bluuebunny/crossref_metadata_2025 huggingface dataset:
ФУНКЦИОНОВАНЄ КОНСТРУКЦИЇ/ФОРМИ ВØ У ПРИПОВЕДКИ ДАВНИ ПАЙТАШКИ ГАВРИЇЛА КОСТЕЛЬНИКА
Authors: Фейса Михайло
Published: March 2017

У роботи анализовани часово-видски одношеня у приповедки Давни аֲйֳ аֵ ки др Гавриїла Костельника, хторого ше трима за основопокладателя руского язика. Гоч увага автора фокусована на часове и видове функционованє конструкциї В-ø, автор, медзитим, увагу пошвецує и шицким дїєсловним формом у хторих дїєслова заступени з форму В-ø, т. є. и гевтим случайом кед форма и  конструкция В-ø идентични и гевтим случайом кед форма В-ø лєм состойна часц других конструкцийох. На тот способ практично цала дїєсловна система руского язика спатрена прейґ найфреквентнєйшей и, функционално патраци, найрозконареншей форми у нєй. Першираз редефинована методолоґия до хторей ше пришло з контрастивну анализу применєна и на конкретни линґвистични материял руского язика. Обезпечени и статистични податки у вязи зоз фреквенцию атотивних (87,98 %) и тотивних дїєсловох (12,02 %).
PSIHONARATOLOŠKI PRISTUP ISPITIVANJU KNJIŽEVNOSTI
Authors: Nenadić Filip
Published: March 2017

Empirijski pristupi ispitivanju književnosti razvili su se tokom pro- teklih tridesetak godina, uglavnom na bazi teorija usmerenih na čitaoca i u sprezi sa različitim naukama poput psihologije, sociologije, neuronauka i drugih. Iako grupe autora imaju raznorodne ciljeve i metode istraživanja, ono što ih povezuje je empirijsko i dosledno ispitivanje jasnih hipoteza o čitanju uz korišćenje stvarnih čitalaca. U ovom radu predstavljen je jedan od empirijskih pristupa ispitivanju književnosti, psihonarato- logija, koja je pokušaj da se sačini teorijski okvir specifičan za empirijsko ispitivanje književnosti. Psihonaratologija svoje osnovne termine, principe i hipoteze crpi iz nara- tologije i kognitivne psihologije, oblasti koja se bavi time kako naš kognitivni sistem bira, osmišljava, skladišti i koristi informacije. Pored ovog, koristi se i znanjima iz lingvi- stike, analize diskursa, statistike i drugim. U radu je prikazan i pregled glavnih istraži- vačkih problema psihonaratologije. Iako je psihonaratologija najobuhvatniji teorijsko-metodološki okvir u oblasti empirijsko-eksperimentalnog ispitivanja književnosti i velik korak napred u ovom polju, ona ipak nije obuhvatna ni kada su u pitanju svi oblici književne umetnosti, ni kada su u pitanju svi aspekti čitanja književnog teksta. Pored ovog, zamerka koja se psihonara- tologiji može uputiti jeste ta što tekstualni eksperiment koji ona predlaže stavlja pod znak pitanja umetničku vrednost izlaganih stimulusa.
ГЛАГОЛИ КРЕТАЊА У СРПСКОМ И ЊИХОВИ ЕНГЛЕСКИ ЕКВИВАЛЕНТИ У РОМАНУ РУСКИ ПРОЗОР ДРАГАНА ВЕЛИКИЋА
Authors: Брдар Сања М.
Published: March 2017

У раду се посматрају глаголи у српском језику којима се обележава људско кретање по копну померањем сопствених удова као и њихови преводни еквиваленти у енглеском језику. Глаголи ће бити подељени у неколико група према два основна критеријума, а то су: доминантне диференцијалне семе и усмереност кретања. Грађа је ексцерпирана из романа Руски прозор Драгана Великића објављеног на оба језика.Циљ рада је указивање на сличности и разлике у употреби ових глагола у српском и енглеском на синтаксичком и семантичком плану. Посебно ће бити скренута пажња на улогу префикса код глагола у српском језику и на значења фразних глагола у енглеском језику.
SINTAKSIČKA STRUKTURA SPECIFIKACIJSKIH I PREDIKATIVNIH KOPULATIVNIH KLAUZA
Authors: Đorić Valentina N.
Published: March 2017

Cilj ovog rada je analiza specifikacijskih kopulativnih klauza u srpskom i njihovih sintaksičkih karakteristika u poređenju sa predikativnim kopulativnim klauzama i predikativnim topikalizovanim klauzama. Specifikacijske kopulativne klauze se sastoje od glagola biti i dva DP-a, od kojih je nereferencijalan na početku rečenice, a referencijalan u finalnoj poziciji u rečenici (Pobednik je Petar). Problem koji se javlja jeste mogućnost primene pristupa inverzije predikata na specifikacijske kopulativne klauze u srpskom. Najvažniji argumenti u korist ove teorije jesu slaganje između subjekta i predikata, kao i distribucija padeža u srpskom. Testovi koje Mikelsen (2004) koristi za razlikovanje danskih specifikacijskih klauza i predikativnih topikalizovanih struktura su korišćene i u srpskom. Tvrdim da se u srpskom DPref, što predstavlja referencijski izraz, u predikativnim klauzama pomera u poziciju subjekta u TP nivo, dobijajući padež, dok se DPpred u specifikacijskim klauzama pomera u poziciju subjekta u SpecTP, dobijajući odliku [top], pri čemu DPref ostaje u istoj poziciji. Osnovna pretpostavka je da ove dve vrste kopulativnih klauza imaju sličnu sintaksičku strukturu u odnosu na topikalizovane strukture.
ВУКОВ РЈЕЧНИК И СМЕХОВНА КУЛТУРА
Authors: Ђурђевић Сава Д.
Published: March 2017

