bluuebunny/crossref_metadata_2025 huggingface dataset:
Apoyo familiar en escolares de alta capacidad intelectual de diferentes contextos socioeducativos
Authors: Castellanos Simons Doris , Bazán Ramírez Aldo , Ferrari Belmont Aldo Mauricio , Hernández Rodríguez César Alberto
Published: September 2020

El objetivo del trabajo fue analizar la percepción del apoyo familiar al aprendizaje en 79 alumnos de 6to grado con aptitud intelectual superior de tres contextos educativos (escuela urbana pública y privada, y rural indígena) en Morelos, México. Los alumnos respondieron la prueba SAGES-2 (Johnson & Corn, 2001) y el Cuestionario de Apoyo Familiar de Bazán& Domínguez (2009). Solamente se encontraron diferencias significativas entre los contex- tos analizados en la percepción de la comunicación regular con maestros relacionada con la materia Español, que fue percibida con mayor frecuencia en el contexto de la escuela privada, respecto al público indígena, independientemente del área de capacidades detectada. Se enfatiza la urgencia de investigar las variables del contexto socioeconómico y familiar para la comprensión de la manifestación, desarrollo y educación de las altas capacidades en alumnos de entornos culturales diferentes.
Early Development and Design of Crowdsourcing Agriculture Mobile Application for Lambsquarters
Authors: Posadas Brianna , Hanumappa Mamatha , Gilbert Juan
Published: September 2020

As big data has become increasingly necessary in modern farming techniques, the dependence on high quality and quantity of ground truth data has risen. Collecting ground truth data is one of the most labor-intensive aspects of the research process. A crowdsourcing platform application to aid lay people in completing ground truth data can improve the quality and quantity of data for growers and agricultural researchers. In this study, a user-centered design process was used to develop a prototype of a mobile application which will teach people how to classify certain characteristics of lambsquarters in the District of Columbia. Focus group results demonstrated that the greatest motivation for the participants was having opportunities to develop their skills and access to educational resources. From the focus groups, design personas were created and wireframe prototypes were produced. The prototypes were evaluated by users using the System Usability Scale and qualitative feedback. The design received an average score of 75.95, which indicates an acceptable design. From the feedback of the users, improvements to the design were made in the mobile application development of the system.
Sobredeterminação e duplicidade dos signos: de Saussure a Freud
Authors: Maniglier Patrice
Published: September 2020

Psicanálise e literatura podem se medir uma à outra somente como saberes a respeito da linguagem, uma vez que elas trazem igualmente à luz uma dimensão linguageira que é resistente ao saber linguístico. A imagem saussurreana da linguagem, a respeito da qual se começa a medir quanto ela estava distante daquela transmitida por esse texto apócrifo que é o Curso de Linguística Geral, permite-nos compreender por que essa dimensão é essencial àquilo que é a língua: pois os signos linguísticos são essencialmente sobredeterminados.
A escrita da voz nos versos do manuscrito Notas sobre uma possível A casa de farinha, de João Cabral de Melo Neto
Authors: Santos Gislaine Goulart dos
Published: September 2020

Notas sobre uma possível A casa de farinha (2013), de João Cabral de Melo Neto, é uma obra inacabada e representa o percurso de uma gênese textual; um planejamento poético escrito no período de 1966 a 1985. Na escrita dos versos, João Cabral atribui ao auto o estatuto da oralidade para representar a voz e o conflito sociocultural dos trabalhadores sobre os possíveis motivos do fechamento da casa de farinha. Na análise dos rascunhos dos versos, pensamos a oralidade baseada no primado do ritmo como organização do discurso e como elemento da voz e da escrita (MESCHONNIC, 1989). A voz dos trabalhadores da casa de farinha é intermediada pela subjetividade, pela ética e pelas leituras que João Cabral realizou para a escrita d’A casa de farinha, ou seja, a voz é dos trabalhadores (cantos de farinha, tradição artesanal), mas o ritmo é cabralino (rima toante, repetição, jogos de palavras).
Termodinâmicas do ato poético: modulações do (fim do) poema na década perdida
Authors: Lucas Fábio Roberto
Published: September 2020

Observando as transformações do campo literário ocorridas durante os anos 1980, o artigo procura algumas das inflexões iniciais do debate contemporâneo sobre a situação do verso e sua relação com a prosa, em um momento de crise na delimitação dos gêneros poéticos e de perda do lastro discursivo (Provase). Para tanto, analisam-se duas poéticas, de Paulo Leminski e de Sebastião Uchoa Leite, desdobradas durante a chamada década perdida e que trazem diferentes consequências para três questões interligadas: a) o estatuto da equivocidade e da modulação poética diante da fluidez das sociedades de controle (Deleuze) e da historicidade presentista (Hartog); b) a soberania artística e sua atuação específica na esfera pública hipersemiotizada da redemocratização; c) os passos iniciais de aproximação entre dilemas da poesia e da ecologia, legíveis na termodinâmica da enunciação literária, ou seja, em seus diferentes modos de equivocar e modular corpos, materiais e linguagens.
Clinical Solutions: Factors and Problematic Situations from the Perspective of Doctors in a Large Russian City
Authors: Gotlib Anna S. , Lekhtsier Vitaly L.
Published: September 2020

