bluuebunny/crossref_metadata_2025 huggingface dataset:
Implantação e avaliação do método de multicateterização em ovinos
Authors: Kozloski Gilberto Vilmar , Lima Lisiane Dorneles de , Fiorentini Giovani , Härter Carla Joice , Raiser Alceu Gaspar , Mazzanti Alexandre
Published: December 2007

O objetivo deste estudo foi avaliar o método de multicateterização utilizado para estudar o metabolismo visceral em ruminantes. Quatro ovinos Ideal ´ Texel (peso vivo (PV) médio de 35 ± 2,5kg) foram implantados com cateteres permanentes nas veias mesentérica, porta e hepática. Sangue arterial foi acessado através de cateteres temporários implantados na carótida. A estimativa de fluxo de sangue portal e visceral foi feita com o uso do indicador paraminohipurato. Todos os cateteres mantiveram-se viáveis durante um período de no mínimo 45 dias. O fluxo de sangue visceral foi em média de 147l h-1 ou 4,2l h-1 kg-1 de PV, similar ao obtido em outros estudos com ovinos. Contudo, os dados de fluxo de sangue portal obtidos na maioria dos animais foram negativos e irreais, provavelmente devido a problemas relacionados à posição da ponta do cateter e à inadequada mistura do indicador no sangue portal. A medida do fluxo de metabólitos pelo sistema visceral utilizando animais multicateterizados pode constituir-se em uma ferramenta adicional útil para avaliar o valor nutricional dos alimentos e o metabolismo dos ruminantes. No entanto, os procedimentos de implantação dos cateteres, assim como o desenho e o protocolo experimental deste tipo de estudo, necessitam ser aperfeiçoados para aumentar a precisão e confiabilidade dos dados.
Investigating oral healthcare in the elderly using grounded theory
Authors: Mello Ana Lúcia Ferreira de , Erdmann Alacoque Lorenzini
Published: December 2007

The present article aimed to describe the foundations and adequacy of the Grounded Theory (GT) to the construction of the substantive theory on the phenomenon of oral health care of institutionalized elderly people. GT is a methodology that allows formulating orderly abstractions from the real life data. Through this referential is possible to elaborate a relevant and functional theory in order to understand the meaning of the elderly oral health care practices. GT allowed an extensive and rich production of information codes submitted to a process of Comparative Analysis. The immersion in the actors' subjective and private view, through interviews performed with the participants, allowed by the open and flexible character of the method, permitted the formulation of comprehensive analysis categories. The text demonstrates the validity of this alternative methodology to the scientific investigation of this complex phenomenon.
Escândalos e voto: as eleições presidenciais brasileiras de 2006
Authors: Rennó Lucio R.
Published: December 2007

O artigo mostra o impacto dos escândalos de corrupção sobre o voto do eleitor brasileiro na eleição presidencial de 2006. A pergunta central é se aqueles que consideraram a corrupção como principal problema deixaram de votar em Lula. O artigo avalia se e como os componentes retrospectivo, ideológico e partidário influem no voto bem como o impacto de fenômenos circunstanciais sobre ele. Os dados mostram que as percepções sobre a corrupção têm um peso maior na escolha de candidatos de partidos políticos vizinhos no espectro ideológico brasileiro e peso menor na escolha de candidatos de coalizões partidárias muito distantes neste espectro. Assim, na escolha de voto entre Lula e Alckmin, fatores como percepções sobre a economia, avaliação do governo Lula e certo componente partidário foram mais importantes e serviram de escudos para proteger Lula das acusações de corrupção no cenário da reeleição.
Propriedades reológicas de matérias-primas do Pólo Cerâmico de Santa Gertrudes provenientes da Formação Corumbataí (região de Rio Claro, SP)
Authors: Prado Ana Candida de Almeida , Del Roveri Carolina , Rocha Rogers Raphael , Zanardo Antenor , Moreno Maria Margarita Torres , Motta José Francisco Marciano , Menegazzo Ana Paula Margarido
Published: December 2007

Siltitos e argilitos da Formação Corumbataí são fontes de matéria-prima para a indústria cerâmica do Pólo de Santa Gertrudes. Litotipos provenientes de três minas (Tute, Granusso e Cruzeiro), localizadas na região de Rio Claro - SP, foram caracterizados quanto à curva de defloculação, conteúdo crítico de sólidos e tempo de envelhecimento (propriedades reológicas). Os litotipos representam desde a base até o topo da coluna estratigráfica dessa formação. Os resultados reológicos foram correlacionados com a composição mineralógica. Os representantes da base estratigráfica apresentaram boa defloculação, quase não necessitando adicionar defloculante, e, de forma geral, continham illita, feldspato, quartzo, hematita, clorita e interestraficados de clorita - argilomineral expansivo ou de illita - argilomineral expansivo. A maioria dos litotipos do topo defloculou, porém a quantidade ideal de defloculante foi superior aos adicionados às amostras da base. Os litotipos do topo continham carbonatos, além dos minerais supracitados. Uma amostra coletada no topo da mina Tute, com sinais evidentes de intemperismo, não defloculou. Os carbonatos presentes nos estratos superiores da formação e a alteração supérgena prejudicaram a defloculação. A quantidade máxima de sólidos na barbotina foi 66% em peso para os litotipos do topo da formação. Os litotipos testados apresentaram o fenômeno de envelhecimento da suspensão, porém as barbotinas, após 120 horas de seus preparos, ainda apresentavam viscosidades semelhantes àquelas usadas pela indústria de placas cerâmicas para revestimento.
O rejeito da mineração de basalto no nordeste do Estado do Rio Grande do Sul: diagnóstico do problema
Authors: Toscan Luciano , Kautzmann Rubens Müller , Sabedot Sydney
Published: December 2007

