bluuebunny/crossref_metadata_2025 huggingface dataset:
A produção sobre o corpo en revistas da educação
Authors: Baptista Tadeu João Ribeiro
Published: January 2020

O corpo é o tema que é discutido há muito tempo em várias áreas. Assim, o objetivo deste texto foi analisar os paradigmas epistemológicos dos artigos sobre corpo publicados em revista classificadas como A-1 no WebQualis na Área da Educação. Foi realizada uma análise documental a partir da Matriz Paradigmática. A análise foi composta por uma parte quantitativa e outra mais qualitativa que permitiu identificar os paradigmas de cada texto. Os resultados demonstram que das matrizes analisadas, o movimento Pós-Moderno responde por 50% do total de publicações. Isso demonstra uma tendência de movimento diferente do que era previsto inicialmente.
CULTURA DOS MEMES NO AMBIENTE CONECTIVO: identidades e criação coletiva
Authors: Vieira Soraya Maria Ferreira , Stefano Luiza de Mello
Published: January 2020

Este artigo propõe uma análise que compreende a autorrepresentação no ambiente conectivo através da criação coletiva de memes como vetor que opera na construção de identidades. A partir do engajamento dos fãs do programa de reality show Big Brother Brasil, observamos os processos cognitivos, estéticos e linguísticos e as práticas de ressignificação de mensagens na produção e consumo de memes. Dado o modo de ser que incidem nas leituras que os fãs realizam, podemos afirmar que a autorrepresentação recai no próprio processo de construção do meme, quando o usuário relaciona e interconecta diversas referências de textos que advêm de sua memória afetiva-social e repertório midiático.
O MAL EM APOCALÍPTICOS E O BEM EM INTEGRADOS
Authors: Feil Gabriel Sausen , Dahleh Simone Munir , Paz Júlia Rocha
Published: January 2020

O tempo é o tema principal de nosso presente trabalho, que traz os conceitos de Mal e Bem, de Georges Bataille (1989), e as concepções de cultura pelo entendimento dos apocalípticos e integrados, de Umberto Eco (2006), com o intuito de aproximar tais conceitos por conta de suas possibilidades de relações com o tempo. Primeiramente, apresentamos os quatro conceitos e, em um segundo momento, aproximamos os conceitos a partir de suas similaridades. Mostramos como esses conceitos são paralelos e não contrários, de forma a criar uma discussão reflexiva e não moral (já que envolve o Mal e Bem) sobre eles.
 
PALAVRAS-CHAVE: Cultura. Filosofia. Comunicação. Linguagem.
 
 
ABSTRACT
The time is the main theme of our work, that brings the concepts of Evil and Good, by Georges Bataille (1989), and the conceptions of culture by the understanding of the apocalyptic and integrated, by Umberto Eco (2006), with the aim of bringing such concepts closer because of their possibilities of relations with time. First, we present the four concepts and, in a second moment, we approach the concepts from the similarities between them. We show how these concepts are parallel and not contrary, in order to create a reflexive and non-moral discussion (since it involves Evil and Good) about them.
 
KEYWORDS: Culture. Philosophy. Communication. Language.
 
 
RESUMEN
El tiempo es lo tema principal de nuestro presente trabajo, que trae los conceptos de mal y bueno, de Georges Bataille (1989), y las concepciones de cultura por el entendimiento de los apocalípticos y integrados, de Umberto Eco (2006), con la intención de aproximar los conceptos en cuenta de sus posibilidades de relaciones con el tiempo. Primeramente, presentamos los cuatro conceptos y, en segundo momento aproximamos los conceptos por sus similaridades. Mostramos como esos conceptos son paralelos y no contrarios, de forma a crear una discusión reflexiva y no moral (ya que envuelve el bien y el mal) sobre ellos.
 
PALABRAS CLAVE: Cultura. Filosofia. Comunicación. Lenguaje.
CONSTRUÇÃO COMPARTILHADA DE VÍDEO PARA EDUCAÇÃO DE IDOSOS HIPERTENSOS
Authors: MIRANDA CAROLINA GALGANE LAGE , Castro Mauro Silveira , Soares-Sobrinho José Lamartine
Published: January 2020

O artigo descreve a experiência sobre elaboração de material educativo, formato de vídeo artístico criado coletivamente por pesquisadores e idosos hipertensos, como estratégia para obtenção de atitude reflexiva, participativa e autônoma sobre sua doença, cuidado de si e uso correto e seguro de medicamentos.

 

PALAVRAS-CHAVE: Vídeo; Educação em Saúde; Idoso; Hipertensão.

 

 

 

ABSTRACT

The article describe the experience about the elaboration of educational material, an artistic video format created collectively by hypertensive researchers and seniors, as a strategy to obtain a reflexive, participatory and autonomous attitude about their illness, self care and correct and safe use of medications.

 

KEYWORDS: Video; Health education; Old man; Hypertension.

