bluuebunny/crossref_metadata_2025_split huggingface dataset:
Managing Operational Challenges to Fulfill Reservoir Management Objectives in Surface Facility Constrained Environment
Authors: Bopiyev Chingiz , Aitzhanov Abzal , Saduakassov Bekzhan , Svyatov Aidar , Kassenov Baurzhan , Shantayev Arman 
Published: October 2018

Abstract
Sour gas injection (SGI) pilot was successfully implemented in Tengizchevroil (TCO) in 2008, successfully achieving pressure maintenance in Tengiz platform, re-injecting gas with high H2S concentration and improving oil recovery within pilot area. Over the years, gas breakthrough and GOR increase has been observed in majority of producers in SGI pattern. Due to limited surface gas handling capacity, producing SGI pattern wells with elevated GOR and H2S has been a challenge. At the same time, it is critical to manage voidage replacement ratio in the pilot area to maintain sufficient miscible gas sweep and ensure enough pressure release. Inability to inject all the sour gas to the reservoir leads to equivalent oil production cut at the Plant.
Specialized SGI Operating Strategy has been in place since the commencement of the project with the aim of developing broader understanding of injected gas front evolution and operating the SGI Pilot in a way to maximize value for TCO by balancing between maximizing lower GOR/H2S front-end plant production vs. maintaining sufficient well injectivity. The production and injection well targets and surveillance activities were tailored towards fulfilling these strategic objectives. The operating strategy has been revisited several times to ensure appropriateness to business needs at any given time.
Specialized reservoir simulation model is utilized for short and long-term injection forecasts to develop plans to provide sufficient well injection capacity at any given time.
This paper will discuss challenges and best practices associated with (1) operating elevated GOR/H2S wells in a gas constrained environment while performing reservoir data acquisition program in highly congested area to fulfill SGI pilot objectives and (2) finding the trade-off between front-end plant production and injection goals.
Sucker Rod String Rod Guide Service Life Estimation
Authors: Clemens Langbauer , Tobias Permanschlager , Viorica Sirghii , Mikhail Pavlov , Herbert Hofstätter 
Published: October 2018

Abstract
The sucker rod string is equipped with rod guides that help to stabilize the sucker rod string and to prevent the contact between rods and tubing, which would end up in rod failures and tubing leaks. The scope of this paper is to present a wear study of sucker rod string rod guides performed at a testing facility to predict the wear and service life.
Sucker rod pumping systems are well known for their high overall performance and their wide range of application. Nevertheless, experience and failure analysis of broken sucker rod pumping systems have shown that more than fifty percent of failures are the result of tubing wear, caused by contact with the rods. To be able to estimate the wear speed of the rod guides and thus the lifetime of the system, extensive testing of rod guides wear behavior was performed under real field conditions. The equipment was tested under realistic temperature, pressure, load, and speed conditions in the testing facility.
A significant number of wear tests were performed under different conditions, and the results have shown that the weight loss and diameter decrease of the rod guides can be essential already after a few hundred hours of operation, reflecting several hundreds of kilometers of distance traveled. A size reduction of some millimeters indicates the importance of rod guide wear on the mean time between failures. A sensitivity analysis has shown the significance of the normal force and the roughness of the tubing string on the wear of the rod guides. This paper presents the conducted case study and the major findings.
The gained knowledge is the basis for the development of a detailed wear prediction tool to properly estimate the lifetime of the rod guides under realistic conditions.
Investigating and Mitigating Asphaltene Precipitation and Deposition in Low Permeability Oil Reservoirs During Carbon Dioxide Flooding to Increase Oil Recovery
Authors: Fakher Sherif , Imqam Abdulmohsin 
Published: October 2018