O objetivo do estudo foi conhecer o setor de extração de basalto, no município de Nova Prata, nordeste do Rio Grande do Sul, visando à qualificação dos procedimentos de gestão do setor. O universo estudado foi de 69 frentes de lavra (63% das existentes no município), Trabalhou-se com dados secundários, principalmente dados econômicos do setor, e dados primários, coletados em visitas às pedreiras. Confirmaram-se a expressiva parcela de microempresas familiares, e o grande impacto da atividade sobre o meio ambiente. As empresas mineradoras se classificam em três grupos: 69 % de pequeno porte; 20,5 % de médio porte e 10 % de grande porte. A produção é basicamente artesanal, empregando marretas, alavancas e talhadeiras. A produção de basalto no ano de 2004 foi de 60.000 m³ de produto acabado, como paralelepípedos, lajes, pedras para alicerces, entre outros. O levantamento dos rejeitos gerados nas atividades de mineração e acabamento estimou o volume anual de 52.400 m³, dos quais uma parte é coletada e transformada em brita e a outra permanece no local da pedreira, constituindo-se em passivo ambiental.
Caracterização tecnológica de resíduos de pedreiras de quartzito da região de Ouro Preto/MG
Authors: Lima Rosa Malena Fernandes , Silva Alexandro Fortes Simões da , Morais Rubhia Marianna Maciel de , Luz José Aurélio Medeiros da
Published: December 2007

Os quartzitos da serra do Taquaral em Ouro Preto-MG são extraídos para serem usados como placa de pisos e revestimentos. Pelo fato dE a rocha ser bastante intemperizada e, por essa razão, ser friável, são geradas, nas frentes de lavra e no beneficiamento, um grande volume de resíduos de ampla distribuição granulométrica. Por essa razão, esse trabalho teve, por objetivo, caracterizar as areias provenientes das frentes de lavra dessas pedreiras, que são, normalmente, depositadas nas encostas dos morros. Através dos estudos realizados com três amostras, verificou-se a viabilidade técnica de utilização das mesmas na construção civil, na fundição e, após purificação por separação magnética de alta intensidade e flotação dos minerais portadores dos elementos químicos deletérios (F2O3, Al2O3 e TiO2), vislumbra-se a possibilidade do uso dessas areias na indústria de vidro, o que é extremamente importante do ponto de vista social, econômico e ambiental.
A escolarização como projeto de civilização
Authors: Veiga Cynthia Greive
Published: December 2007

O artigo discute as contribuições de Michel Foucault e Norbert Elias para a historiografia da educação e para a história da escolarização. Especificamente, desenvolve, a partir de Norbert Elias, uma reflexão sobre o significado da monopolização do ensino elementar pelo Estado, no século XIX e nas sociedades ocidentais, enquanto estratégia fundamental para completar o projeto de civilização.
Capacitações tecnológicas de micro e pequenas empresas inseridas em redes tecnoprodutivas: o caso da eletrometal-mecânica em Joinville (SC)
Authors: Stallivieri Fabio , Campos Renato Ramos , Brito Jorge
Published: December 2007

Este trabalho observa as capacitações desenvolvidas por micro e pequenas empresas inseridas em redes tecnoprodutivas no arranjo produtivo eletrometal-mecânico da microrregião de Joinville, localizada no nordeste do Estado de Santa Catarina. O arranjo é caracterizado por uma densa estrutura produtiva local e pela grande heterogeneidade em relação ao tamanho das empresas, criando especializações e complementaridades por tamanho de estabelecimentos, dentro das diversas atividades do complexo. A análise da divisão do trabalho no arranjo, das especializações por tamanho de empresas, combinadas com as interações de mercado e as formas de subcontratação existentes na estrutura produtiva, possibilitará compreender as características de inserção das micro e pequenas empresas e as capacitações tecnológicas desenvolvidas por essas. O objetivo deste trabalho consiste em analisar, a partir do referencial teórico neo-shumpeteriano, as distintas capacitações tecnológicas desenvolvidas pelas micro e pequenas empresas, derivadas das diferentes formas de inserção na estrutura produtiva local. Para tanto, realizou-se uma pesquisa de campo, na qual foram entrevistadas 83 empresas de diversos portes. Observou-se que há tipos distintos de redes tecnoprodutivas no local, consideradas as formas de governança, as características produtivas e tecnológicas e a natureza dos processos de aprendizagem. Tais especificidades afetaram com diferente intensidade as possibilidades de capacitação tecnológica das empresas, que foram influenciadas também pelas suas relações com agentes externos ao arranjo.
Reestruturação produtiva, sindicatos e a flexibilização das relações de trabalho no Brasil
Authors: Costa Márcia da Silva
Published: December 2007