Предмет овога рада је народно хуморисање, односно смеховни концепт света у српској премодерној или аграрној култури. У том циљу извршена је анализа неколико одредница из првог издања Вуковог Рјечника у чијим илустрацијама су присутни еротски, опсцени и скатолошки изрази који су коришћени пре свега у магијским обредима везаним за потенцирање људске, животињске и аграрне плодности.
КУБО-ЕКСПРЕСИОНИСТИЧКИ ЕЛЕМЕНТИ У ЗБИРЦИ „ОТКРОВЕЊE“ РАСТКА ПЕТРОВИЋА: УТИЦАЈ АПОЛИНЕРОВЕ ПОЕТИКЕ
Authors: Рачић Ивана М.
Published: March 2017

Предмет истраживања у овом раду је збирка пјесама Откровење Растка Петровића. Анализираћемо везе између естетичких погледа и поетика Петровића и Гијома Аполинера. Посебно ћемо освијетлити одлике њихових поетика које су у тијесној вези са покретом кубизма у сликарству како бисмо показали недвосмислене елементе кубизма у њиховим пјесмама. Бавићемо се њиховом тематско-мотивском структуром како бисмо показали сличности на том пољу али размотрићемо и разлике у њиховим књижевним поступцима.
STRAH, LJUBAV I TUGA U "KRABATU" OTFRIDA PROJSLERA I „ČAROBNJAKOVOM ŠEGRTU“ KARELA ZEMANA
Authors: Simurdić Iva M.
Published: March 2017

Emocije čine sastavni deo čitalačkog i gledalačkog iskustva. Što jasniji uvid imamo u duševno stanje likova, to se više možemo poistovetiti s njima i istovremeno postajemo znatiželjniji da pratimo njihovu sudbinu. Književnost i film raspolažu različitim sredstvima kojima mogu svojoj publici da pojasne osećanja likova. Međutim, oba medija imaju i svoja ograničenja, te se postavlja pitanje koliko autentične te emocije mogu da budu. Kada je reč o dečjoj književnosti i filmovima, zadatak postaje dodatno komplikovaniji zbog uzrasta publike. U ovom radu analiziraju se načini obrađivanja sadržaja koji se tiču emocija u Krabatu Otfrida Projslera i ekranizaciji ovog dela Karela Zemana pod naslovom Čarobnjakov šegrt. Kada je reč o ekranizacijama književnih dela neizbežna su poređenja sa originalnom kako bi se odgonetnulo koje ostvarenje je bolje. U ovom radu original i ekranizacija će se posmatrati odvojeno u cilju istraživanja mogućnosti kojima roman i njegova ekranizacija raspolažu da bi svojoj publici predočili osećanja likova. Pratiće se i kako su emocionalne scene iz istog izvornog materijala prikazane u različitim medijima, odnosno kako su pisac i reditelj iskoristili mogućnosti koje im jezik/film pružaju.
ESEJISTIČKI IZRAZ U DJELU GLORIJE ANSALDUE „BORDERLANDS/LA FRONTERA: THE NEW MESTIZA“
Authors: Bijedić Mirna
Published: March 2017

U okviru savremene književnosti često nailazimo na djela koja nije moguće obuhvatiti jednom književnom formom ili žanrom. U takva djela spada i djelo latinoameričke spisateljice Glorije Ansaldue Borderlands/La Frontera: The New Mestizakoje se žanrovski može definisati kao roman-esej, jer istovremeno sadrži elemente romana i esejističkog izraza. Uz to, ovo djelo predstavlja i mješavinu poezije, autobiografskog pisanja, istoriografije i magičnog realizma. Međutim, u ovom istraživanju se primarno razmatra upotreba eseja kao oblika ili forme, s ciljem da se pokaže da je Ansaldua pažljivo birala esejistički izraz u nastojanju da što adekvatnije oslika stvarnost latinoameričke populacije, posebno žena, s obje strane američko-meksičke granice. Istraživanjem se zaključuje da, kada je u pitanju pomenuto djelo, esej predstavlja najprirodniji književni i formalni ekvivalent onoj stvarnosti o kojoj Ansaldua piše i da ga ona s namjerom koristi kada govori o svojim ličnim stavovima vezanim za pitanja kao što su istorija, kultura, tradicija, rodne uloge i identitet latinoameričkih etničkih grupa.
ФИКСНИ БИНОМИ У ЕНГЛЕСКОМ И СРПСКОМ: ФОРМАЛНИ И САДРЖИНСКИ АСПЕКТИ
Authors: Rupar Jovana
Published: March 2017

Предмет истраживања у овом раду су формални и садржински аспекти фиксних бинома у енглеском и српском језику. Корпус коришћен у овој анализи је речнички и садржи 300 фиксних бинома из енглеског језика и 170 фиксних бинома из српског језика. У циљу провере степена сличности ове врсте фразема у два језика, у раду се испитују: (1) ритмичке и фонолошке карактеристике фискних бинома, (2) најзаступљенији структурни обрасци и природа везног елемента, (3) степен садржинске идиоматизације фиксних бинома и (4) врста семантичке везе између његових чланова. Резултати истраживања показују да постоји висок степен сличности у погледу фонолошких, структурних и семантичких аспеката ове врсте фразема у два језика.
Do discurso prático à prática discursiva: a mobilidade urbana e seu contexto sociopolítico. Contradições e lacunas entre a elaboração e execução do planejamento das políticas de transporte nas cidades brasileiras — o caso da Região Metropolitana do Recife (RMR)
Authors: Silva Filho Nivaldo Gerôncio , Raia Junior Archimedes Azevedo
Published: March 2017