 

 

RESUMENEl artículo describe la experiencia en la elaboración de material educativo, un formato de video artístico creado colectivamente por investigadores y ancianos hipertensos, como una estrategia para obtener una actitud reflexiva, participativa y autónoma sobre su enfermedad, el autocuidado y el uso correcto y seguro de los medicamentos.

 

PALABRAS CLAVE: Video; Educación para la Salud; Viejo; Hipertension.
Change Detection Based Building Damage Assessment Method Using Radar Imageries with GLCM Textural Parameters
Authors: Akhmadiya Asset , Nabiyev Nabi , Moldamurat Khuralay , Dyusekeev Kanagat , Atanov Sabyrzhan
Published: January 2020

In this research paper, change detection based methods were considered to find collapsed and intact buildings using radar remote sensing data or radar imageries. Main task of this research paper is collection of most relevant scientific research in field of building damage assessment using radar remote sensing data. Several methods are selected and presented as best methods in present time, there are methods with using interferometric coherence, backscattering coefficients in different spatial resolution. In conclusion, methods are given in end, which show, which methods and radar remote sensing data give more accuracy and more available for building damage assessment. Low resolution Sentinel-1A/B radar remote sensing data are recomended as free available for monitoring of destruction degree in microdistrict level. Change detection and texture based method are used together to increase overall accuracy. Homogeneity and Dissimilarity GLCM texture parameters found as better for separation of a collapsed and intact buildings. Dual polarization (VV,VH) backscattering coefficients and coherence coefficients (before earthquake and coseismic) were fully utilized for this study. There were defined the better multi variable for supervised classification of none building, damaged and intact buildings features in urban areas. In this work, we were achieved overall accuracy 0.77, producer’s accuracy for none building is 0.84, for damaged building case 0.85, for intact building 0.64. Amatrice town was chosen as most damaged from 2016 Central Italy Earthquake.
Intelligent Road Inspection with Advanced Machine Learning; Hybrid Prediction Models for Smart Mobility and Transportation Maintenance Systems
Authors: Karballaeezadeh Nader , Zaremotekhases Farah , Shamshirband Shahaboddin , Mosavi Amir , Nabipour Narjes , Csiba Peter , Várkonyi-Kóczy Annamária R.
Published: January 2020

Prediction models in mobility and transportation maintenance systems have been dramatically improved through using machine learning methods. This paper proposes novel machine learning models for an intelligent road inspection. The traditional road inspection systems based on the pavement condition index (PCI) are often associated with the critical safety, energy and cost issues. Alternatively, the proposed models utilize surface deflection data from falling weight deflectometer (FWD) tests to predict the PCI. Machine learning methods are the single multi-layer perceptron (MLP) and radial basis function (RBF) neural networks as well their hybrids, i.e., Levenberg-Marquardt (MLP-LM), scaled conjugate gradient (MLP-SCG), imperialist competitive (RBF-ICA), and genetic algorithms (RBF-GA). Furthermore, the committee machine intelligent systems (CMIS) method was adopted to combine the results and improve the accuracy of the modeling. The results of the analysis have been verified through using four criteria of average percent relative error (APRE), average absolute percent relative error (AAPRE), root mean square error (RMSE), and standard error (SD). The CMIS model outperforms other models with the promising results of APRE=2.3303, AAPRE=11.6768, RMSE=12.0056, and SD=0.0210.
Сравнение значений концентрации хлорофилла a, восстановленных по данным спектрорадиометра MODIS-Aqua, с результатами измерений в прибрежных водах Чёрного моря в районе Севастополя
Authors: Скороход Е. Ю. , Ефимова Т. В. , Моисеева Н. А. , Землянская Е. А. , Чурилова Т. Я.
Published: January 2020

Представлены результаты сравнения значений, которые были получены с помощью стандартного спутникового продукта «Концентрация хлорофилла a», восстановленных по данным со спектрорадиометра MODIS-Aqua, с данными натурных измерений в прибрежных водах Чёрного моря в районе г. Севастополя с 2009 по 2019 г. в рамках регулярного биооптического мониторинга. Установлены различия между сезонами в характере ошибки стандартного спутникового продукта «Концентрация хлорофилла a» при использовании стандартного алгоритма NASA: в весенний период отмечено существенное занижение значений стандартного спутникового продукта «Концентрация хлорофилла а» (до 2,1 раза) при высоких концентрациях хлорофилла a по результатам натурных измерений, а летом — существенное завышение (до 3,8 раза) при малых концентрациях. На протяжении всего года в зависимости от сезона ошибка в определении стандартного спутникового продукта «Концентрация хлорофилла a» в среднем изменялась от ±24 % до ±51 %. Для повышения точности определения концентрации хлорофилла a при дистанционном зондировании необходимо применение регионального подхода.
Implication of public speaking anxiety on the employability of Omani graduates
Authors: Ibrahim Omer , Devesh Sonal
Published: January 2020

