bluuebunny/crossref_metadata_2025 huggingface dataset:
Leishmaniose visceral: história jornalística de uma epidemia em Belo Horizonte, Brasil
Authors: Bevilacqua Paula Dias , Paixão Helena Heloísa , Castro Maria Ceres Pimenta Spinola , Modena Celina Maria
Published: June 2009

Este trabalho busca recuperar a história jornalística da epidemia de leishmaniose visceral que acomete o município de Belo Horizonte, Brasil, desde 1993. Este resgate se fez através da sua história cronológica e das construções narrativas e discursivas sobre a epidemia em 101 matérias publicadas na grande imprensa, durante o período de 1993 a 1996. Utilizando-se como orientação metodológica a proposta de Foucault (1972), em seu trabalho "A Arqueologia do Saber", a análise aponta para a configuração de três grandes discursos, caracterizando grupos temáticos, nas matérias estudadas: o da Ciência, o do Estado e o da Sociedade. Cada um dos grupos contribui para a construção da doença no espaço jornalístico e veicula opiniões próprias de cada um destes universos. Dessa forma, a leitura dos textos jornalísticos permite o desnudamento de outro processo epidêmico, que se desenvolve paralelamente àquele que acomete as populações humana e canina, expresso nas construções narrativas sobre a leishmaniose visceral nos textos de jornal.
Metabolizable energy levels for semi-heavy laying hens at the second production cycle
Authors: Costa Fernando Guilherme Perazzo , Costa Janaine Sena da , Goulart Cláudia de Castro , Figueiredo-Lima Denise Fontana , Lima Neto Raul da Cunha , Quirino Bárbara Josefina de Sousa
Published: June 2009

This study was carried out to evaluate the energy levels in the diet to obtain better performance rates and quality of eggs from laying hens in the second production cycle. One hundred and eighty Bovans Goldline laying hens with 62 weeks of age were used during four 28-day periods. A completely randomized experimental design was used with four metabolizable energy levels (2,650, 2,725, 2,800, 2,875 and 2,950 kcal/kg), each with six replicates of six birds. The energy level of diet did not affect the weight of the egg, yolk, albumen and eggshell, the percentages of yolk, albumen and eggshell, yolk color and egg specific gravity. Feed intake, egg production, egg mass and feed conversion per egg mass and per dozen eggs increased significantly with increasing levels of metabolizable energy. Feed intake decreased linearly as the energy level in the diet increased. The metabolizable energy levels showed a quadratic effect on egg production, egg mass and feed conversion per egg mass and per dozen eggs. The metabolizable energy level of 2,830 kcal/kg was the most appropriate to promote better performance and quality of eggs from laying hens in the second production cycle.
A percepção de qualidade de vida de pessoas portadoras de deficiência física pode ser influenciada pela prática de atividade física?
Authors: Noce Franco , Simim Mário Antônio de Moura , Mello Marco Túlio de
Published: June 2009

A prática regular de atividade física promove uma série de benefícios que vão além da esfera física. A qualidade de vida, segundo diversas fontes, diz respeito ao grau de satisfação de um indivíduo com os múltiplos aspectos da sua vida. As pessoas portadoras de deficiência física podem apresentar níveis de sedentarismo elevados, influenciando de forma decisiva na percepção de sua qualidade de vida. Assim, o objetivo deste estudo foi verificar o efeito de 12 semanas de prática de atividade física na percepção do nível de qualidade de vida de deficientes físicos. Participaram do estudo 20 deficientes físicos, do gênero masculino, divididos em dois grupos, Sedentários e Ativos. Como instrumento de estudo foi utilizado um questionário de dados demográficos e o World Health Organization Quality of Life (WHOQOL-Bref). Em geral, a média de idade dos voluntários era de 38,1 anos, possuíam o 1º grau incompleto, moradia própria, eram solteiros e predominantemente portadores de poliomielite. O grupo Ativo apresentou escores mais elevados na qualidade de vida em todas as dimensões (física, psicológica, social e ambiental) do instrumento. Os resultados obtidos com o presente estudo comprovaram que o nível de qualidade de vida dos deficientes físicos Ativos foi melhor do que a dos Sedentários.
The Genus Dasymaschalon (Annonaceae) in Thailand
Authors: Wang Jing , Chalermglin Piya , Saunders Richard M. K.
Published: June 2009

A comprehensive taxonomic revision of the genus Dasymaschalon (Annonaceae) in Thailand is presented. Twelve species are recognized, including five that are newly described and one new nomenclatural combination, viz. D. acuminatum sp. nov., D. angustifolium
sp. nov., D. dasymaschalum, D. echinatum sp. nov., D. filipes, D. glaucum, D. grandiflorum sp. nov., D. lomentaceum, D. macrocalyx, D. obtusipetalum sp. nov., D. sootepense, and D. wallichii comb.
nov. Previous taxonomic confusion regarding the relationship between Dasymaschalon and Desmos is discussed. The most significant diagnostic difference between the two genera is the number and arrangement of petals: Dasymaschalon species have only three petals (homologous
with the outer whorl of other Annonaceae) that are apically connivent to form an enclosed pollination chamber, whereas Desmos species have two whorls of three petals which are basally constricted and apically free.
A Morphology-Based Cladistic Analysis of Digitaria (Poaceae, Panicoideae, Paniceae)
Authors: Vega Andrea S. , Rua Gabriel H. , Fabbri Liliana T. , Rúgolo de Agrasar Zulma E.
Published: June 2009