Em pouco mais de seis décadas, o debate em torno das ideias que agregam-se ao conceito da mobilidade urbana mesmo que não associadas diretamente ao termo, têm adquirido uma complexidade bastante acentuada e ao mesmo tempo contraditória, dada a multiplicidade de variáveis que nela passa a interferir, tornando-a passível de uma discussão que vai muito além do campo teórico. Na atualidade, o ângulo de discussão do tema direciona-se a dois aspectos inerentes a tais ideias: I) aquele concernente à relevância que é intrínseca ao espaço urbano que, por sua vez, caracteriza-se como um campo de discussão propício na fomentação do conceito; e II) aquele relativo à amplitude que, relaciona-se ao viés histórico a partir do momento em que o termo ganha ênfase; ao viés econômico no que se refere à produção interna do país; ao viés ambiental principalmente a partir de grandes conferências mundiais sobre o meio ambiente; ao viés social no atendimento inclusivo e essencial à população; e por fim um viés político, no tocante as tomadas de decisões. Assim, de modo geral o trabalho procura questionar as formas de planejamento urbano voltadas para os transportes nas últimas décadas. De modo específico o artigo lança foco nas contradições e lacunas entre a mobilidade urbana e as políticas públicas, ou seja, não nos parece tão claro, o seu processo de elaboração e execução, na medida em que as tais políticas não cumprem de forma efetiva seu papel, este fato traz um ônus muito elevado para os serviços públicos essenciais, tal como é o caso dos transportes. Procurar-se-á investigar essa problemática tomando como estudo de caso a Região Metropolitana do Recife (RMR), através de uma metodologia comparativa entre o discurso teórico e a prática evidenciada nos diversos modais de deslocamentos.
Evolução diária e variação sazonal da turbulência atmosférica em espaços livres de cidades do Oeste Paulista
Authors: Machado Antonio Jaschke
Published: March 2017

Este artigo procura identificar um padrão da turbulência do ar que reflita o efeito de edifícios nas características da turbulência medida em espaços livres de cidades do Oeste Paulista. A turbulência atmosférica foi estimada utilizando-se observações de alta-frequência das três componentes ortogonais do vento (u, v, w). Um anemômetro sônico CSAT3 da Campbell Scientific Inc. (CSI) foi instalado na cobertura de um edifício, e as componentes turbulentas (u', v', w') foram sistematicamente medidas e registradas em intervalos de 0.1 s e 5 min, respectivamente, durante 1 ano entre março de 2015 e fevereiro de 2016 com um sistema automático de aquisição de dados CR3000 (CSI). A análise dos dados considerou a variabilidade diurna e noturna da turbulência, e os resultados experimentais revelaram a existência de um padrão diário de circulação vertical. A componente w variou entre 15 e 45 cm.s-1 em média, e as flutuações turbulentas observadas indicaram que uma componente ascendente com uma velocidade de até 1 m.s-1 predominou durante o meio do dia e início da tarde. Durante a noite até as primeiras horas da manhã, uma componente descendente, menos robusta, com uma velocidade de até 0.5 m.s-1 foi observada. O fluxo horizontal médio (u, v) foi de baixa velocidade (em torno de 1 m.s-1) e predominantemente de sudeste. Houve uma mudança consistente na direção deste vento, que girou para leste durante a manhã conforme o ramo ascendente se desenvolveu. É proposto um modelo para a circulação do ar próximo à superfície na qual esta mudança na direção do vento é o principal efeito do edifício na turbulência observada. Concluiu-se que outros padrões assimétricos observados, do tipo brisas de vale, podem ser compreendidos como circulações secundárias que tem como pano de fundo o efeito do edifício.
Relação entre caso morfológico e caso abstrato na língua Ka'apor
Authors: Cabana Nasle Maria
Published: March 2017

Neste artigo apresento uma análise sobre a relação entre atribuição do Caso abstrato e marcas morfológicas de caso na língua Ka’apor. Mostro que esta língua apresenta alternância na marcação do sujeito e do objeto, mas que são fenômenos resultados de processos diferentes. Em relação ao sujeito, assumo que esta língua apresenta atribuição diferente do Caso abstrato. Alguns sujeitos recebem o Caso  resultado de relações estruturais e outros o Caso inerente tendo em vista que estão evolvidos determinados papéis temáticos. Já os objetos recebem uniformemente o Caso abstrato via relações estruturais, mas apresentam marcas morfológicas diferentes conforme sejam ou não altos considerando a escala de animacidade e de definitude.
Apresentação
Authors: Editorial Comissão
Published: March 2017

Apresentação
An Analysis of Point of Sale Systems Physical Configurations and Security Measures in Zimbabwean SMEs
Authors: Sai Kundai Oliver Shadwell
Published: March 2017