The paper examines the implication of public speaking anxiety on the employability of Omani graduates. The study adopted a sequential, mixed research strategy, starting with in-depth interviews of teachers and managers in industry, followed by a structured questionnaire involving 200 students selected randomly from two colleges in Muscat. The statistical approach included exploratory factor analysis (EFA), and parametric tests. The study found that public speaking anxiety is widespread among students in higher education institutions in Oman, with a prevalence rate amounting to 55%, much higher compared to the rates reported globally. The main factors involving public speaking anxiety in these education institutes in Oman were attributed to a lack of self-confidence, foreign language anxiety, being unprepared in, or fear of, talking in a foreign language, lack of experience, or forgetfulness/loss of memory. The implication of public speaking anxiety on employability of graduates in Oman is identified and some suggestions made based on the findings.
A Laboratory Study of the Impact of Reinjecting Flowback Fluids on Formation Damage in the Marcellus Shale
Authors: Zhang Lifu , Tice Michael , Hascakir Berna
Published: January 2020

Reuse of flowback water in hydraulic fracturing is usually used by industry to reduce consumption, transportation, and disposal cost of water. However, because of complex interactions between injected water and reservoir rocks, induced fractures may be blocked by impurities carried by flowback and mineral precipitation by water/rock interactions, which causes formation damage. Therefore, knowledge of flowback water/rock interactions is important to understand the changes within the formation and effects on hydraulic fracturing performance.

This study focuses on investigating flowback water/rock interactions during hydraulic fracturing in Marcellus Shale. Simple deionized water (DI)/rock interactions and complicated flowback water/rock interactions were studied under static and dynamic conditions. In static experiments, crushed reservoir rock samples were exposed to water for 3 weeks at room condition. In the dynamic experiment, continuous water flow interacted with rock samples through the coreflooding experimental system for 3 hours at reservoir condition. Before and after experiments, rock samples were characterized to determine the change on the rock surfaces. Water samples were analyzed to estimate the particle precipitation tendency and potential to modify flow pathway.

Surface elemental concentrations, mineralogy, and scanning electron microscope (SEM) images of rock samples were characterized. Ion contents, particle size, total dissolved solids (TDS), and zeta-potential in the water samples were analyzed. After flowback water/rock interaction, the surface of the rock sample shows changes in the compositions and more particle attachment. In produced water, Na, Sr, and Cl concentrations are extremely high because of flowback water contamination. Water parameters show that produced water has the highest precipitation tendency relative to all water samples. Therefore, if flowback water without any treatment is reused in hydraulic fracturing, formation damage is more likely to occur from blockage of pores.

Flowback water management is becoming very important due to volumes produced in every hydraulic fracturing operation. Deep well injection is no longer a favorable option because it results in disposal of high volumes of water that cannot be used for other purposes. A second option is the reuse of waste water for fracturing purposes, which reduces freshwater use significantly. However, the impurities present in flowback water may deteriorate the fracturing job and reduce or block the hydraulic fracturing apertures. This study shows that a simple filtration process applied to the flowback water allows for reinjection of the flowback water without further complication to the water/rock interaction, and does not cause significant formation damage in the fractures.
Real-Time Completion Cost Optimization Using Model Predictive Control
Authors: Ben Yuxing , Sankaran Sathish , Harlin Clayton , Perrotte Michael
Published: January 2020

Completion cost structure varies from company to company and is primarily driven by hydraulic horsepower consumption, represented by the average wellhead pressure and slurry rate, given a total amount of proppant and total volume of fluids. In this paper, we use model predictive control (MPC) with system identification to optimize completion cost subject to real-time operational constraints. This can help completion engineers adjust the pumping schedule to optimize completion costs on the fly.

We examined a typical cost structure of hydraulic fracturing service companies and illustrated how well completion costs could have been reduced if we adjusted their pumping schedules. We first developed a data-driven model with system identification that characterized how wellhead pressure responded to changes in slurry rate, proppant concentration, and friction reducer (FR) concentration. A linear transfer function model was shown to give acceptable accuracies if the model was updated every 5 to 10 minutes as real-time data were received. MPC was then used to design an optimal schedule subject to a wellhead pressure setpoint. In multiple scenarios with different kinds of constraints, the target wellhead pressure can be achieved by adjusting friction reducer, slurry rate, and proppant concentration. One can deploy such a model at the edge or in a cloud environment to offer suggestions to engineers in the field or in the office. Completion cost savings can potentially be achieved by following the suggested changes.
A Data Driven Approach in Screenout Detection for Horizontal Wells
Authors: Yu Xiaodan , Trainor-Guitton Whitney , Miskimins Jennifer
Published: January 2020

