bluuebunny/crossref_metadata_2025 huggingface dataset:
Implicações da aprendizagem experiencial e da reflexão pública para o ensino de pesquisa qualitativa e a formação de mestres em administração
Authors: Villardi Beatriz Quiroz , Vergara Sylvia Constant
Published: September 2011

Na pós-graduação stricto sensu em Administração se formam professores e pesquisadores. Esperamos que os mestrandos desenvolvam sua capacidade de aprendizagem para realizar pesquisas. A procrastinação acadêmica e o choque de aprendizagem dos mestrandos, no entanto, dificultam esse processo. O estudo exploratório aqui apresentado se propôs a examinar a prática de ensino-aprendizagem durante e após o processo de aprender a pesquisar, buscando resposta para a seguinte questão: como mestrandos aprendem, por meio de prática experiencial, a realizar pesquisa qualitativa em administração? Apoiado em referencial teórico que trata de processos de ensino-aprendizagem, reflexão e pesquisa qualitativa, o estudo realizou percurso metodológico inspirado na fenomenologia e na abordagem socioconstrutivista, privilegiando a experiência vivida de professores e alunos. Chegamos à conclusão de que a vivência de pesquisa de campo e a prática de reflexão pública no e sobre o campo: (a) ampliou a consciência dos participantes sobre a sua importância no processo de ensino-aprendizagem; e (b) revelou duas implicações, quais sejam: pode auxiliar docentes de cursos de mestrado em administração na reflexão de suas próprias práticas, e gestores de IES na formulação de políticas para capacitação de docentes e de políticas didático-pedagógicas.
Carreiras sem fronteiras na gestão pessoal da transição profissional: um estudo com ex-funcionários de uma instituição privatizada
Authors: Veloso Elza Fátima Rosa , Dutra Joel Souza
Published: September 2011

As atuais opções profissionais são diferentes das vislumbradas no planejamento original da carreira de certas pessoas, como, por exemplo, os ex-funcionários do Banespa, privatizado no ano 2000. A pesquisa apresentada neste artigo teve como objetivo identificar se e como as carreiras sem fronteiras se manifestam na gestão pessoal da transição profissional desses trabalhadores. O procedimento metodológico foi o quantitativo, aplicando-se um questionário fechado a uma amostra aleatória proporcional, estratificada em dois grupos: os que permaneceram trabalhando na instituição após a privatização, e os que foram desligados voluntariamente em 2001. A suposição, levantada na hipótese 3, de que as respostas desses dois grupos apresentariam diferenças, foi negada. Os resultados, que levaram à aceitação da hipótese 2, apontaram que a maneira como a pessoa gerencia sua carreira enquanto trabalha na empresa estável influencia a gestão pessoal da sua transição profissional, influenciando também a manifestação das carreiras sem fronteiras. Não foi possível estabelecer um padrão para essa manifestação durante a transição profissional; dessa forma, aceitou-se a hipótese 1. Foi possível concluir que as carreiras sem fronteiras podem não corresponder à realidade absoluta das carreiras atuais, mas certamente ajudam na compreensão dessa realidade.
Uma generalização empírica sobre comunicação boca a boca usando metanálise
Authors: Matos Celso Augusto de
Published: September 2011

Com base em uma revisão da literatura nacional e estrangeira sobre comunicação boca a boca, propõe-se um modelo teórico no qual o constructo boca a boca (BAB) é considerado como foco; a satisfação e a lealdade são os antecedentes; e a valência de BAB (positivo, neutro ou negativo) é a moderadora. Esse modelo teórico é testado usando dados obtidos de uma metanálise. Após revisar 664 estudos, um subconjunto de 90 é submetido às análises, por conter as relações de interesse e trazer as estatísticas essenciais para a metanálise: a correlação entre os constructos e/ou estatísticas de diferenças de grupos. O subconjunto analisado produziu 119 amostras independentes e 36.673 respondentes. Os resultados mostraram uma associação significativa da satisfação e da lealdade com BAB. Além disso, a valência de BAB apresentou um efeito moderador significativo. Esse efeito moderador é proposto por esse trabalho como a seguinte generalização empírica: considerando a satisfação e a lealdade como variáveis associadas ao boca a boca, é a satisfação que possui relação mais forte com o boca a boca positivo, enquanto a lealdade é a que possui relação mais forte com o boca a boca negativo. Essa generalização pode ser simplificada pela expressão SAT→BAB(+), LEA→BAB(-).
Trabalho imaterial bancário, lazer e a vivência de dilemas pessoais contemporâneos
Authors: Weber Letícia , Grisci Carmem Ligia Iochins
Published: September 2011