A experiência de adaptação competitiva brasileira ao mercado global deu início à reestruturação produtiva nas empresas. Trouxe, também, mudanças políticas e institucionais importantes, notadamente no que se refere ao mercado de trabalho. No presente texto, analiso o reflexo dessas mudanças no sistema de relações de trabalho do país. Busco reconstruir alguns condicionantes conjunturais e políticos que configuraram o posicionamento de seus principais atores no momento que precede àquelas mudanças e no atual contexto. Procuro indicar os desdobramentos daquelas transformações e as formas pelas quais sindicatos e empresas buscaram imprimir a sua perspectiva às mesmas. A partir desse referencial mais amplo, defendo o argumento de que a história das relações de trabalho no país foi construída sob condições de forte autoritarismo gerencial, e seu corolário, de debilidade das organizações sindicais. Em função disso, a tendência recente de flexibilização da legislação trabalhista (CLT) põe em risco a garantia de direitos, investe na possibilidade de seu rebaixamento.
Reproductive and population dynamics of the Bay whiff Citharichthys spilopterus Günther, 1862 (Pleuronectiformes: Paralichthyidae) in the Mamanguá Inlet, Rio de Janeiro, Brazil
Authors: Dias June Ferraz , Fiadi Carla Bertolucci , Silbiger Helcy Lylian Nogueira , Soares Lucy Satiko Hashimoto
Published: December 2007

Bay whiffs, Citharichthys spilopterus, were sampled in Mamanguá Inlet between March 1990 and March 1992 for evaluation of its reproductive dynamic. Bay whiffs presented a crescent gradient of abundance from the deepest to the shallowest stations. The mean total length by oceanographic station showed a clear tendency of a relationship between bigger sizes and higher depths. Males predominated along the studied period and on the smallest length groups. Higher values of alometric condition factor, gonadosomatic relationship and spawning stage of maturity indicated a higher degree of development of the gonads on March and November. Histological analysis showed spawning females in March and May 1990 in the stations closer to the mouth of the Inlet, and spawned females with old post-ovulatory follicles and high frequency of atresia at shallow stations, suggesting a migration to shallow and protected areas after spawning. Length of first gonadal maturation was 117 mm TL. We could conclude that C. spilopterus completes its life cycle within the Mamanguá Inlet, spawning during autumn (March to May) and possibly November.
Reproductive biology and development of sexually dimorphic structures in Aphyocharax anisitsi (Ostariophysi: Characidae)
Authors: Gonçalves Taís K. , Azevedo Marco A. , Malabarba Luiz R. , Fialho Clarice B.
Published: December 2007

The reproductive period of Aphyocharax anisitsi is described through the analysis of specimens collected monthly from April 2001 to March 2002 in the arroio do Salso (3022'27"S, 5502'06"W), Rosário do Sul, Rio Grande do Sul, Brazil. The monthly variation of the Gonadosomatic Index mean (GSI) of both males and females allowed the recognition of a defined seasonal reproductive period occurring between September and February, showing a positive correlation with temperature and day-length. Absolute fecundity was 344.8 oocytes and relative fecundity 0.68 oocytes per mg of body weight. Absolute fecundity was correlated with standard length and total body weight. It was possible to identify two categories of males through the analysis of the number of rays bearing hooks on the anal fin: those with few or no rays bearing hooks identified as young males hatched in the last reproductive season, and those with a higher number of anal-fin rays bearing hooks identified as males that had already reproduced once or that are maturing and participating in their first reproductive period. Once developed, anal-fin rays are maintained permanently. A positive correlation was found between the GSI of maturing and mature males and the number of anal-fin rays bearing hooks from August to January. All specimens bearing gill glands were mature or undergoing maturation, and the frequency of occurrence of the gill glands increased with a rise of GSI.
Offshore Production Facilities Design And Operation
Authors: Dacy J. R. , Holburn J. D.
Published: December 2007

This paper has been prepared to present the basic criteria used to ensure that an offshore production facility is as simple as possible to construct as well as being easy and safe to operate. The information presented here is applicable to any offshore design, however, it draws heavily on the authors' experiences in the British sector of the North Sea.

The design of North Sea platforms has been an active effort since the early 1970s. The experience gained to date has resulted in an increasingly greater degree of maximising the work performed onshore, thus minimising the the amount of offshore hook-up. Since these projects are complex and expensive, the success of performing the work on schedule and within budget is determined to a greater extent by the initial decisions taken at the conceptual stage of the project.