This article focuses on the main results of a quantitative empirical study of clinical decisions made by doctors in medical institutions of various profiles in a large Russian city. The study was conducted in 2019 and is based on the results of the previous qualitative analysis stage — within the research “mix-strategy”. The main point of analytical interest is the factors which influence the doctors’ clinical decisions in two basic clinical situations — in the situation of disease diagnosis and in the situation of treatment prescription. The object of the research was doctors from Samara medical clinics. Factors and decisions made by doctors were studied from the point of view of doctors themselves. The degree of influence of each factor on the decisions made by doctors was assessed with the help of the Influence Index, an integral index on a fully ordered scale. The article presents a hierarchy of factors influencing medical decision-making in diagnosis and treatment situations; the top group of factors in both situations is identified and interpreted. At the same time, additional problematic situations were studied in the research. In particular, the range of clinical decisions and factors determining them, in case of it being necessary to conduct an examination not provided by standard state medical care, in a situation when this examination is provided, but the limit of prescriptions is exhausted, in a situation when the medical institution (hospital) does not have the best quality medication for the patient in the quantities needed, in a situation when the state standard on a specific nosology is ineffective for a specific patient, as well as other problematic situations.
“Es Sudamérica mi voz”
Authors: Gomes Caio de Souza
Published: September 2020

Na década de 1960, em toda a América Latina se desenvolveram projetos de renovação da canção folclórica que buscavam fazer da música uma arma de intervenção política. Neste contexto, foi lançado na Argentina o movimento do nuevo cancionero, que propunha novos caminhos para a canção popular daquele país, mas também apontava para a necessidade de integração entre as experiências de música engajada de todo o continente. O objetivo deste artigo é discutir esse projeto de unidade da América do Sul por meio da canção a partir do álbum argentino Cantata Sudamericana (1972), resultado da parceria do músico Ariel Ramírez com o historiador Félix Luna, que contou com a voz da cantora Mercedes Sosa e propunha uma aproximação dos países do continente visando a luta pela emancipação da região, que neste momento se via dominada pelas experiências das ditaduras civil-militares.
Ethnopharmacological and botanical evaluation of medicinal plants used by Brazilian Amazon Indian community
Authors: Zandonadi Meneguelli Alexandre , Saranz Camargo Ely Eduardo , Buccini Danieli Fernanda , Cardoso Roriz Beatriz , Cerqueira Gabriela Ramos , Moreno Susana Elisa
Published: September 2020

Plants have been widely used to treat many diseases, especially by traditional communities as Indians, that can be considered as an important source of empirical knowledge about the medicinal potential of the Brazilian biodiversity. This study aimed to investigate the use of medicinal plants by a particular Amazon-Indian community named Ikólóéhj (Gavião). The data was obtained based on a semi-structured interview and long-term visits along the indigenous area to harvest the botanical material to subsequent identification and storage in herbarium. In the present work, we identify 23 plant species and three morphospecies, distributed into Ferns / Lycophytes and Angiosperms. In addition, we show that leaves (78%), bark (13%) and roots (9%) were used via maceration (49%), topical use (26%), infusion and bath (13%), and decoction (9%). These plants were used to treat pain, diarrhea, malnutrition, parasites infection, wounds, and snakebites. We also observe that the knowledge about medicinal plants is shared to the older members of the community and this information is transmitted orally to the next generations. Thus, the present study contributes to the regrowth and preservation of knowledge about the use of medicinal plants providing important subsidies for understanding of therapeutic properties of Amazonian plants.
A New Validity Index Based on Fuzzy Energy and Fuzzy Entropy Measures in Fuzzy Clustering Problems
Authors: Martino Ferdinando Di , sessa salvatore
Published: September 2020

Two well-known drawbacks in fuzzy clustering are the requirement of assign in advance the number of clusters and random initialization of cluster centers.; the quality of the final fuzzy clusters depends heavily on the initial choice of the number of clusters and the initialization of the clusters, then it is necessary to apply a validity index to measure the compactness and the separability of the final clusters and run the clustering algorithm several times. We propose a new fuzzy C-means algorithm in which a validity index based on the concepts of maximum fuzzy energy and minimum fuzzy entropy is applied to initialize the cluster centers and to find the optimal number of clusters and initial cluster centers in order to obtain a good clustering quality, without increasing time consumption. We test our algorithm on UCI machine learning classification datasets comparing the results with the ones obtained by using well-known validity indices and variations of FCM using optimization algorithms in the initialization phase. The comparison results show that our algorithm represents an optimal trade-off between the quality of clustering and the time consumption.
Human Tendon Repair Following Injection of Autologous, Unmodified Stem Cells: A Comprehensive Immunohistochemical Evaluation
Authors: Alt Eckhard , Rothoerl Ralf , Hoppert Matthias , Frank Hans-Georg , Alt Christopher , Schmitz Christoph
Published: September 2020