Este artigo busca compreender a interação do trabalho imaterial com o lazer nos modos de trabalhar e de viver de bancários inseridos em um Banco Múltiplo Privado; pondera-se também se tal interação se configura em dilemas pessoais contemporâneos. O estudo, de caráter exploratório, contou com a participação de 15 sujeitos que foram entrevistados em seus locais de trabalho. A análise de conteúdo se deu à luz do referencial teórico sobre trabalho imaterial bancário, lazer e dilemas pessoais contemporâneos, tendo como suporte autores como Bauman (2007), Castells (2000), Dumazedier (2008), Dejours (2008) e Gaulejac (2007). Os resultados indicam que o trabalho imaterial bancário interfere no lazer dos bancários; pode até mesmo impedi-lo, desencadeando vivências de dilemas pessoais, uma vez que constantemente suas escolhas relativas ao dever e ao lazer não encontram alternativas satisfatórias. Se optam pelo lazer, preservam as relações familiares, mas sofrem o desprezo dos colegas; se optam pelo trabalho, preservam as relações de coleguismo, mas sofrem as reclamações da família, por exemplo.
Estimando o prêmio de mercado brasileiro
Authors: Gonçalves Junior Walter , Rochman Ricardo Ratner , Eid Junior William , Chalela Luciana Ribeiro
Published: September 2011

Investimentos de risco pressupõem que, em média, os ganhos sejam superiores aos obtidos por ativos livres de risco, diferencial este tradicionalmente denominado prêmio de mercado; sua importância é indiscutível para investidores nas decisões quanto à exposição aos riscos da Bolsa, para gestores de empresa, ao selecionar projetos, ou ainda para órgãos governamentais na regulação de concessionárias e na supervisão dos fundos de pensão; tal aplicabilidade demanda, entretanto, valores confiáveis para uso nos modelos. No presente trabalho são analisadas estimativas segundo três abordagens distintas, compreendendo o período de janeiro de 1996 a dezembro de 2008: na histórica, os valores encontrados variaram de 5% a 7% para os índices IBrX e FGV-100; na prospectiva (que reflete prêmios esperados) obteve-se 3,35%; por fim, na indireta (ou por modelos de mercado), encontraram-se prêmios negativos, algo inesperado porém significativo.
Estratégia de crescimento no mercado brasileiro de cursos pré-vestibular: caso Sistema Elite de Ensino
Authors: Evangelista Oscar Camilo Silva , Santos Cristiane Pizzutti dos
Published: September 2011

O Sistema Elite de Ensino atua no mercado brasileiro de cursos pré-vestibular, com foco na preparação para os exames mais concorridos do país. Fundado em 1998 por quatro sócios, está presente em dez cidades pelo Brasil. Após um período de expansão desorganizada, onde o desenvolvimento individual das unidades foi privilegiado em detrimento da padronização e integração entre elas, a empresa teve o seu crescimento refreado por conta da falta de concordância entre os proprietários em relação aos caminhos que deveriam ser adotados para tal crescimento. O presente caso de ensino tem como objetivo colocar o aluno no papel de um dos sócios do Sistema Elite de Ensino, que precisa atingir um consenso com os demais proprietários para desenvolver a estratégia de expansão da organização para os próximos anos. Espera-se que o aluno pondere qual a direção mais apropriada para o desenvolvimento de uma empresa de serviços. Pode ser utilizado em aulas sobre marketing de serviços, estratégia de marketing ou empreendedorismo, em cursos de extensão ou pós-graduação lato sensu e stricto sensu.
Processamento fonológico e desempenho escolar nas séries iniciais do ensino fundamental
Authors: Tenório Sabrina Mª Pimentel da Cunha Pinto , Ávila Clara Regina Brandão de
Published: September 2011

OBJETIVO: caracterizar o desempenho escolar e o processamento fonológico de escolares da 1ª e 2ª séries, segundo o sexo e grau de escolaridade e investigar a existência de correlações entre essas variáveis. MÉTODO: participaram 88 escolares (48 meninos e 40 meninas) entre cinco e oito anos de idade, sem queixas relacionadas à fala ou à aprendizagem. Foram avaliados por meio do Teste de Desempenho Escolar (Stein,1994) e pelas provas de nomeação rápida, repetição de pseudopalavras e consciência fonológica, habilidades relacionadas ao processamento fonológico. A análise estatística se deu pelo teste de Mann-Withney U e pelo coeficiente de Spearman, com intervalo de confiança de 95%. RESULTADOS: a maioria dos escolares apresentou classificação de desempenho inferior nos subtestes do Teste de Desempenho Escolar, com maior média de acertos para leitura. Não houve diferença significante entre meninos e meninas. Os escolares da 2ª série mostraram melhor desempenho em escrita, leitura e aritmética, quando comparados aos alunos da 1ª série. Ao contrário dos desempenhos em leitura, escrita, aritmética e consciência fonológica, os desempenhos em acesso lexical e memória fonológica não diferenciaram as séries. Na 1ª série, encontraram-se correlações positivas entre o acesso ao léxico mental e a consciência fonológica, entre leitura e escrita e consciência fonológica, e entre aritmética e consciência fonológica. Na 2ª série, identificaram-se correlações positivas entre escrita, leitura e aritmética e com a consciência fonológica, acesso ao léxico com memória fonológica e consciência fonológica. CONCLUSÃO: os escolares da 2ª série apresentaram melhores escores de desempenho escolar e de consciência fonológica quando comparados aos alunos 1ª, apesar da maioria ter alcançado classificação inferior à esperada para a série, definida pelo Teste. Diferentes variáveis do processamento fonológico correlacionaram-se positivamente com o desempenho escolar.
Reabilitação das funções do olfato e do paladar em laringectomizados totais: revisão sistemática
Authors: Caldas Ada Salvetti Cavalcanti , Facundes Vera Lúcia Dutra , Silva Hilton Justino da
Published: September 2011

