bluuebunny/crossref_metadata_2025 huggingface dataset:
Relação entre perfil psicomotor e estilo de vida de crianças de escolas do município de João Pessoa, PB
Authors: Lucena Neide Maria Gomes de , Lucena Larissa Coutinho de , Aragão Paulo Ortiz Rocha de , Melo Luana Gadê Bandeira de , Rocha Thiago do Valle , Andrade Suellen Marinho
Published: April 2012

O objetivo do estudo foi comparar o grau de desenvolvimento psicomotor e o estilo de vida de crianças matriculadas nas redes pública e privada de ensino do município de João Pessoa, PB. O estilo de vida foi estimado pelo desempenho de atividades escolares e não-escolares. Participaram do estudo 74 crianças de 9 a 12 anos (10,5±1,2 anos), 38 meninas e 36 meninos. Para avaliação, foi aplicada a bateria de testes psicomotores de Picq e Vayer e um formulário com questões sobre atividades desempenhadas na escola e fora dela. Os dados revelam que, das 74 crianças avaliadas, 63 (85%) apresentavam distúrbios no desenvolvimento psicomotor, com maior incidência nas escolas da rede pública. Dentre as atividades escolares, 35% das crianças com distúrbio psicomotor indicaram não fazer atividade alguma no recreio; das que apresentaram desenvolvimento típico, nenhuma disse não fazer atividade alguma e 36% indicaram fazer esporte (contra 5% daquelas com distúrbio); quanto às atividades não-escolares, televisão, jogos eletrônicos e internet foram apontadas como preferidas por 44,3% das crianças com distúrbio, e por nenhuma com desenvolvimento típico. A preferência das crianças que apresentaram distúrbio por atividades mais estáticas sugere associação entre estilo de vida e perfil psicomotor.
Ergoespirometria em indivíduos com escoliose idiopática
Authors: Trevisan Maria Elaine , Portela Luiz Osório Cruz , Moraes Eliane Zenir Correia de
Published: April 2012

Escoliose idiopática é uma disfunção na coluna vertebral que tende a diminuir os diâmetros, a flexibilidade e a excursão da caixa torácica, com possíveis efeitos deletérios na função pulmonar. O objetivo deste estudo foi verificar se há relação entre o grau de curvatura escoliótica e a função pulmonar e capacidade de exercício em indivíduos com escoliose idiopática de grau leve e moderado. Dezessete indivíduos com escoliose idiopática leve e moderada e 19 controles foram submetidos a teste pulmonar em repouso e exercício em esteira. As médias das variáveis pulmonares em repouso encontraram-se dentro da normalidade nos dois grupos; as variáveis de exercício consumo de oxigênio de pico (p=0,81), tempo de exercício (p=0,68), freqüência cardíaca (p=0,39), ventilação minuto (p=0,82), produção de dióxido de carbono (p=0,95), quociente respiratório (p=0,09), equivalente ventilatório para o oxigênio (p=0,90), lactato sangüíneo (p=0,98) não mostraram diferença estatisticamente significante entre os grupos. Não foi possível estabelecer relação de causa e efeito entre o grau de escoliose, função pulmonar e capacidade aeróbia, sugerindo que a escoliose não implica necessariamente perdas funcionais, sendo o treinamento uma importante medida de prevenção.
Força de preensão palmar e pinça digital em diferentes grupos de pilotos da Academia da Força Aérea brasileira
Authors: Gonçalves Gláucia Helena , Gomes Daniele Aparecida , Teixeira Marcela Donatelli Meibach , Shimano Suraya Gomes Novais , Shimano Antonio Carlos , Fonseca Marisa de Cássia Registro
Published: April 2012

Pilotos da Academia de Força Aérea (AFA) brasileira, durante vôos, realizam movimentos com grande solicitação da musculatura da mão que comanda o manche, o que pode modificar a força muscular. Este estudo teve por objetivo analisar as forças musculares isométricas de preensão palmar e pinças polpa-a-polpa, trípode e lateral de três grupos de pilotos da AFA. Foram avaliados 15 pilotos da Esquadrilha da Fumaça (EDA), 16 instrutores de vôo (PI) e 6 pilotos em treinamento (PT), todos do sexo masculino. Para a avaliação, o posicionamento corporal dos pilotos seguiu a padronização da Sociedade Americana de Terapeutas da Mão e a ordem dos movimentos analisados foi predefinida, evitando fadiga muscular. A força muscular isométrica máxima foi coletada em uma contração sustentada por 6 segundos. Os resultados mostram diferenças significativas na preensão, com superioridade das mãos dominantes em relação às não-dominantes em todos os grupos, tendo ainda o grupo EDA obtido valores significativamente superiores em relação aos demais. Nas medidas da pinça trípode, o grupo EDA apresentou significativos valores superiores aos do grupo PT, sendo encontrados valores das mãos dominantes superiores aos das não-dominantes nos grupos EDA e PI. Conclui-se que o treino específico da musculatura da mão durante o vôo, a especificidade e o período de treinamento interferem na força muscular isométrica da mão.
Desempenho do membro não-acometido em pacientes com reconstrução do ligamento cruzado anterior
Authors: Noronha Neta Maria Isabel de , Braga Nícia Farias , Augusto Denise Dal'Ava , Câmara Ariane Emerenciano da , Brasileiro Jamilson Simões
Published: April 2012