Current clinical treatment options for symptomatic rotator cuff tear offer only limited potential for true tissue healing and improvement of clinical results. In animal models, injections of adult stem cells isolated from adipose tissue into tendon injuries evidenced histological regeneration of tendon tissue. However, it is unclear whether such beneficial effects could also be observed in a human tendon treated with autologous, adipose derived regenerative cells. Here we demonstrate, for the first time, a comprehensive histological and immunohistochemical analysis of the biopsy of a supraspinatus tendon of a 66-year-old subject with traumatic rotator cuff injury, taken ten weeks after local injection of fresh, uncultured, autologous, adipose derived regenerative cells (UA-ADRCs), prepared at the point of care. Our analysis demonstrated clear evidence towards regenerative healing of the injured supraspinatus tendon. Of note, no formation of adipocytes was observed. These findings indicate that injected autologous, unmodified stem cells can indeed form new tendon tissue and regenerate an injured human tendon.
Tetramethylbenzidine: A Photoacoustic Probe for Reactive Oxygen Species Detection
Authors: Bresolí-Obach Roger , Frattini Marcello , Abbruzzetti Stefania , Viappiani Cristiano , Agut Montserrat , Nonell Santi
Published: September 2020

Photoacoustic imaging is attracting a great deal of interest owing to its distinct advantages over other imaging techniques such as fluorescence or magnetic resonance image. Availability of photoacoustic probes for reactive oxygen and nitrogen species (ROS/RNS) could shed light on a plethora of biological processes mediated by these key intermediates. Tetramethylbenzidine (TMB) is a non-toxic and non-mutagenic colorless dye that develops a distinctive blue color upon oxidation. In this work we have investigated the potential of TMB as photoacoustic probe for ROS/RNS. Our results indicate that TMB reacts with hypochlorite, hydrogen peroxide, singlet oxygen and nitrogen dioxide to produce the blue oxidation product, while ROS such as the superoxide radical anion, sodium peroxide, hydroxyl radical or peroxynitrite yield a colorless oxidation product. TMB does not penetrate Escherichia coli cytoplasm but is capable of detecting singlet oxygen generated in its outer membrane.
Axillary Artery Pseudoaneurysm After Revision Plate Osteosynthesis of a Midshaft Clavicle Fracture Nonunion
Authors: Firoozabadi Reza , Wilkerson Jacob , Hemingway Jake , Tran Nam
Published: September 2020

Case:

A patient with history of nonunion repair of traumatic midshaft clavicle fracture was referred to our orthopaedic trauma clinic for new-onset shoulder pain and paresthesias involving the ipsilateral arm. Computed tomography angiography revealed an axillary artery pseudoaneurysm adjacent to the instrumentation and recurrent nonunion of the fracture site. The patient underwent coil embolization of the pseudoaneurysm and nonunion repair.

Conclusion:

This case demonstrates that iatrogenic neurovascular injury during clavicle fracture nonunion repairs can present in a delayed fashion requiring more thorough clinical and imaging evaluation to achieve successful treatment.
The usefulness of surface electromyography in rehabilitation and physiotherapy: systematic review
Authors: Radecka Aleksandra , Lubkowska Anna
Published: September 2020

Introduction: Technological developments in surface electro-myography (sEMG) equipment are providing more and more new opportunities in the application of this technique in different fields, not just in clinical medicine but also in physiotherapy. The purpose of this study is an educational review that provides examples of the clinical use of sEMG in rehabilitation and physiotherapy.

Materials and methods: Studies were searched for on the Pub-Med and ScienceDirect databases using the following descriptors: “sEMG rehabilitation”, “sEMG physiotherapy”, “surface electro-myography physiotherapy”, “surface electromyography rehabilitation”, resulting in 28,040 citations in total. After reviewing for inclusion criteria – methodological quality assessment using the Physiotherapy Evidence Database (PEDro) scale and consistency with the theme of systematic review – 28,023 studies were removed from the analysis.

Results: The qualified 14 works were divided into 4 categories depending on the sEMG application area: urogenital system dysfunction (322 patients, PEDro scale average rating of 6.33), central nervous system damage (120 patients, PEDro scale average rating of 6.6), lower back pain (181 patients, PEDro scale average rating of 5.33) and musculoskeletal disorders (244 patients, PEDro scale average rating of 6.66).

Conclusions: The most recent examples of the use of sEMG in intervention studies in rehabilitation and physiotherapy in the last 5 years concerned neurology, urology, gynaecology, paediatrics, pulmonary medicine and orthopaedics.
Experimental Study of Gas/Liquid Diffusion in Porous Rocks and Bulk Fluids To Investigate the Effect of Rock-Matrix Hindrance
Authors: Lou Xuanqing , Chakraborty Nirjhor , Karpyn Zuleima T. , Ayala Luis F. , Nagarajan Narayana , Wijaya Zein
Published: September 2020