TEMA: na laringectomia total ocorre a transferência do fluxo aéreo nasal definitivamente ao traqueostoma, podendo provocar diminuição na percepção do olfato e do paladar. Recentemente tem sido desenvolvidos métodos de intervenção a fim de melhorar a performance olfativa e gustativa em laringectomizados, embora sejam escassos os estudos que abordam esse tema. OBJETIVO: rever de forma sistemática as evidências de como as técnicas envolvidas na reabilitação das funções do olfato e do paladar tem efeito em indivíduos laringectomizados totais. CONCLUSÃO: nesta revisão todos os estudos selecionados demonstraram eficácia na utilização de técnicas de reabilitação para a função do olfato em laringectomizados totais. Para o paladar não houve propostas para intervir diretamente nesta função.
Características do cuidado em saúde mental em um CAPS na perspectiva dos profissionais
Authors: Mielke Fernanda Barreto , Kantorski Luciane Prado , Olschowsky Agnes , Jardim Vanda Maria da Rosa
Published: September 2011

Neste estudo qualitativo, subprojeto da pesquisa "Avaliação dos CAPSs da região sul do Brasil", temos o objetivo de conhecer as características do cuidado em saúde mental oferecido por um centro de atenção psicossocial (CAPS) na perspectiva de seus profissionais. A coleta de dados foi realizada por meio de entrevistas individuais. Utilizou-se a análise temática, emergindo dos dados três temáticas. Neste artigo, destacamos a temática intitulada 'caracterização do cuidado em saúde mental prestado pelos profissionais do CAPS'. As características do cuidado em saúde mental advindas das entrevistas foram autonomia do usuário, que, juntamente com a questão da alta do serviço, deve ser mais desenvolvida; atendimento centrado especificamente na doença como herança do tratamento hospitalar; e preocupação da equipe com a implementação de práticas psicossociais inclusivas e cidadãs.
Imagens do pensamento em Gilles Deleuze: representação e criação
Authors: Mauricio Eduardo , Mangueira Mauricio
Published: September 2011

Um dos principais objetivos da filosofia de Gilles Deleuze foi restituir ao pensamento sua potência criadora, que se encontrava sufocada pela hegemonia da perspectiva representacional. Combatendo a ideia de que pensar é uma atividade voluntária, reflexiva e universal, o filósofo francês explicita, em Proust e os signos, de que modo o ato de pensar encontra-se relacionado a um procedimento inventivo. Efetuando uma completa modificação nos principais conceitos do modelo da representação, tais como os conceitos de signo, essência e verdade, Deleuze nos mostra que se o pensamento diz respeito a algo, é, sobretudo, à afirmação de um estilo criador.
A subjetividade fora da mente
Authors: Simões Alexandre , Gonçalves Gesianni Amaral , Corgozinho Batistina Maria de Sousa , Lopes Ana Mônica Henrique
Published: September 2011

O artigo contextualiza uma tradição que se apresenta de maneira recorrente nas práticas clínicas da psicologia e da saúde mental: o Mentalismo. O Mentalismo pressupõe uma concepção interiorizada do sujeito em prol de modelos instrumentais de clínica. A partir da crítica ao Mentalismo, os autores examinam outras possibilidades de se lidar não mais com o sujeito essencializado, porém, com os complexos processos de subjetivação. Esta é uma perspectiva clínica que recorrendo a Deleuze, Guattari e à Filosofia da Diferença oferece estratégias mais condizentes com a complexidade do mundo contemporâneo, introduzindo debates éticos, políticos e estéticos na dimensão psíquica.
Time to Deterioration in Quality of Life Score as a Modality of Longitudinal Analysis in Patients with Breast Cancer
Authors: Hamidou Zeinab , Dabakuyo Tienhan S. , Mercier Mariette , Fraisse Jean , Causeret Sylvain , Tixier Hervé , Padeano Marie-Martine , Loustalot Catherine , Cuisenier Jean , Sauzedde Jean-Marc , Smail Marc , Combier Jean-Philibert , Chevillote Patrick , Rosburger Christian , Arveux Patrick , Bonnetain Franck
Published: September 2011

Purpose.

This prospective multicenter study explored different definitions of time to deterioration (TTD) in quality of life (QoL) scores, according to different cutoffs of the minimal clinically important difference (MCID) as a modality for longitudinal QoL assessment in breast cancer patients.

Methods.

QoL was assessed using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire C30 and BR-23 before surgery, after surgery, and 6 and 12 months later. The global health score, arm symptoms score (BRAS), and breast symptoms score were analyzed. For a given baseline score, QoL was considered to have deteriorated if this score decreased by ≥5 points at any time point after baseline. Analyses were repeated using an MCID of 10 points and taking the score after surgery as the reference score (to explore the occurrence of response shift). TTD was calculated using the Kaplan–Meier method and Cox regression was used to identify independent factors associated with TTD.

Results.

Two hundred thirty-five patients underwent axillary lymph node dissection (ALND), 222 underwent sentinel lymph node biopsy (SLNB), and 61 underwent SLNB plus ALND. Patients who underwent SLNB had a significantly longer TTD for the BRAS dimension than those who underwent ALND. Cox multivariate analyses showed that treatment using SLNB and age >59 years were independently associated with longer TTD for the BRAS, whereas surgery elsewhere than at the Centre Georges François Leclerc was associated with a shorter TTD.