Défices sensoriais persistentes após a reconstrução do ligamento cruzado anterior (LCA) podem causar alterações como fraqueza muscular e comprometimento do equilíbrio e do desempenho funcional. Diversos estudos discutem se essas alterações também estão presentes no membro inferior não-acometido e se esse membro pode ser utilizado como referência nas avaliações desses pacientes. O objetivo do presente estudo foi comparar o torque extensor e flexor do joelho, o equilíbrio unipodal e o desempenho funcional sobre o membro não-acometido de pacientes submetidos à reconstrução do LCA, com membros inferiores de sujeitos saudáveis. Participaram do estudo 23 indivíduos submetidos à reconstrução do LCA e 22 sujeitos saudáveis, que foram avaliados quanto ao torque extensor e flexor do joelho durante contração isocinética concêntrica a 60 graus/s no dinamômetro isocinético, à velocidade média de oscilação do centro de pressão em apoio unipodal no baropodômetro, e submetidos a dois testes de salto para avaliar o desempenho funcional. Os resultados não revelaram diferenças entre o membro não-acometido e os membros inferiores do grupo controle em todas as variáveis estudadas (p>0,05). Esses resultados sugerem que o membro não-acometido de pacientes submetidos à reconstrução do LCA pode ser utilizado como referência nos estudos de avaliação desses pacientes.
Comparação entre indivíduos hemiparéticos com e sem histórico de quedas com base nos componentes da Classificação Internacional de Funcionalidade, Incapacidade e Saúde
Authors: Faria Christina Danielli Coelho de Morais , Saliba Viviane Amaral , Teixeira-Salmela Luci Fuscaldi , Nadeau Sylvie
Published: April 2012

O objetivo deste estudo foi comparar hemiparéticos com e sem histórico de quedas nos últimos seis meses (caidores e não-caidores) segundo os componentes da Classificação Internacional de Funcionalidade, Incapacidade e Saúde. Dezesseis hemiparéticos não-caidores (62,3±16,6 anos), com tempo de acidente vascular encefálico (AVE) de 38,0±48,3 meses, e 16 caidores (61,0±17,0 anos), tempo de AVE de 48,0±50,7 meses, de ambos os sexos, comunitários e deambuladores, foram avaliados quanto a funções e estruturas do corpo (torque do músculo quadríceps do lado parético e escala de depressão geriátrica), atividade - velocidade de marcha (VM) natural e máxima, teste de levantar e caminhar cronometrado (timed up & go) e escala de equilíbrio de Berg - e participação (pelo perfil de saúde de Nottingham e escala de qualidade de vida específica para AVE). Os dados foram tratados estatisticamente, com nível de significância α<0,05. Não houve diferença significativa entre os grupos quanto à idade, sexo e tempo de AVE (0,56<p<0,82), nem quanto às demais caracteristicas medidas (torque, depressão, VM, equilíbrio e qualidade de vida (0,12<p<0,60). Portanto, hemiparéticos caidores apresentaram-se semelhantes aos não-caidores nos domínios funções e estruturas do corpo, atividades e participação. Fatores contextuais ambientais, não analisados, podem estar mais relacionados a episódio(s) de queda nesses indivíduos.
Predição da força de reação do solo durante a corrida na água
Authors: Haupenthal Alessandro , Fontana Heiliane de Brito , Ruschel Caroline , Roesler Helio , Borgatto Adriano Ferreti
Published: April 2012

Este estudo visou desenvolver um modelo para a predição da força de reação do solo na corrida subaquática. Participaram 20 sujeitos (9 homens e 11 mulheres), que realizaram corrida subaquática em dois níveis de imersão e três velocidades. Para cada sujeito foram coletadas seis passagens válidas em cada condição, com a utilização de uma plataforma subaquática de força. O modelo para predição da força foi construído por regressão linear múltipla. Foram consideradas variáveis dependentes a componente vertical e a componente ântero-posterior da força de reação do solo. As variáveis imersão, sexo, velocidade, massa corporal, densidade corporal e percentual de gordura foram consideradas independentes. Permaneceu no modelo final de regressão para a componente vertical a velocidade (p<0,001), enquanto no modelo da componente ântero-posterior permaneceram a velocidade, a imersão e a massa corporal (todas com p<0,001). O modelo preditivo para a componente ântero-posterior da força de reação do solo pode ser considerado satisfatório (o coeficiente de determinação ajustado foi 0,79). Entretanto, o modelo para a componente vertical não pode ser recomendado para a predição dessa variável durante a corrida na água (coeficiente encontrado 0,18). Ressalva-se que o modelo preditivo criado aplica-se a sujeitos com características semelhantes (idade e medidas antropométricas) às dos participantes do estudo.
Efeitos dos exercícios resistidos sobre o equilíbrio e a funcionalidade de idosos saudáveis: artigo de atualização
Authors: Araújo Marina Lorenzi Monteiro de , Fló Claudia Marina , Muchale Sabrina Michels
Published: April 2012