A phylogenetic analysis was performed on 67 species of Digitaria belonging to four subgenera and 26 of the 32 sections recognized in Henrard's monograph. The analysis was based on 113 discrete and six continuous morphological characters. In the resulting topologies the genus
Digitaria was monophyletic. In spite of the low support for most groupings, several clades were recovered. The subdivision of Digitaria in the four subgenera proposed by Henrard was not supported since the large subgenus Digitaria appears as a paraphyletic assemblage within
which the other three subgenera are nested. Nevertheless, the monophyly of some of Henrard's sections was supported. This is the first approach to the phylogeny of Digitaria. Se llevó a cabo un análisis cladístico. Se incluyeron 67 especies de Digitaria
pertenecientes a los 4 subgéneros y a 26 de las 32 secciones reconocidas en la monografía de Henrard. El análisis fue basado en 113 caracteres morfológicos discretos y 6 continuos En las topologías resultantes el género Digitaria resultó
monofilético. A pesar del bajo soporte de la mayoría de los grupos, fueron recuperados varios clados. Los resultados no fueron consistentes con la subdivisión de Digitaria en 4 subgéneros propuesta por Henrard, ya que el extenso subgénero Digitaria
aparece como un agregado parafilético dentro del cual se hallan anidados los otros tres subgéneros. Sin embargo, la monofilia de algunas secciones fue confirmada. El presente estudio constituye el primer análisis filogenético de Digitaria.
Systematics of the Neotropical Blueberry Genus Disterigma (Ericaceae)
Authors: Pedraza-Peñalosa Paola
Published: June 2009

Disterigma s. l. comprises 37 species of small shrubs found in Central and South America, mostly in cloud forests and páramos. The notion that the morphological circumscription of Disterigma s. l. is too wide and that it may not be a monophyletic group was supported
by recent molecular evidence extracted from only a few species of Disterigma. This study addresses the monophyly and position of Disterigma s. l. within the complex blueberry tribe Vaccinieae through an intensive taxon sampling. Seventy-nine species are sampled, including 84%
of the species of Disterigma s. l. and 13 genera of neotropical Vaccinieae. The parsimony analysis of nrITS and ndhF data reveal that Disterigma s. l. is polyphyletic with three independent origins within Vaccinieae. The majority of the species form a well supported monophyletic
group, Disterigma s. s., which is located within a large Andean clade; all Disterigma s. s. species share the presence of a differentiated pair of apical bracteoles. Segregated from Disterigma s. s., but also Andean in origin, is the novel Central Andes Segregated Disterigma
clade, where D. bracteatum, D. pentandrum, D. rimbachii, and D. ulei are found. Also resolved outside of Disterigma s. s. is D. trimerum, a taxon of Mesoamerican origin.
Synopsis of the Genus Chamaeangis (Orchidaceae), Including Two New Taxa
Authors: Droissart Vincent , Sonké Bonaventure , Nguembou K. Charlemagne , Djuikouo K. Marie-Noël , Parmentier Ingrid , Stévart Tariq
Published: June 2009

A synopsis of Chamaeangis (Orchidaceae) with a taxonomic key to the genus is provided. Twelve taxa are recognized. Detailed examination of the specimens revealed two novelties: Chamaeangis spiralis from Nigeria and Cameroon, and Chamaeangis lecomtei
var. tenuicalcar, a new variety from Ivory Coast, Ghana, and Gabon. Chamaeangis pauciflora is shown to be synonymous with Chamaeangis letouzeyi, which is here redescribed in detail. Chamaeangis thomensis is neotypified, and Chamaeangis lecomtei var.
lecomtei is lectotypified. Chamaeangis gracilis is treated as an excluded species. Several new country records of Chamaeangis are provided.
Taxonomic Study of the Carex tenera Group (Cyperaceae)
Authors: Rothrock Paul E. , Reznicek Anton A. , Hipp Andrew L.
Published: June 2009