Conclusion.

Exploration of different definitions of TTD in QoL provides meaningful longitudinal QoL results for clinicians.
Molecular Modeling and Its Application to Developing Chemicals for Wettability Alteration to Gas-wetness
Authors: Zhou Minghui , Li Kewen
Published: September 2011

Many gas-condensate reservoirs experience a sharp drop in gas production owing to condensation near the wellbore as pressure drops lower than the dew point. It has been a challenge for a long time to reduce the dramatic decline in gas production caused by the low liquid return efficiency after fracturing or by the liquid blocking due to retrograde condensation as well bottom pressure decreases in low permeability gas-condensate reservoirs. To find a solution to this problem, researchers have reported that the wettability of rocks could be changed from strongly liquid-wetness to preferential gas- wetness in gas-liquid-rock systems and demonstrated that such wettability alteration could increase the gas production successfully in these cases. However, the core of this technology, the chemicals for wettability alteration are very expensive and may not be economically feasible to deploy in the field applications. It is essential to develop cheaper chemicals for wettability alteration to enhance gas production economically. In this study, an approach to calculating contact angle and then evaluating wettability was proposed using the data from molecular modeling. New chemicals were designed according to the contact angles in gas-water-quartz systems predicted using molecular modeling. Then these chemicals were synthesized and their properties were measured. The contact angles in the gas-water-quartz systems with and without the treatment of chemicals were calculated using molecular modeling and measured experimentally. The results from both molecular modeling and experimental measurements were compared and analyzed. According to experimental observations, the new chemicals were able to alter the wettability of quartz and sandstone core significantly.
Effect of Lithology on the Flow of Chelating Agents in Porous Media during Matrix Acid Treatments
Authors: Mahmoud M. A. , Nasr-El-Din H. A. , De Wolf C. A. , Alex A. K.
Published: September 2011

Chelating agents such as GLDA, EDTA, and HEDTA have been used to stimulate calcite reservoirs as alternatives to HCl. HCl based stimulation fluids are very corrosive at high temperatures and should be loaded with many additives to reduce corrosion problems. In addition, the application of HCl can lead to face dissolution at low flow rates. GLDA chelating agent was used to stimulate calcium carbonate cores up to temperature of 300°F and at low rates without any face dissolution problems. The dissolution of dolomite by chelating agents has not been thoroughly investigated. Preliminary experiments with EDTA at ambient temperature revealed no significant dolomite dissolution. The dissolution mechanism is probably inhibited by the low stability of the magnesium chelate at that temperature.

In this study, we will investigate the ability of GLDA (glutamic -N,N- diacetic acid) to stimulate dolomite cores as well as calcite cores. GLDA with different pH (1.7, 3 and 13) was used for this study. Dolomite and Indiana limestone cores with dimensions of 1.5 in. diameter, 6 and 20 in. length were used. The coreflood experiments were run at different flow rates and temperatures to determine the optimum rate at which GLDA solutions can create wormholes in both dolomite and calcite cores. Complete fluid analysis for the coreflood effluent was done to study the reaction of GLDA with both dolomite and calcite cores.

GLDA was very effective in stimulating both dolomite and calcite cores at different pH levels over a wide range of temperatures (180, 250 and 300°F). There was no well defined optimum injection rate at which the amount of GLDA needed to create wormholes was minimum, instead a broad range of injection rates was found for which the amount of GLDA needed to breakthrough the core was minimum. Also, GLDA effectively chelated magnesium and calcium from dolomite cores. GLDA was stable up to temperatures of 300°F and the concentration of GLDA after the treatment was the same as that before the treatment, further confirming the thermal stability of GLDA at this temperature.
Laboratory and Field Studies of Long-term Release Rates for a Solid Scale Inhibitor
Authors: Brown J. Mike , Shen Dong , Gupta D. V. , Taylor Grahame , Self Richard W.
Published: September 2011

Mineral scale build-up decreases permeability of the formation, reduces well productivity and shortens the lifetime of production equipment. Chemical scale inhibitors are commonly used in production wells to prevent scaling in the formation and/or in the production lines downhole and at the surface. An ideal scale inhibition treatment will last as long as possible and minimize the production interruption for treatment. In the art for introducing scale inhibitors into production wells, adding a solid scale inhibitor into the producing formation in conjunction with a hydraulic fracturing operation is often preferred to extend scale inhibition lifetime.

This study quantified release rates of a solid scale inhibitor for use in fracturing treatment. Tests were conducted under dynamic conditions with various loading rates as a percentage of sand proppant. Results show that this solid derivative of a phosphonate inhibitor has a sustained long-term release profile. Inhibitor release rate gradually increases with solid inhibitor loading. However, this effect slows when the loading exceeds 5% (wt/wt).