A diminuição da força muscular com o envelhecimento e os baixos níveis de atividade física contribuem para défices funcionais e de equilíbrio. Esta revisão sistemática teve como objetivo analisar os estudos que correlacionaram o treino resistido (TR) isolado, o equilíbrio e a função de idosos saudáveis. A busca nas bases do Google Acadêmico e na BVS levou à seleção de 35 estudos controlados. O TR isolado mostrou ser relevante para a função dos idosos (90% dos estudos) devido sobretudo ao ganho de força e mobilidade. Exercícios de baixa e moderada intensidade tiveram melhores resultados sobre a função de idosas, frágeis e sedentários. Em relação ao equilíbrio, apesar da inconsistência dos dados, o TR parece exercer efeitos positivos, sobretudo devido a fatores neuromusculares. Estudos com parâmetros de treino e amostra uniformes são necessários para melhor comparação dos resultados, sobretudo em idosos com padrão funcional elevado.
CO2 Injection into Oil Reservoir Associated with Structural Deformation
Authors: El-Amin M. F. , Negara A. , Salama A. , Bao K. , Sun S.
Published: April 2012

In this work, the problem of structural deformation with two-phase flow of carbon sequestration is presented. A model to simulate miscible CO2 injection with structural deformation in the aqueous phase is established. In the first part of this paper, we developed analytical solution for the problem under consideration with certain types of boundary conditions, namely, Dirichlet and Neumann boundary conditions. The second part concerns to numerical simulation using IMPDES scheme. A simulator based on cell-centered finite difference method is used to solve this equations system. Distributions of CO2 saturation, and horizontal and vertical displacements have been introduced.
Upstream Data Standards at Saudi Aramco
Authors: AlShehry M. A. , Al-Khudiri M. M. , Al-Sanie F. S. , Miyajan R. A. , AlTaiban A. A. , Al-Zawawi A. S. , Khakwani M. S.
Published: April 2012

This paper describes the upstream data standards that Saudi Aramco has recently implemented for Drilling and is in progress to implement them for other areas such as Production and Reservoir Characterization. These standards enable us to make wider use of our monitoring and collaboration centers through a common approach. It also allows us to leverage the evolving WITSML, PRODML and RESQML standards more effectively in our upstream operations.

Saudi Aramco relies on many service organizations to deliver the generated data which requires common and standard data classification when exporting data from source A then importing to destination B. Applying a common approach to information access on a global basis has enabled us to streamline our operations and make wider use of emerging analysis, monitoring and collaboration technologies.

Real-time technologies have been utilized to capture, monitor and analyze operational data from well sites so that critical decisions can be made in real-time to reduce and eliminate operational and safety problems, thus reducing non-productive time. That includes high-tech rigs, smart wells, monitoring & collaboration tools and real-time data visualization systems.

Our aim has been to implement standard upstream information architecture. Our full implementation of WITSML was the vehicle which allowed this to happen in Drilling & Workover operations. We still believe that over the next years with the advancements of technologies there will be more challenges to support open connectivity between different vendors and services supporting the increasing upstream functions.
Coiled Tubing Best Practices in Conjunction with Multistage Completions in the Tight Gas Fields of Saudi Arabia
Authors: Al-Ghazal Mohammed , Abel Justin Tate , Al-Buali Muhammad , Al-Ruwaished Azmi , Al-Saqr Abdulaziz , Al-Driweesh Saad , Wilson Stuart
Published: April 2012

Open hole multistage fracturing (MSF) completions are becoming standard practice in the south gas fields development in Saudi Arabia with more than 25 wells completed to date using open hole packers and selective port technology.

Overall, the production results from the use of MSF completions have been very positive and the forecast is that MSF technology usage will grow considerably over the next several years. In general, MSF completions provide an excellent advantage in that they are intervention-less in their standard mode of operation. An aspect that is evolving is the secondary use of coiled tubing (CT) to handle the planned and unplanned (contingency) operations occasionally required to reach well production objectives. Without optimum operational planning and the selection of correct CT downhole tools, completion problems can be encountered and this ultimately can result in the job objective not being reached at all or only at increased costs.

This paper presents MSF case studies where CT has been deployed and investigates the operational impact and productivity enhancement. Correlations taken from the key hardware variables, such as fracturing port size and type, motor type, mill bit type, and CT size, are also considered and analyzed.

Following the lessons learned and best practices from these experiences, with correct implementation, the findings from this paper should increase the potential for successful multistage completion operations and ultimate improvements in productivity.
Inversion in the Transient Temperature Behavior in the Intervals of Oil and Water Inflow: Theory and Technique for Application
Authors: Ramazanov Ayrat , Valiullin Rim
Published: April 2012

In this paper we discuss on forward modeling of the transient temperature responses during the well testing.

Well thermometry is conducted at all stages in the life of a reservoir: exploration, development, production and injection. Temperature measurements are especially informative ones when we use a transient processes in the well and formations.

The transient temperature variations in saturated porous medium are connected with fluid expansion/compression, heat convection, viscous dissipation and heat conduction. The combined viscous dissipation (frictional heating) and fluid expansion/compression terms comprise the barothermal effect. The barothermal effect is the same as the classical throttling (Joule-Thomson) one in the particular case of steady state flow. The value of the Joule-Thomson coefficient for oil is about (0.04–0.06) K/bar and for water is about 0.02 K/bar. Therefore the steady temperature variation in the oil inflow intervals (under the same pressure drop) is always more than in the water inflow intervals.