Multi-stage hydraulic fracturing has gained popularity all over the world as more tight geologic formations are developed economically for hydrocarbon resources. However, due to the stages' operating complexity, different kinds of disruptions in fracturing operations may occur and even result in great economic loss. Screenout is one of the issues caused by the blockage of proppant inside the fractures. This paper presents a screenout classification system based on Gaussian Hidden Markov Models (GHMMs), trained on simulated data, that predicts screenouts and provides early warning by learning pre-screenout patterns in the simulated surface pressure signals. The simulated data are generated in a hydraulic fracturing software using a horizontal well with three fracturing stages landing in the Niobrara B shale, Denver-Julesburg (DJ) Basin. During the 270 simulations, various synthetic fracturing treatment data are forward modeled for both screenout and non-screenout scenarios. The classification system consists of two Gaussian Hidden Markov Models (screenout and non-screenout), each of which is fitted and optimized by its respective training set. Both Hidden Markov Models are assigned with two 1D Gaussian probability density functions to represent the distribution of their associated simulated surface pressure signals. During the classification process, once a new surface pressure sequence is observed, the maximum log likelihood is calculated under both fitted models and the model with a greater likelihood will be predicted as the class of this new observation. The classification system is validated with a hold-out testing data set from the simulations and the statistics of the performance is visualized in a confusion matrix. The results indicate the classification system achieves an overall classification accuracy of 81% and an accuracy of 86% for successfully predicting screenout events around 8.5 minutes prior to screenout occurring in the simulation. The described methodology is demonstrated to be a useful tool for early screenout detection and shows its promising feasibility of other fracturing time-series data analysis.
An Interesting Look at Multiple Fractures: Stress Shadowing and Propagation
Authors: Morales Raul H.
Published: January 2020

The objectives of this paper are twofold. First to evaluate the extent, or shadowing, of the stresses and displacements resulting from an internally pressurized crack and second to show how a creative testing apparatus can model the interaction of multiple fractures and display the influence of stress shadowing.

The solution for 2-D planar crack in elliptical-cylindrical coordinates was used to evaluate the stress and displacement shadowing. This analysis indicated that the compressive stresses for a pressurized crack of length H, will dissipate by 100% within a distance d/H = 3/4. The analysis also showed that the shear stresses and displacements are concentrated in a small area around the crack tip of radial distance equal to d/H = 0.05. H is crack length and d is distance from the crack. Following this analysis, the mechanical apparatus was used to visualize the influence of the stress and displacement shadows in the propagation of multiple fractures.

The example that validated the application of the apparatus consisted of modeling the merging of two fractures observed in the 2017 Puebla, Mexico earthquake. In this case, both the testing apparatus and the numerical results given by a two dimensional Finite Element (FE) code closely reproduced the field observations. Following this validation, the application of the testing apparatus was extended to model the propagation and interaction of multiple fractures. Three cases were considered. Case 1, consisted of a main fracture propagating between pre-existing fracture-pockets filled with fluid (pressurized pockets). Case 2, included the propagation of multiple parallel fractures. Case 3, considered hydraulic fractures propagating through zones populated with micro-fissures.

Case 1, showed how a hydraulic fracture can activate and propagate pre-existing frac-pockets. This example could explain how some frac-hits occur. Case 2, illustrated that from a cluster of several parallel fractures that are close to each other (D/H < 1), only one or two dominant fractures will propagate. D is distance between parallel fractures. The experimental results for Case 3 indicated that the micro-fissures diverted the direction of fracture propagation and also increased the tortuosity. The extent of departure and degree of tortuosity depended on the orientation of the micro-fissures. Micro-fissures normal to the crack resulted in more diversion and more tortuosity compared to the diversion and tortuosity resulting from micro-fissures parallel to the crack. Further the tests also showed that the micro-fissures not aligned with the fracture also suffered significant dilation.
The Unconventional Unconventionals: Tectonically Influenced Regions, Stress States and Casing Failures
Authors: Casero A. , Rylance M.
Published: January 2020

Not all unconventional plays are created equal, in a substantial number of regions around the world the tectonic environment is quite different from the typically relaxed and more passive states found widely in most, if not all, of the US unconventional plays. This is merely a function of the relative proximity of such plays to distinct geological features characterized by active tectonic plates and with dynamic margins and recent activity.

The Nazca plate associated with the Andes, the Arabian plate linked with the Al-Hajar mountains and the Indian plate connected with the Himalayan mountain range are just a few examples of tectonically influenced regions, where potential hydrocarbon traps are subject to complex states of stress generated by convergent plates, subduction zones and associated faulting. This scenario often translates into severe strike-slip and reverse fault stress states. Additionally, the presence of both multi-layered and laminated formation geology as well as the presence of overpressure and pressure differentials, typical of tight gas and shale gas, can exacerbate this situation even further. This situation can result in an extremely challenging environment for the successful execution of hydraulic fracturing and the associated development of unconventional resources.

This paper will demonstrate, that such complex stress-states will directly affect well completions and hydraulic fracturing in a multitude of ways, but that some of the most impactful consequences are often severe casing failures, production-liner restrictions and complex fracture initiation scenarios. Casing failures are responsible for increased intervention costs as well as higher costs for the upgraded and strengthened wells. Equally, such issues can severely impair efficient execution of the completion plan and create a bottle-neck to subsequent well production. Horizontal, complex and pancake fractures will typically develop in strike-slip / reverse fault stress states, often resulting in fracture conductivity and connectivity loss that will greatly impair the eventual well performance.