This paper undertook to establish the correlation between the Point of Sale configurations (setup) employed by Small and Medium Enterprises and the security controls and measures implemented for the prevention and detection of possible security threats. Quantitative data was collected from 30 Small and Medium Enterprises in the retail sector using a self-administered questionnaire. The participants were selected using purposive sampling. The data was analysed using descriptive statistics and the Chi square test was used to test for correlation between the variables. The research showed that only three of the recommended security measures for Small and Medium Enterprises are directly affected by the Point of Sale configuration in use and these are: Password Policy; Physical Security and Antivirus.
The Relationship Between Muscular Strength and Dance Injuries: A Systematic Review
Authors: Moita João P , Nunes Alexandre , Esteves José , Oliveira Raul , Xarez Luis
Published: March 2017

BACKGROUND: The physical demands placed on dancers put them at significant risk for injury, with rates similar to ones sustained by athletes in sports at the same level of performance. Muscle strength has been suggested to play a preventative role against injury in dancers. OBJECTIVE:
To systematically search and examine the available evidence on the protective role of muscle strength in dance injuries. METHODS: Five electronic databases and two dance-specific science publications were screened up to September 2015. Study selection was based on a priori inclusion criteria
on the relation between muscle strength components and injuries. Methodologic quality and level of evidence were assessed using the Downs and Black (DB) checklist and the Oxford Centre of Evidence- Based Medicine (OCEBM) 2011 model. RESULTS: From 186 titles found, only 8 studies met the inclusion
criteria and were considered for review. Because of the significant heterogeneity of the included studies, meta-analysis was deemed inappropriate. The DB quality assessment results ranged from 18.7% to 75% (mean 42.3±16.9) and the OCEBM between 2b and 4. Some level 2b evidence from
2 studies suggested that pre-professional ballet dancers who get injured exhibit lower overall muscle strength scores on the lower extremity, and that lower extremity power gains may be associated with decreased bodily pain but not injury rate. CONCLUSIONS: Although there might be an association
trend toward low muscle strength and dance injuries, the nature of that relation remains unclear, and presently the state of knowledge does not provide a solid basis for designing interventions for prevention.
Movements of the Glottis During Horn Performance: A Pilot Study
Authors: Iltis Peter W , Gillespie Sarah L , Frahm Jens , Voit Dirk , Joseph Arun , Altenmuller Eckart
Published: March 2017

OBJECTIVE: The functional role of the glottis in brass performance is poorly understood and controversial, particularly with respect to pedagogy. Technological limitations have prevented the non-invasive, systematic study of the glottis in the past, but developments in real-time magnetic
resonance imaging (RT-MRI) allow representations of glottal movement during performance on a MRI-compatible horn to be recorded and quantified. METHODS: We present RT-MRI data obtained on 6 advanced-level horn players from serial images acquired at an acquisition time of 33.3 ms as they performed
sustained note exercises on three notes (concert Eb2, Eb4, and Bb4) at each of three dynamics (pp, mf, and ff) and a staccato exercise. An advanced-level trumpet player was also studied performing a modification of the staccato exercise designed to minimize vertical movement of the larynx.
Glottal movements and positions in the coronal plane were analyzed using a customized MATLAB toolkit. RESULTS: In sustained note playing, there is a significant influence of dynamic on the degree of glottal adduction/abduction. There is greater adduction with softer notes, and greater abduction
with louder notes. In slow staccato playing, glottal closure accompanies the cessation of each note and persists until iteration of the next note in the sequence. CONCLUSIONS: We demonstrate that RT-MRI provides a suitable method to identify and quantify glottal movement during horn playing.
We further show that there is a direct relationship between dynamic level and glottal adduction/abduction, and that the glottis is involved in performing notes during slow staccato playing.
Rethinking the Typical Line-Item DWOP Exercise: Does it Present a Complete Picture?
Authors: Nwokoma Precious , Knobben Xander
Published: March 2017

The Drill Well on Paper (DWOP) exercise is an accepted tool for use in planning an offshore well, and in post-drilling analysis to demonstrate real and potential efficiency gains when comparing latest generation drilling and floater designs. However, given accelerated advances in drilling systems and operational practices, does the DWOP methodology of strictly analyzing fixed line-item data adequately capture non-apparent flat time and enhance overall operational efficiencies?

This paper explores areas where the traditional DWOP may not clearly reflect the efficiencies and HSE gains intrinsic of the latest generation drilling environment, and makes the case for transforming to more of a project management-like approach. For instance, efficiencies demonstrating reduced well delivery days would logically translate into a corresponding reduction in injuries/man-hour, but results of that accepted metric are not recorded in a post-well DWOP. Additionally, despite simultaneous rig operations, often denoted as off-line activities, the typical DWOP only looks at one operation, or line item, at a time. Thus, any efficiencies or bottlenecks in these parallel operations are often neither identified nor recorded in the DWOP.

The authors will present direct comparisons to illustrate how a typical DWOP exercise may not capture and detail the consequential reductions in lost time incident rates (LTIR), flat times and invisible lost time (ILT) achievable with advanced rigs and drilling systems. Standardized robotic pipe manipulators, floaters with increased storage capacity for casing and other consumables that reduce supply vessel requirements, and new rig designs and/or moon pool dimensions that widen the operable window and reduce weather-related downtime, are among the efficiency drivers the authors suggest should be reflected in a DWOP analysis. Additionally, improved operational practices, like pre-installation of casing centralizers, and automated pipe tally and monitoring systems contribute to improved efficiencies and economics, which further justify modifications to the standard DWOP thought process.