The temperature profile in well changes with time and depends on many other factors, including flow rate, fluid and formation properties and completion configuration. As the result the situation is possible, when specific flow rate of water is more than for oil and the inversion of the throttling temperature anomalies is observed. In this case during the time t less than inversion time tinv the water is heated more than oil. And it is observed the "normal" ratio of throttling anomalies for oil and water for time t>tinv.

Analytical and numerical models of barothermal effect in the saturated porous medium are developed. It was received the formulas for estimation of inversion time. It is suggested the technique of application of temperature anomalies inversion for the determination of water inflow intervals to well by thermal logs.

The field cases corroborate the real practical application of this phenomenon.
Using Histogram Equalization and Edge Detection to Enhance Stratigraphic
Authors: Al Garni Khalid , Al Ghamdi Ahmed
Published: April 2012

In this paper we introduce a workflow to improve stratigraphie and lithologie interpretations. In particular, we demonstrate the use of histogram equalization followed by edge detection to enhance geological features such as faults, fractures, and channels. Post-stack and migrated seismic data is often subjected to automatic gain control (AGC) to increase the visibility of low-strength reflections. Unfortunately, AGC can mask stratigraphic details by drastically changing relative amplitude levels and by producing low-amplitude "shadow-zones" near strong reflectors and near unconformity terminations.

Histogram equalization was originally developed for image processing but serves a useful purpose for seismic analysis. Unlike AGC, histogram equalization preserves subtle stratigraphic features and does not create "shadow-zones" beneath strong reflectors. Histogram equalization enhances the sharpness of stratigraphic features thereby allowing edge detection algorithms to more effectively highlight discontinuities in the amplitude level even if the change is small.

The effect of histogram equalization followed by edge detection is demonstrated using 128-fold 3D seismic land data (Figure 1). Using this data we analyze the ability to map a fluvial channel of noticeable thickness. The channel is the result of Hirnantain (Late Ordovician) glaciations subjected to a local tectonic uplift. A time slice of histogram equalized data shows the channel boundary more clearly than the AGC-processed version.

Figure 1 E-W line extracted from 3D seismic data shows the channel system.
Coil Tubing Fill Cleanout Implemented on Plugged Stand Alone Screens: Highly Successful Campaign in Saudi Arabian Gas Producers
Authors: AlTammar Murtadha J. , Asiri Khalid S. , Al-Driweesh Saad M. , Asiri Mohammed A.
Published: April 2012

Gas wells in Field X, south of the giant Ghawar Field, are completed with stand alone screens across a Pre-Khuff sandstone formation as a sand control measure. Although prolific producers, some suffer a severe decline in performance after a period of production, triggering diagnostic work to be performed. Consequently, screen plugging is confirmed and collected samples of present fill are analyzed. Results called for a coil tubing cleanout campaign in order to restore lost productivity. The objective of this paper is to detail the whole operation journey of the fill cleanout jobs that includes fill diagnostic process, assessment of cleanout methods, initial job design, choice of fluids, CT bottomhole assembly tools, execution and field experience, and post-cleanout performance evaluation.

A CT wiper trip method has been implemented with either milling or jetting tools. A newly developed rate-activated circulation valve is deployed to aid in lifting solids at high pumping rates as well as jetting acid across the screen interval after fill removal. The fill cleanout campaign has been very successful in restoring well productivity as compared to pre-cleanout and initial post-drilling well performance. A total of 340 MMSCFD of incremental gas rate were restored to-date from 16 cleanout operations. Unprecedentedly, interesting and valuable findings are shared regarding the nature of fill formed inside and/or above the stand alone screens, recommended milling practices to protect CT bottomhole assembly and minimize CT fatigue, the experience of incorporating acid jetting and squeeze in the CT wiper trip method to stimulate damaged formation pack behind the screens, and the preventive measures taken to cope with the fill accumulation issue.
Aqueous Foams Stabilized with Particles and Surfactants
Authors: Li Zhaomin , Liu Zupeng , Li Binfei , Li Songyan , Sun Qian , Wang Shuhua
Published: April 2012

Foam is a proven method for decreasing gas mobility in both homogeneous and heterogeneous reservoirs. A new foam system, called multi-phase foam system composed of gas, liquid, and particles has been studied in China recently since it has better performance than general gas-liquid foam system in profile control.

The aqueous foams prepared by mixtures of pre-performed particles and surfactants were studied in detail. In this article a new method focusing on liquid drainage velocity was used to estimate the stability of multi-phase foam system compared with classical foam stability studies that record foam height variation versus time. A synergistic effect on foam stability occurs and becomes more obvious with increasing surfactant concentration. The synergistic effect mainly comes from the adsorption of particles on the bubble surface and the formation of a three-dimensional network in the coherent phase. In addition, particle size is a significant factor affecting foam formation and stability. Foam prepared by 3 different size particles indicates that foam formability and stability decrease with increasing of particle size. It is hypothesized that the decrease in the foam formation and stability is related to the particle gravity. Finally, experiments about reservoir conditions like high temperature and salinity were also conducted. It shows that increasing temperature will accelerate the velocity of foam decay and the increase of calcium chloride concentration help to stabilize foam while sodium chloride has an optimum concentration for foam stability.
Innovative Technique to Liven Dead Wells with a Rigless Gas Lift System
Authors: Sunbul Ahmed , Barlow Steve , Khalifa Mohammed , Hernandez Jeremias , Zamka Saleh
Published: April 2012

An innovative gas lift technique was used to restore production of a high water cut oil producer, by using gas directly from a gas well without compression or treatment. The system included a 2" gas line from the gas well to the oil producer (2 km), and a gas measurement and flow control skid located at the producer. A chemical corrosion inhibitor was injected into the gas line at the gas well site to protect downstream piping and casing. Downhole gas lift equipment in the producer was installed using a wireline; a rigless installation resulted in a low cost installation.