Layer interface slippage and natural fault re-activation are dominant mechanisms for hydraulic fracture induced casing failures. Examples of micro-fracs, micro-seismic and other diagnostics will be presented aiming to document the practical difficulties encountered while completing wells in these complex environments. This paper will demonstrate that unconventional development in such environments requires a renewed focus on all aspects of well design and construction, from directional drilling and lateral placement to casing selection and lower completion design. All these considerations are made with the goal of enabling the competent delivery of a highly effective and conductive fracture network, to efficiently access and produce the hydrocarbon resource.
Use of Reservoir Simulation to Forecast Field EOR Response - An Eagle Ford Gas Injection Huff-N-Puff Application
Authors: Kerr Erich , Venepalli Kiran Kumar , Patel K , Ambrose Raymond , Erdle James
Published: January 2020

Enhanced oil recovery in unconventional plays has been a focus of many E&P operators to increase recovery factors. Conventional displacement-based secondary (e.g. water flooding) and tertiary EOR methods are not viable options due to their low injectivity in these ultra-low permeability formations. As such, huff-n-puff (HnP) EOR techniques involving field gas injection may be the most effective EOR methods to increase the recovery factors from these shale formations. Several numerical reservoir simulation studies have showed the efficiency of CO2 HnP process in shale and tight formations (Yu et al, 2014); however, these studies show little to no field results to support the simulation predictions. This paper describes the conceptual development of the reservoir simulation models to investigate the viability of gas injection HnP in unconventional reservoirs and the results of applying those methods in Eagle Ford field test sites.

Single-well and multi-well models with multi-stage hydraulic fractures were constructed and history matched using their primary production period performance. Sensitivity studies were conducted on well communication behavior/impacts, injection gas compositions, injection rates, injection/production cycling, and reservoir fluid types to optimize the pilot project well location(s) and to inform development strategies. Optimal cases from the simulation study were successfully applied to multi-well pads in the Eagle Ford formation across multiple fluid types.

The simulation and the field application results were summarized and compared to provide detailed insights of unconventional HnP EOR. This study indicates the importance of confinement of the gases to afford optimal recovery factors during unconventional gas HnP EOR. An optimization engine was used in this study to optimize key operational parameters, such as injection pressures and slug sizes, to maximize recovery and efficiency. The resulting EOR designs were successfully implemented in field operations. Field recovery factors are within 10% of those predicted by simulation, indicating the value of numerical reservoir simulation prior to field trials and subsequent future development.
Nuances and Frequently Asked Questions in Field-Scale Hydraulic Fracture Modeling
Authors: McClure Mark , Picone Matteo , Fowler Garrett , Ratcliff Dave , Kang Charles , Medam Soma , Frantz Joe
Published: January 2020

Hydraulic fracturing and reservoir simulation are used by operators in shale to optimize design parameters such as well spacing, cluster spacing, and injection schedule. In this paper, we address ‘freqently asked questions’ that we encounter when working on hydraulic fracture modeling projects with operators. First, we discuss three high-level topics: (1) data-driven and physics-based models, (2) the modeling workflow, and (3) planar-fracture modeling versus ‘complex fracture network’ modeling. Next, we address specific technical topics related to modeling and the overall physics of hydraulic fracturing: (1) interrelationships between cluster spacing and other design parameters, (2) processes affecting fracture size, (3) fracture symmetry/asymmetry, (4) proppant settling versus trapping, (5) applications of Rate-Transient Analysis (RTA), (6) net pressure matching, (7) Initial Shut-In Pressure (ISIP) trends along the wellbore, and (8) the effect of understressed/underpressured layers. We discuss practical modeling decisions in the context of field observations.
High Viscosity Friction Reducers - Potential for Fracture Damage and Impact of Brines on Proppant Transport Capability
Authors: Hlidek Barry , Duenckel Robert
Published: January 2020

High viscosity friction reducer (HVFR) fracturing fluids are widely implemented for unconventional reservoir development. HVFR's are easy to apply and reduce chemical costs. The research objective of this paper is to measure polymer cleanup in both propped and unpropped fractures utilizing multiple methods. Additionally, the study will compare rheological measurements to proppant transport observations in brines using a large-scale slot flow device.

API conductivity cells determined pack damage over a range of proppant sizes, HVFR's, and temperatures. An extended length conductivity (ELC) apparatus was utilized for comparison with the API cell. Cleanup in unpropped fractures employed a core holder using fractured core plugs. HVFR rheological property measurements include low and high steady shear measurements, and oscillatory measurements used to determine elastic properties. Mix waters include fresh water, salt solutions, and a simulated field brine. Proppant transport in fresh and simulated field brine is evaluated in a 1 × 8 foot slot flow device. Proppant deposition rates are recorded using video cameras.

