributing the pressure increase in the heterogeneous reservoir. The optimization process is designed to continually enhance the injection strategy, aiming to minimize the potential for caprock fracturing by maximizing the stress differences between the minimum effective stress and the fracture opening stress. The paper highlights the importance of employing coupled flow and geomechanics, along with fracture mechanics, in accurately modeling and predicting the potential CO2 leakage. This approach enables the development of injection strategies that prioritize caprock integrity, effectively addressing the challenges associated with optimizing CO2 storage while minimizing the risk of caprock failure.
Non-Intuitive Choke Control During Clean-Up Operations Allows Significant Reduction of Emissions
Authors: Theuveny B. , Rashid K. , Bailey W. , Gemmell D. , Comley R. 
Published: October 2023

Abstract
Every well needs to be cleaned-up, at least once – after the end of the well construction phase but could be after stimulation operations or workovers over their full life.
The clean-up / flowback operations are sometimes executed with a full or partial disposal of the fluids as either no production system is available (the case of most exploration and appraisal wells) or when the production system is intolerant to the fluids produced (low pH. High solid content, excess water, or for rheology incompatibilities). The disposed fluids are sent to a flare and their combustion induce a significant amount of emissions. These operations are typically executed according to the prior experience of similar wells.
The paper presents a novel approach to significantly reduce emissions by optimizing the clean-up operation by varying the choke settings in rapid interval at surface. Field case confirm the ability to significantly reduce the duration and the quantity of fluids flared in these operations and accelerating the time to shift the flow to the production line – if available.
The challenge is that every well configuration leads to a different choke schedule that minimizes emissions. This is due to the complex combination of near wellbore properties of the formation and the invaded fluids, the complexity of the well trajectory and the variability of fluids used to kick-start the well. It is intuitive that the acceleration of the choke change would lead to a reduction of the emissions. This leads to a reduction of 10 to 30% of the CO2 balance. To achieve superior savings, it is necessary to consider a reduction of the maximum rate – which can lead to 50% range of reduction in some wells. Further improvements are achieved with more complex choke sequences that the paper describes.
This novel method consists in the detailed prediction of the dynamics of the flow during the clean-up operation is a key element to optimize the choke sequence. A rapid model allows to evaluate several scenarios and select the optimum settings that will achieve a significant reduction in emission while keeping the near well bore in a safe operating zone (geomechanical phenomena), protect the integrity of stimulated zones, and guarantee the safety of the completion (collapse). Finally, several contingency cases are considered to ensure that a robust operation can safely be delivered.
A Comprehensive Study of a Novel Submersible Pump
Authors: Banjar Hattan , Xiao Jinjiang , Ejim Chidirim , Badr Hassan , Al-Sarkhi AbdelSalam 
Published: October 2023

Abstract
Electric submersible pumps (ESPs) are over a century-old technology. As reservoirs mature, water cut increases, motor electric load increases which in turn, increases the required equipment size, mainly the pump and motor lengths. In addition, in alternative ESP deployment methods, length of the ESP is a critical factor during installation and retrieval due to crane limitations especially for offshore. To mitigate the downhole assembly length, a novel motor and pump system is designed. The primary advantage of this design is manifested by the elimination of the protector section that represents a problematic component in a typical electric submersible pump (ESP). This study focuses on the feasibility assessment of the concept at given conditions, where the motor and the pump are integrated concentrically in one unit inside a cylindrical housing in an arrangement suitable for downhole.
A comprehensive system design involving electrical, mechanical and hydraulic analysis was carried out to develop a Permanent Magnet Pump (PMP) with performance characteristics matching a typical conventional ESP. A number of factors affecting the new ESP system were considered. They include maximum radial dimension constraint, high flow rate and total dynamic head requirements, motor cooling, the need to maintain reasonably high efficiency over a wide range of flow rates, sand and gas handling, and finally the ease of manufacturing and system assembly.
An architecture based on a labyrinth screw pump was found to be the most appropriate one for use in the 562 series motorized pump design. Detailed calculations on pump and motor were conducted to determine the system dimensions and performances. For typical field applications with rates ranging from 4000 to 5000 BPD and total dynamic heads ranging from 3000 to 4000 ft, a system made of forty-five stages with an approximate length of 45 ft was found to be sufficient. The PMP overall efficiency ranged from 52% to 58% while the operating speed ranged from 3700 to 4500 RPM. Motor cooling was achieved by circulating part of the pumped fluid back to the pump suction side through the air gap. The fluid temperature increase ranged from 20°F to 30°F, when brine is the pumped fluid.
This comprehensive work assessed the feasibility of developing a novel, motorized pump for downhole artificial lift applications. It is clearly shown that this new ESP architecture is feasible and practical. With this new design, a next generation of ESPs can be built without the conventional motor seal/protector sections, eliminating one of frequent failure components. In addition, the ESP overall length can be shortened, paving the way to develop a more compact, rigless ESP deployment and retrieval technology for further reduction in operational cost and production deferral.
Novel Single Phase Retarded Acid System for Effective Stimulation of Limestone Reservoirs
Authors: Qamruzzaman Mohammed , Nain Pooja , Mhaske Ganesh , Ravishankar Burla , Nischal Rajiv 
Published: October 2023