Benefits of this gas lift system include:

No requirement to install and operate expensive compressors. No requirement for gas separation and treatment prior to well injection. Simple low cost wireline installation of downhole equipment. Several producers could potentially be gas lifted by a single gas well. No well site high capacity electrical power is needed.

In September 2011, the system was successfully commissioned, production stabilized at 2,500 barrels of fluid per day (BFPD) at 80% water cut and gas injection rate of 1 million standard cubic feet per day (MMscfd).

This gas lift system is potentially an economical alternative to the electrical submersible pump (ESP) artificial lift where suitable high-pressure gas wells are located near oil producers. The performance of this gas lift system will be closely monitored and evaluated as an artificial lift option for other similar fields.
Technologies for Monitoring Matrix Oil Saturation for TA-GOGD
Authors: Edwards John , Hammami Ahmed , Bachman Nate , Fordham Edmund , Flaum Mark , Bakker Gossen , Bettembourg Solenn , Putra Pristiwanto , Rawnsley Keith
Published: April 2012

TA-GOGD is thermally assisted gas-oil gravity drainage suited for heavy oil in highly fractured formations. Steam is injected into the fractures to serve two purposes: to apply a gas gradient across the matrix blocks so that the oil in the matrix drops down by gravity and to heat the carbonate matrix blocks so that the reduced viscosity oil drips out faster. The reservoir has two fluid systems, which are gas/oil/water levels in the fractures and gas/oil/water contacts in the matrix blocks that are separated by the fractures. Reservoir surveillance requires logs of the remaining oil saturation to confirm the recovery, which is dependent upon the heterogeneities of fracture intensity and vertical permeability. The changing fluid saturations in the matrix are primarily oil replaced by hydrocarbon gas, but six fluids could be present and change: methane and steam, hot low-viscosity and cold high-viscosity oil, formation water, and condensed steam. The important zone is above the fracture gas/oil contact, where drained oil is replaced by the secondary gas cap or steam. Time-lapse pulsed neutron capture logs during the pilot phase did not provide the required matrix fluid saturations due to interference from variable annular fluids in the poorly cemented casing that masked the reservoir response. There is no logging tool available that is capable of measuring the matrix oil saturation change without being influenced by the other fluids in the matrix or the fracture-controlled fluid levels in the casing annulus, or characterized for an open gas-filled borehole, and built to withstand 247°C. The physics of nuclear magnetic resonance (NMR) provides the best chance to fulfill this reservoir surveillance requirement. This paper recounts the decision process that preceded this conclusion, and suggests a method of building a high-temperature non-metallic and non¬magnetic flask to facilitate NMR time-lapse logging in dedicated openhole observation wells in TA-GOGD developments.
Advanced Fluid Technologies for Tight Gas Reservoir Stimulation
Authors: Huang Tianping , Clark David E.
Published: April 2012

Wells drilled in tight sand and shale gas reservoirs require hydraulic fracturing treatments to become economically profitable. The primary objectives for these treatments are twofold: (1) create high-conductivity paths from the wellbore to deep penetration; (2) and/or connect natural microfractures within the reservoirs.

Current fracturing fluid systems generate formation damage and/or fracture damage due to fluid leakoff into natural fractures and matrix or polymer residues. This makes tight gas reservoir stimulation much less effective than expected.

This paper will briefly evaluate the damage mechanisms of current fluid systems and introduce an advanced surfactant micelle fluid technology for tight gas reservoir stimulation. Surfactant micelle fluids structured from very low-molecular-weight surfactants into elongated micelles have been used as stimulation fluids in an attempt to remove the drawback of polymer fluids. The viscoelastic behavior of these surfactant micelle fluids is believed to be rooted in the overlap and entanglement of elongated micelles. This yields both the viscous and elastic characteristics to the fluid.

High fluid leakoff and difficult cleanup associated with traditional surfactant micelle fluids have, however, limited their use in tight gas stimulation applications. Recent work has shown that adding carefully selected inorganic nano-crystals—less than 100 nm in size—to a surfactant micelle fluid formulation can overcome damage limitations. This can be done without negatively affecting the internal breaking mechanisms. Recent results highlight the mechanism of fluid loss control and easy cleanup of this nanoparticle reinforced surfactant micelle fluid system for tight gas stimulation applications.
Improved Model for Predicting the Required Minimum Gas Injection Rate for Removal of Cutting during Underbalanced Drilling
Authors: Samson Fadairo Adesina , Churchill Ako , Emmanuel Nwaokete , Olugbenga Falode
Published: April 2012

It has been widely recognized that maintaining adequate air/gas injection rate is vitally important to achieving hole cleaning both against drilling cutting and liquid accumulations. It is highly imperative to accurately predict the annulus pressure drop for determining the critical air/gas injection rate required for cleaning formation both cutting and liquid influx during underbalanced drilling.

