bluuebunny/crossref_metadata_2025_split huggingface dataset:
Asociación de la enfermedad periodontal con factores de riesgo en adolescentes de 15 años de una institución educativa
Authors: Yataco Barreda Danitza Geraldine , Gomez Diaz Wendy Alejandra , Carrasco Loyola Milagros Bertha , Orejuela Ramirez Francisco Jose 
Published: October 2021

La enfermedad periodontal es una condición inflamatoria que destruye de forma irreversible a los tejidos que soportan al diente, siendo las principales características la profundidad al sondaje, inflamación, edema y eritema. Objetivo: Determinar la asociación de la enfermedad periodontal con factores de riesgo en adolescentes de 15 años de una institución educativa. Material y Métodos: El estudio fue observacional, descriptivo, retrospectivo y transversal basado en los registros de la base de datos del levantamiento epidemiológico de salud bucal del año 2018, contando con una muestra de 29 escolares de 15 años matriculados en el año académico 2018. Las variables fueron enfermedad periodontal, profundidad al sondaje, sangrado gingival, sexo, frecuencia de cepillado, frecuencia de visita al dentista, frecuencia de consumo de tabaco y frecuencia de consumo de alcohol. Para el manejo de los datos se utilizó Excel versión 10 y se exportó a Stata versión 15 en donde se realizaron las pruebas estadísticas. Resultados: La frecuencia de cepillado menor a dos veces al día y el consumo de tabaco se comportaron como factores que aumentan la posibilidad del desarrollo de la enfermedad periodontal con RP: 4,684, IC 95% (0,406 - 54,002) y RP: 1,468, IC 95% (0,489 – 4,412), respectivamente; sin embargo, los valores obtenidos no son estadísticamente significativos (p>0,05). Conclusión: Existe una asociación de la enfermedad periodontal tanto con el cepillado menor de dos veces al día como con el consumo de tabaco en adolescentes de 15 años de una institución educativa.
The Age of Popular Protests
Authors: ŞÖHRET Mesut 
Published: October 2021

Purpose: The purpose of this research is to examine the difference between the global protests, which have increased unexpectedly in the last decade, from the global protests in the past. In this way, it is to show the main points between the global protests and to reveal how the mass demonstrations taking place around the world have changed numerically and regionally.
Design/Methodology: In the research, qualitative and quantitative research methods were used and the global protests that took place around the world, especially the developments that took place in the last ten years, were supported by graphics and maps. This study is a research article and literature review technique was used.
Findings: While every mass protest over the past decade has its own context, these global mass protests are based on common grievances such as economic hardship, ineffective governance, political crisis, ethnic and religious discrimination, and corruption. The interesting thing is that while our world is witnessing new technological inventions and discoveries every day, this dissatisfaction is increasing. At this point, not only the number of countries where these mass demonstrations took place has increased significantly in the last ten years, but also the number of participants in these demonstrations is increasing day by day. In addition, mass demonstrations are increasing not only in underdeveloped countries but also in developed and developing countries.
Limitations: The study examines the developments of the global protests that occurred around the world in the 10-year period between 2009-2019. In addition, it tries to examine the similarities between the protests from a global perspective by aiming to explain the global protests that took place in general.
Originality/Value: The originality of the research is that it examines the development of global protests, especially taking into account the last ten years, and tries to explain the difference between these protests and global protests in the past. In addition, the study tries to support the arguments it defends with graphics and maps obtained from statistical data.
A Hybrid Model for Simulating Fracturing Fluid Flowback in Tight Sandstone Gas Wells considering a Three-Dimensional Discrete Fracture
Authors: Wang Suran , Bai Yuhu , Xu Bingxiang , Li Yanzun , Chen Ling , Dong Zhiqiang , Li Wenlan , Zheng Xiaowen , Wang Xudong 
Published: October 2021

Abstract
Two-phase (gas+water) flow is quite common in tight sandstone gas reservoirs during flowback and early-time production periods. However, many analytical models are restricted to single-phase flow problems and three-dimensional fracture characteristics are seldom considered. Numerical simulations are good choices for this problem, but it is time consuming in gridding and simulating. This paper presents a comprehensive hybrid model to characterize two-phase flow behaviour and predict the production performance of a fractured tight gas well with a three-dimensional discrete fracture. In this approach, the hydraulic fracture is discretized into several panels and the transient flow equation is solved by the finite difference method numerically. A three-dimensional volumetric source function and superposition principle are deployed to capture the flow behaviour in the reservoir analytically. The transient responses are obtained by coupling the flow in the reservoir and three-dimensional discrete fracture dynamically. The accuracy and practicability of the proposed model are validated by the numerical simulation result. The results indicate that the proposed model is highly efficient and precise in simulating the gas/water two-phase flow and evaluating the early-time production performance of fractured tight sandstone gas wells considering a three-dimensional discrete fracture. The results also show that the gas production rate will be overestimated without considering the two-phase flow in the hydraulic fracture. In addition, the influences of fracture permeability, fracture half-length, and matrix permeability on production performance are significant. The gas production rate will be higher with larger fracture permeability at the early production period, but the production curves will merge after fracturing fluid flows back. A larger fracture half-length and matrix permeability can enhance the gas production rate.
Innovative Method to Optimize Down Hole Control Valves by Well Modeling
Authors: Barghouti Akram R. , Javed M. Imran , Al-Shuwaier Saud A 
Published: October 2021