Based on the test results, a mathematical model was developed to describe the release rate profile and thereby predict the long-term behavior of inhibitor returns from initial solid inhibitor loading. Actual data collected from treated wells were compared to the mathematical model. The earliest wells treated with this type of product have achieved 5 years of production with continued effective residual chemical measured in the produced water. Other wells treated have achieved greater than 1 million barrels of produced water with continued effective residual chemical measured in the produced fluid. The data from this laboratory release study have verified that additional long-term protection can be achieved by increasing initial loading rates.
The Laboratory Evaluation and Optimization of Hydrogen Sulphide Scavengers Using Sulphur Specific Flame Photometric Gas Chromatography
Authors: Taylor Grahame N. , Matherly Ron
Published: September 2011

A laboratory method for the evaluation and screening of hydrogen sulphide scavengers is presented using a gas sampling technique coupled with sulphur specific gas chromatography analysis to detect hydrogen sulphide breakthrough. Data is presented for 1,3,5-Tris(2-hydroxyethyl)hexahydro-s-triazine and 1,3,5-Trimethyl-hexahydro-s-triazine together with the effect of carbon dioxide upon the performance of the former scavenger. This methodology was also used to compare simple aldehydes with triazine based scavengers.
An Example of Chemical Recycling in the Oil and Gas Industry - A By-product from Hydrogen Sulphide Scavenging is Identified, Isolated and Formulated into a Highly Effective Corrosion Inhibitor
Authors: Taylor Grahame N.
Published: September 2011

This paper describes the isolation and formulation of highly effective corrosion inhibitors from the waste product of hexahydrotriazine based hydrogen sulphide scavengers. Although it has been generally regarded that "spent scavengers are corrosion inhibitors" for some time, this paper uses this generally held belief as a starting point and greatly expands upon this observation. The active species has been identified by analytical methods, isolated from the spent fluid and formulated into highly effective corrosion inhibitors. This is believed to be a unique synergistic chemical recycling process. The application of one chemical product, in its actual operation, acts as a means to chemically synthesize a second chemical in a very highly pure state, such that it can be separated and formulated into a second chemical product, namely a corrosion inhibitor. Analytical data and structural confirmation of the active species are presented together with data to verify its corrosion inhibition properties and also the synergistic formulation of this intermediate to further improve its corrosion inhibition properties. It is believed that this work represents an example of chemical recycling rarely, if ever, seen in our industry.
Environmentally Acceptable Polymeric Corrosion Inhibitors
Authors: Hellberg Per-Erik
Published: September 2011

This paper will introduce newly developed polymeric corrosion inhibitors intended primarily for use within the oil- and gas production application area. Some of the products fulfill British and Norwegian environmental criteria for off-shore use, which are considered to be the most stringent in the world. In this paper the products are characterized with respect to e.g. static and dynamic surface tension as well as critical micelle concentration. Further, surface adsorption characteristics on different relevant surfaces using QCM-D (Quartz Chrystal Microbalance with Dissipation) are presented and correlated with the results of standard oilfield corrosion inhibition tests such as two-phase static bubble tests and RCE tests. In the paper possibly unique flow sequences with different oilfield-relevant liquids using the QCM-D equipment to assess the adsorbed layer persistance under various conditions are presented.

Additionally the polymeric surfactants in all aspects detailed above are compared with standard monomeric oilfield corrosion inhibitors having related chemistry. Finally, environmental test data of the new products according to North Sea regulations are discussed.
Challenges and Opportunities Heavy Oil Development Offshore UK
Authors: Berg Eirik A
Published: September 2011

This paper discusses the most important field development challenges of Mariner and Bressay with focus on subsurface related issues on Bressay. The fields have 11-14 o API oil. The reservoir viscosity is from 65 cp to 540 cp. No other offshore fields have yet been developed with 540 cp oil viscosity or more. Challenges include achieving high oil rate and recovery. Unconsolidated sand means limited availability of high quality exploration data and limitation to production well design. Lack of seismic resolution between the sands and shales limits the mapping potential in some of the reservoirs. Old well data means lack of high quality data. Significance of relative permeability and PVT uncertainties has been assessed and a reduced uncertainty span has been suggested by reinterpreting old data in combination with new laboratory experiments. Cuttings and log data is used primarly to establish permability distribution. Reservoir development strategy has been significantly revised compared to the previous Operator. The Mariner and Bressay field development sanction work is ongoing. This includes an updated flow assurance strategy using diluent to reduced challenges relegated to production and processing of heavy oil.
Improvements to Hydrophobically Modified Water-Soluble Polymer Technology to Extend the Range of Oilfield Applications
Authors: Eoff Larry
Published: September 2011

Hydrophobically modified water-soluble polymers have unique associative and adsorption properties that make them attractive for oilfield use. Previous publications have outlined the use or potential use of these materials for water reduction in producing wells, fluid diversion, leakoff control, brine viscosification, stimulation treatments (fracturing and acidizing), and enhanced oil recovery (EOR) applications. The commercial success of a hydrophobically modified polymer based on a C16 modified acrylate in such applications has been well documented. A brief summary of case histories for each of these operations is presented.

