bluuebunny/crossref_metadata_2025 huggingface dataset:
Observations on the influence of vine covering by means of a transparent plastic sheet on berry ripening and wine quality (Saint-Emilion, 1995 and 1996)
Authors: Van Leeuwen Cornelis , Guigal Ph. , Pieri Philippe
Published: September 2016

Given the climat of the Bordeaux area, major climatic accidents can affect both the yield and the quality of the crop. Spring frost can destroy the future harvest, as happened in 1977 and 1991. Heavy rain in September can compromise a promising grape potential, evaluated at the end of August, and cause major Botrytis problems, as happened in 1963, 1965, 1968, and, more recently, in 1993. In this paper we discuss how soil and vine covering can contribute to avoid these problems. Vine covering, by means of a transparent plastic sheet, was experimented with in 1995 and 1996, between the end of March and early May, to reduce frost harm. In September of the same years, at the end of the ripening period, we studied the influence of soil covering (mentionned "BS") as well as soil and vine covering (mentionned as « BT ») on water status of the vines, microclimate, berry ripening and wine quality.

In 1996, 14 p. cent of the buds were frozen in the control plot. No frost damage was noted underneath the plastic cover. In the same year, when most of our observations were made, supranormal rainfall in August preceeded the second period of soil and vine covering, carried out on 27th August. Under these conditions, we did not mesure any difference in vine water status until the harvest on the three plots. Microclimate was warmer and drier on the covered plots, especially underneath the over-vine cover.

On the covered plots, yields were higher. In 1996, on BT, the vines carried more bunches, the bunches carried more berries and berry weight was higher. The control vines were significantly more affected by Botrytis compared to BS ; BT showed almost no rot. Berries on the covered plots showed a tendancy of having more sugar and total phenolics, and less malic acid. Separate microvinifications were done with 50 kg of grapes from each plot. Wine from BT was preferred over BS. Wine from the control plot was the least appreciated.
Effect of ethanol on yeast film formation
Authors: Alexandre Hervé , Bertrand Fanny , Charpentier Claudine
Published: September 2016

In this study, we have investigated the influence of ethanol on yeast film formation and cell surface hydrophobicity (CSH). A yeast strain (P3) previously isolated from film yeast was grown in a medium containing increasing ethanol concentration ranging from 0 to 14 p. cent (v/v). It results from this study that up to 10 p. cent ethanol, the greater was the ethanol concentration, the greater was the growth of film. Using two different techniques (phase partition method, magnobead assay), we have shown that ethanol altered the CSH of the yeast. The measured hydrophobicity (p. cent) of cells grown without ethanol was 65 p. cent compared with 81 p. cent with 14 p. cent (v/v) ethanol. Taking into account the increase in CSH with increasing ethanol concentration which leads to greater film development, it seems likely that CSH alteration constitutes an adaptation mechanism which allows the cell to rise to the surface where growth conditions are favoured i.e oxydative metabolism. The role of CSH on yeast film formation was sustained by using a wine strain (3079) enable to form a film on the liquid surface, thus we have shown that this yeast possess a lower CSH (50 p. cent) compared to P3 strain (80 p. cent). However, CSH is not the only determinant for film formation since a respiratory deficient mutant (P3 rho-) with high cell surface hydrophobicity (80 p. cent) could not form a film. Treatment of cells with lyticase which dramatically reduced CSH of P3 strain from 80 to 15 p. cent points out the protein or glycoprotein nature of the component responsible for CSH.
Rapid detection of microbial contamination in grape juice by flow cytometry
Authors: Bouix Marielle , Grabowski Agnès , Charpentier Monique , Leveau Jean-Yves , Duteurtre Bruno
Published: September 2016