The design of oil-recovery processes by gas injection or vapor solvent relies on the knowledge of diffusion coefficients to enable meaningful production predictions. However, laboratory measurements of diffusion coefficients are often performed on bulk fluids, without accountability for the hindrance caused by the pore-network structure and tortuosity of porous media. As such, our ability to predict effective diffusion coefficients in porous rocks is inadequate, and additional laboratory work is needed to investigate the impact of the medium itself on transport by diffusion. A vast number of studies focus on measurements of diffusion coefficients on simple binary systems and a few heavy-oil systems. This study proposes an experimental methodology, based on the pressure-decay technique, to measure diffusion of gas (methane) in crude oil within a porous rock. A diffusion experiment of gas into bulk oil (without porous medium) provides an upper-limit estimation of the gas/liquid-diffusion coefficient. Diffusion experiments using Indiana Limestone and Bakken Shale provide insight into different degrees of rock-matrix hindrance. Two analytical models and one numerical model were implemented to estimate the diffusion coefficients from time-dependent experimental pressure-decay data. These diffusion coefficients were found to be in agreement with literature on corresponding data, demonstrating the validity of the modeling approaches used. Results indicate considerable hindrance to diffusion in porous media relative to bulk oil and relate to the tortuosity of the rock matrix. The diffusion coefficient of methane in bulk oil was found to be 3.8×10−9 m2/s. In the limestone sample, this diffusion coefficient dropped by one order of magnitude, ranging between 1.5 and 6.5×10−10 m2/s, and decreased by another order of magnitude in the Bakken Shale sample to 2.0×10−11 m2/s. By comparing the influence of tortuosity with increasing the initial pressure, results show that tortuosity has a more-significant impact on the effective diffusion coefficient than the initial pressure.
Pseudorelative Permeabilities for Simulation of Unstable Viscous Oil Displacement
Authors: Doorwar Shashvat , Ambastha Anil
Published: September 2020

Relative permeabilities are well understood for light oils involving stable displacement. However, conflicting arguments have been presented in the literature regarding relative permeabilities for viscous oils. Most nonthermal viscous oil displacements are unstable. Depending on the magnitude of mobility ratio, displacement is influenced by varying degrees of viscous instability, often referred to as fingering. For viscous oils (>500 cp), even a polymer flood must be designed at partially stable conditions (mobility ratio > 1) to maintain an economical processing rate [% pore volume (PV) injected (PVI) per year]. Typically, viscous fingering is difficult to model in full-field simulation because of the large grid sizes used. To design and optimize a partially stable polymer or waterflood, it is critical to correctly upscale the laboratory-generated relative-permeability curves for reservoir simulation. In recent years, such models have been published in the Society of Petroleum Engineers literature. Unfortunately, most of these models require multiple fitting parameters (at least three). In this work, we present a simplified technique that requires systematic change in only one parameter to generate upscaled relative permeability curve for a given viscosity ratio.

Using fine-grid simulations, we show that the flow at high-viscosity ratio is channelized even in a core perceived to be homogeneous at laboratory scale. This happens because of small-scale heterogeneities that are present in every rock. Upscaling averages these fine variations in heterogeneities, causing the grids to be overswept, thus overpredicting recovery. To compensate for this shortcoming, it is recommended to upscale the relative-permeability curves in the simulation model.
Prospects for Oil-and Gas-Bearing Capacity of the Khadum Shale Deposits in the Eastern Fore-Caucasus
Authors: Kalabin Vasiliy Viktorovich
Published: September 2020

The Khadum horizon is of interest for discovery of shale oil, which deposits were discovered within the boundaries of Zhuravskoye, Vorobyevskoye and other fields. Within the boundaries of the Buynak depression the Khadum horizon is characterized by a manyfold increase in thickness, and the results of the field and laboratory studies show a high potential for oil-bearing capacity of these deposits. Regional study of the structure of the Khadum deposits was conducted. Criteria for oil-bearing capacity prospects were identified and a priority site for development was identified.
The Results of Pilot and Industrial Application of Thermal-Gas-Chemical Well Treatment with Binary Mixtures and Development of Mathematical Models for Reservoir Processes in Source Oil Rock
Authors: Lishcuk Alexander Nikolaevich , Kravchenko Marina Nikolaevna , Shesternina Nataliia Viktorovna , Dieva Nina Nikolaevna , Nafikov Askhat Ahtjamovich , Khisametdinov Marat Rakipovich , Kataev Alexey Valerijavich
Published: September 2020

The purpose of this paper is to generalize the experience of applying the thermo-gas-chemical treatment methods (TGCT) using binary mixtures based on ammonium nitrate to enhance the inflow at oil fields. More than a decade of industrial tests of binary mixtures injection into mature fields’ marginal wells showed a multiple long-term increase in oil inflow. The positive experience of TGCT application to Tatarstan oil fields strongly suggests the perspective of its application to the layers with high content of organic substance in rock matrix including Bazhenov formation reservoirs for those technologies have been only battle-tested. The development of mathematical methods for describing the TGCT process considering the multiphase and multi-component nature of the process, chemical reactions and transformation of the reservoir structure allow to respond to the features of each field at the macro scale, to identify micro-scale features and changes in the reservoir matrix structure, using a percolation approach, and allowed to assess the current state of the bottom-hole zone adequately and conduct pilot tests on specific wells in strict accordance with the established technological regulations and control of hydrodynamic parameters.
Integrated Approach to the Analysis of Achimov Deposits for the Purpose of Optimizing Drilling
Authors: Gilmiyanova Alfiya , Sukhova Maria , Andreeva Svetlana , Kulbaeva Diana , Suleymanov Eldar , Mironenko Artem
Published: September 2020