According to previous molecular study, the Carex tenera group sensu lato consists of C. tenera s. l. and C. normalis in one clade and C. festucacea, C. oronensis, and C. tincta in a sister clade. We found that Carex tincta, clarified
by thorough review of herbarium materials, has a much narrower geographic range than previously thought, centering on Maine (U. S. A.), adjacent states, and adjacent portions of Canada with rare scattered occurrences to western Lake Superior. Carex tenera has traditionally been thought
to consist of two varieties: the transcontinental variety tenera and the upper Midwest (U. S. A.) variety echinodes. In light of ecological and chromosomal differences, AFLP genetic distances, and morphological analysis the latter should be recognized as a distinct species, Carex
echinodes comb. et stat. nov. Carex echinodes and narrow-leaved forms of C. normalis can be challenging to differentiate morphologically, but widest leaf width, inflorescence internode length, peduncle diameter, and growth habit separate the two taxa. New chromosome numbers
are reported, with those of C. tenera (n = 24 + 2III, 26, 27, 28) having a lower range than either those of C. echinodes (n = 37, 38, 39) or C. normalis (n = 34, 35, 36).
A conceptual selenium management model
Authors: Chapman Peter M , McDonald Blair G , Ohlendorf Harry M , Jones Ron
Published: June 2009

We describe herein a conceptual selenium (Se) management model, directed toward coal mining in western Canada, but which can be applied to other coal mines and, with appropriate modification, to other industrial sources of Se to aquatic and terrestrial environments. This conceptual model provides a transparent means to integrate and synthesize existing information that can be used to provide an adaptive approach for managing ecological exposures and associated risk. It is particularly useful for visualizing and subsequently developing management interventions for Se control and risk reduction. The model provides a structured process by which critical information needs can be identified and addressed. It effectively provides the foundation for making management decisions related to Se discharges to aquatic and terrestrial environments by showing interrelationships of the various media and receptors as well as primary sources, release mechanisms, secondary sources, and exposure pathways.
Bioaccumulation Assessment Using Predictive Approaches
Authors: Nichols John W , Bonnell Mark , Dimitrov Sabcho D , Escher Beate I , Han Xing , Kramer Nynke I
Published: June 2009

Mandated efforts to assess chemicals for their potential to bioaccumulate within the environment are increasingly moving into the realm of data inadequacy. Consequently, there is an increasing reliance on predictive tools to complete regulatory requirements in a timely and cost-effective manner. The kinetic processes of absorption, distribution, metabolism, and elimination (ADME) determine the extent to which chemicals accumulate in fish and other biota. Current mathematical models of bioaccumulation implicitly or explicitly consider these ADME processes, but there is a lack of data needed to specify critical model input parameters. This is particularly true for compounds that are metabolized, exhibit restricted diffusion across biological membranes, or do not partition simply to tissue lipid. Here we discuss the potential of in vitro test systems to provide needed data for bioaccumulation modeling efforts. Recent studies demonstrate the utility of these systems and provide a “proof of concept” for the prediction models. Computational methods that predict ADME processes from an evaluation of chemical structure are also described. Most regulatory agencies perform bioaccumulation assessments using a weight-of-evidence approach. A strategy is presented for incorporating predictive methods into this approach. To implement this strategy it is important to understand the “domain of applicability” of both in vitro and structure-based approaches, and the context in which they are applied.
Laboratory Study of Miscible Carbon Dioxide Flooding of UAE Carbonate Oil Reservoirs
Authors: Almehaideb Reyadh , Shedid Shedid A. , Zekri Abdulrazaq Y.
Published: June 2009

This laboratory study describes the technical feasibility of applying CO2 miscible flooding in a major field in Abu Dhabi, UAE. The field section considered is a low permeability carbonate that had so far poorly responded to water flooding.

The study had two major aspects, phase behavior and core flooding. In phase behavior, the field's petroleum was studied with its minimum miscibility pressure with CO2 determined. Also, asphaltene precipitation due to CO2 injection was measured and included in the phase behavior model. In core flooding, detailed rock characterization was carried out using SEM, EDS, and ICP. Thereafter, core floods were carried out to evaluate the additional recovery from miscible CO2 injection and the optimum CO2 slug sizes. Core floods were also used to evaluate recoveries from different initial saturations, for less than miscible conditions, and for side effects such as asphaltene precipitation, sulfur deposition, and effect of CO2 on the limestone rock.
Matrix Stimulation of Thick Carbonate Formation: High Rate Acid and CT Acid Treatments—A Case History
Authors: Rachmawati Fitria Dewi , Andika Rizky , Simanjuntak Timur M. , Aimar Amritzar , Wijaya Rio , Abubakar Prihatiningdiah
Published: June 2009

Most of oil and gas wells in Indonesia are developed in Sumatra and Java. Central Sulawesi is one area in Indonesia that previously didn't really have high activity in oil and gas because of its location that drives the logistics to become an issue. Central Sulawesi now is showing more activities on oil and gas exploration and production with the presence of Tiaka field that produced about 2,981 BOPD (Dec-07). This paper covers several stimulation works performed in Tiaka field, Central Sulawesi. The produced oil is being temporaryly stored in an FSO facility and then transported to refinery in Indonesia or exported.

Tiaka wells are drilled at some angles into Tomori formation, a thick carbonate formation which ranges from 70′ – 131′ in thickness containing 28 API oil. Porosity varies from 10% – 15%. Four wells (Tiaka #5, 6, 7, 8) were completed with cemented casing and perforated across the target zone. Two wells (Tiaka #9, 10) were completed with uncemented pre-perforated liner across the target zone. Length of perforation for stimulation work ranges from 170′ – 840′.