This study presents an application of flow cytometry to evaluate rapidly the viable micro-organisms in grape juice. In this method, viable cells are firstly specitically labelled with a fluorescent reagent. The sample is then injected into the flow cytometer where the labelled micro-organisms are individually illuminated by a laser beam. The emission of fluorescence is measured. The system counts the number of fluorescent events and prints out a histogram of the fluorescence intensity which is characteristic of the micro-organism being analysed. In laboratory conditions, preliminary trials have been undertaken with an artificially inoculated grape juice with pure yeast and bacteria cultures. This method succeeded in counting simultaneously yeasts and bacteria within 15 minutes, with a high degree of sensitivity, 5.103 yeasts perml and 5.104 bacteria per ml. This technique can also be applied to the detection of mould contamination and the test has been done with Botrytis spores. The method makes direct cell counts possible and is capable of analysing 30 samples per hour. It can be automatised and easily used in industrial laboratory. During the last harvest, more than a thousand of must samples were controled using this technique. The results let to determine the yeast contamination level of a grape juice tank even before unloading. The results obtained by flow cytometry were compared to the plate count reference method. The correlation between cytometry and count by plate culture was 99 p. cent for the threshold of 5.1 04 yeasts/ml which seemed to point out a high contamination. By using this flow cytometry method during the harvest period, the results were supplied in real time. This allowed a rapid selection of the musts, depending upon the scale of their contamination and improved the quality of the wine by corrective actions.
The main amino acids in xylem sap of Vitis vinifera L. var. Cabernet Franc during the vegetative cycle. Search for an amino acid marker
Authors: Larchevêque Corine , Casanova A.
Published: September 2016

Numerous studies have been carried out on the vine, must and wine, but few on sap. Main phenological stages i.e. bud burst, the flowering period, veraison and the ripening period have been well described. However, at the present time, no study is available identifying the main amino acids of the xylem sap, at the formentioned periods. Located within the « Graves de Pessac-Léognan » vineyard, the plot area studied has a clayey-chalky soil with a small amount of sand present. The cultivar Cabernet franc was grafted on the Fercal rootstock. Planted in June 1982, the vine was trained with Guyot pruning and no tillage. The density of the plantation was 5.550 vines per ha. Four rows of 21 vines were sampled.

Analysis of xylem sap, by H.P.L.C., at the four stages, taken from several vintages, showed that the global content of amino acids varied year to year (LARCHEVÊQUE, 1998). The experiment reported on herein was carried out in order to determine both the main amino acids in the xylem sap and to identify a marker amongst them, having the same evolution as that of the global amino acid content from one phenological stage to the next. A pool of eight amino acids, all present in large quantities (about 80 p. cent of total amino acid content), was always noted : asparagine/glutamine, tyrosine, arginine, aspartic acid, glutamic acid, histidine and proline. Concentration levels of these components differed in sap, depending on the vintage, at the same phenological stage. At bud burst, as at the flowering period, the sap had a similar qualitative composition.

It was noteworthy that aspartic acid evidenced the same evolution that of the total amino acid content (i.e. the same variation in percentage) from one phenological stage to the next. Aspartic acid should therefore be regarded as a « marker » of total amino acid content evolution during the vegetative cycle.
Heavy metal (Pb, Cu, Zn and Cd) content in wine produced from grape cultivar Mavrud, grown in an industrially polluted region
Authors: Angelova Violina , Ivanov Angel , Braikov Dimitar , Ivanov Krasimir
Published: September 2016

The investigation was carried out in the period 1991-1993 with cv. Mavrud, grown in the region with a major industrial pollutant the Non-Ferrous-Metal Works (NFMW) and a region with no industrial pollutants (as a control). The heavy metal content in soil, grapes and wine was determined. Most of the heavy metals in the grapes precipitate during fermentation into the sediments, which is the reason for their significantly lower content in the wine. Water washing of grape before processing leads to about 2 time decrease in the Pb, Cu, Zn and Cd contents of wine. The pre-washing of grapes does not lead to any quality deterioration in the wine produced. The amounts of Cu, Zn and Cd in the wine from cv. Mavrud, grown in the region of the NFMW-Plovdiv, are lower than the maximum admissible levels, while the Pb content exceeds them about two times.
Evaluation of the efficiency of the polystyrene cone and geotextile fabric for the protection of the vine against late spring frosts in Québec for small exploitations and tree plantations
Authors: Jolivet Yvon , Dubois Jean-Marie , Granberg Hardy
Published: September 2016

Based on temperature measurements recorded within the aerial portions of the Vitis vinifera L. var. Melon vine variety during spring frosts, it was possible to evaluate the efficiency of two methods of phytoprotection : the polystyrene cone and geotextil~ fabric. Experimentation was carried out in a vineyard located near the City of Sherbrooke in Québec during the critical hours (3 h 00 and 6 hOO, local lime), on may 14, 1994. Measurements of interstitial temperatures were acquired using electronic thennometers inserted into the vine shoots and trunks and relayed to a data acquisition system. Result show that: 1) the lowest temperatures are recorded in shoots and trunks located close the ground in the case of vine stocks without protection; 2) of the two methods of protection, the polystyrene cone is the most efficient since it maintains the mean temperature of the shoots and trunks 1,7 oC above those protected by geotextile fabric ; 3) under both types of protection, the coldest temperature are recorded in the highest shoots; 4) since fruit buds are more numerous towards the summit of the stock, it becomes clearly disadvantageous to use geotextile fabric in case of radiative frost because temperatures are col der by 1,5 oC than in the case of shoots \\-ithout protection.
Study of the polyphenolic structure of red wines by physical-chemical and sensory analyses
Authors: Blouin Jacques , Papet Nathalie , Stonestreet Erick
Published: September 2016