This paper aims to broaden the readers our understanding of how deepwater rigs can be assessed with respect to efficiency and HSE gains; thereby, leading to a rethinking of the current methodology used in rig comparison DWOPs.
Kick Tolerance and Frictional Pressure Losses, Added Safety or Added Risk?
Authors: Mosti I. , Morrell D. , Anfinsen B. T. , Vielma W. E. , Nergaard K.
Published: March 2017

Annulus frictional pressure losses can be significant in certain application and should be considered in the planning phase to correctly calculate a meaningful safety margin for kick tolerance. Kick tolerance is an integral part of the well construction workflow. The formation, casing and well control equipment should withstand the pressure when shutting in and circulating a given kick volume to surface. At its simplest, the kick tolerance will be calculated based on the pressure in the well when the kick front is at the casing shoe, giving the highest pressure load at the shoe.

Safety margins are factored in by adding a given additional pressure as a safety factor in the calculations. This is often a pre-defined value in the technical requirements within the company. In deep water applications, the choke line frictional pressure losses are normally evaluated and can also be included, but in operations onshore or in shallow waters these frictional pressure losses are often excluded. Annulus friction pressure losses are often neglected entirely because they are considered insignificant or considered to be an extra safety factor.

Conventional well control procedures normally start the kick circulation by ramping up the pumps to speed while keeping the choke pressure constant. This procedure implies that any frictional pressure losses in the annulus and choke lines will be added to the wellbore pressure (considered a "nice to have" safety margin). An additional safety margin may be applied before starting the actual circulation, by pumping a few strokes into the shut in well to give some additional overpressure. This additional pressure does not represent a problem if it is accounted for in the planning phase, but, if not considered it could impose a risk to the operation if the actual kick tolerance in the operation is less than the calculated. In deep wells, typically with high mud density, the frictional pressure losses in the annulus can be significant, also at the slow circulation rates during a kick circulation. The standard safety margin applied in planning may or may not match this reality.
Understanding Lost Circulation While Cementing: Field Study and Laboratory Research
Authors: Therond E. , Taoutaou S. , James S. G. , Way P. W. , Gomes P. , Dondale A.
Published: March 2017

Lost circulation is a time consuming and expensive challenge, costing the oil and gas industry billions of dollars each year in materials and non-productive time. To mitigate lost circulation during cementing operations, a better understanding of how wellbore strengthening mechanisms apply to cement slurries is necessary. The ability to control cementing fluid properties to strengthen the wellbore and minimize losses during cementing operations is imperative for achieving adequate zonal isolation.

A comprehensive field analysis was performed to understand lost circulation initiation during different phases of drilling and primary cementing. Offshore wells from four different locations were studied: Gulf of Mexico, United Kingdom, Angola and Azerbaijan. In parallel, laboratory research was performed to understand the behavior of cement slurries in controlled lost circulation scenarios using a block tester. Measurement of formation breakdown pressure and formation propagation pressure were made with different cement slurry compositions and compared with pressures obtained with drilling muds.

In an analysis of 40 well sections that reported losses prior to, or during, primary cementing operations, the rate and severity of lost circulation varied for the wells studied, but it was concluded that losses were commonly induced while running casing or pre-cement job mud circulation, but rarely during cement placement.

The laboratory research confirmed the field observation: It would take much more pressure to open or re-open an existing fracture with cement slurry than with a synthetic oil-based mud.

This paper will present findings from the field analysis and laboratory research. It will also discuss strategies to prepare the wellbore for preventing losses before the cementing operation and to optimize cement formulations in case losses have been induced during drilling, casing running or pre-job mud circulation.
True Self-Healing Geopolymer Cements for Improved Zonal Isolation and Well Abandonment
Authors: Liu Xiangyu , Ramos Matthew J. , Nair Sriramya D. , Lee Hanna , Espinoza D. Nicolas , van Oort Eric
Published: March 2017

Targeting the incompatibility issue between traditional Portland cements and non-aqueous drilling muds, a mud solidification technique based on geopolymer cements was recently introduced to the industry. This technique was achieved by incorporating non-aqueous fluids (NAF) such as synthetic-based or oil-based drilling mud in a geopolymer cement that is formed by blending an aluminosilicate powder with an alkaline activating solution. In a previously completed study, the consolidated mud, or "geopolymer hybrid", was evaluated for its compressive strength, thickening time and stability for applications including primary cementing as well as lost circulation control. In an effort to further develop the geopolymer hybrid system as a new generation well cementing material, the present work comprehensively studies their mechanical properties, self-healing capabilities and cement-to-pipe bond strength.

One of the concerns currently preventing the use of geopolymers for well cementing is its low early compressive strength. This study shows that although the early age uniaxial compressive strength of geopolymer is lower than that of Portland cement, with an applied confining stress, geopolymers have more than sufficient strength for primary cementing applications.

Furthermore, the abilities of cement to properly bond with steel casing and rock formations, as well as to withstand subsurface stress changes over time are of paramount importance for long-term cement integrity. The triaxial tests performed in this study show that geopolymers are less brittle than Portland cement, and can therefore accommodate stress changes without localized failure. The geopolymer bond strength measurements showed that geopolymer could bond to steel even in presence of non-aqueous drilling muds. In addition, the triaxial tests revealed that geopolymers exhibit true self-healing capabilities, characterized by samples fully regaining their mechanical competence with 28 day post-failure strength exceeding the native 7-day strength. Portland cement, in comparison, retained lower ultimate strength than its 7-day strength. The self-healing capability of geopolymers is ideally suited to adapt to subsurface stress changes, making such materials ideally suited for use as permanent barriers in plug and abandonment operations.
MWD Surveying Enhancement Techniques and Survey Management Workflows Applied at a Barents Sea Field for Accurate Wellbore Positioning
Authors: Monterrosa Leida C. , Rego Marina Ferreira , Blackburn Jason D.
Published: March 2017

This paper aims to provide an understanding of the various measurement-while-drilling (MWD) surveying enhancement techniques applied in drilling operations at the Goliat Field located in the Barents Sea to assure accurate wellbore positioning.