It should be noted that this paper is based on the authors' experience with the most complex type of platforms. The harsh environmental conditions with 30 metre high waves require platforms of usual complexity and strength, together with advanced design features to protect operating equipment. Many platforms in other parts of the world do not have to operate under these conditions and therefore tend to be simpler and less expensive installations.

While this paper is written primarily from the stand point of a Consultant/Contractor, the concerns of the owner/operator also are recognised.
The Use of Seismic Data in the Preparation of Wells Prognoses for Wildcat Wells
Authors: Daines Stephen R.
Published: December 2007

As exploration continues, the number of areas having hydrocarbon potential that have yet to be tapped by the drill are rapidly decreasing. Concomitant with the rising costs of subsurface evaluation, these areas have diminished to the most inaccessible, requiring the development of new practices and technology. Most of the unexplored areas are offshore, and require evaluation of the geology from increasing water depths. The successful drilling and completion of rank wildcat wells is thus becoming more difficult but also more important. Much of the success of a well is determined in the planning stage, and it is here that careful interpretation of seismic data can provide extremely useful information on potential drilling hazards such as shallow gas, geopressures, and fluctuating fracture pressures, all of which provide information for the casing and mud program.

A good well plan begins with the prospect generation by the geophysicists and geologists, and then involves further analysis for engineering hazards by joint interpretation. Good communication and cooperation at this point is essential. Based on the results of these interpretations, the well plan outline may be drawn up; the final operations being contingent upon the actual conditions encountered by the borehole.

The interpreters must be aware that the limitations of their initial plan are dependent upon the resolution of the available data. Flexibility in the well plan is thus a major requirement. It is to be expected that errors in the prognosis (due to errors in the seismic interpretation) will occur; therefore, extra margins are necessary in materials and emergency contingencies. Errors in the predicted depths of events, magnitudes of geopressures, and the occurrence of unexpected lithologies and phenomena must be within the capabilities of the operation.
The Prudhoe Bay Field: Simulation of a Complex Reservoir
Authors: Killough John Edwin , Pavlas Emmerick J. , Martin Charles , Doughty Roger K.
Published: December 2007

The Prudhoe Bay Field-Sadlerochit Reservoir presents many complexities which make reservoir simulation of this large oil accumulation difficult. The presence of major faults, the existence of large shale complexes, the enormous gas cap and associated coning of wells, and the heavy oil/tar mat could cause, even if each existed separately, major problems for a standard reservoir simulation model. This paper describes the techniques which were used by ARCO Oil and Gas to overcome these difficulties in modeling the Prudhoe Bay Field. Because of the large areal extent of the field, a unique grid in radial coordinates was used to reduce the number of grid cells to a manageable number. A new form of velocity-dependence was introduced into the gas/oil relative permeability and capillary pressure pseudo function relationships in order to more accurately model the gravity drainage and coning behavior in the field. A special pressure solution technique was developed to handle the extensive faults throughout the reservoir. Finally, an overall well and facility management routine was added to control the production/injection of the field and to give realism to the complex boundary conditions involved in these controls. Validation of the modeling techniques was carried out in small scale models, larger cross-sectional models, and finally through history matching of the field. These validations gave excellent results.
Consequences of Salting Well Cements
Authors: Beach Horace J.
Published: December 2007

Salted cement remains active long after hydrating and hardening. In contact with less salted water, it exchanges salt for water through the permeable membrane continuum of the cement. Osmotic stresses in time produce multiple fractures. In Arctic uses, water imbibed from alternately thawed and frozen formations can freeze, expand, and rubble salted cement. Salt misuses can be reduced by balancing ion concentrations in cement with those in formations. Salt addition or any other mechanism of freezing point depression is unnecessary. Inclusion in the slurry of a small amount of hydrophilic material prevents expansion damage from the freeze of free water in hydrated cement.
Perforating Techniques for Maximizing Well Productivity
Authors: Bell W. T.
Published: December 2007

A major objective of any well completion is to attain maximum production. The perforating equipment and techniques that are used have a very important bearing on determining the production that results.

According to the nature of the reservoir, wells may be completed either naturally, with sand-control measures, or with formation stimulation by acidization and/or hydraulic fracturing. The well-bore-to-formation pressure relationship at the time of perforating may be overbalanced, balanced, or underbalanced. Perforating guns may be retrievable, semi-expendable, or expendable; designed for operation through tubing or in open casing; run on wireline or on tubing.

This paper describes the various combinations of guns and techniques that are in common use, with the advantages and disadvantages of each. The four basic performance parameters, i.e., shot density, perforation diameter, penetration depth, and gun phasing, are ranked in order of relative importance for natural, sand-control, and stimulated completions. Where justified, the author makes recommendations and draws conclusions.
Massive Hydraulic Fracture Design for the East Texas Cotton Valley Sands
Authors: Schlottman Bernard W. , Miller William K. , Lueders R. Kent
Published: December 2007

Since Amoco stimulated its first well in the East Texas Cotton Valley Sands much has been learned about its geology and reservoir properties as well as what type and size stimulations are optimum for the varying geologic and reservoir conditions. Similarly, substantial advances have been made in recent years on how to economically achieve the desired fracture lengths and conductivity. The major geologic and reservoir parameters which affect massive hydraulic fracture (MHF) designs are the presence of marine vs. non marine sands, the existence of natural fractures, and reservoir permeability differences.