This paper presents the results of an integrated approach to the analysis of the geological structure and the subsequent of the productive Achimov deposits development: deposits X and Y located in Western Siberia. The main difficulties in the development of the Achimov deposits are associated with a high heterogeneity, a low degree of prediction of effective thicknesses, the difficulty of correctly calculating well flow rates, saturation behavior and, accordingly, water cut, and high production decline rates identified as a result of putting new wells into operation.
Wait or Get the Oil: How SAGD Technology Implementation Options will Vary Future Production
Authors: Terentiyev Aleksey Alekseyevich , Roschin Pavel Valeriyevich , Nikitin Aleksandr Valeriyevich , Kozhin Vladimir Nikolaevich , Pchela Konstantin Vasiliyevich , Kireyev Ivan Ivanovich , Demin Sergei Valerevich , Litvin Aleksandr Tarasovich , Struchkov Ivan Aleksandrovich
Published: September 2020

One of the complications at the stage with steam injection start into the SAGD injection well in the Terrigenous reservoir with extra-heavy oil (EHO) is its injectivity rate. Traditionally, preheating the well bottom-hole (BH) zone with steam and subsequent recovery of hot water or steam through the annulus is used to get adequate injectivity. As an alternative to steam preheating it is proposed to inject an aromatic solvent/reagent to ensure sufficient well injectivity. Calculations were performed with the real reservoir model. The mutual influence of wells in SAGD blocks under the conditions of solvent/reagent injection was studied for this.
Wettability of Carbonate Reservoirs: Effects of Fluid and Aging
Authors: Kumar Sikandar , Burukhin Alexander Alexandrovich , Cheremisin Alexey Nikolaevich , Grishin Pavel Andreevich
Published: September 2020

As the production of hydrocarbons from the carbonate reservoir increases, there is a necessity to enhance oil recovery methods to increase recovery factors and improve the economic efficiency of field development. The knowledge of wettability's role and fluid distribution at the pore scale is required to comprehend the mechanisms for oil displacement from porous media. The X-ray computed micro-CT technology provides opportunities to study the complex fluid displacement process at the pore level.

This work discusses wettability restoration in carbonate cores and its effect on fluid distribution in porous space. Wettability restoration refers to restoring the original wettability of the core after extraction. We investigate wettability change and two-phase fluid distribution at pore-scale with the help of micro-CT technique along with Amott spontaneous imbibition methods.

The Amott spontaneous imbibition experiments performed on the core under ambient pressure. The micro-CT experiments conducted for steady flow core flooding experiments on harsh cleaned cores. The three-dimensional images acquired for dry core, core saturated with brine and kerosene followed by oil injection. For better visualization of the fluid-fluid and fluid-rock surface and to remove voxel artifacts, iodo-octane is mixed with oil with 10 % wt/wt. The experiments allow us to envisage the structures of fluid in each phase during the displacement of fluid in carbonate rocks with high resolution (3 μm/voxel). The novelty of this approach lies in efficiently capturing the CT images of the fluid distribution and its influence on wettability during the "core-aging" procedure and validating the results of it with the Amott imbibition wettability index.

The initial wettability of harsh cleaned carbonate cores was identified as water-wet compare to mixed wettability for mild cleaned carbonates. Nevertheless, all the samples become strongly oil-wet regardless of the cleaning methods after long-term saturation with crude oil. The X-ray CT technique revealed the fast evolution of contact angle of brine corresponding the wettability changes to strong oil-wet after contact with crude oil under the reservoir conditions.
Overcoming Back-Produced Polymer Challenges - Development of an Advanced and Economic Filtration Technology for CEOR Application
Authors: Marx Markus , Grottendorfer Stefan , Krenn Christof , Grillneder Roland
Published: September 2020

The implementation of highly effective polishing filter technologies plays a key role in polymer EOR where reservoir characteristics require extremely good water qualities. Few filter technologies are capable of handling volatile inlet fluid conditions such as back-produced polymer concentrations up to 420 ppm and OIW contents up to 70 ppm while targeting treated water qualities of less than 5 ppm OIW.

A fully integrated field trial was set up in the Matzen field in Austria where producing wells from EOR operations provide sufficiently high polymer concentrations for technology evaluations. A three-phase separator and a multi-chamber flotation unit were used as upstream treatment to supply produced water to the different filtration technologies under evaluation. With this setup, a broad range of entry criteria like OIW, solid content, polymer concentration and oil droplet size could be adjusted to challenge each filtration technology to its limit.