While this class of polymer has shown a wide variety of commercial uses to date, its full potential remains unrealized because of its low critical solution temperature (LCST) (<160°F). This is the temperature at which the polymer precipitates, especially in high-pH fluids, such as those used in borate-crosslinked fracturing gels. The LCST values vary inversely with the pH of the fluid containing the polymer. While this temperature-limitation problem can be partially mitigated by using pH-control agents, it was desired to develop systems that do not suffer from this limitation and allow for extension of the use of such polymers in a variety of wellbore-treatment fluids and well conditions. This paper describes laboratory results from a two-pronged approach to overcome this limitation—(1) synthesis of alternate polymers that would retain the performance characteristics of the original polymer without its limitations and (2) chemical alteration of the formulations containing the original polymer to eliminate the LCST/pH limitation. Laboratory-testing data will include LCST dependence on pH for different polymers, fluid compositions, as well as core-flow comparisons. Ultimately, a simple yet effective chemical solution that not only maintains the performance of the original polymer but also potentially expands the area of usefulness was found.
Permeability Change during CO2 injection in Carbonate Rock: A Coreflood Study
Authors: Mohamed I. M. , He J. , Nasr-El-Din H. A.
Published: September 2011

Carbon capture and storage (CCS) has been proposed to mitigate the accumulation of the CO2 in the atmosphere. Although CO2 is captured from large point source and stored in underground formations (depleted oil reservoir, water aquifer, and salt cavern) as a mitigation of global warming, CO2 has been injected for various purposes like in enhanced oil recovery (EOR), and enhanced coal bed methane (ECBM) recovery. Water alternating gas (WAG) technique is used to inject CO2 into underground formation either in sequestration or in EOR. Injected CO2 dissolves into the water, generating carbonic acid which dissolves carbonate rock.

The composition of the water is a critical factor that affects the rock dissolution and the formation permeability change during sequestration, especially while using sea water that contains sodium sulfate. This paper addresses the effect of brine salinity and salt type on the formation during sequestration.

A core flood study was conducted using limestone cores. The CO2 was injected under supercritical conditions. Core effluent samples were collected and concentrations of calcium and magnesium, and sodium were measured. Cores permeability was measured before and after the experiment.

The results showed that no change in permeability noted when NaCl brine was injected. Calcium chloride has the main effect in calcium dissolution and change in core permeability. Also, increasing the concentration of magnesium chloride caused more damage to the core. The experimental data was used to develop an empirical correlation to calculate the maximum calcium concentration in the core effluent, which gives good indications on various reactions that might occur inside the core.
An Assessment of Completion Efficiency Comparing Actual Production Results to NMR Predicted Rates in the Rocky and Ammunition Fields - Oklahoma
Authors: Brinska John , Smith Charles H , Bray Jim , Ramakrishna Sandeep , Menendez Eli
Published: September 2011

These two fields in Washita County, Oklahoma present extensive traditional log interpretation problems. The wells contain a variety of sandstone reservoirs, including Britt, Boatwright, Cunningham and Schneberger. Each provides unique log interpretation issues. A clear definition of log derived porosity is extremely difficult for these reservoirs in the best of circumstances. Permeability is also an issue. Well to well correlations are unreliable due to the variability within the formations. In many cases, the expectation for the performance of the well was subject to little science and much conjecture.

In order to arrive at effective porosity and an estimate of permeability, NMR logs were added to the traditional logging program. At the time of logging, the technique employed for analysis of this log relied heavily on work done in the area. Parameters for analysis of a specific reservoir in a specific area were held constant with raw measurements of the tool considered to make changes to the base model. The Bray-Smith permeability model was applied to present estimates of permeability utilizing only the data generated by the NMR device.

This paper attempts to compare the results of this new permeability measurement technique with the production actually observed from this field. We will compare and contrast the results of three methods of developing permeability from NMR measurements. These will all be compared to the actual results achieved in the wells in the Rocky and Ammunition fields in Western Oklahoma.
Experimental Study of Spreading and Wettability Effects by Surfactants in Condensate Reservoirs at Reservoir Conditions
Authors: Zheng Y. , Rao D. N.
Published: September 2011

Gas condensate reservoirs suffer a rapid decline in productivity as the flowing bottom-hole pressure falls below the dew point. This reduction is caused by condensate accumulation near the wellbore. This study aims to perform an experimental investigation into potential remedies through chemical treatments to modify the fluid-fluid spreading coefficient and wettability in condensate buildup regions to enhance condensate recovery and gas productivity.

In this study, experiments were conducted at reservoir conditions of 2264 psia and 210 °F by using representative condensate reservoir fluids. Spreading coefficients were determined through measurements of oil-water, water-gas and gas-oil interfacial tensions using the Drop Shape Analysis (DSA) and capillary rise techniques. Dynamic contact angles were measured using the Dual-Drop-Dual-Crystal (DDDC) technique to characterize reservoir wettability. An advancing angle of 153° obtained from the experiments indicated that this representative sandstone condensate reservoir had a strongly oil-wet nature at reservoir conditions.

In order to examine the capability of certain chemicals to alter spreading and wettability behavior at reservoir conditions, an anionic surfactant was screened for use in the experiments at the concentration levels of 500, 1500, and 3000 ppm. Although spreading coefficients were all positive for the gas-condensate-brine (with and without surfactants) systems, a decreasing trend was observed in the systems after the surfactant application. This indicates that condensate recovery is still enhanced from surfactants usage in this strongly oil-wet system. The low concentration 500 ppm of anionic surfactant was not found to change this sandstone reservoir wettability at reservoir conditions, however, the wettability alteration from strongly oil-wet to weakly oil-wet or intermediate-wet was observed as the surfactant concentrations increased to 1500 and 3000 ppm. This study thus demonstrates the potential for surfactant-induced wettability alteration and spreading coefficient reduction in resolving condensate blockage problems.
Use of the NMR and Resistivity Logs to Quantify Movable Hydrocarbon; Solution for the Tight and Low-Resistivity Carbonate Reservoirs
Authors: Mohammadlou M. H. , Langeland H. , Mørk M. B.
Published: September 2011