This study indicates the repeatability of various structure indices of phenolic compounds (GLORIES Indices). It is excellent for the gelatine index, the HCl index and tanning ability, good for the ethanol index, total tannins and the DMACH index, but less satisfactory for the dialysis index. A relationship which is not directly proportional can be observed between the gelatine index and tanning ability, but also a certain relation between tanning ability on one hand and total tannins-TAI on the other. There is a good correlation between gustatory astringency, the gelatine index and tanning ability, and the latter measurement, being the most rapid (only 45 mn), turns out to be interesting for sorting wines before fine tasting sessions.

Different techniques of pre-fermentation (cold or hot maceration, bleeding), fermentation (submerged cap) or postfermentation (final hot maceration, maturing on the lees) are tested. The results are very variable according to the wines and their age. Favourable results with young wines are not always confirmed after a few months’ maturing. The choice of each technique should be made according to the characteristics of the grapes and the probable consumption dates.
Yeast hulls: effect on spontaneous fermentation in different vinification conditions
Authors: López Rosa , Santamaría Pilar , Epifanio Sara , Garijo Patrocinio , Gutiérrez Ana Rosa
Published: September 2016

The effect of the addition of yeast hulls in vinification was investigated during three consecutive years. The study was carried out in the experimental winery of C.I.D.A in La Rioja (Spain) with free running white grape juice of the Viura variety. Four different vinifications were studied. In two of these vinifications, stuck fermentations were detected. In all the studies, the addition of yeast hulls (yeast ghosts) improved the fermentation kinetics, increasing the number of viable yeasts at the end of the exponential stage and decreasing the final content of reducing sugars. This work revealed a new effect of yeast hull addition which had not been identified previously; their selection effect on the wild yeast strain in spontaneous fermentation.
Evolution of wild and feral vines from the Ega river gallery forest (Basque country and Navarra, Spain) from 1995 to 2015
Authors: Meléndez Elena , Puras Pedro , García José Luis , Cantos Manuel , Gómez-Rodríguez Juan Antonio , Íñiguez Montserrat , Rodríguez Álvaro , Valle José Manuel , Arnold Claire , Ocete Carlos Alvar , Ocete Rafael
Published: September 2016

Aims: The present paper is focused on wild and feral grapevines from the Ega River gallery forest (Alder grove), one of the most important tributaries of the Ebro River. Since this area was preliminary prospected in 1995, it was our intention to assess the evolution of the ecosystem during this time.

Methods and results: Ampelographic description of wild grapevines shows that all male plants had flowers with fully developed stamens and no gynoecium. No hermaphrodite individuals were detected. No virus infection and symptoms caused by Phylloxera on roots were detected. The Erineum strain of Colomerus vitis constitutes the main phytophagous arthropod. Damages caused by powdery and downy mildew were not lethal for the vines. Around 73% of the wild grapevine individuals found in 1995 had disappeared due to human impacts. The number of rootstocks and producer hybrids (French hybrids) had increased in this period by about 30%. Microvinification of wild berries yielded a wine with very high color intensity and total polyphenol index with a low pH.

Conclusion: The wild grapevine population described has suffered a dramatic regression in the 20-year period between prospections, together with a significant increase of feral accessions thus endangering the endurance of the ecosystem and remaining wild grapevine.

Significance and impact of the study : Wild grapevines are a valuable genetic resource for the genetic improvement of cultivated vines. However, our study shows that human impacts and increasing pressure of feral accessions are threatening wild grapevine populations.
Life Cycle Assessment of viticultural technical management routes (TMRs): comparison between an organic and an integrated management route
Authors: Rouault Anthony , Beauchet Sandra , Renaud-Gentie Christel , Jourjon Frédérique
Published: September 2016

Aims: Using Life Cycle Assessment (LCA), this study aims to compare the environmental impacts of two different viticultural technical management routes (TMRs); integrated and organic) and to identify the operations that contribute the most to the impacts.