None of the tested technologies such as nutshell filters, conventional multi-media-filters, coated media, or vendor specific technologies were able to handle the challenging inlet water conditions while providing the required water qualities for polymer flooding projects. A new concept was developed, combining conventional multi-media filtration design with a type of media that, thus far, was not common in the oil and gas industry. A system-specific operating envelope was developed, describing the strong impact of inlet water conditions such as oil droplet size D50 values down to 15 micron, OIW concentrations up to 70 ppm, solid contents up to 10 mg/l and viscosities up to 3 cp. Where state-of-the-art technologies did not fulfill the performance criteria, it was possible to achieve less than 5 ppm at the filter outlet. Not only the filter performance but also the crucial aspect of effective media regeneration was solved with a novel filter backwash design, since known backwash systems completely failed with the newly implemented media.
Design, Qualification and Field Deployment of Low ECD Organoclay-Free Invert Emulsion Drilling Fluids
Authors: Wagle Vikrant , Yami Abdullah , Onoriode Michael , Butcher Jacques
Published: September 2020

High pressure and high temperature (HPHT) wells especially those with narrow pore / fracture pressure gradient margins present challenges in drilling. Maintaining optimum and low rheology for such wells becomes a challenge where a slight change in the bottom-hole pressure conditions can lead to non-productive time. However maintaining low viscosity profile for a drilling fluid can pose a dual challenge in terms of maintaining effective hole-cleaning and barite-sag resistance.

This paper describes the formulation of 95pcf medium-density organoclay-free invert emulsion drilling fluids (OCIEF). These fluids were formulated with acid-soluble manganese tetroxide as weighting agent and specially designed bridging-agent package. The fluids were hot rolled at 300°F and their filtration and rheological properties were measured. The paper describes the static-aging, contamination, HTHP rheology measurements and filter-cake breaking studies of the fluids at 300°F. Particle plugging experiments were performed on both the fluids in order to determine the invasion characteristics and the non-damaging nature of the fluids. These organoclay-free invert emulsion fluids were then field-trialed in different wells with good results.

The OCIEFs showed optimum rheology and filtration properties. The fluids gave lower PV, which ensured that the fluid presents low ECD contribution while drilling/circulating. Sag factor analysis for the fluids after static aging for 24 and 48hours showed excellent stability and minimal sag propensity. HTHP rheology showed that the fluids had consistent PV and YP values across a range of temperatures and pressures. Contamination studies showed that the effect of contaminants on the organoclay-free fluid was minimal and any change in properties can be easily controlled using conventional treatments. The paper thus demonstrates the superior performance of the developed fluid in achieving the desired lab and field performance.

Field deployment of the 95pcf organoclay-free invert emulsion fluid helped to maintain the required hole stability in the HTHP well. The well was displaced to 95pcf production screen test (PST) fluid and completed with a 4 ½" sand screen.
The First Implementation of MPD Technology in Conditions of Brine with AHRP at Kovykta Gas Condensate Field
Authors: Tomchenko Andrey Sergeevich , Kulikov Stanislav , Velyiev Gurban , Myazin Oleg Gavrilovich , Kazakov Evgeny Olegovych , Kaasa Glenn-Ole
Published: September 2020

This article describes general information about the geological structure, the identified complications during the construction of wells at the Kovykta gas condensate field associated with abnormally high reservoir pressure (AHRP). Based on the initial data and analysis of previously drilled wells, the requirements for equipment, the choice of drilling fluid density and the applied engineering solutions were formed. The goals and objectives of the project are outlined and the conditions in the process of drilling the section are presented, technological schemes and procedures are compiled during operation. Introductory training on managed pressure drilling technology was conducted with the personnel of the drilling and oilfield service companies. The revealed new mining and geological conditions and the complications that arose with them, and well-timed decisions allowed us to achieve the design depth of the section. The possibility of using brine for drilling the section using mudcap drilling technology was also confirmed. According to the final data, after drilling and fastening the section, new goals have been set for new wells at AHRP intervals.

During the section drilling, various works were repeatedly performed in the presence of wellhead excess pressure, but the developed procedures, analysis, and risk assessment allowed to complete the project without incidents or accidents. Based on the gained experience, a number of decisions were made to optimize the well construction process at the field.
Impact of Casing Pressure Test After Waiting on Cement on Cement Bond Quality
Authors: Vavilov Mikhail Borisovich , Sekacheva Yulia Viktorovna , Chernov Vladimir Igorevich , Lyutikov Kirill Vladimirovich , Perebatov Alexander Sergeyevich
Published: September 2020

A high percentage of continuous cement bond with casing is an indicator of high-quality cementing and a good approach to cost efficient construction of oil and gas wells. However, the pressure created inside the casing after waiting on cement (WOC) leads to expansion and contraction of the pipe which has a considerable negative effect on the cement bond quality. This article describes the effect of a casing pressure test on the result of cement bonding, integrity of annular spaces and isolation of formations.

Ensuring the cementing quality prior to the cement job requires an engineering approach to the design of the entire job, namely: duration of circulation after casing running, volume of spacer fluids, design and weight of cement slurry, type and quantity of casing equipment, casing reciprocation or rotation, displacement fluid pumping rate, etc. However, even with all these conditions optimized, the blowout preventer (BOP)/casing pressure test after WOC will apply destructive casing tensile forces on hardened cement because of excessive internal pressure resulting in the loss of a significant percentage of good cement bond.