The major items which must be established in fracture designs are polymer loading, sand scheduling, pump rate scheduling, and fluid loss control. In addition to these items, quality control and equipment layout must be carefully considered for optimum results. Rather than low pump rates, low polymer concentration gels are being used in MHF stimulations to control viscosity and, therefore, downhole treating pressure and fracture height. Pump rate was determined to have marginal effects on downhole treating pressure. High sand concentrations are needed to enhance fracture conductivity along with certain fluid loss additives to control fluid leak-off. The results have been more efficient MHF stimulations and increased gas recovery per well.
A Forecast Of Domestic Petroleum Demands For The Next Two Decades
Authors: Halbouty Michel T.
Published: December 2007

Publication Rights Reserved

This paper is to be presented at the California Regional Meeting in Los Angeles, Calif., Nov. 5–6, 1964, and is considered the property of the Society of Petroleum Engineers. Permission to publish is hereby restricted to an abstract of not more than 300 words, with no illustrations, unless the paper is specifically released to the press by the Editor of the JOURNAL OF PETROLEUM TECHNOLOGY or SOCIETY OF PETROLEUM ENGINEERS JOURNAL is granted on request, providing proper credit is given that publication and the original presentation of the paper.

Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and considered for publication in one of the two SPE magazines with the paper.

It is always a genuine pleasure for a Texan to visit in California. This is probably the only state we can visit and feel perfectly at ease with things that are bigger and better than they are at home.

Any where a Texan goes outside of California, those who listen to him think he is lying or bragging or exaggerating.

In California, no matter what we say, the natives seem to sympathize with our real modesty and our lack of imagination.

My assignment here today is to make "A Forecast of Domestic Petroleum Demands for the Next Two Decades". In order to do this, I certainly will have to forego any of my modesty and use all of my imagination.

Forecasting demand is, to say the least, an unusual role for an oil finder and explorer. I certainly cannot qualify as a petroleum economist.

With the exception of very short-term forecasts, no one has ever made accurate predictions of domestic petroleum demands in the past. Therefore, it is appropriate to assume that this forecast will not be any more accurate than those made in the past.

In recent years, long-term supply and demand forecasts have broken out like a rash. The fact is that almost any figure one desires is available. The difference in them, if analyzed closely, lies in the specific interest of the experts and their companies or institutions at the particular time the forecasts are made.

Of course, all such long-term forecasts are quite safe because, by the time the end of the period has been reached, people have either forgotten the figures, the forecaster has retired, died, gone broke, or become such a big man in the industry that no one dare recall the error he made 20 years earlier.

There are too many hidden and unknown factors which control forecasts. Who knows what indicators are lurking in the darkness? What kind of government will we have in the future? To what extent will other energy sources move in on conventional energy sources? And about population, is it possible that the trend in population will change? War or disease, or even new pills could change the whole picture in population forecasts.
Gas Resources in Low Permeability Formations and The Effect of Price and Technology
Authors: Baker Ovid
Published: December 2007

I will report on a recent estimate of a 40% increase in our natural gas resources. This gas is in low permeability or tight reservoirs. It has been too expensive to produce in the past. New higher prices for gas make this resource important. Massive fracturing technology allows us to produce it.

I will tell you why unconventional gas is a good energy resource at today's prices. We have measured how the resource has expanded as price has increased and as technology improves. A new major gas province will be developed in the Rocky Mountains. The development of this gas is a profitable business venture now. In the future, today's unconventional gas will become the major gas supply for the United States.

This estimate was made by the National Petroleum Council. The National Petroleum Council is an Advisory Council to the U.S. Government created by Congress about 40 years ago.
The Development and Operation of the Forties Flare System
Authors: Webber N. J. W. , Moir E. R.
Published: December 2007

The U.K. North Sea Forties Oilfield has been on production for six years. It was recognised in the design state of the four integrated production, drilling and accommodation platforms that the safe and efficient combustion of residual gas, remaining after the extraction of NGL components, was an important design parameter.

The specification of the Forties flare system was based on a requirement for low noise, low radiation, high combustion efficiency, and robustness for service in a hostile environment.

The resulting flare system has given safe and efficient operation for six years, and provided a test bed for extending the frontiers of flare design and materials science.

This paper details the development of the Forties flare system from its inception to the current state of the art which has generated one new type of flare, and a means of quickly extinguishing oilfield flares so improving the safety of offshore oil production platforms.
Operational Experience with Continuous Density Measurement of Crude Oil
Authors: Smith J. H. O.
Published: December 2007

Fields producing crude oil into the Brent System pipeline are required to measure and account for production in units of mass, whereas traditionally volumetric units are usually preferred. The measurement of mass is currently done indirectly, by continuously multiplying volume and density measured at line pressure and temperature: the density being measured by continuous on-line transducers of the vibrating element type.