Until an accurate fluid saturation tool is designed, the lack of a solid link between the petrophysical properties of reservoir rock and fluid is a real problem. The reservoir water saturation models are normally based on the standard Archie model to calculate fluid volumes. However, in tight carbonate reservoirs with heterogeneous wettability this model may present unrealistic results for the fluid volume (e.g., water/oil/gas) estimates. An integrated model using resistivity and NMR logs is introduced to quantify the movability of hydrocarbons in the reservoir transition zone. Pay zones may be missed in low-resistivity reservoirs (i.e., transition zones) due to the high water volume estimated from conventional logs.

New synthetic resistivity logs are made in both the invaded and non-invaded zones based on assumptions made on the basis of pore and fluid interaction in the NMR log T2 distribution. The differences between the original and synthetic resistivity logs in connection with other log data are dominant signatures of the fluid volumes and movability in the formation. The new approach is developed on basis of exploration well data from a complex and heterogeneous carbonate reservoir in the Norwegian Barents Sea. The estimated fluid movability results are in agreement with the wireline formation tester (WFT) measurements of the well.

This model, in addition to the transition zone, can also be applied for hydrocarbon bearing intervals which contain connate water. This approach shows that the reservoir wettability signature can also be identified by comparing the measured and constructed resistivity logs.
Practical Method for Measurement of Injection-gas Throughput of Each Gas-Lift Valve before Well Installation
Authors: Shahri Mehdi A. , Winkler Herald W.
Published: September 2011

The tester set initial opening pressure of a gas-lift valve (GLV) and port size are no indication of its injection-gas passage at a given injection-gas pressure for unloading and/or gas lifting a well. The initial test rack opening pressure (Ptro) of a GLV creates an opening force that slightly exceeds the valve’s closing force. The importance of the required injection-gas throughput performance of a GLV for unloading and gas lifting a well increases for very high daily liquid production rate wells and for wells that the workovers are very costly.

A test procedure that allows individual injection-gas throughput rate testing of every GLV and check valve prior to being installed in a well is described in this paper. The method includes GLVs with cross-over seats that prevent stem travel probe test measurements. The test requires very little gas volume and is based on a rapid pressure decline (blow-down).

Recent computer electronics as National Instruments LabVIEW software and 4 channel data acquisition instrument control hardware can record up to 12,500 pressure readings per second per channel. Test procedures are now possible to dynamically test the gas throughput performance of a GLV in a fraction of a second.

GLV replacement can be very costly – even by wireline in wells with subsea wellheads. After setting the Ptro and aging (stabilizing) this set opening pressure, the dynamic blow-down test can be performed on each GLV with check valve. If the GLV passes this test, the valve will have the injection-gas throughput required to unload and/or gas lift the well. Every supplier of gas-lift valves should offer this testing option to the producer.
Environmentally-acceptable Replacement of 2-Butoxyethanol: A High Performance Alternative for Fracturing Applications
Authors: Wylde Jonathan J. , O’Neil Bill
Published: September 2011

This paper concerns the development and implementation of a replacement chemistry for 2-butoxyethanol used in fracturing. The new product was synthesized to provide mutual solvency, wettability modification and clay swelling inhibition.

Recently, 2-butoxyethanol has come under scrutiny in North America (e.g. prompting Environment and Health Canada to add it to Schedule 1 of the Canadian Environmental Protection Act). Precautions need to be taken when working with 2-butoxyethanol due to toxicity concerns. Exposure to high levels has led to reported nose and eye irritation, headaches and vomiting.

Introduction of an alternate product has had a profound effect on the stimulation market in Canada. So far, 400,000 kg of the alternative product has replaced an estimated annual usage total of 3 to 4 million kg of 2- butoxyethanol. The new product also has had successful applications in the US, Latin America and Europe. There has been a significant environmental impact already realized through the use of this alternative product, and there is even greater unrealized potential. Additionally, as a non-regulated product for use and handling, the safety and material handling implications are greatly improved.

This paper details the chemistry of the replacement product, as well as environmental information to support the use of this product as a benign replacement for 2-butoxyethanol. An in-depth description of the laboratory testing used to identify, evaluate and select the appropriate treatment parameters also is given. The paper concludes with two case histories from northeast Alberta where this product was successfully used as part of a fracture treatment for long, horizontal, multi-zone shale gas plays. Furthermore comparisons are made using 2-butoxyethanol and no mutual solvent chemistry in a fracture treatment. This data shows the clear benefit of using this new chemistry.
Evaluation of Scale Inhibitors in Marcellus Waters Containing High Levels of Dissolved Iron
Authors: Shen Dong , Shcolnik David , Perkins Randall , Taylor Grahame , Brown J. Mike
Published: September 2011