A study was performed and special attention was drawn to the fact that the casing test after WOC results in instances of micro-annuli which are recognized by the cement bond log (CBL) tool as no bond or partial bond, however these micro-annuli may be non-permeable. The micro-annuli occurrence process is confirmed by hydraulic calculations.

As a result, a joint decision was made to carry out experimental work with casing pressure tests at the bump pressure point and further BOP tests against a wellhead packer, to eliminate casing pressurization. According to the Oil and Gas Industry Safety Regulations this would require the cement slurry to be displaced with water instead of the drilling mud usually pumped for displacement. Immediately after bumping the plug the casing shall be tested for integrity by pressuring up to the required pressure and holding it for 30 minutes. Then, after BOP nippling up, a special wellhead packer is run and the BOPs are pressure tested without any impact on the casing.

CBL results for the operations performed showed a significant increase in good cement bond with casing (from 31% to 56%) as well as a reduction of absent bonding (from 10% to 0.5%) and microannuli. This topic is important, as in most cases BOPs are pressure tested together with the casing. This results in lower quality of the well cementing. In this paper, details of the increase in the bond quality through adjustments to the well construction process are shown to improve well profitability by preventing micro annuli and increasing the productive life of the well.
Russian National Oil Company Successfully Implemented Selective Flotation of 9 5/8-in Production Liner in Ultra-Extended Reach Drilling Well in Sakhalin
Authors: Shakhova Anna , Lebedeva Irina , Valshin Oleg , Famiev Robert , Marushkin Dmitry , Savinov Roman , Dementyev Alexander , Abdullayev Suleiman , Bochkarev Vladimir , Surmin Vladimir
Published: September 2020

This paper provides insights of planning, execution and the results of the application of selective flotation or "mud over air" technique while running 9 5/8-in production liner into an extreme-extended-reach well in Sakhalin, the longest well ever drilled by RN-Sakhalinmorneftegaz to date.

Extreme Reach Drilling (ERD) well has a shallow true vertical depth and a long horizontal departure imposing significant challenges of conveying 9 5/8-in liner to the required depth. When both conventional and full flotation methods cannot guarantee delivering casing to planned depth due to high torque and drag, lack of weight and string buckling, a new operational approach of selective flotation was considered. Mud over air, specifically "air cavity" technique implies running a bottom portion of the casing filled with mud, then an empty portion to reduce drag and a top portion filled with drilling fluid for additional weight to provide some additional push to overcome residual drag.

This article outlines unique practices of selective flotation technique covering the job specific features, its main risks and corresponding mitigation measures.

The selective flotation or "mud over air" concept together with detailed risk assessment and engineering of a single hydro-mechanical liner hanger and flotation collar system enabled successful conveyance of 9 5/8-in liner to its setting depth during drilling the longest extended reach well in the project.
Development and Practical Application of Requirements for Drilling Fluid Based on Geomechanical Modeling and Physicochemical Studies of Unstable Highly Lithified Clay Formations
Authors: Kazakov Dmitry Alexandrovich , Nekrasova Irina Leonidovna , Khvoschin Pavel Alexandrovich , Predein Andrey Alexandrovich , Garshina Olga Vladimirovna , Okromelidze Gennadiy Vladimirovich
Published: September 2020

The requirements to the drilling fluid weight, determined by the geomechanical modeling results, without taking into account all the factors affecting the wellbore stability, cannot guarantee accident-free well drilling in the intervals of unstable terrigenous deposits. The composition and properties of drilling fluid have a significant impact on the wellbore stability.

This article has developed an approach to minimizing the problems associated with loss of wellbore stability, combining modern achievements in geomechanical modeling and physical and chemical studies of the effects of oil-based drilling fluids on core properties, which seems more effective in reducing the probability of the above problems compared to the separate use of geomechanical models and the results of physical and chemical studies.

The proposed approach is based on the joint application of geomechanical modeling, hydraulic calculations and physical and chemical studies with the use of natural core from the intervals of the most unstable deposits, which allows developing a set of requirements to the composition and properties of drilling fluid to penetrate unstable rocks of a particular field. The specified set of requirements includes: requirements for weight, plastic viscosity, dynamic and static shear stresses of drilling fluid, providing mechanical stability of the borehole walls and effective cuttings transport; requirements for aqueous phase composition, the value of voltage stability of the mud, providing minimization of fracturing (according to the X-ray tomography results), softening and swelling of the rocks under consideration due to the hydration process; requirements for the fractional composition of microcolmatants corresponding to the fracture size in the rocks under consideration; requirements for the inhibiting and bridging abilities of the drilling fluid.

This approach has been successfully applied when drilling a well with horizontal completion at one of the fields in the Perm Territory in the interval of unstable Carboniferous terrigenous deposits, which are prone to collapse and are penetrated at inclination angles of more than 70 degrees. The set of requirements for a hydrocarbon-based drilling fluid is established based on the results of geomechanical modeling and the above detailed studies. A drilling fluid formulation that meets the specified requirements has been developed. Engineering and technological support was carried out for the drilling of the considered well using the developed drilling fluid and monitoring of compliance with the specified requirements, which avoided problems associated with the wellbore instability.
High Viscosity Oil Preparation at the Vostochnoye-Messoyakhskoye Field
Authors: Khasanov Irek Zufarovich
Published: September 2020

There are situations where one needs to solve a hard problem, but have limited time, lack of material resources and the necessary information.