Abstract
Carbon dioxide (CO2) flooding has been applied extensively worldwide to improve oil recovery from hydrocarbon reservoirs. One of the main problems associated with CO2 flooding is asphaltene precipitation, which leads to pore plugging, and eventually, low oil recovery. Asphaltene precipitation during CO2 flooding has been extensively studied for conventional oil reservoirs, however, with recent applications of CO2 flooding in unconventional shale reservoirs, it is important to study asphaltene precipitation and mitigation in nano-sized pores. This research investigates the main factors that can affect asphaltene precipitation in nano-sized pores during CO2 flooding, and attempts to mitigate this precipitation using common asphaltene mitigation chemical agents. Filter membranes with 0.2, 10, and 100 nm pores size were used in this study. The factors impacting asphaltene precipitation studied include the CO2 injection pressure, using 200, 400, and 750 psi, the experimental vessel temperature, using 60, 100, and 150 °C, crude oil viscosity, including 470, 260, and 67 cp, CO2 soaking time using 0.5 and 2 hours, filter membrane thickness, including 0.2, 0.6, and 1 mm, and pore size heterogeneity by combining different pore sized filter membranes together. The mitigation chemicals used include kerosene, xylene, naphtha, heptane, and water. The asphaltene wt% for both the produced oil and the bypassed, unproduced, oil was measured for all experiments. Compared to the pure crude oil, not used in any experiment, the asphaltene wt% for the produced oil in all experiments was lower, while the asphaltene wt% for the bypassed oil was higher. The wt% of the asphaltene decreased with the increase in pressure due to the oil being forced out of the nano pores, while an increase in temperature resulted in an increase in asphaltene due to the higher temperatures resulting in instability of the asphaltenes in the oil. The higher viscosity oil had a higher asphaltene wt% in all experiments. Decreasing the CO2 soaking time reduced the asphaltene precipitation. The 100 nm pore size had an asphaltene wt% close to that of the normal crude oil. For the mitigation experiments, xylene and kerosene proved the best, while naphtha and heptane facilitated the precipitation of asphaltene. Pore plugging in conventional oil reservoirs is considered a large problem, and so it is considered extremely drastic if it occurs in the nan-sized pores of shale reservoirs. This research shows the main parameters that will impact asphaltene precipitation during CO2 flooding and illustrates the most effective chemical agent, form the ones applied in the study, to mitigate this precipitation.
Maximum Reservoir Contact in Horizontal Wells Achieved with Multilayer Bed Boundary Detection Technology, Case Study from Kyzylorda Region
Authors: Tyran Serik , Giesemann Carl , Lukpanov Akimzhan , Yermekov Milat , Abzhanov Nariman , Popov Timofey , Evdokimova Inna , Kurmangaliyev Daulet , Makhambetov Amangeldi , Kozhakhmetov Mirat , Leontyev Dmitry 
Published: October 2018

Abstract
In general, the objective of horizontal drilling is to maximize reservoir contact within the target interval to achieve the planned well performance in a thin layer or when drilling within a thin oil deposit, when the distance between the reservoir top and the oil-water contact (OWC) is short and there is a risk or borehole exit into the overlying formation or water-bearing zone.
In horizontal drilling, there always exist risks associated with geological uncertainties. If the structural dip is different from expected, lateral thickness or reservoir property variations exist; if subseismic faults are present, the horizontal well, drilled as per plan, may not achieve sufficient reservoir contact. As a result, the well may underperform.
Well placement (or geosteering) is used in horizontal wells to accomplish geological objectives. The well placement process is an interactive approach to well construction, combining technology and people to deliver optimally placed wellbores in a given geological setting to maximize production or injection performance. In Akshabulak field, southern Kazakhstan, multilayer bed boundary detection technology was applied for geosteering in two horizontal wells.
Integrated Approach to Identify and Control the Water-Injection Induced Fractures in the Low-Permeability Reservoir
Authors: Jinfang Wang , Xingfan Zheng , Zhengmao Wang , Baozhu Li , Yong Li 
Published: October 2018