In high-latitude locations such as the Barents Sea, the elevated, time-dependent variations in the magnetic field create a challenge to the azimuthal measurements provided by the MWD tool. This will induce large uncertainty levels in the MWD surveys compromising the azimuthal errors established within the standard industry error models. To compensate for this effect, crustal magnetic field and time-based magnetic field disturbances were acquired to understand their impact on the MWD surveys and any associated error. This permitted drilling without compromising rig time, and the resultant reduction in lateral uncertainty was approximately 65%.

With regards to true vertical depth (TVD) optimization, the nature of the reservoir targets required tight TVD tolerances. To reduce the TVD uncertainty and maximize these targets, dual inclination analysis was performed while drilling. Control checks of the continuous and static inclination data from the MWD and rotary steerable system (RSS) reduced the sensor error term of the TVD error model definition and hence produced an improvement of up to 67%.

Seven wells have been drilled in the Goliat Field based on the methodology described in this article. In the planning phase, it was noticed that extra surveying techniques would be required to achieve the objectives for lateral and TVD placement. Survey management workflows were implemented to ensure consistency with regards to surveying accuracy.

Drilling and environmental challenges encountered in the Barents Sea push the boundaries of every aspect of current surveying techniques. Adherence to survey management procedures and understanding of the impact in the measurements generated by the disturbance in the magnetic field improved efficiency in the drilling operation and helped to achieve the critical well positioning objectives for this field.
The Role of Phosphate Conversion Coatings in Make-Up of Casing Connections
Authors: Ernens D. , Riet E. J. , de Rooij M. B. , Pasaribu H. R. , van Haaften W M. , Schipper D. J.
Published: March 2017

Phosphate conversion coatings are widely used on (premium) casing connections for protection against corrosion. Next to that, in conjunction with the lubricant these coatings provide galling protection. The friction and wear that occurs during make-up and subsequent load cycling determines the sealing performance of the metal-to-metal seal. Therefore, phosphate conversion coatings play an important role in the sealing performance of metal-to-metal seals. An extensive test program was set-up to investigate the role of phosphate coatings during make-up. With pin-on-disc, anvil-on-strip and ring-on-ring tests the interactions between substrate, lubricant and phosphate coating was investigated. A comparison was made between uncoated and coated specimens using base greases, and formulated greases: API modified and two commercially available yellow dopes. The results indicate a strong influence of the phosphate coating leading to damage free make-up, low wear, and less dependence on the lubricant. This is attributed to the formation of a hard and smooth dissimilar surface, the ability to adsorb the lubricant and the generation of a transfer layer on the uncoated counter surface. It is concluded that taking the interaction with phosphates into account could enable lubricants to be tailored for sealing performance and thus can ease the transition to environmentally friendly rated lubricants.
Experimentally Validated First-Principles Multivariate Modeling for Rheological Study and Design of Complex Drilling Nanofluid Systems
Authors: Gerogiorgis Dimitrios I. , Reilly Simon , Vryzas Zisis , Kelessidis Vassilios C.
Published: March 2017

The demand for more efficient and reliable oil and gas drilling fluid systems drives their development with unprecedented sophistication: the key challenge is to achieve predictable rheological properties, but also to enable their judicious customization, particularly for High Temperature High Pressure) (HTHP) applications and tough environments. This study presents the development and validation of a first-principles multivariate rheological model, allowing yield stress and viscosity prediction for new drilling fluids with iron oxide nanoparticles (NP).

Previous studies show that water-bentonite suspensions of variable Fe3O4 NP concentration exhibit non-Newtonian shear-thinning behavior, accurately captured via a tri-parametric nonisothermal Herschel-Bulkley (HB) rheological model form; nonlinear least squares regression yields reliable parameter sets. The resulting fluid shear stress and viscosity are expressed as explicit functions of independent variables (shear rate, temperature, NP concentration) and the correlations are validated against experimental data. A new parameter set must be computed by nonlinear regression for each combination of conditions, a necessity compromising the predictive potential of this data-driven rheological modeling approach.

To obtain truly predictive, first-principles rheological models, a systematic strategy is presented: shear stress and viscosity have now been expressed as physics-based (not data-driven) multivariate correlations of the aforementioned independent variables, using microscopic arguments for colloidal particle behavior, as confirmed by Transmission/Scanning Electron Microscopy (TEM/SEM) images. Shear stress is thus studied by distinguishing key additive contributions, on the basis of explicit bounds on colloidal inter-particle distances: our novel functional forms consistently capture the non-Newtonian fluid behavior, but require only one parameter set computation for the entire dataset.
Real Time Engineering-Based Simulation Training Addresses Risk in Managed Pressure Drilling
Authors: Rommetveit Rolv , Davidson Ian , Svendsen Morten
Published: March 2017

Managed Pressure Drilling (MPD) enables safer operations and reduces non-productive time and thus provides the opportunity to reduce well costs. Many operators however, are not fully embracing the opportunity offered by the technology, due to strict regulatory requirements, and their perception that MPD is complicated and increases risk. A basis for this perception is that operator engineers in their designs, and contractor drilling crews in day-to-day operations, are insufficiently MPD experienced to fully and safely exploit the benefits of the technology.