In that case we have to rely on one's own experience and all the available resources.

The Vostochnoye - Messoyakhskoye oilfield was put into operation and maintenance phase in September 2016, and from that point on the oil treatment facility is associated with the oil emulsion destruction problem and consequently the quality decrease of the crude oil.
Virtual Flowmetering NovyPort Field Examples
Authors: Vinogradov Dmitrii , Vorobev Daniil
Published: September 2020

Virtual flow meter becomes increasingly relevant due to the need for continuous monitoring of the production system. This need nearly always arises at gas and gas condensate fields, because in many cases gas restricts the pipeline and the processing system, which inevitably results in loss of production. The technology becomes more interesting for oil and gas condensate fields, such as Novoportovskoye field.

Numerous wells, low frequency of production rate tests, the use of mobile test separators, as well as quality of measurements at high and frequently varying gas-oil ratio (GOR) reduce promptness of the operating production management at the field. Virtual flow metering reduces the effect of these factors allowing the information on well performance to be received every minute, and adding elements of modeling to this tool makes it possible to understand quickly the performance of wells and other production objects.

The virtual flow metering technology requires, first of all, a high level of field equipment with online sensors. At Novoportovskoye field, a program has been launched since 2019 to equip wellheads with sensors to measure pressure and temperature. Pressure and temperature measurements from each sensor pass every minute to a model where current production rate of the well is calculated and the result is compared with previous value. If a significant deviation is detected, a specialist from production team gets a warning and finds out a reason of the deviation. As opposed to daily analysis, the every-minute analysis of well performance opens a wide range of opportunities for prompt response to deviations in well operation, especially in combination with well remote control systems. Early detected deviations, such as deposits accumulated in tubing and pipelines, degradation of ESP head and rate, etc., allow considerable reduce production losses, increase promptness of response to deviations, and optimize distribution of resources in advance.

Also, this technology allows to perform production allocation of daily production from processing facility, thus avoiding uniform distribution of errors of measuring devices through the use of back allocation coefficients.

In the future, the use of virtual flow meters can give the opportunity to stop using of several rate measuring devices (like test separators or MPFM), which would result in reduced capital expenditures for well infrastructure development. Also, this technology opens opportunities for automatic control of well performance.

Currently, virtual flow metering is uncommon at gas fields, so the implementation of this technology at an oil and gas condensate facility is a challenge for high-tech companies. Gazpromneft-Yamal have achieved good results in the use of integrated model, and virtual flow meter will be a next step for further achievements.
Analysis of Self Flowing through Annulus of wells operated with Electric Submersible Pumps, Western and Eastern Siberia Fields Cases
Authors: Goridko Kirill Alexandrovich , Kobzar Oleg Sergeevich , Khabibullin Rinat Alfredovich , Verbitsky Vladimir Sergeevich , Litvinenko Konstantin Vladimirovich , Grishaev Maksim Stanislavovich
Published: September 2020

When operating production oil wells with electric submersible pump units in conditions of high free gas content in the pump, the mode of flowing through the annular (FTA) may occur due to a combination of factors, such as: relatively high pump intake pressure sufficient to maintain self-flowing conditions through annulus, large amount of gas coming to annulus, high degradation of ESP parameters which prevents decreasing BHP and others.

The authors of the article have reviewed literary sources, formulated the relevance of the problem of flowing in annular space of artificially lifted wells. The full characteristics of ESP was adapted by the results of flow loop tests with gas-liquid mixture. It made it possible to develop the model of ESP operation under FTA conditions, which was proven on field cases (four examples). Recommendations for FTA mode optimization discussed.
New Applications of Transient Multiphase Flow Models in Wells and Pipelines for Production Management
Authors: Yudin Evgeny , Khabibullin Rinat , Smirnov Nikita , Vodopyan Alexey , Goridko Kirill , Chigarev Grigorii , Zamakhov Sergey
Published: September 2020

The increase in the count of fields with deteriorating flow properties and, as a result, long nonstationary flow, leads to an increasing spread of periodic lift method.

Classic multiphase pipe flow models used by most commercial simulators are not able to account for transient processes occurring during intermittent operation.

The purpose of this work is to develop a method for calculating the pressure distribution in the wellbore and pipelines, taking into account the unsteadiness of the multiphase flow, as well as its testing on the example of solving various problems of production management: analysis of bringing wells on to stable production, monitoring and optimization of periodic well performance, analysis of processes during the start-up and shutdown of processing trains of the oil gathering system.
Submersible Low-Frequency Electric Motor Developed by LLC System-Service MC for Operation of Progressive Cavity Pumps
Authors: Vostrukhin Aleksandr
Published: September 2020

Today, traditional methods of lifting oil do not always provide the desired results. An inactive well stock is growing due to low profitability, so the company is actively looking for alternative, more efficient methods based on low energy and metal hardware. One of the effective methods is the use of the induction electric motor of the System-Service company.