A new numerical model for determining annulus pressure drop model has been developed that is required for accurately predicting minimum air/gas injection rate for simultaneous removal of both cutting and liquid during underbalanced drilling. The new model has incorporated the influence of cutting volume which has been overlooked by most researchers. Since the required minimum flow rate needs to be determined at the surface condition, temperature and pressure dependent variables such as gas formation volume factor, (Bg), Oil formation factor, (Bo), and water formation factor, Bw has been considered in the model. The results generated show that the existing models have underestimated the required minimum air/gas flow rate for continuous lifting of both cutting and liquid during underbalanced drilling. Engineering charts have also been generated for predicting cutting and liquid-carrying capacity of air/gas that is injected into the borehole at various rates. This project provides drilling engineers the necessary knowledge and a useful tool for minimizing complications in air/gas drilling operations
Enhanced Oil Recovery Using Nanoparticles
Authors: Ogolo N. A. , Olafuyi O. A. , Onyekonwu M. O.
Published: April 2012

Nanoparticles have been speculated as good in-situ agents for solving reservoir engineering problems. Some selected types of nanoparticles that are likely to be used include oxides of Aluminium, Zinc, Magnesium, Iron, Zirconium, Nickel, Tin and Silicon. It is therefore imperative to find out the effect of these nanoparticle oxides on oil recovery since this is the primary objective of the oil industry. These nanoparticles were used to conduct EOR experiments under surface conditions. Distilled water, brine, ethanol and diesel were used as the dispersing media for the nanoparticles. Two sets of experiments were conducted. The first involved displacing the injected oil with the nanofluids. In the second case, the sands were soaked in nanofluids for 60 days before oil was injected into the system and displaced with low salinity brine. Generally, using nanofluids to displace injected oil produced a better result.

Results obtained from the experiments indicate that Aluminium oxide and Silicon oxide are good agents for EOR. Aluminium oxide nanoparticle is good for oil recovery when used with distilled water and brine as dispersing agents. For the use of ethanol, Silane treated Silicon oxide gave the highest recovery in all the conducted experiments while hydrophobic Silicon oxide in ethanol also yielded good results. Aluminium oxide reduces oil viscosity while Silicon oxide changes rock wettability in addition to reduction of interfacial tension between oil and water caused by the presence of ethanol. For the use of diesel as a nanoparticle dispersing fluid, because diesel and crude oil are miscible, the actual crude oil recovery cannot be determined but the overall result with Aluminium, Nickel and Iron oxides appears good. Magnesium oxide and Zinc oxide dispersed in distilled water and brine cause permeability problems. Generally, distilled water lowers oil recovery. This emphasizes the significant role a fluid plays as a nanoparticle dispersing agent in the formation because it can contribute positively or negatively in oil recovery apart from the effect of the nanoparticles.
A New, Low Corrosive Fluid to Stimulate Wells with Carbon Steel Tubular and Internals
Authors: Nasr-El-Din H. A. , de Wolf C. A. , Bouwman A. , Bang E. R. , Naylor E. , Alex A.
Published: April 2012

For many reasons acidizing treatments represent a real challenge to the oil and gas industry. On one side acidizing can significantly improve the productivity of the well, but on the other side the intrinsic corrosive character of the acids form a severe threat to the well's integrity. Therefore traditional acidizing treatments with fluids involve significant loadings of corrosion inhibitors and corrosion inhibitor intensifiers to help mitigate the corrosion. However, the additives can cause their own damage to the formation, reduce overall effectiveness of the acidizing fluid, and come with significant additional costs to the overall acidizing program.

Recently studies with a new environmentally friendly stimulation fluid, glutamic acid diacetic acid (GLDA), were presented for both carbonate and sandstone reservoirs. The studies have shown that GLDA can dissolve calcite & dolomite, does not destabilize clays particles, and can significantly improve permeability in both carbonate and sandstone formations across wide field conditions. In the present paper the corrosion rate of GLDA is compared with other chelates and simple organic acids that are used for carbonate dissolution, such as hydroxyethylethylenediaminetriacetic acid (HEDTA), acetic, citric and formic acid. All corrosion tests were conducted at high temperature and pressure and extended for up to 6 hour at temperature and pressure.

The results show that GLDA at 20 wt% has the least impact on low carbon steel, in comparison to the other stimulation fluids examined in this study. A very minimal amount of corrosion inhibitor loading was needed to keep the corrosion rate below the acceptable rate for GLDA, even at elevated temperatures or in the presence of corrosive gases like H2S and CO2. On more corrosion resistant Cr-based metals, like Cr-13 and duplex, the corrosion rate of GLDA is far below the acceptable limit with no corrosion inhibition even at 300°F. Based on the results, GLDA solutions can be used to stimulate carbonate and sandstone wells completed with various types of metallurgies with no or very minimal amount of corrosion inhibitors and effectively maintain the integrity of the tubular & internals.
Production Enhancement Using a Multiphase Helico-Axial Pump in a Remote Hilly-Terrain Oil Field in Saudi Arabia
Authors: Samsudin Zulkifli B. , Ajmi Shaleh M. , Qudaihy Dia S. , Dossary Faisal M. , Gharaibeh Alaa , Tvedt Jostein
Published: April 2012

Some of the wells in the southern part of a remote field in Saudi Aramco are either producing intermittently or ceasing to flow against the high trunk line pressure. Saudi Aramco had considered various options along with horizontal thrust boring direct drilling under the sand dunes to reduce this high back pressure. A helico-axial multiphase pumping (MPP) technology was selected for the trial test in this field since in 2005 the horizontal thrust boring technology was limited to distance up to 2 km. In addition, the multiphase pump provides the flexibility such as reducing the back pressure and particularly, the helico-axial technology has a wider operating envelope as some wells will be weaker in the long run.