Combinations of hydrochloric acid and acetic acid were used and the composition was held constant for all acid stimulated Tiaka wells. However several acid volume loadings (in gal per ft of interval treated) were tried to optimize the treatment. Several acid placement methods were tried: high rate acid treatment with gelled acid and acid through CT.

All stimulated wells showed significant production increase compared to their production rates prior to stimulation. Discussion is made on which methods gives the best production result for the existing wells and the preferred method of stimulation for the future Tiaka development wells.

This paper details the application of acid stimulation works in 5 Tiaka wells, post treatment well performance, best practices, and lessons learned.
A New Approach to Dealing With High Pressure Cemented Annulus in Re-Entry Wells
Authors: Al Ashhab Jamal , Khan Naeem , Boyd Doug
Published: June 2009

Sustainable Annulus Pressure (SAP) is a major safety and cost issue for Zakum Development Company (ZADCO) directly impacting it's ongoing development program and strategy. As part of its field development plan, ZADCO is in the process of horizontalizing many of its older deviated and vertical wells. During the well re-entry process, significant numbers of high outer annulus pressure cases are encountered. Attempts to remedy the situation using remedial cement squeezes are rarely successful, leaving a more complicated well, slowing drilling activity and occasionally resulting in abandonment of the well. A robust diagnostic and monitoring program lead to the conclusion, many high annulus pressure instances were due to thermal effects on fluids trapped in cement channels behind casing1.
Multiphase Well Rate Measurements Applied to Reservoir Analysis
Authors: Tosic S. , Medhizadeh P.
Published: June 2009

The new technology of multiphase measurement has been widely adopted by the oil industry. The meters that utilize this technology are either permanently installed or periodic usage such as well testing during the flow back, well appraisal, trials, etc. The consistent, reliable and accurate flow measurement plays an important role in reservoir and production engineering. However, the industry trends show that many practitioners do not fully utilize the potential of continuous on-line measurements for reservoir and production engineering assessments. This paper will show how online multiphase measurement data can be applied to reservoir and production analyses and how additional useful results can be obtained. Field examples from the Gulf of Mexico (GOM) will be presented to support the process.

To begin with, the paper reviews the role of pressure transient analysis (PTA) and flux rate for assessing the health of the reservoir. PTA gives useful information about the health of the well (skin) and the reservoir properties. It is an established analysis methodology that requires two important inputs, bottom-hole pressure and flow rate. If the flow rates are not accurate, then the results from PTA would be erroneous. Also, the calculation of down-hole flow velocity would be incorrect. These uncertainties could result in wells to be produced below or above optimal levels. Either case would lead to production loss or well damage and the need for remedial work-over. Unfortunately, the maximum safe-rate term is not easy to predict. With high producing wells, minor measurement error can create significant errors in related calculations for reservoir or well parameters. For instance, if the well flow velocity in the formation exceeds the critical velocity for fines movement, the formation fines would start moving. Once they are moving, the additional near-wellbore region damage would be created or the screen may get eroded.

Production data analysis (PDA) such as Rate Normalized Pressure (RNP) analysis in conjunction with continuous flow rate measurements, provided by online multiphase meter, can be used to obtain additional reservoir parameters. In the applications discussed in this paper, the flow rates from the multiphase meters were extensively used for reservoir and well surveillance, flow assurance and the well production allocation.
Strategic Approach in Tackling Performance
Authors: Carroll T. , Beaumont R. N. , Gill J.
Published: June 2009

Operators face continued challenges in maintaining and operating their plants cost effectively while attempting to drive improvements in reliability and performance. In pursuit of this goal, many operators have recognised the benefits of effectively managing their rotating equipment using centralised management systems, such as DCS, Historians and CMMS where data can be stored, modelled using predictive analytics, and remotely accessed and interrogated. However, the effectiveness of these systems is wholly dependant on the quality of the information in the system. Industry wide programmes, such as refinery of the future and digital oil field of the future, have driven, and continues to drive, the modelling and predictive analytics capability of many systems being implemented. However, the quality of rotating equipment data upon which this modelling is based is still, in many cases, poor.

This paper presents a system that is aligned with these operator goals and integrates with current business systems to improve reliability of rotating equipment. The primary goal is improvement of maintenance activities, through continual review and optimisation of the modelling and measurement. Finally measurement and prevention of failures on rotating equipment can be achieved through the use of innovative wireless technologies developed specifically for machinery monitoring in industrial and hazardous areas. These devices determine machinery condition and allow the implementation of preventative maintenance regimes and thorough root cause analysis (RCA) to be undertaken; this would deliver a steady improvement in performance.
4C Seismic Data Analysis for Reservoir Monitoring in Shallow-water Environment
Authors: Sun Yuefeng , Berteussen Karl
Published: June 2009

In this report, we present results of seismic modeling and data analysis from a study of a 2D 4C OBC data set acquired in the shallow-water environment typical of the Arabian Gulf.