Abstract
The revolution of smart well completions has been significantly enhancing the oil & gas industry in the recent years, The completions allow for higher PIs, better sweep, longer well life, longer reservoir contact and better water management. These effects came into play and needed once O&G industry moved to drilling multi-lateral wells.
This paper represents a tri-lateral well that was drilled with high reservoir contact. The production optimization was completed to evaluate the contribution of each lateral and decide on the future production strategy for the well. This evaluation also allowed to test the functionality of the Down Hole Flow Control Valves (DHFCVs). Further, determining this functionality allowed identifying cross flow between the ICVs and the laterals. The optimization included multi-stage testing of each lateral to ascertain the high oil & water contributors. The water contribution was recorded across each lateral to optimize the water production and enhance the well productivity. The productivity index was calculated using IPR modeling utilizing Pipe-Sim software based on the commingled multi-rate tests. To further plan the way forward on the well production, a flowchart was established during the optimization operation to guide through the optimization process, identify each lateral water contribution, and production strategy after the operation.
This optimization has resulted in a significant cost avoidance, avoiding coil tubing horizontal logging intervention operations in all the three laterals. The details of the testing stages scenarios and the recommendations of the production strategies will be shared in this paper.
Modelling and Upscaling Unstable Miscible Displacement Processes: Characterisation of Physical Instabilities
Authors: Ogbeiwi Precious , Stephen Karl 
Published: October 2021

Abstract
The compositional simulations are required to model CO2 flooding are computationally expensive particularly for fine-gridded models that have high resolutions, and many components. Upscaling procedures can be used in the subsurface flow models to reduce the high computation requirements of the fine grid simulations and accurately model miscible CO2 flooding. However, the effects of physical instabilities are often not well represented and captured by the upscaling procedures. This paper presents an approach for upscaling of miscible displacements is presented which adequately represents physical instabilities such as viscous and heterogeneity induced fingering on coarser grids using pseudoisation techniques. The approach was applied to compositional numerical simulations of two-dimensional reservoir models with a focus on CO2 injection. Our approach is based on the pseudoisation of relative permeability and the application of transport coefficients to upscale viscous fingering and heterogeneity-induced channelling in a multi-contact miscible CO2 injection. Pseudo-relative permeability curves were computed using a pseudoisation technique and applied in combination with transport coefficients to upscale the behaviour of fine-scale miscible CO2 flood simulations to coarser scales. The accuracy of the results of the pseudoisation procedures were assessed by applying statistical analysis to compare them to the results of the fine grid simulations. It is observed from the results that the coarse models provide accurate predictions of the miscible displacement process and that the fingering regimes are adequately captured in the coarse models. The study presents a framework that can be employed to represent the dynamics of physical instabilities associated with miscible CO2 displacements in upscaled coarser grid reservoir models.
Comparative Evaluation of Gas-Condensate Enhanced Recovery Methods for Deep Ukrainian Reservoirs: Synthetic Case Study
Authors: Burachok Oleksandr , Kondrat Oleksandr , Matkivskyi Serhii , Pershyn Dmytro 
Published: October 2021