Methods and results: LCA impact scores were expressed in two functional units: 1 ha of cultivated area and 1 kg of collected grape. We studied all operations from field preparation before planting to the end-of-life of the vine. Inputs and outputs were transformed into potential environmental impacts thanks to SALCA™ (V1.02) and USETox™ (V1.03) methods. Plant protection treatments were a major cause of impact for both TMRs for fuel-related impact categories. For both TMRs, the main contributors to natural resource depletion and freshwater ecotoxicity were trellis system installation and background heavy metal emissions, respectively.

Conclusion: This study shows that the studied organic TMR has higher impact scores than the integrated TMR for all the chosen impact categories except eutrophication. However, the chosen TMRs are only typical of integrated and organic viticulture in Loire Valley and some emission models (heavy metal, fuel-related emissions, and nitrogen emissions) have to be improved in order to better assess the environmental impacts of viticulture. Soil quality should also be integrated to LCA results in viticulture because this lack may be a disadvantage for organic viticulture.
Significance and impact of study: This study is among the first to compare LCA results of an integrated and an organic TMR.
Determination of major anthocyanin pigments and flavonols in red grape skin of some table grape varieties (Vitis vinifera sp.) by high-performance liquid chromatography–photodiode array detection (HPLC-DAD)
Authors: Benmeziane Farida , Cadot Yves , Djamai Rachid , Djermoun Lynda
Published: September 2016

Aim: The aim of this study was the investigation of the anthocyanin and flavonol content in grape skin extracts. Five prevalent anthocyanin-types and four flavonol-types were determined in the skin of three red table grape varieties widely cultivated in El-Tarf (Algeria).

Methods and results: The identification of the compounds was performed by HPLC-DAD based on C-18 reversed phase column separation. Results from HPLC analysis showed that malvidin and petunidin-3-O-glucoside were the major anthocyanin glucoside, whereas quercetin-3-O-glucoside was the major flavonol among the four identified.

Conclusion: The content of anthocyanins and flavonols in the grape skin of three grapevine (Vitis vinifera) varieties exhibits notable differences among the cultivars studied, confirming their importance in the varietal characterization. The highest concentrations of total anthocyanins and flavonols corresponded to the Gros noir variety. The results of the present study also indicate that the grape skin extracts of these Algerian cultivars can be used as easily accessible source of natural antioxidants.  
Significance and impact of the study: To the best of our knowledge, this is the first report on the identification of different anthocyanins and flavonols in berry skin from some red grape varieties largely cultivated in this region of Algeria.
Technical Efficiency and Its Determinants of Rice Production in Cambodia
Authors: Kea Sokvibol , Li Hua , Pich Linvolak
Published: September 2016

The present study aims to measure the technical efficiency and establish core factors effecting rice production in Cambodia. Four-years dataset generated from the central government document “Profile on Economics and Social” of entire 25 provinces between 2012-2015 and the stochastic production frontier model (SFA) was applied. The results indicated that the level of output (quantity) of Cambodian rice production varied according to the different level of capital investment in agricultural machineries, total rice actual harvested area, and technically fertilizers application within provinces. Furthermore, evidence revealed the overall mean efficiency of rice production is 78.4% implies that there is still room to further improve technical efficiency by given the same level of inputs and technology. More importantly, the findings revealed that irrigation, production technique and amount of agricultural supporting staffs are being as the most important influencing factors of rice production’s technical efficiency in Cambodia. In conclusion, present study strongly recommends the development of irrigation systems and good water management practices to be considered and bring into more effective actions by the central government as well as related agencies for improving rice production in Cambodia in addition to capital investment and improving technical skills of supporting staffs and rural farmers.
Assessment of Carbon Flux and Soil Moisture in Wetlands Applying Sentinel-1 Data
Authors: Dabrowska–Zielinska Katarzyna , Budzynska Maria , Tomaszewska Monika , Malinska Alicja , Gatkowska Martyna , Bartold Maciej , Malek Iwona
Published: September 2016