Abstract
HCl based stimulation fluids occupy the dominant space in matrix acidizing of limestone reservoirs. To initiate wormhole propagation at high temperature/low injection rates and provide deeper penetration, the reactivity of HCl is generally retarded by emulsifying it with an external hydrocarbon phase like diesel. Although it solves the issue of high HCl reactivity, its performance is found to compromised for reservoirs with bottom hole temperature more than 135°C where the emulsion suffers from stability issues. The high viscosity of emulsified acid restricts the pumping rate especially for the cases where the well is having ESP completion or the job is being done through CTU. Also, around 30% of emulsion comprises of diesel which poses health hazard, reduces rock dissolution capacity and incurs extra cost. To counter these challenges, this paper presents a new single phase/aqueous retarded acid formulation that consists of special water-soluble acid retarders which slow down the rate of consumption of HCl. The retardation effect observed is even more than what is observed with emulsified acids while maintaining a high dissolution capacity and low fluid viscosity. A comparative analysis of acid retarders on HCl reactivity has been shown through bench top reaction studies. Suitable corrosion inhibitors compatible with the acid retarders have been identified and the final formulation has been tested through core flooding experiments coupled with Micro CT scan for its effectiveness. Results from lab study indicate that the single-phase retarded acid system requires lesser pore volumes to breakthrough than the conventional acids over wide range of injection rates. Also, dominant wormhole regime has been observed with its use under the conditions where facial dissolution and conical wormholes were found with plain acid and emulsified acid respectively. The developed formulation will be very helpful in increasing the effectiveness of stimulation in limestone reservoirs with special applications in high temperature, horizontal and injectivity compromised wells. Replacing the emulsified acid application with the developed formulation will help in reducing carbon footprint and make job execution simpler, safer and easier.
Evaluation of Metabolic Profiles of Berari Goats in the Transition Period
Authors: Hajare Nikhil Dansing , Kuralkar Prajakta Shailendra , Hajare Sunil W. , Deshmukh Shyam G. , Deshpande Kuldeep Y. , Kuralkar Shailendra Vasantrao , Murkute Pranjali 
Published: October 2023

AbstractThe study aimed to investigate the influence of physiological status on the blood metabolic profile of Berari goats in Vidarbha climatic conditions. Blood samples were collected from 12 healthy pregnant goats 21 days before kidding, on the day of kidding, and 21 days after kidding. The samples were analyzed for non-esterified fatty acid (NEFA), total cholesterol (TC), triglyceride (TG), glucose (Glu), total protein (TP), albumin (Alb), globulin (Glb), alanine transaminase (ALT), aspartate transaminase (AST), calcium (Ca) and phosphorous (P). The transition period had significant effect on TG (26.71 ± 2.52a, 17.05 ± 1.90b, 20.83 ± 1.66abmg/dl), TP (6.13 ± 0.23b, 6.57 ± 0.35b, 8.22 ± 0.29ag/dl), globulin (1.48 ± 0.30b, 1.67 ± 0.34b, 3.69 ± 0.32ag/dl), glucose (66.78 ± 3.30b, 183.47 ± 32.65a, 81.41 ± 6.60bmg/dl) and phosphorus (8.96 ± 0.67a, 5.38 ± 0.79b, 6.59 ± 0.29bmg/dl). The study indicates that the Berari goats were not under metabolic stress and were well-adapted to the tropical and arid climatic conditions of the region. The higher glucose level observed during kidding suggests that the animals were in positive energy status and well-managed during the transition period.
Femoral nerve palsy as a complication due to COVID-19 coagulopathy and iliopsoas muscle hematoma after total hip replacement – case report
Authors: Tutak Sławomir , Bartosz Paweł , Burda Bartosz , Sztwiertnia Paweł , Białecki Jerzy 
Published: October 2023

Abstract
Background: COVID-19 (Coronavirus disease 2019) pandemic is the main medical problem around the world from the end of 2019. We found until now many symptoms of this disease, but one of the most problematic was thrombosis. Wide recommendation on COVID-19 treatment was pharmacological thromboprophylaxis. In some papers we found that clinicians face the problem of bleeding in those patients. Is still unknown that coronavirus could led to the coagulopathy.
Case presentation: We described case report of patient who with COVID-19 disease present femoral nerve palsy caused by the iliopsoas hematoma. There were no deviations in coaguology parameters, patient got standard thromboprophylaxis, besides above probably COVID-19 was risk factor of hematoma formation. Non-operative treatment was applied, thrombophylaxis was discontinued. In the follow up in the radiological exam we saw reduction of the haematoma and patient report decrease of symptoms.
Conclusions: We should assess individually patient with COVID-19 according to thrombosis risk factors. Probably we should be more careful in ordering thrombophylaxis medications in COVID-19 patients.
The future of MEG: Improved task-related responses using optically-pumped magnetometers compared to a conventional system
Authors: Safar Kristina , Vandewouw Marlee , Sato Julie , Devasagayam Jasen , Hill Ryan , Rea Molly , Brookes Matthew , Taylor Margot 
Published: October 2023

Abstract
Optically-pumped magnetometers (OPMs) offer a new wearable means to measure magnetoencephalography (MEG) signals, with many advantages compared to conventional systems. However, OPMs are an emerging technology, thus characterizing and replicating MEG recordings is essential. Using OPM and cryogenic MEG, this study investigated evoked responses, oscillatory power, and functional connectivity during emotion processing in 21 adults, to establish replicability across the two technologies. Five participants with dental fixtures were included to assess the validity of OPM recordings in those with irremovable metal. Replicable task-related evoked responses were observed in both modalities, with the OPMs demonstrating higher peak amplitude and improved signal-to-noise. Similar patterns of oscillatory power to faces were observed in both systems. Increased connectivity was found in cryogenic versus OPM MEG in an occipital and parietal anchored network. Notably, high quality OPM data were retained in participants with metallic fixtures, from whom no useable data was collected using cryogenic MEG.