Abstract
Low value of final condensate recoveries achieved under natural depletion require implementation of enhanced gas recovery (EGR) methods to be implemented for the efficient development of gas-condensate reservoirs. The study was performed using synthetic numerical 9-component compositional simulation model that approximated the typical conditions of deep gas-condensate reservoirs of Dnieper-Donetsk Basin in Easter Ukraine. Injection of water, methane, nitrogen, carbon dioxide, mixture of methane and nitrogen, mixture of methane, ethane and propane at different concentrations were evaluated at 50% and 100% voidage replacement for reservoir fluids with 100 g/m3, 300 g/m3 and 500g/m3 potential condensate yield. Condensate recovery studied at different stages after primary depletion, when reservoir pressure reached 25, 50, 75% from dew point and at pressure of maximum liquid dropout.
Results comparison was done based on the two criteria: technical efficiency – incremental condensate recovery towards the base depletion cases and economic efficiency – cumulative NPV. Status of initial depletion as well as voidage replacement have a direct impact on breakthrough time and negative economic indicators. Despite providing the highest incremental condensate recovery by injecting CO2 at 100% voidage, it has a strong negative economic effect. Based on incremental condensate recovery EGR methods are ranked as following for all condensate potential yields and levels of primary depletion: CO2 100%; solvent gas mixture of C1 90%, C2 5%, C3 5%; solvent gas mixture C1 98%, C2 1%, C3 1%; C1 100%; mixture of C1 50% and N2 50%; N2 100%; water. Economically, the highest efficiency was shown for C1 100% injection, due to the fact, that produced re-cycled gas has a sales value as well. For the maximum incremental recovery it is advisable to start the injection as early as possible, while highest economic increments received for the cases of delayed injection, particularly when the reservoir pressure is equal to the pressure of maximum liquid condensation.
The results of study can be used a guidance for rapid screening of applicable EGR method for gas-condensate fields depending on depletion stage and potential condensate yield.
Offset Data Analysis and Seam Less Execution Through Real Time Monitoring Results in Step Change in Drilling Performance
Authors: Yadav Singh Anurag , Chohan Imran Muhammad 
Published: October 2021

Abstract
In oil and gas drilling, consistency of performance delivery heavily depends upon rig capability and its ability to maintain performance assurance through its execution cycle. It's not an uncommon occurrence that a rig is found with an underperforming top drive, one such scenario was observed in an in-fill oil well drilling project. This project was essentially drilling horizontal wells with bottom hole assemblies which had primary drive mechanism as a top drive. The rig in question was struggling to provide not only the requisite RPM but also not been able to deliver consistent torque needed to drill the well. This study analyzes how severe rig limitations were overcome through an optimization plan in which most optimal BHA was designed and drilling practices were customized for safe and successful execution of wells.
In order to understand root cause of the challenge, an offset well analysis was conducted, it identified that high torque was mostly generated while drilling through inter-bedded formations which typically caused top drive to stall. In addition, multiple tool failures were encountered due to the high stick slip which rig couldn't mitigate due to the low RPM yield of the top drive. To manage the rpm and torque limitations, a motorized RSS BHA was designed as a solution. Further, based on micro-stall events of motor only BHA's across the inter-bedded formations in the field, a stick slip management tool was placed below the motor so that a potential twist-off and/or motor damages can be avoided. Also, different bottom hole assembly's drilling dynamics response were analyzed to come up with optimal stabilization and connection practices to avoid back reaming while trip outs.
This paper would showcase actual results which highlight improvements achieved in stagnant drilling performance of the project. The analysis would demonstrate how multiple wells were drilled in one run following the risk assessment developed from the optimization study and subsequent real time monitoring of mitigating actions while execution.
The comprehensive bottoms-up drilling optimization approach helped save 4 planned days for each well, this really paves way to pursue applied-engineering solutions to achieve step change in drilling performances, especially on rigs which are severely limited either due to capacity or malperformance issues. The bottoms up approach taken to understand the drilling challenges followed by a methodical approach to address each of the challenges demonstrate importance of effective pre-job planning. Learnings from this study can be adopted as a template to mitigate similar drilling challenges.
Restoring Erroneous or Missing Rates in Interfering Wells Using Multiwell Deconvolution
Authors: Razminia Kambiz , Gringarten Alain C. 
Published: October 2021

Abstract

Objectives/Scope
Single well deconvolution (von Schroeter et al., 2001) has been added to the well test interpretation toolbox nearly twenty years ago. In recent years, the single well deconvolution algorithm has been extended to multiple interfering wells (Cumming et al., 2013), and further improved with the additions of constraints to account for existing a-priory knowledge on the reservoir (constrained multiwell deconvolution, Cumming et al., 2019).
The main objective of multiwell deconvolution is to identify the signatures of all wells involved and the interference signals between wells, from which information can be extracted about the reservoir that may not be obtainable otherwise, e.g. heterogeneities, boundaries and compartmentalization. The single well deconvolution algorithm has also been shown to be capable of restoring erroneous or missing rates (Gringarten, 2010).
As shown in this paper, the same is true with multiwell deconvolution, which is able to restore erroneous or missing rates in all the wells involved.

Methods, Procedures, Process
Starting with arbitrary initial guesses for the missing rates in the various wells involved, we use multiwell deconvolution to estimate these missing flow rates or correct for erroneous ones.
Two methods are presented: (1) we use unconstrained multiwell deconvolution as a first step to estimate the missing/erroneous rates, then use constrained multiwell deconvolution with these rates to estimate deconvolved derivatives; and (2) we restore/correct the flow rates and derive deconvolved derivatives simultaneously using constrained multiwell deconvolution. We show that the first approach is more accurate than the second one. In both approaches, we only obtain rates that are proportional to the true flow rates. To obtain the true flow rates, we need to know either one of the actual flow rates in each well, or the corresponding permeabilities.