The objectives of the study were to determine the spatial rate of CO2 flux (Net Ecosystem Exchange) and soil moisture in a wetland ecosystem applying Sentinel-1 IW (Interferometric Wide) data of VH (Vertical Transmit/Horizontal Receive—cross polarization) and VV (Vertical Transmit/Vertical Receive—like polarization) polarization. In-situ measurements of carbon flux, soil moisture, and LAI (Leaf Area Index) were carried out over the Biebrza Wetland in north-eastern Poland. The impact of soil moisture and LAI on backscattering coefficient (σ°) calculated from Sentinel-1 data showed that LAI dominates the influence on σ° when soil moisture is low. The models for soil moisture have been derived for wetland vegetation habitat types applying VH polarization (R2 = 0.70 to 0.76). The vegetation habitats: reeds, sedge-moss, sedges, grass-herbs, and grass were classified using combined one Landsat 8 OLI (Operational Land Imager) and three TerraSAR-X (TSX) ScanSAR VV data. The model for the assessment of Net Ecosystem Exchange (NEE) has been developed based on the assumption that soil moisture and biomass represented by LAI have an influence on it. The σ° VH and σ° VV describe soil moisture and LAI, and have been the input to the NEE model. The model, created for classified habitats, is as follows: NEE = f (σ° Sentinel-1 VH, σ° Sentinel-1 VV). Reasonably good predictions of NEE have been achieved for classified habitats (R2 = 0.51 to 0.58). The developed model has been used for mapping spatial and temporal distribution of NEE over Biebrza wetland habitat types. Eventually, emissions of CO2 to the atmosphere (NEE positive) has been noted when soil moisture (SM) and biomass were low. This study demonstrates the importance of the capability of Sentinel-1 microwave data to calculate soil moisture and estimate NEE with all-weather acquisition conditions, offering an important advantage for frequent wetlands monitoring.
Consideraciones metodológicas para un mejor uso del Food Choice Questionnaire en población adolescente
Authors: Rivero Bárbara , Arenas Mariana , Segura Eddy R.
Published: September 2016

Recientemente leímos con gran interés el artículo titulado “Aplicación del Food Choice Questionnaire en jóvenes adolescentes y su relación con el sobrepeso y otras variables socio-demográficas”. El uso del instrumento Food Choice Questionnaire (FCQ) permite conocer y entender mejor los hábitos nutricionales de la gente y, con base fundamentada, proponer estrategias para promover una alimentación saludable y facilitar la adherencia a tratamientos nutricionales.
Função de Produção de Saúde para o Rio Grande do Sul em 2008
Authors: Silva Cristiane , Santos Anderson , Balbinotto Neto Giácomo
Published: September 2016

Objetivo: estimar uma função de produção de saúde para indivíduos adultos entre 25 e 85 anos que residem no Estado do Rio Grande do Sul, utilizando a base de dados da PNAD (2008), através de estimações de modelos Probit. Busca-se entender qual a relação entre as variáveis analisadas no estudo com o estado de saúde da população e quais suas implicações para a formulação de políticas públicas. Uma função produção de saúde é a relação entre insumos e produtos, ou seja, entre assistência médica, serviços de saúde e estado de saúde da população. Resultados: Observou-se uma associação positiva entre saúde e escolaridade. Entre os que possuem zero ano de escolaridade, 59% são saudáveis, já entre as pessoas com 15 anos de escolaridade, esse percentual é de 92%. Encontrou-se também que, quanto maior a idade, menor a proporção de indivíduos com saúde boa ou muito boa. Na faixa de idade entre 25 e 34 anos, 88% são saudáveis, enquanto na faixa de 60 anos ou mais, esse número se reduz para 53%. Conclusão: As principais conclusões deste trabalho foram que maiores níveis de escolaridade e renda, menores níveis de idade, residir na área urbana, ser do sexo masculino, possuir internet, não fumar e praticar exercício físico estão associados a uma melhor saúde do indivíduo. Observou-se que o efeito da educação sobre a saúde é maior para as mulheres; já a renda domiciliar per capita mostrou-se significativa apenas para a amostra do sexo masculino.
Análise de custo-efetividade do n-butil-cianoacrilato para fixação de telas em hernioplastias inguinais sob a perspectiva da saúde suplementar brasileira
Authors: Mensor Luciana , Contadin Regina , Pepe Camila , Cardoso Elisanio
Published: September 2016