Although surface and interface waves are stronger than in deep-water environment, adequate data processing combined with modelling reveals both high quality reflected P and converted S waves. A combination of shallow water depth and hard bottom rather results in a favorable effective waveform similar to the original source signal. More importantly, we discover that this combination enables inline geophone records to be interpreted as PS-S reflections due to P-S energy conversion at the water/rock interface, stronger than other converted modes. Seismic changes due to water flooding or CO2 injection can be detectable on hydrophone records.

Our preliminary analysis indicates that 4C seismic data acquired in shallow-water environment could be helpful for carbonate reservoir production monitoring. In contrast to deep water environment where water column reverberations can present severe problems for seismic imaging and reservoir characterization, the source, the air/water and the water/rock interfaces in shallow-water environment rather act as an effective source that has a similar waveform and short duration as the original source signal. For near-offset data where the energy of converted PS-S reflections are strong, inline geophone data at shallow depths correlate well with synthetic S-wave modeling results using log data.
Understanding the Corrosion Inhibitor Partitioning in Oil and Gas Pipelines
Authors: Achour Mohsen , Johlman Carolyn , Blumer David
Published: June 2009

The use of corrosion inhibition has been a common practice in industry to protect oil and gas pipelines made of carbon steel and exposed to wet hydrocarbons containing CO2 and H2S. It is however important to emphasize that the inhibitor efficiency is highly dependent on its capability to be present in the water phase and reach the pipe wall. Therefore, for a given corrosion inhibitor injection rate, there is a need to quantify the amounts of the active components present in the water and the oil phases as well as any loss to the solid surfaces, particularly to scale and corrosion products or sand if present.

This paper focuses on the use of an in-house developed laboratory method to quantify the partitioning of the corrosion inhibitor between the oil, water and solid phases and evaluate its performance as such. The partitioning of the inhibitor is evaluated using a modified standard LPR (Linear Polarization Resistance) corrosion test, followed by an analysis of the corrosion inhibitor residuals in the various phases using an LC-MS (Liquid Chromatography-Mass Spectroscopy) analytical method (Blumer and Johlman, 2008). The major active components of the inhibitor are traced using such analysis. The paper presents an illustration of the testing method and the obtained results.
Impact of ERD Wells with HP/HT Downhole Conditions on Drill String Integrity
Authors: Franchi J. , Gamisans W. , Drilling VAM , Baryshnikov A.
Published: June 2009

Continuous developments in oil and gas drilling operations have resulted in a significant increase in the application of extended reach wells sometimes combined with HP/HT down-hole conditions.

HP/HT conditions are generally taken into account as key inputs for directional drilling equipment and casing and tubing strings selection. Indeed, high downhole pressures and temperatures limit the selection of materials for these equipments and also drive their design properties.

Concerning tubulars, casing and tubing strings designed for HP/HT wells incorporate heavier body walls, high grades and special premium connections to withstand pressure levels associated with high to extreme tension or compression.

Recent drilling operations in the North Sea have shown that drill string tubulars can also be impacted by the combination of high levels of torque & drag associated with ERD and high temperatures. Not anticipating the effect of such combinations in the well planning and drill string selection phases can result into severe operational issues.

This paper describes the lessons learned during recent extended reach drilling operations with HP/HT downhole conditions and presents the key factors to be considered for appropriate drill string specification and field running in such cases.
Company Growth through Challenges and Innovations for Well Construction
Authors: Kikuchi Shuichi , Fada'q Abdulla S.
Published: June 2009

Our current company's perspectives focus on increasing in production and injection potential, HSE excellence, cost effective field development, enhancement of learning organization and the effective use of new technology.

At present, the early delivery of quality well, minimizing production/injection losses due to offshore rig and barge activities, and HSE enhancement, as well as introducing new technologies to add values to our field development become major challenges for our well construction team composed of ZADCO (Zakum Development Company) and ADMA-OPCO (Abu Dhabi Marine Operating Company).

Analyzing the issues, identifying the required changes, creating implementation strategies, setting targets with full commitments, and continuous monitoring the progress of the challenges are essential to mobilize them ahead and make them last.

This paper describes our challenges and technical innovations required for our company growth as well as highlighting following initiatives, which have been taken by the team -: The change of business process for well construction to enhance learning organization.Application of WCPMS (Well Construction Performance Management System) consisting of three performance measures, i.e., Drilling Efficiency KPI (Key Performance Indicator), Well Quality KPI and Well Cost KPI.Effective use of a barge to reduce the work load for offshore rigs.The identification of root causes for the main NPT (Non Productive Time) and the preparations of the counter procedures and the introductions of new technologies for well construction performance breakthrough.Updating the SIMOPS (Simultaneous Drilling and Production Operation) procedure through required risk assessments to minimize production and injection losses.The establishment of procedure for zero oil flaring and high quality water for discharge to minimize the emission of a green house gas (CO2) and maintain marine ecosystem.Successful implementations of MLC (Multi-Lateral Completion) technologies to create the technical basis of MRC (Multi-Reservoir Contract) with full access functions.
The CTour Process, An Pption to Comply with Zero Harmful Discharge Legislation in Norwegian Waters - Experience of CTour Installation on Ekofisk After Start up 4th Quarter 2007
Authors: Voldum Kåre , Garpestad Eimund , Anderssen Nils Olav , Henriksen Inge Brun
Published: June 2009