Propped fracture cleanup in the API cell and ELC apparatus is a function of proppant mesh size and HVFR type. As mesh size decreased, the potential for damage increased. Tests with 50/140 mesh proppants in the API cell in some cases showed significantly impaired regain conductivities as low as 65%. When compared to the ELC, API cell cleanups were in some cases significantly optimistic. Cleanup also varied greatly with HVFR product. Even with a low loading of HVFR of 1 gallon per thousand gallons of fluid (gpt) significant damage was sometimes noted. The tests of the unpropped fractures showed that very severe damage to unpropped fractures may occur. The presence of salts significantly and negatively affects HVFR rheological properties for most of the materials selected for this study. Viscosity at higher shear rates (10-511/sec) do not necessarily reflect HVFR performance at lower shear rates. In all tests, the rheological performance between different products exhibited a wide variation in properties, likely reflecting the potentially wide variation in chemical composition. Proppant transport testing validates the rheology measurements. The slot flow evaluations showed a significant loss of transport capability in brines. Commercial HVFR's are not equivalent and require laboratory performance evaluations.

The study demonstrated that the potential for significant damage to the proppant pack and reservoir is present with HVFR fluid systems. Even low salt concentrations significantly influence the HVFR rheological performance. Mix water compatibility must be a primary concern when selecting HVFR's. The results of this study provide useful information to engineers for selecting HVFR's and describes a methodology for evaluating damage potential, and proppant transport.
Using Automation While Pumping to Improve Stimulation Uniformity and Consistency: A Series of Case Studies
Authors: Holley Eric , Martysevich Vladimir , Cook Katie , Gale Scott
Published: January 2020

Within the hydraulic fracturing domain, automation has begun to play a substantial role in logistics, supply chain, and manufacturing. A review of automation opportunities generally focuses on cost reduction arising from throughput improvements for service delivery. Although cost reduction efforts are important and are delivered in many ways, the automation efforts discussed in this paper take a different approach. Automation now plays a larger role in how stimulation operations are performed from the subsurface perspective.

The automation processes reviewed in these studies focus on making more consistent decisions while breaking down the formation to promote an even distribution of fracture fluid placement for all stages. The metric for success is not necessarily focused on cost or time reduction; although these outcomes are occurring, the success metrics focus on the concept that more effective fracturing treatments can be consistently delivered by removing human inconsistency through automation during stimulation operations. This is accomplished is by automatically controlling the pump rate, based on the pressure response from the formation in real time.

This paper highlights a series of cases in North American shale basins that include wells that are instrumented with fiber optics and downhole pressure gauges, as well as non-instrumented wells with wellhead pressure and flowrate measurements only. It reviews how automation improves placement consistency in stimulation operations, eliminating some of the risks associated with traditional approaches that can lead to inconsistent outcomes. All of the results communicated are based on the capability to place fracturing fluid and proppant with more uniformity and consistency across the target interval while making real-time automated rate adjustments during pumping operations. The studies include work conducted in all major North American plays. The major findings include a discernable capacity to treat more clusters within a given stage, using automated rate controls, and achieving more even distribution of proppant to the target clusters within a given stage.
Perforating Trends, Technology and Evaluation in North America
Authors: Squires Christopher , Ramos Claudio , Clay Matthew
Published: January 2020

Perforating cemented casing is a staple for completing wells in every major basin in North America. The objective is to provide a highly conductive pathway between the wellbore and the target formation for both the stimulation and production fluids. New technology, statistical analysis, experimentation and trial-and-error are all used to find the optimal method for creating this pathway. Diagnostics like proppant tracers, downhole cameras, distributed temperature sensing (DTS), distributed acoustic sensing (DAS) and perforation friction pressure analysis can also be used to help evaluate the successes associated with the different methods for perforating.

New technology in creating consistent hole perforations in a horizontal wellbore, without the need for mechanical centralization or positioning systems, has recently been developed. This method of perforating employs a specialty shaped charge that allows for more control in the distribution of entry hole diameter (EHD) across a given cluster. This provides operators a more predictable and consistent pathway from the wellbore to the formation.

Not only is a consistent hole desirable in a standard multi-cluster stage treatment, but other recent completions trends can also benefit from increased precision in perforating. High density perforating (HDP) is being used in order to create more transverse fractures along the length of the well. A consistent hole allows for more precise estimations of pressure drop across each cluster in these mostly limited-entry or extreme limited entry (XLE) completions. Additionally, near-wellbore (NWB) perf sealing pods are being used to divert treatments from initially open clusters to bypassed or partially open clusters in an attempt to force perf cluster efficiencies higher and distribute stimulation fluids and proppant more evenly. Having a consistent hole for every perforation is ideal in attempting to seal the perforations in the NWB region with a fixed diameter pod. SPE 189900 (Senters, et al 2018) provides more detail on diversion optimization. Engineered completions design is employed in an attempt to selectively perforate rock within a stage with similar mechanical properties to drive stimulated cluster efficiencies higher. Perforating similar rock with a consistent hole shaped charge only stands to improve the chances of distributing the treatment more evenly throughout the clusters.