Although the vibrating element density transducer is capable of very high orders of accuracy and has been widely used for clean hydrocarbon liquids and gases, its use for fiscal or custody transfer measurements on crude oil to date has been limited.

In this paper the experience gained since the beginning of 1980 with a twin density transducer system on the Thistle ‘A’ platform is described in order that operators intending to install similar systems may benefit from BNOC's experience.
Water Control for Enhanced Oil Recovery
Authors: Cole R. Clay , Mody Bharat , Pace Jim
Published: December 2007

Gains in recovery efficiency in West Texas oil and gas fields have been realized as a result of applying four different chemical processes, either singly or in combination. Each of the four chemical processes reviewed has been tailored to meet certain specific reservoir requirements. For example, complete plugging of high flow capacity channels can often be accomplished. If desired, the high water production portion of a producing zone can be sealed by injection of gel-forming chemicals into the matrix. Both floodwater diversion and water-oil mobility ratio improvement can be attained by in situ polymerization of a unique one-stage polymer bank in the reservoir. In producing wells, the water-oil production ratio often can be favourably changed by treating certain formulations with a nonplugging polymer which tends to restrict water flow but not oil.

One feature which each of the four processes has in common is the ability to invade deeply into matrix which may produce long lasting results.

A description of each process is presented along with various placement techniques which have been used to obtain optimum results. Data from fields which have benefited from these treatments are presented. The paper describes what may be expected with each of these proven processes based on field results.
New Teshniques of Pipeline Inspection
Authors: Herve J. L. , Ling M. T. S. , Undeli J.
Published: December 2007

The Frigg Field Transportation System was commissioned in 1977. Since starting production, Total Oil Marine has initiated and maintained an in service inspection programme designed to identify any condition of the line which may lead to failure of the line either in the short or long term. Until 1980, the main problems on the pipeline were identified as short term stability problems. We believe that our current inspection programme is adequate to identify rapidly any area of concern. In 1981 our main effort is to determine the best methods for identifying longer term problems such as internal and external corrosion. Our current programme therefore now has three main aspects. The external inspection, performed routinely over the past four years, cathodic protection inspection tested in 1980, and an internal pigging programme which was initiated in 1978.

The full inspection programme will be the subject of this paper.
"Offshore Cranes" - A Case History
Authors: Barber J. C. , Wheeler M. , Adams A.
Published: December 2007

Prior to July 1978 several pedestal crane accidents occurred which resulted in considerable investigation by the Department of Energy. The outcome of the investigation resulted in legislative changes in crane operation, the most stringent being the requirement for inspection of the slewing ring bearings within a fixed period of time and thereafter at three yearly intervals.

Total Oil Marine (TOM), as a result of this legislation, commenced various studies to investigate the safest and most economical methods of completing the required inspection.

These studies confirmed that for TOM the best method would be to lift the cranes from the pedestals to provide maximum flexibility for undertaking all work envisaged. The lifting would be done, using a derrick crane for which the primary installation already existed on the north deck of the platform (MCP-01).
Waterflooding of Channel Sandstone Reservoirs
Authors: Yinan Qiu , Ziqi Chen , Shice Xu
Published: December 2007

Channel sandstones occupy a particularly important place among the sandstone reservoirs deposited in lake basin. According to statistics of fourteen main oilfields in China, the oil reserves in channel sandstones are more than half of total ones. Within a depositional system the channel sand stones are always deposited in a intermediate position and they have moderate grain size and sorting to become main reservoirs with highest permeability. The inner sequence of grain size of channel sandbodies is characterized by normal rhythm, which leads to serious in-layer heterogeneity, less conformance factor in thickness and rapid rising of water cut. Channel sandbodies exhibit significant directional permeability. Injected water rapidly tongue along the ancient channels and preferentially flow toward the down stream direction. Various channel sandstones are different in-layer heterogeneity, and so in production performance.
Application of Water-Base Mud in Deep Well Drilling
Authors: Yingan Li , Fayuan Qian , Pingya Lo
Published: December 2007

This paper deals with the major problems in the application of high-temperature resistant muds for deep well drilling, based on laboratory research and the practice in the drilling operation of 6000-7000m wells in Sichuan Province, China. Major problems, such as the stability of the mud, property adjustment and control of the mud under high temperature and pressure, and effect of PH on the properties of the mud system etc., and the way to solve these problems. Prevention of drill pipe stuck in deep well drilling using weighted mud, and prevention of H2S contamination on the mud system are also discussed. Mechanism of high-temperature effects on mud system are investigated preliminary. Laboratory work and field practice about the application of SMC, SWT and SMP to establish high-temperature and high salt content water base mud systems are presented.
Casson Rheological Model In Drilling Fluid Mechanics
Authors: Wang Zhongying , Tang Songran
Published: December 2007

The Casson rheological model gives a better description of the rheological characteristics of drilling fluids than the Bingham and power law models. In this paper, a method for experimental verification is given, relevant test results are reported, flow profiles in pipe and annulus are analysed and several rheological formula concerning pressure drop, thinning index are derived.