Results, Observations, Conclusions
We prove the ability of multiwell deconvolution to estimate rates on synthetic oil reservoirs and gas reservoirs with moderate average reservoir pressure depletion, that include non-interfering wells. We then apply to oil and gas field examples and compare restored vs. actually measured rates. In all cases, the agreement is very good.

Novel/Additive Information
Using only measured pressure data, constrained multiwell deconvolution can be used to restore unknown flow rates and/or correct for erroneous rates, in addition to estimating deconvolved derivatives of all wells. This is particularly useful in the case of allocated rates or when rates are missing in some of the interfering wells.
Inertial Effect on Spontaneous Oil-Water Imbibition by Molecular Kinetic Theory
Authors: Tian Weibing Tian , Wu Keliu , Chen Zhangxin , Gao Yanling , Gao Yin , Li Jing 
Published: October 2021

Abstract
Imbibition is one of the most common physical phenomena in nature, and it plays an important role in enhanced oil recovery, hydrology, and environmental engineering. For the tight reservoirs, the imbibition method has an obvious advantage in fracturing, shut-in, and huff-puff development. Although the current imbibition studies focus on oil recovery, and the inertial effect in imbibition is neglected and its mechanism is also unclear.
In this paper, the inertial effect on spontaneous oil-water imbibition at micron-scale is studied by molecular kinetic theory (MKT). The frictional coefficient in the model is a fitted parameter to match the experimental data during the total imbibition process. Then, the simulation of the initial imbibition stage is conducted and the inertial effect on imbibition is identified by the difference between the model considering the inertial effect (CI) and the model neglecting the inertial effect (NI), or by the proportion of inertial force to the total resistance.
Results show that (i) with an increase in the water phase viscosity, the inertial effect time shortens, maximum imbibition height and rate decrease, and thus the inertial effect on imbibition weakens; (ii) with an increase in the oil phase viscosity, the inertial effect time changes little, the maximum imbibition height and rate decrease slightly, namely, the inertial effect depends slightly on the oil phase. (iii) with an increase in the capillary wettability (hydrophilicity), the inertial effect time shortens, the maximum imbibition rate first increases and then decreases, and the inertial effect on imbibition weakens.
This work sheds light on the inertial effect on oil-water imbibition by MKT, considering the effects of dynamic contact angle, water phase viscosity, oil phase viscosity, and wettabilities, which is helpful to understand the role of inertia in the oil-water or oil-fracturing fluid imbibition process.
Numerical Simulations of Surfactant Flooding in Carbonate Reservoirs: The Impact of Geological Heterogeneities Across Scales
Authors: Pola Jackson , Geiger Sebastian , Mackay Eric , Maier Christine , Al-Rudaini Ali 
Published: October 2021

Abstract
We demonstrate how geological heterogeneity impacts the effectiveness of surfactant-based enhanced oil recovery (EOR) at larger (inter-well and sector) scales when upscaling small (core) scale heterogeneity and physicochemical processes. We used two experimental datasets of surfactant-based EOR where spontaneous imbibition and viscous displacement, respectively dominate recovery. We built 3D core-scale simulation models to match the data and parameterize surfactant models. The results were deployed in high-resolution models that preserve the complexity and heterogeneity of carbonate formations in the inter-well and sector scale. These larger-scale models were based on two outcrop analogues from France and Morroco, respectively, which capture the reservoir architectures inherent to the productive carbonate reservoir systems in the Middle East. We then assessed and quantified the error in production forecast that arises due to upscaling, upgridding, and simplification of geological heterogeneity.
Simulation results showed a broad range of recovery predictions. The variability arises from the choice of surfactant model parameterization (i.e., spontaneous imbibition vs viscous displacement) and the way the heterogeneity in the inter-well and sector models was upscaled and simplified. We found that the parameterization of surfactant models has a significant impact on recovery predictions. Oil recovery at the larger scale was observed to be higher when using the parametrization derived from viscous displacement experiments compared to parameterization from spontaneous imbibition experiments. This observation clearly demonstrated how core-scale processes impact recovery predictions at the larger scales. Also, the variability in recovery prediction due to the choice of surfactant model was as large as the variability arising from upscaling and upgridding. Upscaled and upgridded models overestimated recovery because of the simplified geology. Grid coarsening exacerbated this effect because of the increased numerical dispersion. These results emphasize the need to use correctly configured surfactant models, appropriate grid resolution that minimizes numerical dispersion, and properly upscaled reservoir models to accurately forecast surfactant floods. Our findings present new insights into how the uncertainty in production forecasts during surfactant flooding depends on the way surfactant models are parameterized, how the reservoir geology is upscaled, and how numerical dispersion is impacted by grid coarsening.