Saudi Aramco has successfully re-commissioned the MPP in January 2011, and it was trial tested for a nine month period at the remote area with three dead wells and two marginal flowing wells. A total of 7,000 to 8,000 barrel oil per day incremental production was realized by lowering the back pressure on these wells using the MPP.

This paper describes the testing, field operational experience and recommended improvement of a rotodynamic (helico-axial) MPP system at a remote, hilly terrain onshore oil field in Saudi Arabia. This paper is a sequent to SPE-117462 paper, Deployment of Rotodynamic Multiphase Pump in a Remote Hilly-Terrain Oil Field in Saudi Arabia," presented at the 2008 Abu Dhabi International Petroleum Exhibition and Conference, Abu Dhabi, UAE.
Application of Latest Generation Inflow Control Devices in Non-Horizontal Wells in India, Case Study
Authors: McKenzie Tim , Wenk Andrew , Chavan Chetan , Kumar Sanjay , Khan Parvez , Garcia Gonzalo
Published: April 2012

Bhagyam is the second largest oilfield discovered to date in the Barmer Basin, India with more than 400mmb of viscous, waxy crude in place. This paper describes the evaluation, design and selection process for the use of the latest generation ICD in non-horizontal wells.

Sandface completions comprise sand screens coupled with an ICD. Inflow control was highly desirable due to the oil viscosity variation, high permeability, heterogeneity and adverse mobility ratio and the fact the completions could not be easily accessed below a PCP. Oil viscosity ranges from 20 to 250cp varying with depth. The variation in reservoir thickness, produced fluid viscosity and well productivity required a field adjustable pressure drop capability in the ICD. The ICD had to perform at high viscosity and needed to be tolerant to wax and sand production. The operator's experience in nearby fields observed the benefits of ICDs for providing efficient sandface cleanup in horizontal wells. It was vital to model this system accurately however there were significant challenges as no previous examples of using these devices in non-horizontal wells could be found and the ICD completion had not been modeled in a dynamic simulator for this scale of field development.

A dynamic simulation model which included the ICD completion was used to evaluate various completion options. A significant amount of work was performed to ensure the ICD was accurately modeled in the simulator. The simulations showed a long term benefit from using the ICD. To date 22 production wells have been completed with the ICD screen systems.

This is one of the first applications of the latest generation ICD in non-horizontal wells particularly on a full field scale. It is also a case study of modeling the ICD completion with a dynamic simulator.
Precise Approach to Isolate Fractured Water Bearing Lower Zone in Complex Saudi Arabian Gas Well by Placing Ceramic Proppant and Cement in Restricted Depth Utilizing HPCT to Withstand High Bottom-hole Pressure during Fracturing Treatment in the Upper Zone: A Case History
Authors: Malik Ataur R. , Duarte Jorge E. , Kulaib Hamad F. , Atwi Mohammed A. , Eduardo Vejarano R. , Riefky Abdurrahman
Published: April 2012

Success of Multi-Stage Fracture treatment in deviated cased hole completion largely depends on isolation mechanism of the previously created fractures in the lower zones under the presence of complex reservoir characteristics and wellbore conditions. The lower zones need to be temporarily or permanently isolated utilizing cast iron, composite or sand plugs capped with cement that must maintain integrity and be able to tolerate high differential pressure across the plug during hydraulically fracturing the upper zones.

The subject paper is a review of the design philosophy, planning, laboratory testing, execution and results of successful isolation of lower complex zone with high stress, high pressure and high temperature (BHST = 315 deg F) where proppant fracturing treatment prematurely screened out exceeding maximum bottomhole treating pressure limit of the completion of a gas well in Saudi Arabia. The high differential pressure (greater than 10000 psi) requirement of the isolation plug eliminated the mechanical bridge plug options as a result of uncertainty of the liner condition from unprecedented high screenout pressure and dubious cement quality behind the pipe. The only viable option that remained was a customized plug made up of ceramic proppant capped with 100 mesh sand and high temperature cement. The objective of ceramic proppant from plug back depth to top of perforated interval of the lower zone and capped with 100 mesh sand was to work as base for cement and controlling leak-off of cement into the lower fractured zone. The short distance between the perforated intervals of lower and upper zones, maintaining balanced condition during placement of proppant and cement plugs and controlling leak-off of cement across the fractured lower zone required high level of scrutiny in the selection of proppant type, designing cement properties in the laboratory, quality control and ultimately placement of the slurries utilizing high pressure coiled tubing (HPCT). The real time monitoring of temperature and pressure data from permanent downhole gauges enabled to maintain balanced to slightly overbalanced condition that significantly contributed the set a plug in target depth with desired strength. The plug was successfully pressure tested to a bottomhole pressure of 15000 psi. The plug maintained it's integrity during the DataFrac performed in the upper zone after perforation. The successful application of this isolation method enabled two additional fracture treatments in layers at the shallower depths of the same well.
Molecular Design Synthesis and Simulation on a Novel Gemini Surfactant for EOR From Low Permeability Reservoirs
Authors: Wei Heng
Published: April 2012

High injection pressure and the imbalance between water injection and oil production are two of the difficulties in developing low permeability oil reservoirs. Injecting gemini surfactants is a promising technique to overcome the difficulties to enhance oil recovery from low permeability oil reservoirs. Based on fractal analyses, a novel gemini surfactant is designed, and its possible synthesis route is suggested.