The Marcellus waters of Pennsylvania and West Virginia commonly contain elevated levels of calcium, barium, and iron. Theoretical analyses of these waters indicate a propensity toward the formation of calcium carbonate, barium sulfate, strontium sulfate, and iron-related scales. The high level of dissolved iron commonly present in the water adversely affects the ability of the scale inhibitor to inhibit calcium carbonate scale. In this study, the inhibition performance of two new chemicals and some commercial products was evaluated under static and dynamic test conditions using synthetic Marcellus waters at varying iron concentrations. It was shown that both new chemicals were able to control calcium carbonate scale effectively in the presence of dissolved iron up to 200 ppm, whereas the performance of Polycarboxylic acid, Amino Tri(methylene phosphonic) acid and Carboxymethyl Inulin dropped sharply even in the presence of small amounts of Fe2+ (5 ppm). The inclusion of iron sequestering agents with these chemicals and the effect of iron upon calcium sulfate inhibition were also discussed in this paper.
Rheology and Stability of Non-Aqueous Micro Bubble Based Drilling Fluids
Authors: Shivhare S. , Kuru E.
Published: September 2011

The micro bubble (colloidal gas aphron) based drilling fluids have the unique pore blocking ability which helps reducing the drilling fluid invasion into the reservoir. The effects of time, temperature and pressure on the size and stability of the microbubbles need to be better understood in order to design a fluid that will have minimum filtration loss into high permeability zones.

A non-aqueous micro bubble based drilling fluid was formulated by using mineral oil (light paraffin oil composed mainly of alkanes and cyclic paraffins) as a base fluid, an oil soluble polymer (Styrene Ethylene/ Propylene Linear copolymer) and a non-ionic oil-soluble surfactant (Sorbitan Fatty Acid Ester). The effect of polymer and surfactant concentration on the aphronized drilling fluid characteristics was studied earlier to formulate an optimum drilling fluid composition.

In this study, effects of temperature and pressure on the rheology, filtration loss characteristics, and the stability of non- aqueous micro bubble based drilling fluids were investigated. PVT analysis was also conducted to develop an equation of state for non-aqueous micro bubble based drilling fluids.
Treatment of Mercaptans in Canadian Condensate
Authors: Arensdorf Joseph , Horaska Darin
Published: September 2011

Mercaptans occur naturally in sour crude and condensate and cause an unpleasant odor which is a nuisance to operators and surrounding communities. Regulatory authorities often require control of mercaptan odors.

A facility in Alberta stores condensate for use as a bitumen diluent. The condensate, which is stored in a large 110,000 barrel (bbl) (17,500 m3) holding tank, typically contains 150 to 400 ppm of total mercaptans (as sulfur). The odor resulting from these mercaptans can be detected off-site and is a nuisance to neighboring facilities.

Acrolein was selected as a sulfide scavenger to reduce the mercaptan level in the condensate. At the time of treatment, the condensate had a total mercaptan level of 224 ppm. Impellers in the tank were started to mix the condensate, and then 9,260 liters of acrolein were injected into the bottom of the tank while mixing. This amount of acrolein was calculated to achieve a 50% reduction in total mercaptan content.

The total mercaptan level in the condensate was actually reduced by 59%, from 224 ppm to 91 ppm (133 ppm scavenged). Acrolein scavenges all mercaptans, but preferentially reacts with the lighter mercaptans first. Ethyl and propyl mercaptan were reduced 88% and 53%, respectively. These light mercaptans were the most volatile and worst smelling mercaptans present, so their selective removal made the treatment efficient for odor reduction. Mercaptan odor was not detected at the site during the application even though the tanks were being stirred. After the application, mercaptan odors were significantly reduced and not detectable off-site.

The condensate was not adversely impacted by the treatment and was able to be transported by pipeline for use in processing bitumen. This application demonstrates that condensate containing problematic levels of mercaptans can be successfully treated using acrolein, and subsequently be safely transported and used as a bitumen diluent.
The Bottom-Line of Horizontal Well Production Decline in the Barnett Shale
Authors: Fan Li , Luo Fang , Lindsay Garrett , Thompson John , Robinson John
Published: September 2011

During the last five years, many shale gas plays have emerged, such as the Woodford, Haynesville, Fayetteville, Marcellus, Eagle Ford, etc. However, the Barnett Shale is the most mature of the currently producing gas shale plays in the US. Understanding the production mechanism and the production decline characteristics of the Barnett Shale will contribute to a better understanding of how newer shale plays will behave in a longer term. A production decline curve analysis (DCA) in the Barnett Shale is presented that incorporates public production data from over 8,700 horizontal wells. This analysis is performed by grouping wells based on years on production. Production data are normalized to zero-time, and regression history-matching is performed to estimate decline curve parameters. Long-term production is forecasted for 30 years. Production decline results strongly suggest hyperbolic decline. Particularly, the b value ranges from 1.3 to 1.6. First-year decline rate ranges from 56% to 74%. Thirty-year cumulative production ranges from 2.0 to 3.0 Bscf. The Best 12-month average gas rate and first 24-month cumulative gas production show a consistent trend and correlate very well with the predicted 30-year cumulative gas production. In spite of the advancement in completion and drilling practices, the gas recovery from newer wells is slightly worse than that of the older wells. This may be attributed to the poorer reservoir quality outside the core area or interference between wells due to down-spacing. Wells producing more than 5 years are often restimulated using hydraulic fracturing techniques. It is still too early to tell the impact of re-stimulation on ultimate gas recovery. However, the re-stimulated wells all show an increase in the short-term well productivity.