In 1998 the Norwegian Government issued a White Paper (1) requiring the oil industry in the Norwegian sector of the North Sea to develop a strategy of reaching "zero discharges" of produced water within 2005. Operationally, zero discharge has since been defined as "zero harmful discharge" (2). In order to quantify the "harmfulness" of these components, a management tool, the EIF (Environmental Impact Factor), has been developed (3,4,5).

ConocoPhillips originally projected to achieve a combined 95 % reduction in EIF at Ekofisk by introducing Produced Water Re-injection (PWRI). However, after a pilot PWRI test was performed, the conclusion was that re-injection was not cost efficient and most importantly, it became apparent that it introduced a risk of reservoir souring, and could also cause substantial loss of oil produced.

It was then decided to evaluate best available produced water cleaning technologies (7,8,9). Based on previous test data, the results showed that Solvent Extraction (CTour) was the most promising technology for removal of dispersed oil and dissolved aromatic components. Pilot tests of CTour were conducted in 2004-05, and the results showed an 80% EIF reduction, reaching residual oil of <2 mg/l and Naphtalenes and PAH reduction by 80-95%. The CTour Process was successfully scaled up to 300 000 BWPD full field installation, and was started up and commissioned 4'Th quarter 2007. The results from performance testing indicate that the efficiency from the original pilot tests had been successfully reproduced, yielding residual OiW of 1-2 ppm and Naphtalenes and PAH reduction by 86-92%.

It is further concluded that the process yield residual discharge reduction in accordance to the guaranty parameters originally issued upon signing of the licence agreement.

The CTour Process is generally based on using available condensate from suction scrubbers as solvent, but at Ekofisk, NGL is used as extraction fluid.
Optimization of Drilling Operational Parameters and UBD Feasibility Study in a Mature UAE Field Wells
Authors: Jarwan Abdullah Humaid Al , Menhali Adnan Mohammed Ahmed Al , Kindi Khalid Abdul Menem Saif Al , Kuru Ergun , Akgun Ferda
Published: June 2009

Mechanical efficiency concept derived from the specific energy theory was used for a comprehensive drilling performance analysis. Data from 17 wells drilled in a mature UAE field were evaluated.

A wellbore stability analysis of the wells was also conducted by using linear elastic theory of rock deformation. Potential application of the UBD techniques in has been evaluated, based on the results of the wellbore stability analysis.

Results have shown that: The mechanical efficiency concept is applicable for the evaluation and improvement of the drilling performance of the wells drilled in the field under consideration.Based on the drilling Mechanical Efficiency concept, the optimum operational parameters such as weight on bit, rotations per minute, bit type, and bit hydraulic horsepower could be identified.The operational window between formation pore pressure and minimum drilling fluid pressure to avoid borehole collapse was found to be too narrow both in vertical and horizontal wells.Results of the wellbore stability analysis indicate that there will be a risk of borehole collapse if UBD techniques are used.

Therefore, it is recommended to carry out more in depth analysis of in-situ stresses before making any decision on the use of UBD techniques for drilling vertical and horizontal wells in this mature UAE field.
HR Evolution - Dynamics of Paradigm
Authors: AL-HAJJI Sultan
Published: June 2009

Challenges on full cycle of employment

■ Attract ■ Recruit ■ Retain

From Oil & Gas Industries to

■ Intra Oil & Gas Industries ■ Multinational to National Oil Companies ■ To other industries ■ Entrepreneurship ■ Financial Institutions ■ Hospitality Industry
Evaluation of Wellbore Clean Up Fluids by Comparing Laboratory Test Results with Field Production Data
Authors: Al-Kitany N. , Ghosh B. , Eldin Y. Fakhr , Al-Bemani A. S. , Al-Hadhrami H.
Published: June 2009

Wellbore clean up has become an integral part of well completion operation aiming to maximize well productivity from a near skinless wellbore. The awareness has become more widespread with more and more horizontal and sand packed openhole wells being completed with so-called non damaging Drill-In-Fluids (DIF). Although drill-in-fluids control fluid loss and saturation related damage to a great extent, they tend to leave a sticky filter cake containing polymers and Calcium Carbonate particulates which can severely restrict well flow. Acids, oxidizers, chelating agents and enzymes have been often used as wellbore clean up fluids with mixed success. This article demonstrates laboratory and field evidences on superior efficiency of some recently developed bio-enzymes and explains the reason of their not so satisfactory treatment result in some wells.