The novel gemini surfactant is put into computer simulation. The results show that the novel gemini surfactant has better effects on washing oil than conventional gemini surfactants. The novel gemini surfactant has a great potential in enhancing oil recovery.

The fractal dimension of the spacer group of the novel gemini surfactant is close to the fractal dimension of the microstructure of the reservoirs. This is the key point in designing the novel gemini surfactant.

The fractal analyses of the key molecular structures help design more exact and efficient oilfield chemicals. Once the novel gemini surfactant is put into practical use, it will have active effects on both oil development and refinery industries.
Comparisons and Contrasts of Shale Gas and Tight Gas Developments, North American Experience and Trends
Authors: Kennedy Robert L. , Knecht William N. , Georgi Daniel T.
Published: April 2012

All Shale Gas reservoirs are not the same. There are no typical Tight Gas reservoirs. These two statements can be found numerous times in the literature on shale gas and tight gas reservoirs. The one common aspect of developing these unconventional resources is that wells in both must be ‘hydraulically fractured’ in order to produce commercial amounts of gas. Operator challenges and objectives to be accomplished during each phase of the Asset Life Cycle (Exploration, Appraisal, Development, Production, and Rejuvenation) of both shale gas and tight gas are similar. Drilling, well design, completion methods and hydraulic fracturing are somewhat similar; but formation evaluation, reservoir analysis, and some of the production techniques are quite different.

Much of the experience in shale and tight gas has been developed in the US and in Canada, to a lesser extent; and most of the technologies that have been developed by operators and service companies are transferable to other parts of the world. However, the infrastructure, including equipment and service company availability, governmental regulations, logistics, processing, environmental considerations, and pricing are not the same as in the US. This may impact the rate of the technology transfer as well as the selection of some of the technology. This paper is focused on operations challenges, technologies, and experience associated with shale and tight gas projects. It is likely that environmental concerns and the drive to reduce development costs of tight and shale gas reservoirs will drive new approaches to the development of these reservoirs in China, Latin America, Middle East, North Africa, and other parts of the world.
Powering Through a Lateral Junction for ERC Wells – Is It Really a Step Too Far?
Authors: Bouldin Brett , Verma Chandresh , Dyer Steve , Singh Parvesh , Oliveira Thales
Published: April 2012

Saudi Aramco and Schlumberger recently embarked on a phased field implementation to build "Extreme Reservoir Contact" wells (ERC). The paper presents the experiences on a recent trial well that deployed an intelligent completion through a multilateral junction in an open hole lateral. We present the conceptual design, tools, techniques and learnings associated with this test.

The application of this technology lies in the construction of ERC well infrastructure to actively control segmented lateral inflow and improve reservoir sweep. A key stumbling block in realizing this vision is to branch the lateral junction with power and communication.

The well trial demonstrated the ability to deploy a completion assembly with umbilical to the bottom of an openhole lateral.

The major design and operational steps discussed herein include:

Installing and cementing an umbilical behind casing Milling the junction window without causing damage to the umbilical Drilling, clean out and fluids used in the lateral to reduce drag Dressing and drifting of the junction Installation and retrieval of a dummy lateral completion assembly with umbilical through a window and without rotation

"Extreme Reservoir Contact" is one of the key technologies in Saudi Aramco's vision of increasing recovery factors from their fields. They differ from the current "Maximum Reservoir Contact" (MRC) practice in further increasing reservoir contact, while also increasing well compartmentalization with individual compartment control. Laterals can be instrumented with enhanced sensor systems to efficiently monitor hydrocarbon reserve drainage.

The reliable deployment of remote control valves and sensing devices through milled junction windows is a key step in realizing this vision. The full benefit in drilling these downhole well structures demands pro-active control of reservoir fluid production and the mitigation of early water or gas breakthrough. Bringing emerging new intelligent completion technology into the laterals will significantly impact the industry in this regard.
Exploring and Evaluating Eastern Hemisphere Proppants in Fracturing Applications
Authors: Kothamasu Ramya , Das Prasanta , Karadkar Prasad
Published: April 2012

As the market for fracture stimulation emerges internationally, selecting the proper proppant is essential. Comparing data from different proppants can aid proper selection for particular reservoir applications. Correlations between the test data can be used to forecast the proppant behavior inside the formation.

API and ISO standards were used for qualifying tests, such as specific gravity (SG), bulk density, acid solubility, turbidity, sphericity, roundness, sieve analysis, crush strength, and long-term fracture conductivity. The significance of each test is discussed, the results are compared, and correlations are developed. Each test has been weighted, and a scoring index is provided to demonstrate how the quality of proppant should be considered to help select the optimum proppant.

This work provides insight into proppants manufactured in different regions in the eastern hemisphere. The characterization of different proppants from the tests performed reflects how different local sourcing options can impact proppant quality. The scoring index can be used as a quick guide for the preferred proppant selection for a specific well stimulation.