This paper will provide insight into the recent trends in perforating which show an increase in the amount of consistent hole shaped charges versus conventional shaped charges like deep penetrating and large hole. Diagnostic data accompanies entry hole diameter statistics and friction pressure calculations for the consistent hole shaped charges in order to demonstrate how they differ from conventional shaped charges. Finally, proppant tracer diagnostics will highlight several case studies where consistent hole shaped charges or other recent perforating methods were employed.
Delineating Far Field Prropped Fracture Geometry Using Electromagnetic Geophysics and its Potential Impact on Well Planning and Reservoir Modeling
Authors: Palisch Terry , Mukherjee Souvik , Al-Tailji Wadhah
Published: January 2020

Several field trials since 2016 have showcased the early development of a novel borehole to surface geophysical technique to characterize propped fractures in the far field of the well bore. Recent advancements have been made with the technique with regards to the processing and inversion algorithms, that have improved the confidence level and extent of the proppant imaged. These advancements will be presented in detail, along with field examples of its application.

The imaging technique is broadly classified into three phases: (a) survey design, (b) data acquisition and processing, and (c) inversion to provide propped fracture dimensions and location. The survey design phase includes acquisition of geophysical noise data and synthetic data generation using a realistic simulation of the target and its ambience. This helps determine source receiver locations to maximize response from the propped fracture. Acquired data is digitally processed to remove potential sources of noise arising out of cultural debris, acquisition anomolies, etc. Geophysical inversion of processed data utilizing known geological, engineering, and other constraints then provides the propped fracture image.

The novel electromagnetic method for determining propped fracture location and geometry has been developed and deployed safely and successfully in multiple field trials. The recent advancements in modelling and processing have been successfully used to analyze recent field applications, providing key insights on depletion effects of parent wells on bi-wing fracture growth in child wells, as well as proppant settling and stress shadowing impacts. Additional learnings on proppant/fracture fluid interactions, well landing location, and other important issues have demonstrated the potential to impact the planning of future wells in this area. This paper will present the current full-physics methods for processing, modelling and imaging the proppant location. It will include confidence levels and probability functions of the mapped proppant. The paper will also show field examples of the various insights gained from the results (mentioned above), which can be used for future development objectives.

The latest advancements in modeling, processing and inversion will be of interest to those who are knowledgeable with forward modeling and inversion theory. In addition, the field results will be useful to development engineers who are interested in optimizing well/lateral spacing, both areally and vertically, as well as understanding the impact of parent-child depletion, stress shadowing and cluster efficiency.
Proppant Flowback: Can We Mitigate the Risk?
Authors: Chuprakov Dimitry , Belyakova Ludmila , Iuldasheva Aliia , Alekseev Alexey , Syresin Denis , Chertov Maxim , Spesivtsev Pavel , Salazar Suarez Franck Ivan , Velikanov Ivan , Semin Leonid , Bannikov Denis
Published: January 2020

We propose a new model and workflow to predict, quantify and mitigate undesired flowback of proppant from created hydraulic fractures. We demonstrate several field cases in which we predict significant proppant flowback and propose options for mitigation. Mitigation of proppant flowback is based on case- specific changes in the fracturing treatment design and modifications in the well startup schedule that preserve near-wellbore conductivity. The presented workflow integrates four key components of proppant flowback study: (A) simulation of the fracturing job with a high-resolution model of proppant placement inside a fracture; (B) subsequent simulation of flowback from the created fractures equipped by a validated proppant flowback model; (C) a series of laboratory experiments, which quantify the proppant flowback for a wide range of commercial proppants; and (D) an accurate mathematical model, which is validated by the results of laboratory experiments and integrated into a flowback simulator to predict the behavior of injected proppant. Each component is presented with sufficient details to demonstrate its necessity for accurate modeling of a coupled solid-and-fluid flow inside a fracture. The presented theory of proppant pack mobilization is based on the concept of a proppant pack erosion process evolving from free boundaries of proppant packs. The theory confirms that proppant flowback critically depends on flow rate, proppant, fracture, and reservoir parameters. Laboratory experiments on proppant flowback in a cell support these theoretical predictions. The theoretical model of proppant flowback is integrated into the numerical simulator of early-time production from a fractured reservoir and predicts flowback of both injected solids and fluids from a fracture. We show that the combination of the proppant flowback model, laboratory experiments, hydraulic fracturing design tool, and early-time production simulator result in a useful workflow for prediction and mitigation of issues with proppant flowback and production decline.

The entire workflow was validated using field cases where proppant flowback was observed. Modeled amounts of flowed back proppant are in good agreement with amounts of proppant observed in the field. Hydraulic fracturing design optimization was performed to minimize or eliminate proppant flowback. The novelty of the proposed study is related to the model of proppant flowback, which accounts for erosion of the proppant pack and is calibrated against unique laboratory experiments. The presented model and proppant flowback mitigation workflow can assist in understanding and mitigating proppant flowback events that can occur during wide range of oilfield operations.
Fighting the Fear: Overcoming Preconceived Notions of Low Polymer Cross-Linked Gels and High Viscosity Polyacrylamides in Unconventional Fracturing
Authors: Poppel Benjamin
Published: January 2020

The objective of this paper is to highlight the preconceived notions that both ultra-low polymer cross-linked gels and high viscosity polyacrylamide fluid systems are difficult to work with or damaging to formations. The paper discusses when such systems are beneficial as well as define some design restrictions. Historically these types of fluid systems have fallen into a gray area of technology that have now become accepted by some operators in the current low-cost market.