Today, the advanced, and field proven, engineering (mathematical) models that are part and parcel of the software used in well design are also available in state of the art simulators. These engineering models and model based simulators are used by engineers during the design phase of MPD projects to replicate the conditions that will be encountered during actual well construction; picking optimal casing setting depths, using different equipment set-ups, selecting optimal drilling parameters and demonstrating the integrity of the design under a wide scenario of well conditions.

Once the well design is finalized, and before drilling operations commence, the same well design is programmed into a real-time drilling simulator. During subsequent simulator exercises,, rig personnel are exposed to the range of scenarios that can unfold during actual operations, taking into account uncertainties and unexpected events. Crews, at the hard end of operations, are able to hone their competence to deal with the unexpected in a team environment under the supervision and guidance of experienced coaches.

During actual MPD operations, the same advanced models can be used for automatic simulation and well monitoring purposes; they can also be integrated into the MPD control system to accurately maintain the required well pressures.

This paper describes the models used and both the classroom simulator-based engineering training and the real-time rig floor simulator training that will respectively provide operator engineers and contractor well site staff the in-depth understanding of MPD that will enable them to develop their respective skills to safely and cost effectively exploit the many benefits offered by MPD.
Real-Time Borehole Condition Monitoring using Novel 3D Cuttings Sensing Technology
Authors: Han Runqi , Ashok Pradeepkumar , Pryor Mitchell , Oort Eric van , Scott Paul , Reese Isaac , Hampton Kyle
Published: March 2017

Wellbore instability and stuck pipe incidents are large contributors to drilling-related non-productive time (NPT). Drilling cuttings/cavings monitoring is crucial for early detection and mitigation of such events. Currently, monitoring is done manually and lacks a streamlined approach. Automating this process would be very beneficial, and is possible due to recent advances in sensing technology. Real-time cuttings/cavings monitoring can be used to quantify cuttings volume, measure size distribution, and analyze shape. By correlating these measurements with ongoing drilling operations, the hole condition (in particular hole cleaning/cuttings transport efficiency, wellbore stability situation, etc.) can be automatically assessed in real-time. This makes pro-active prevention and mitigation of NPT related to hole cleaning and wellbore instability possible.

In this paper, we detail a system designed and prototyped to allow us to measure cuttings/cavings in real-time. A highly portable device employs a 2D high-resolution camera and a 3D laser sensor to determine the physical properties of cuttings. The 3D point cloud/depth data obtained by this device provides cuttings size distribution, volume and shape characteristics. Comparisons and discrepancies between expected and sensed quantities can then be used for alarming purposes and taking appropriate corrective action.

A prototype experimental setup was constructed to evaluate the ability to quantify relevant cuttings properties and profiles in the presence of drilling fluids. In a controlled environment, the cuttings slide down a shaker table's clearing chute while simulating various realistic external variable scenarios. The environmental impact on the accuracy, repeatability and robustness of the various sensors under investigation was determined to identify the sensors best suited for the task at hand. The optimum device configuration was then implemented and evaluated to verify that the system is viable for use in the field. The automated cuttings monitoring system can warn drillers to potential hazards associated with poor hole cleaning conditions, ongoing wellbore breakout, and the likelihood of stuck pipe events.
Saving a Hole Section by Using Real-Time Wellbore Stability Analysis
Authors: Odunlami Tosin , Amorocho Claudia
Published: March 2017

A real-time wellbore stability analysis capability was developed to help an operator reduce high costs of nonproductive time (NPT) in an area prone to stuck pipe, lost borehole assemblies (BHAs), and lost hole sections. A multidisciplinary team created integrated processes for predrill, dynamic real-time, and post-drill modeling to help identify wellbore instability and pore pressure events that cause kicks, tight holes, and stuck pipe incidents.

A Predrill wellbore stability model for the proposed well was built based on offset well data. The model enabled the identification of depth intervals and formations where there are potential wellbore stability issues. A multidisciplinary team consisting of geomechanics engineers, pore pressure specialists and drilling optimization engineers provided 24-hour monitoring of drilling parameter trends and analyzed quad-combo logging-while-drilling (LWD) data in real time to determine the health of the wellbore. This enabled calibration of the predrill model in real time, which consequently served as an ahead-of-bit prediction of undrilled sections of the well.

Four wells were drilled in this project. The first two wells had lost hole sections resulting from wellbore stability challenges that caused high NPT costs. The new process was instituted on the third well which resulted in no lost time due to troubled hole sections and subsequently resulting in 30% lower well cost due to reduction in expected NPT. The same results were achieved on the fourth well, which demonstrated repeatability of the new process. The predrill model indicated that a pore pressure ramp was expected and that the operator's planned mudweight and casing program posed potential risks of formation fluid influx and hole breakout with resultant cavings falling into the wellbore. During drilling operations the expected pressure ramp was confirmed by an observed increase in connection gas and cavings across the depth intervals identified in the predrill model. This was communicated to the operator and informed their timely decision to increase the mud weight range for the hole interval and to set the casing shallower than planned to avoid potential hole problems.