Simulated Reservoir Condition Core Flow (RCCF) and return permeability measurement was the basis of laboratory evaluation and comparison of various clean up formulations, including inorganic/organic acids, oxidizing agents, various enzymes and combination treatments. Mud filter cake was developed by simulating drilling and reservoir parameters. Cleaning treatments were mimicked as per realistic field operation. Photographic evidences were produced on clean up efficiency and final conclusion was drawn based on return permeability.

Well treatment methodologies are discussed and production data from over twenty wells/legs were produced, analyzed and compared. An effort is made to analyze unsatisfactory treatment outcome in some of the enzyme treated wells and to establish the best practice approach for wellbore clean up operations.
Uncertainty Signal Analysis for a 4D-Seismic in a Middle East Carbonate
Authors: Vega S. , Berteussent K. A.
Published: June 2009

To fully evaluate the results and achievement of a time-lapse seismic, we need to determine the uncertainties of the seismic signature changes. In this paper, we study the uncertainty of a time-lapse seismic in a carbonate reservoir in the Middle East. We combine statistics and analytical methods to study the uncertainties in compressional velocity, acoustic impedance and seismic amplitude. We find, in general, that the uncertainty increases with thickness. The uncertainty at the facies is considered intermediate as it honors the geology but it carries variations in fluid content along. In addition, Gassmann predictions seem to under-estimate fluid changes. We propose an approximated equation to evaluate uncertainties in seismic amplitude. Finally, we calculate that the signal-to-noise ratio should be higher than 6 (15.56 dB), for detecting physical time-lapse seismic changes in this data.
Challenges of Seismic Processing of Transition-Zone Data: Comparison of Three State-of-the-Art Approaches
Authors: Hadidi M. T. , Nehaid H. A. , Abousetta A. , Yahia A. , Soroka W. L.
Published: June 2009

A program of 2D seismic lines was acquired in a transition zone in Abu Dhabi in early 2007. The objective was to firm up exploration concepts in the cretaceous, including subtle reefal buildups. Three data issues were of concern, namely, matching the different seismic sources and receivers, static corrections, and noise attenuation for improved signal-to-noise ratio. Because transition-zone acquisition entails dealing with a variety of environments, it was necessary to use two types of sources, namely air gun arrays and dynamite, and three types of receivers - marsh geophones, hydrophones, and dual sensor units. Matching of the resulting six source-receiver combinations was a key challenge. The dynamic and complex nature of transition zones, situated between land and marine environments, causes noise levels to be particularly high. Mitigation of seismic noise was the second processing challenge. Finally, the low-relief structures that were the targets in this area placed stringent demands on the static solutions. Coming up with an accurate static solution was the third processing challenge.

This project provided a unique case study in transition-zone processing, because the data was sent for processing by three contractors. This was done to verify that optimum processing has been performed on the data to meet the interpretation objectives. This afforded a rare and unique opportunity to compare three state-of the-art approaches to transition-zone seismic processing.

This paper presents comparisons of the final migrated images obtained using the three processing approaches. It also refers to further analysis carried out using well-to-seismic ties and acoustic impedance sections produced by post-stack inversion. We will conclude with the key lessons gained from this experience, which we hope will find application to other projects dealing with this particularly challenging problem.
Platform and Field Life Assessment and Extension
Authors: Hudson Brian G.
Published: June 2009

Improved extraction technology combined with high energy prices has resulted in requirements to extend the operating life of offshore installations well beyond the ‘retirement’ dates anticipated at the time of installation.

A typical design life for an offshore installation would be 25 years. Many installations around the world are approaching or have already exceeded this figure but are now required to remain in productive operations for a further 20 or 25 years. Operating the installations beyond their design life does not mean that they are no longer fit for service, but the owner operators of such facilities face a common challenge namely, "how to maintain production capability against changing operational demands in a cost effective way whilst preserving integrity?"

A significant element of this desire is the need to develop an effective asset integrity management approach. Implementing asset integrity management requires that all aspects of operations essential to safety and integrity are properly designed, constructed, tested, operated, inspected and maintained in a sustainable, holistic and systematic way, thus allowing continued beneficial operation.

In certain regions, such as the North Sea, there is a requirement to gain consent from the regulator to continue to operate an asset beyond its original design life. A structured asset life review, as described in the paper is one means of developing a case to support ongoing operation. A structured asset life review also delivers potential financial benefits through protecting or improving Overall Equipment Effectiveness as well as facilitating effective management of OPEX and CAPEX expenditure.

The chosen approach must apply not just to the traditional interpretation of asset integrity management focusing only on mechanical equipment, but also be extended to cover all factors with an impact on ongoing operation, including safety critical protective systems, electrical, instrumentation, control systems, maintenance practices, operations, engineering and human factors. This paper will highlight the key relevant issues, principally with regard to topside equipment and provide a practical approach or insight into a suitable methodology to achieve this with optimal use of time and resources.
Effective Recruitment Strategy in a Short Skills Market
Authors: Strathdee Donald
Published: June 2009

A tightening of resources within the Oil & Gas industry has in the past, been attributed to the volatile nature of the pricing structure for a barrel of oil - the boom and bust business model can put many people off. However, this explanation is not applicable to the past 5 years where prices have been stable and demand continues to increase.