The fluids technology discussed in this paper have blossomed not solely because of their technological advancement, but also due to the market. Industry downturns have forced operators and service companies to find more cost-effective means to stimulate the reservoirs in question. This paper examines the use of these new systems in two regions (Williston and DJ Basins), where hundreds of wells have been pumped with these new systems as well as regained conductivity tests performed in 3rd party labs. We also compare production results of thousands of stages pumped with these new systems versus a more traditional approach.

Over the past decade the DJ Basin has be primarily been stimulated with high-priced low pH zirconate CMHPG fluid systems, as a result of the notion that they leave less residue in the fractures. However, with the very cost sensitive market and the new ultra-low polymer systems testing with higher regained conductivity than the incumbent system, change was inevitable.

In the Williston Basin high rate slickwater jobs have become more commonplace. Hybrid designs have been used to increase proppant loadings. However, a new trend to use significantly higher FR concentrations to achieve a system capable of placing higher proppant concentrations is gaining market share.

This leads to the current obstacles for both systems’ further use in the field. These obstacles are threefold: The notion that the system is contaminating the proppant pack with residue. Lab testing shows this not to be the case.Reconditioning field personnel to run the new systems as designed.Ensure that these systems are not used in designs that do not fit the operational criteria without understanding the limitations.

The success of all of these items remain attached to the final product, a well producing as much as, or more, for a lower total cost than the more traditional method.

This paper uses data from the lab and field to challenge many of the preconceived notions about what it takes to successfully place a solid stimulation package. Also, it will address how some of the largest barriers to new technology are predominantly mental, while the new products are technically sound and economically superior.
High Frequency Pressure Monitoring and Data Analytics for Stimulation Efficiency Determination: New Perspectives or Potential Limits
Authors: Korkin Roman , Parkhonyuk Sergey , Fedorov Andrey , Badazhkov Dmitry , Kabannik Artem
Published: January 2020

A method of nonintrusive hydraulic fracturing monitoring based on high frequency pressure measurements has been known since 1985. Since that time, multiple attempts of its implementation into a commercial product have been tried. A new method using a wellhead pressure sensor during well stimulation was developed in 2017. The method discussed here is a continuation and improvement of this method. It is based on an advanced signal processing algorithm used for detection and analysis of tube waves in a wellbore and on the data science approaches for further processing of tube wave parameters and providing the answers of fluid entry point depth, plug failure probability, and casing leak detection. Use of the wellhead pressure sensor with a data acquisition box eliminates the need for sophisticated hardware. This enables cost-effective and timely decisions at the wellsite. The technique was validated in the field in several fracturing and refracturing jobs.
Weight Development Between Age 5 And 10 Years And Its Associations With Dietary Patterns At Age 5 In The Abcd Cohort
Authors: Rashid Viyan , Streppel Martinette T , Engberink Marielle F. , Weijs Peter J.M. , Nicolaou Mary , Verhoeff Arnoud P.
Published: January 2020

Background: Social inequalities in bodyweight start early in life and track into adulthood. Dietary patterns are an important determinant of weight development in children, towards both overweight and underweight. T herefore, w e aimed to examine weight development between age 5 and 10 years by ethnicity, SES and thereafter by BMI category at age 5, to explore its association with dietary patterns at age 5.

Methods: Participants were 1 765 children from the Amsterdam Born Children and their Development (ABCD) cohort that had valid data on BMI at age 5 and 10 and diet at age 5. Linear mixed model analysis was used to examine weight development between age 5 and 10 years and to assess if four previously identified dietary patterns at age 5 (snacking, full-fat, meat and healthy) were associated with weight development. Analyses were adjusted for relevant confounders, stratified by ethnicity and SES and thereafter stratified per BMI category at age 5.

Results: Overall, weight decreased in Dutch and high SES children and increased in non-Dutch and low/middle SES children. Across the range of bodyweight categories at age 5, we observed a conversion to normal weight, which was stronger in Dutch and high SES children but less pronounced in non-Dutch and low/middle SES children. Overall, the observed associations between weight development and dietary patterns were mixed with some unexpected findings: a healthy dietary pattern was positively associated with weight development in most groups, regardless of ethnicity and SES (e.g. Dutch B 0.084, 95% CI 0.038;0.130 and high SES B 0.096, 95% CI 0.047;0.143) whereas the full-fat pattern was negatively associated with weight development (e.g. Dutch B -0.069, 95% CI -0.114;-0.024 and high SES B -0.072, 95% CI -0.119;-0.026).

Conclusions: We observed differential weight development per ethnic and SES group. Our results indicate that each ethnic and SES group follows its own path of weight development. Associations between dietary patterns and weight development showed some unexpected findings; follow-up research is needed to understand the association between dietary patterns and weight development.

Keywords: BMI, body mass index, thinness, normal weight, overweight, obesity, socio-economic position, ethnicity, children, young children.