Abstract
The water-injection induced fractures are key factors influencing successful water injection development in the extra-low permeability reservoir. As water flooding, the water-injection induced fractures have the distinctive characteristic of dynamic fracture growth, which fasten the water breakthrough time and decrease the production and final oil recovery rate. However, it is difficult to analyze the distribution of micro-fractures using logging or seismic data, because of the small size. This paper presents the integrated methods to recognize the water-injection induced fractures, and gives the water-flooding policy limit to control the dynamic fracture growth.
The methods integrate well testing, water injection outflow relation performance curve and tracer test. Firstly, the log-log type curve analysis of injector well drawdown test shows the characteristic of dual porous media model with fracture. Secondly, during deliverability test, a series of injection pressure can be obtained as water injection rate changes from small to big. The relationship curve type between different injection pressure points and the injection rates can be considered as a good indicator of ater injection outflow relation performance curve. Finally, the water flow velocity, direction and path is monitored through use of tracer. Once the injection pressure is more than 6-8 MPa, the slope of the OPR curves increases obviously. The three methods evaluate the distribution and growth of the water-injection induced fractures.
The integrated methods are applied to Ansai oilfield in China, with the permeability 5 ×10-3μm2. The reservoir's mid-depth is around 1400m, and formation pressure factor about 0.8. Once the water breakthrough is indicated form field data, the water cut ratio rise sharply, which result in the invalid circulation of water flooding. To evaluate the dynamic fracture, the injector well drawdown test is carried out. Furthermore, the tracer monitoring show the water flow direction and path, which help to design infill wells. The ater injection outflow relation performance curves show that the injection pressure should be less than 6 MPa, which can control injection-induced fractures propagating into the reservoir towards the producer wells, and postpone the water breakthrough time.
This systematic technique provides a reliable method to evaluate the water injection induced fracture and control dynamic fracture growth, which is helpful for significantly improving water management strategies, potentially increasing oil recovery and reducing operational costs (invalid circulation of water and water treatment facilities reduction), thereby enhancing the project economics.
Brain Network Connectivity Mediates Education-related Cognitive Performance in Healthy Elderly Adults
Authors: Chen Yaojing , Qi Di , Qin Ting , Chen Kewei , Ai Meishan , Li Xin , Li He , Zhang Junying , Mao Haohao , Yang Yiru , Zhang Zhanjun 
Published: October 2018

Background:
Among the protective factors for cognitive decline related to aging and Alzheimer’s
disease, education level is one of the most prominent. However, the mechanisms underlying
the protective effects of education on cognition remain to be elucidated. In this study, we aimed to systematically
assess the role of Functional Connectivity (FC) of resting-state brain networks playing in the
cognition-protection effect of education.

Methods:

Data from a battery of neuropsychological tests and functional magnetic resonance imaging in
resting-state were acquired in 77 cognitively normal elderly participants from local communities in Beijing,
China. Six resting-state networks related to primary function or complex cognition were extracted
through independent component analysis. We then explored the relationships between education level,
cognition, and FC of these networks.

Results:

We found that education level was positively associated with a wide range of complex cognitive
domains including general mental status, episodic memory, language, attention, executive function
and visuospatial processing, and it showed significantly negative correlations with FC of multiple areas
in the Default Mode Network (DMN) and Left Frontal-parietal Network (LFP) which are related to
complex cognition. And regional connectivity of DMN was significantly negatively correlated with episodic
memory performance. Further mediation analysis suggested that higher education level was associated
with higher episodic memory performance through lower regional connectivity of DMN.

Conclusion:

Our findings indicate that inhibitory modulation in the resting-state brain networks related
to complex cognition is one of the main routes through which education exerts its protective effects on
cognition in normal aging.
Screening and Molecular Characterization of Cellulase Producing Actinobacteria from Litchi Orchard
Authors: Kumari Sanju , Sharma Utkarshini , Krishna Rohit , Sinha Kanak , Kumar Santosh 
Published: October 2018