Introduction

Drilling muds are fluids with complicated constitutions. Both the Bingham and power law models have been widely used in the research for the description of the shear stress vs. shear rate relationship in drilling fluids. As it is well known, the Bingham model is good enough in medium and high rate ranges.
Gravel Transport in Deviated Wellbores
Authors: Hodge Richard M.
Published: December 2007

A computer program has been developed to predict gravel placement effectiveness for a specific gravel-pack design. This program was developed as the direct result of recent studies using a large-scale, transparent, deviated wellbore model.

Earlier studies have addressed the problems associated with gravel packing deviated wellbores. Each of these studies has utilized wellbore models and circulatory techniques to illustrate the placement of gravel packs. Each also proposed various solutions to maximize the packing efficiency. A mathematical model was reported in these earlier studies which related wellbore condition and fluid properties to gravel placement effectiveness for a specific gravel-pack design. This most recent work was conducted in order to determine the accuracy of that math model prediction.

The accuracy of the computer predictions was evaluated by the use of a series of test gravel packs performed with the wellbore model. Throughout the testing, fluid density, fluid viscosity, particle size, particle density and concentration, percentage of flow loss, and casing I.D. were held constant. The pump rate, screen and tailpipe size, and angle of deviation were varied.

In each test predicted to produce a complete pack, 95 to 100% of the casing volume throughout the length of the screen was packed properly.
Effect of Flow Rate and Rheology on Shear Strength of Migrating Formation Fines Due to Flow of Pseudoplastic Fluids
Authors: SenGupta Sujit Kumar , Hayatdavoudi A. , Tiab J. O. , Kalra Satish Kumar , LeBlanc James L. , Schluntz E. K.
Published: December 2007

Recent investigations have established the fact that authigenic clays may be dislodged during the enhanced oil recovery operations. However no mechanical stabilization of these clays along with chemical treatments has been fully used or investigated. The mechanical unstability of the clays is due to stress variation at the pore surfaces of the reservoir rock during the flow of pseudoplastic fluid such as polymer, etc. An equation has been derived which shows the relationship between the stress developed and the radial distance from the well bore at constant injection pressure.

The analysis of this equation shows that the stress is maximum near the well bore and decreases rapidly with distance. Graphs have been plotted to show further the effect of flow rate and power law coefficient on the stress.
Laboratory Evaluation of Sodium Hydroxide and Sodium Orthosilicate for Tertiary Oil Recovery in an Alberta Reservoir
Authors: Novosad Zdenka , McCaffery Frank G.
Published: December 2007

Laboratory evaluations of sodium hydroxide and sodium orthosilicate as improved oil recovery agents have been made for the Wainwright reservoir of Alberta. This reservoir contains acidic oil and has undergone extensive waterflooding. Both the in-place brine and the brine presently being injected into the Wainwright reservoir are very hard, suggesting that the injection of the two alkaline agents as slugs in the tertiary mode might result in different oil recoveries.

Preliminary phases of the study involved evaluation of interfacial tension (IFT) between Wainwright oil and solutions of both alkaline agents at various concentration levels as a function of salinity and hardness. Included were tests of chemical reactivity of hard Wainwright waters with the two alkaline agents. With soft Water, the measured IFT values for crude oil/alkaline solutions did not vary widely, and were generally less than or equal to 0.5 mN/m. Tests with hard water confirmed the superior ability of sodium orthosilicate to remove free hardness ions from solution.

The relative oil recovery efficiencies of 50% PV slugs of the two alkaline agents at a 1.0 wt% concentration were studied in six Berea core displacement tests. The effects of the addition of salt to the slugs and of applying soft water pre- and post-flushes were also evaluated. Sodium orthosilicate performed better than NaOH in the core subjected to soft water pre- and post-flushes when no NaCl was added to the alkaline slug. The improvement in oil recovery over waterflooding amounted to 15% OOIP. Oil recoveries were very similar for both agents when no soft water preflush was conducted, or when 1% NaCl was added to the alkaline and preflush slugs. Chemical losses evaluated in the core floods were found to be similar for both agents. The oil recovery and pressure drop data are reviewed and discussed in terms of the alkaline flooding mechanisms that appear to prevail.
California Offshore Platform Development
Authors: Visser Robert C.
Published: December 2007

This paper presents a historical overview of platform design and construction offshore California. Twenty-two platforms and seven islands have been installed since the first island was installed offshore Seal Beach in 1948. Seismic design requirements, steeply sloping ocean bottoms, limited availability of heavy derrick barge equipment and unusual producing requirements resulted in a number of innovative platform designs.