This multidisciplinary approach to address well challenges by integrating technology, tailored expert response, and collaboratively managed delivery helps to reduce uncertainty, improve safety, and increase efficiency of planned wells and depth intervals. The new process comprising predrill, dynamic real-time, and post-drill phases identifies drilling hazards for correct mitigation. Lessons learned during the drilling operations are documented and applied to subsequent wells for continued improvement of operational parameters and best practices.
Mitigating Drilling Dysfunctions and Enhancing Performance with Self-Adjusting Bit Technology: Analytical and Experimental Case Studies
Authors: Jain Jayesh R. , Ricks Gregory , Ledgerwood L. W. , Phillips Anthony
Published: March 2017

Mitigating drilling vibrations and pushing the upper limit of performance while drilling long sections in a single bit run remains a challenge for fixed polycrystalline-diamond-compact (PDC) bits. Recently, new self-adjusting depth-of-cut (DOC) control technology was introduced to help overcome these challenges. This paper presents further details of how the technology works in a wide range of drilling conditions and demonstrates performance benefits in research wells.

Building on the conceptual illustration presented in SPE-178815, time domain modeling is performed to study influence of the self-adjusting mechanism on the drilling system response. The results of simulations are corroborated with full-scale testing in the laboratory. Additionally, field testing is conducted in research wells to demonstrate the ability of the technology to reduce drilling vibrations and push the performance envelop. Scenarios such as torsional stick/slip vibrations, weight-on-bit (WOB) transfer issues, improper starting procedures, and heave excitation in offshore wells are considered on conventional rotary as well as motor bottom-hole assemblies.

The technology provides the bit with the ability to continuously adjust its DOC control characteristics to suit the drilling environment: it engages DOC control when encountering vibrations to mitigate them and disengages when drilling smoothly to deliver high rate of penetration (ROP). Significant benefits are observed when drilling with self-adjusting PDC bits in a variety of operating conditions. In addition to mitigation of stick/slip vibrations, reduction in cutter overload is observed when sudden loading is encountered, such as during weight stack-up events or re-starting after connections. When subjected to oscillating WOB, which mimics heave excitation, downhole measurements of vibrations show self-adjusting bits exhibiting reduced levels of torsional vibrations compared to fixed PDC bits. The testing also shows promise in reducing cutter wear and extending bit life.

The paper enhances the understanding of how the novel self-adjusting DOC control technology works in realistic drilling conditions. The simulation and testing results demonstrate applicability of the technology in a variety of drilling dysfunctions experienced in the field.
Innovative Drill Stem Rotary Shoulder Connection Designed for Cost Efficient Operations in the Most Challenging Drilling Environments
Authors: Lafuente Marta , Carrois Fabien
Published: March 2017

For the last century, the oil and gas industry has been pushing the limits of the existing drilling envelope to reach deeper more remote hydrocarbon reservoirs. The evolution of drilling programs has driven drill string manufacturers to engineer new drill pipe solutions able to safely develop the most challenging horizontal and extended reach drilling (ERD) well profiles.

In response to the development of newer drilling challenges, drill stem elements evolved to provide better mechanical and hydraulic performances. Based on industry requirements, drilling products steadily improved its tensile strength-to-weight ratio and its torque ability in order to help operators overcome frictional drag forces and achieve improved hydraulic performances, rates of penetration, control of well trajectories and hole cleaning.

But with the latest economic trends in the oil and gas industry, drilling economics has become an equally, if not more, important factor for operators when choosing their drill string.

Today, when operators plan their projects they seek for technologies that will allow them to drill these further reach wellbores successfully and more economically. Drilling equipment is required, not only to provide the required mechanical performances but also to be reliable and easy to handle on the rig floor.

A new ultra high-torque Rotary Shoulder Connection was designed and extensively tested to verify its ability to improve the operational and economic performances of drilling operations in the most challenging drilling environments.

The new connection's unique and innovative design provides the following advantages: The highest available torque in the market for a double shoulder connector without compromising on other performances such as tensile strength which allows for deeper, further drilling operationsEngineered single start thread design which allows for faster trip timesMake-up to break-out torque ratio between 0.7 and 1.1, which reduces the risk of the string backing out while drillingInnovative thread form that reduces the stress on the critical cross section and enhances fatigue resistanceOptimized taper and thread design that allows for a deeper stabbing and eliminates the need for stabbing guidesThe ability to design tool joints with a reduced OD and an enlarged ID which reduces the pressure and hydraulic horsepower requirements for circulating drilling fluids, viscous pills, and cement.

This paper describes the design of a new Drill Stem Rotary Shoulder Connection Design, the rigorous testing program used to qualify it, and the operational and economic benefits that this new technology brings to the drilling operation.
Nail‐patella syndrome in pregnancy
Authors: Wood Daniel , Silva Savihtri , Selvan Dinesh
Published: March 2017

Nail‐patella syndrome is a genetic condition estimated to affect approximately 1 in 50 000 people. Classically described as a tetrad of abnormal development of the nails, patellae and elbows with the presence of iliac horns. The phenotype and the number of organs involved are variable. Here we describe the successful management of a pregnant patient with nail‐patella syndrome.
Paediatric airway obstruction induced by separation of laryngeal mask airway components
Authors: Evans Lucy , Hussey Joseph
Published: March 2017

We describe a case of airway obstruction secondary to the cuff of a laryngeal mask airway (LMA) becoming separated from the breathing tube whilst in situ in a fit and healthy 1‐yr‐old child. The incident occurred midway through an elective hypospadias repair. Recognition and management of the problem was timely such that the operation was safely completed. The child was woken up postoperatively and discharged home without injury.