Background:Cellulolysis is of considerable economic importance in laundry detergents, textile and pulp and paper industries and in fermentation of biomass into biofuels.Objective:The aim was to screen cellulase producing actinobacteria from the fruit orchard because of its requirement in several chemical reactions.Methods:Strains of actinobacteria were isolated on Sabouraud’s agar medium. Similarities in cultural and biochemical characterization by growing the strains on ISP medium and dissimilarities among them perpetuated to recognise nine groups of actinobacteria. Cellulase activity was measured by the diameter of clear zone around colonies on CMC agar and the amount of reducing sugar liberated from carboxymethyl cellulose in the supernatant of the CMC broth. Further, 16S rRNA gene sequencing and molecular characterization were placed before NCBI for obtaining recognition with accession numbers.Results:Prominent clear zones on spraying Congo Red were found around the cultures of strains of three groups SK703, SK706, SK708 on CMC agar plates. The enzyme assay for carboxymethylcellulase displayed extra cellulase activity in broth: 0.14, 0.82 and 0.66 &#181;mol mL-1 min-1, respectively at optimum conditions of 35°C, pH 7.3 and 96 h of incubation. However, the specific cellulase activities per 1 mg of protein did not differ that way. It was 1.55, 1.71 and 1.83 μmol mL-1 min-1. The growing mycelia possessed short compact chains of 10-20 conidia on aerial branches. These morphological and biochemical characteristics, followed by their verification by Bergey’s Manual, categorically allowed the strains to be placed under actinobacteria. Further, 16S rRNA gene sequencing, molecular characterization and their evolutionary relationship through phylogenetics also confirmed the putative cellulase producing isolates of SK706 and SK708 subgroups to be the strains of Streptomyces. These strains on getting NCBI recognition were christened as Streptomyces glaucescens strain SK91L (KF527284) and Streptomyces rochei strain SK78L (KF515951), respectively.Conclusion:Conclusive evidence on the basis of different parameters established the presence of cellulase producing actinobacteria in the litchi orchard which can convert cellulose into fermentable sugar.
Grouping of Nodes in Social Networks Based on Multiphase Approach
Authors: Boobalan Parimala M. 
Published: October 2018

Background:
Recent advances in the field of information and social network has led to
the problem of community detection that has got much attention among the researchers.

Objective:
This paper focus on community discovery, a fundamental task in network analysis by
balancing both attribute and structural similarity. The attribute similarity is evaluated using the Jaccard
coefficient and Structural similarity is achieved through modularity.

Methods:
The proposed algorithm is designed for identifying communities in social networks by
fusing attribute and structural similarity. The algorithm retains the node which has high influence on
the other nodes within the neighbourhood and subsequently groups the objects based on the similarity
of the information among the nodes. The extensive analysis is performed on real world datasets
like Facebook, DBLP, Twitter and Flickr with different sizes that demonstrates the effectiveness and
efficiency of the proposed algorithm over the other algorithms.

Results:
The results depicts that the generated clusters have a good balance between the structural
and attribute with high intracluster similarity and less intracluster similarity. The algorithm helps to
achieve faster runtime for moderately-sized datasets and better runtime for large datasets with superior
clustering quality.
Towards An Implementation of A Modified Static Load Balancing Algorithm To Minimize Execution Time
Authors: Ouided Hioual , Tayeb Laskri Mhamed , Mounine Hemam Sofiane , Ouassila Hioual , Lyes Maifi 
Published: October 2018

Purpose: The aim of this article is to discuss the impact of static load balancing over a set
of heterogeneous processors, where tasks are independent and unitary in static environments, by
showing how to distribute task in order to optimize both the average response time and the degree of
the resources used.

Methods:
Implementation of a modified scheduling algorithm, the latter is based on two parameters
which are the execution time and the failure probability. The algorithm is based on the results of an
optimal algorithm that already exists, with only one parameter that is execution time.

Results:
The obtained results show that the modified scheduling algorithm gives us the good results.

Conclusion:
The modified algorithm assumes that the processor has smallest execute time. So, the
failure probability increases because of it’s frequently use. The results obtained by testing this proposed
algorithm are better than the optimal algorithm.
Kinerja bursa kerja khusus (BKK) SMK Negeri bidang keahlian teknologi dan rekayasa di Kabupaten Sleman
Authors: Pambayun Nirmala Adhi Yoga , Wagiran Wagiran 
Published: October 2018