The first platform was installed offshore California in 1958. This structure, platform Hazel, was also the world's first gravity platform. Platform Hilda was the first tilt-up structure. Platform Hondo, in 850 feet of water, was fabricated in two sections and these were joined underwater after they were launched. Platform Emmy is one of the few platforms that were equipped with pumping units for artificial lift. The paper describes the design considerations involved with these platforms as well as the fabrication and installation methods employed.
Obtaining Quality Primary Cement Jobs in the Williston Basin
Authors: Ford Randle E. , Turcich Thomas A. , Pierson Ronald A. , Ramsey Leland K. , Divan Daniel J.
Published: December 2007

A compilation of literature dealing with drilling and completing through salt formations is examined and summarized. This literature is adapted to the special conditions present in the Williston Basin, especially in the Madison Group.

Discussion includes drilling in-gauge hole through the Charles and the Spearfish and getting adequate mud removal throughout the hole. Mechanical means of insuring cement bond to the pipe and to the formation are discussed as is the failure mode of cement in salt. A cement and casing design is proposed which keep the hydrostatic head on the Mission Canyon within tolerable limits while still providing for a strong cement.

The suggestion is made that a major contributor to early casing failure in salt formations is pipe set in compression loading. This hypothesis is discussed at length. A method for ensuring tension loading through the Charles and Spearfish is presented.
Transient Pressure Analysis of Hydraulically Fractured Wells in the Western Tight Sands
Authors: Ahmed Usman
Published: December 2007

Currently there are five basic techniques which can be used to analyze transient pressure data from hydraulically fractured wells. They are: modified pseudo-radial flow (semi-log analysis), formation linear flow (square-root time analysis), bilinear flow (fourth-root time analysis), type curve analysis, and reservoir simulation history matching analysis. These techniques are applied to evaluate the following parameters: formation matrix permeability, created fracture half length and fracture conductivity. Each technique has its advantages and disadvantages in estimating the above-mentioned parameters. Examples of transient pressure analysis for hydraulically fractured wells in the Western Tight Sands area have been used to demonstrate how the different techniques can provide a range of values for the above parameters. Specific techniques, however, can provide accurate results of some parameters. A representative example shows the matrix permeability calculations to range between 0.02 and 0.051 rnd as compared to the design parameter of 0.025 md. The fracture half length and conductivity estimates varied between 242-1425 ft and 56-253 md-ft compared to the design parameter of 500 ft and 200 md-ft, respectively.
Higher Sand Concentrations in East Texas
Authors: Watkins Hunter
Published: December 2007

As more gas wells have been completed in East Texas on 160 acre spacing, fracturing down casing has become more prevalent as the best way to stimulate these wells. Field trends have been toward higher sand concentrations. Most wells were fractured earlier through 2 7/8″ tubing with maximum concentrations of 3 lbs./gal. 20-40 Mesh Sand. However, as wells were produced, it became evident that longer fractures and higher flow capacities were needed. The casing fracturing technique permitted higher pumping rates which allowed higher sand concentrations to be placed. These began to be placed at 4 lbs. and 5 lbs./gal. and have now successfully been placed at concentrations in the 7 lbs. to 10 lbs./gal. range. Recently several jobs have been placed at 15 lbs./gal.

These higher sand concentrations as compared to a lower sand concentration in an equal predicted propped fracture length seem to be giving improved clean-up of fracture fluids and longer stabilized flow rates. This improved clean-up is probably due to the higher fracture flow capacity to a multi-phase fluid which is present in the fractures immediately after fracturing. The higher fracture flow capacity also would be maintained even with fines and residue from treatment fluids thus yielding the better stabilized flow rates.
Measurement of Salinity Effects on Tight Gas Sands With a Computer Controlled Permeameter
Authors: Walls Joel D.
Published: December 2007

A completely computer controlled pulse-decay permeameter has been designed and constructed. This system can rapidly and accurately measure gas permeability on five samples simultaneously. The samples can be partially saturated with brine or oil and can be placed under confining pressure up to 100 MPa (15,000 psi) and pore pressure to 70 MPa (10,000 psi). The range of permeabilities measurable is 10−8 μm2 (0.00001 md) to 10−3 μm2 (1 md).

To determine the effect of different brine mixtures on tight gas sand permeability, we saturated five adjacently cut Spirit River sandstones with five different fluids; distilled water, 5 NaCl, 10% NaCl, 1% KC1 and 5% KC1. The samples were dried to 66% saturation and gas permeability was measured under in situ pore pressure and confining pressure. This process was repeated, with appropriate equilibration time, for 55, 44, 33 and 22% saturation. The gas permeability vs. saturation curves are very similar, indicating that the samples are not sensitive to the type of fluid in the pores. This can be important in selecting fluid compositions for fracturing procedures. Scanning electron microscope photos of the samples made before and after saturation show no change in the structure of the clays which were primarily chlorite and illite.
Secondary Gas Recovery From a Watered-Out Reservoir
Authors: Boyd W. E. , Christian L. D. , Danielsen C. L.
Published: December 2007

A field test of the depressuring process used to remobilize and produce trapped gas from a watered-out reservoir is described. Actual performance is compared with predictions at two different points in time showing the modifications to the reservoir-aquifer simulation model that were required to obtain pressure matches. Increased water production rates, justified by the improved simulation model, led to the production of secondary recovery gas and, in turn, to the conclusion that the depressuring process is working.