Studies carried out in Europe conclude that the number of students entering engineering and science in the last 10 years is in decline. Many students are instead choosing to follow careers within Finance or the Media because they are perceived to be dynamic and "clean" with fast track career potential. This problem will soon come to a head as much of the current workforce reaches retirement age - this having been termed "The Big Crew Change".

The current situation must be addressed in order to avoid future delays to projects through a lack of human resources. Now more than ever before, the industry must adopt a robust and effective recruitment strategy which will counteract the predicted deficit in talent.
Benchmarking Safety Through Safety Perception Surveys
Authors: Griffioen Govert
Published: June 2009

Safety practitioners know only too well that simply implementing appropriate procedures and training is not enough to ensure a successful safety program. But why is it that some programs are not effectively executed or simply not followed by employees? Is there a way to identify the hidden pitfalls in a safety process? How does a company establish a benchmark by which to measure future safety performance?

Eight years ago DuPont safety and consulting professionals set out to find a way to answer these questions, and the result was the Safety Culture Improvement Process (SCIP) Survey. The goal of the survey is to evaluate organizations' perceptions of their safety process and identify behaviors, attitudes and other factors that can derail a safety program. Since its inception, the SCIP survey has been given to more than 200,000 employees in 61 countries across a range of industries.

This paper will review nearly ten years' worth of data from the SCIP Survey, sharing insights, trends and analysis related to safety perceptions and safety culture. The goal is to help executives, management and safety professionals better understand and overcome the obstacles to world-class performance.

One of the unique aspects of the survey is that it queries all levels of an organization, collecting responses not only from company leaders but also from the workers who will eventually adopt the new behaviors and attitudes. Once the information is gathered, the results are benchmarked against world class safety programs.

The resulting insights get right to the heart of what employees think about safety and help companies understand the hidden issues that can negatively impact the implementation of a safety culture program. An all too common example includes inconsistent communication from the company leadership, such as conflicting messages about safety and costs.
Behavioral Safety at RasGas Company Limited Doha Qatar, Success Factors
Authors: Arunachalam Ramasamy
Published: June 2009

Among the causative factors for accidents, unsafe acts account for almost 88%; followed by unsafe conditions 10%; and acts of providence 2%. Unsafe acts result from unsafe behavior. In an analysis of Management System faults that trigger accidents, unsafe behavior is seen as the most common one. (M W Heinrich 1931)

Most traditional safety systems focus on tracking injury-related incidents (e.g. OSHA Occupational Health and Safety Administration-recordable, lost-time accidents) as means of evaluating safety success. Although it is important to track these events, the incidents themselves are most likely the result of actions taken by one or more people. Thus, the incidents are outcomes of behavior, or lagging indicators of safety. (Center for Behavioral Safety)
Optimizing Fracturing Fluids From Flowback Water
Authors: Rimassa S. M. , Howard P. R. , Blow K. A.
Published: June 2009

As mature fields produce larger quantities of water, operators and service companies find themselves challenged with disposing flowback and produced water to reduce costs, handling the logistics of getting enough water to hydraulically fracture the well, as well as complying with stricter governmental regulations. As produced water is recycled and used in fracturing applications, each cycle of re-used water returns with a more complex chemical make up than before. Therefore, the usable lifetime of the recycled water is shortened or requires expensive cleaning or dilution with fresh water to make it a viable solvent base for fracturing fluids.

This paper describes the process to properly design fracturing fluids using flowback and produced water. The importance of flowback water analysis is highlighted for optimizing fluid performance downhole. Recent developments in proper selection of fluid additives and viscosifiers for slickwater and crosslinked fluids are discussed. We will describe in detail how the salinity, biological activity, and scaling tendency of these waters can impact fluid performance. Other factors, including organics and suspended solids will be included in the discussion. Laboratory examples will be shown to demonstrate the importance of following a systematic approach. Ultimately, this paper focuses on how to optimize well performance using recycled waters in stimulation applications.
Selective Stimulation in Sand Control Completions Using Inflatable Straddle Packers
Authors: De Landro W. , Holder G. M. , Attong D. J. , Crow W. P. , Stewart W. A.
Published: June 2009

Selective acid stimulation has been performed effectively to treatcompletion damage, scale buildup and remove calcium-based drilling fluidfiltrate with the use of inflatable straddle packers run on coiled tubing, inboth horizontal and deviated sand control completions. Production resultsindicate that mechanical method of treatment diversion is extremely effectiveand provides information of formation response in discrete intervals. Two casehistories are discussed which resulted in a 100% production gain and acorresponding injectivity increase from 0 to -16 bbls/day/psi for somesections. A horizontal completion had 980 ft treated in 20 ft sections and a 70degrees deviated wellbore had over 300 ft of interval stimulated using the sametechnique. Stimulation pressure limitations are discussed with respect to theinflation ratio of the packer elements and the deformation, after use.