Penelitian ini bertujuan untuk mengevaluasi kinerja Bursa Kerja Khusus (BKK) SMK Negeri Bidang Keahlian Teknologi dan Rekayasa di Kabupaten Sleman ditinjau dari dimensi input, proses dan output. Penelitian ini merupakan penelitian evaluasi dengan model discrepancy. Responden pada penelitian ini adalah pengurus BKK dan siswa tingkat akhir (kelas XII atau XIII) di SMK Negeri Bidang Keahlian Teknologi dan Rekayasa di Kabupaten Sleman yang terdiri dari SMKN 2 Depok, SMKN 1 Seyegan, dan SMKN 1 Cangkringan. Penarikan sampel dilakukan pada responden siswa dengan teknik proportional random sampling. Data dikumpulkan dengan menggunakan inventori, lembar observasi, lembar dokumentasi dan wawancara. Pengujian validitas instrumen menggunakan validitas isi dengan penilaian dari ahli (expert judgement). Hasil penelitian ini menunjukkan bahwa kinerja BKK SMK Negeri Bidang Keahlian Teknologi dan Rekayasa baik ditinjau dari dimensi input, proses dan output secara umum masih masuk dalam kategori rendah. THE PERFORMANCE OF CAREER CENTER IN STATE VOCATIONAL HIGH SCHOOL TECHNOLOGY AND ENGINEER EXPERTISE SECTOR IN SLEMAN REGENCYAbstractThis study aims to evaluate the performance of Career Center in State Vocational High School Technology and Engineer Expertise Sector Sleman Regency in terms of input, process and output dimension. This study was evaluation research with discrepancy model. Respondent in this study were the Career Center administrators and the latest grade students (class XII or XIII) in State Vocational High School Technology and Engineer Expertise Sector in Sleman Regency which consist of SMKN 2 Depok, SMKN 1 Seyegan, dan SMKN 1 Cangkringan. Sampling technique for students used proportional random sampling. Data was collected with inventory, observation sheets, documentation sheets and interview. The result of this study show that, in general the performance of Career Center in State Vocational High School Technology and Engineer Expertise Sector in Sleman Regency in input, process, and output dimension is included into low category.
CARACTERIZAÇÃO EPIDEMIOLÓGICA DE TRABALHADORES COM CÂNCER EM UMA REGIÃO DE FRUTICULTURA IRRIGADA
Authors: Moura Luiza Taciana Rodrigues de , Lopes de Carvalho Aninger Paula Rayanne , Vieira Barbosa Amanda , Galindo Bedor Cheila Nataly 
Published: October 2018

A exposição humana a agrotóxicos pode causar intoxicações agudas e crônicas com diversas implicações no processo saúde-doença dos indivíduos; dentre os efeitos da exposição crônica aos agrotóxicos encontram-se as neoplasias malignas. O objetivo deste trabalho foi descrever o perfil clínico-epidemiológico dos trabalhadores com câncer em tratamento em um centro de oncologia. Participaram do estudo 83 pacientes com câncer divididos em dois grupos. Um constituído por 36 trabalhadores rurais expostos a agrotóxicos e outro por 47 participantes de outras profissões. Foi realizada entrevista com instrumento estruturado que abordou características clínico-epidemiológicas, ambientais e de morbidade. Realizou-se análise estatística descritiva e aplicou-se teste de Mann-Whitney. Os resultados indicam maioria de participantes do sexo masculino com predominância de neoplasias do sistema hematológico e câncer de próstata, evidenciando um perfil de adoecimento por câncer diferenciado das estimativas para o Brasil e região nordeste. Nos trabalhadores rurais, foram identificadas vulnerabilidades durante a exposição ocupacional como baixa escolaridade, longo tempo de exposição e descarte incorreto das embalagens vazias. Concluiu-se que o perfil de adoecimento dos trabalhadores rurais pode estar relacionado ao modo de produção agrário vigente na região, associado às vulnerabilidades durante a exposição ocupacional. A alta prevalência de câncer do sistema hematológico nos participantes não diretamente expostos a agrotóxicos pode sugerir a importância da exposição indireta a esses compostos.
Palavras-chave: Agroquímicos. Neoplasias. Saúde do trabalhador. Epidemiologia.