Objetivo: Estimar a custo-efetividade do n-butil-cianoacrilato (NBCA) para fixação de telas em pacientes submetidos a hernioplastias inguinais por reparo aberto ou laparoscópico, sob a perspectiva da Saúde Suplementar do Brasil. Métodos: Foi elaborado modelo analítico de decisão para estimar a razão de custo efetividade incremental (RCEI) em horizonte de tempo de um ano após procedimento cirúrgico com o uso do adesivo sintético versus técnicas tradicionais de fixação (sutura e grampos). Alternativamente, o uso de NBCA foi comparado à cola de fibrina. Os desfechos clínicos avaliados foram incidência de dor aguda e crônica. A estimativa de custos médicos diretos totais para as diferentes abordagens cirúrgicas e terapia da dor foi elaborada a partir da opinião de especialistas e coletadas em bases de dados secundárias. Resultados: A RCEI obtida através do modelo evidenciou economia substancial de recursos financeiros relacionada ao uso de NBCA de aproximadamente R$ 2.800 por procedimento após reparo laparoscópico e R$ 60 reais por procedimento para reparo aberto, resultados direcionados majoritariamente pela menor tendência de dor (efetividade incremental de 21,74% em termos de dor evitada) versus métodos de fixação tradicional. No cenário alternativo, no qual comparou-se NBCA com a cola biológica (adesivo de fibrina), atingiu-se economia financeira com nível de efetividade equivalente do ponto de vista estatístico entre os comparadores. Conclusão: Pode-se atribuir que o uso de NBCA para fixação de telas em cirurgias de reparo de hérnia inguinal constitui alternativa segura, efetiva e viável economicamente, quando comparado tanto a técnicas de fixação tradicionais como à cola biológica.
Tratamento cosmético com OnabotulinumtoxinA (Botox®): relação entre avaliação clínica inicial, dosagem e custos
Authors: Chu Raphael , Saito Fábio , Biasi Thiago
Published: September 2016

Objetivo: O objetivo deste trabalho é demonstrar como a correta avaliação clínica pode influenciar na dosagem utilizada no tratamento cosmético de onabotulinumtoxinA (Botox®, Allergan, Inc, Dublin, UK) e sua consequente relação com custo e valor do tratamento a longo prazo. Método: Foram selecionados quatro pacientes para tratamento cosmético com Toxina Botulínica tipo A. Foi realizado registro fotográfico pré-procedimento, com 15 dias pós-procedimento; 3, 4, 7 e 10 meses pós-procedimento. A avaliação inicial dos pacientes, a técnica, objetivo e as dosagens utilizadas foram comentadas pelo médico que efetuou o tratamento. A avaliação e os comentários das fotos pós-procedimentos foram realizados por outro médico especialista. Resultados: Todos os pacientes tiveram as regiões frontal, glabelar e peri-orbital tratadas. As doses totais utilizadas em cada paciente foram: paciente 1: 64U; paciente 2: 69U; paciente 3: 78U e paciente 4: 81U. Conclusões: A correta avaliação clínica é fundamental para o adequado planejamento do tratamento cosmético com Botox®. Resultados duradouros, que geram alta satisfação aos pacientes, estão associados à correta escolha das doses. O custo do tratamento cosmético de Botox® deve ser avaliado de forma global e a longo prazo.
Design of Autonomous Inflow Control Device Completions in Heavy Oil for Complex Reservoir Structures
Authors: Thornton Kim
Published: September 2016

Understanding reservoir structures is necessary when using autonomous inflow control devices (AICDs). Without a sound knowledge of nearby structures or manmade elements, such as injectors, production from heavy oil applications or any advanced completion may fall short of operator expectations. This paper provides several field examples to help illustrate the importance of understanding reservoir structures when using AICDs.

The approach of this study is based on using a near wellbore (NWB) hydraulic simulator coupled with a reservoir simulator to capture holistically the completion/reservoir effects and interaction. With this approach, the production of unwanted fluids is delayed. When unwanted fluids do eventually break through, the AICD can greatly reduce the negative effects of the unwanted fluids on well production. Usually, the unwanted fluids are water and/or gas. Unwanted water is typically (but not limited to) coning or fingering from bottom or edge water drive or from nearby injectors. Gas is coned or fingered downward from the gas cap.

Results show that, without understanding the structure and nearby anomalies of the reservoir, operators utilizing ICDs or AICDs can exacerbate the production of unwanted fluids. Field examples are derived primarily from heavy oil well completions designed for multiple operators in Columbia, Ecuador, Argentina, Brazil, Mexico, Alaska, and Canada over the last eight year period. Typically, completion design must change as more information is gathered about the reservoir. Structural maps are often difficult to obtain, however importing the reservoir model into the design reservoir simulator model adds value. However, the field simulator grid blocks can be too large, creating a lack of definition along the horizontal well, and log data may not be included. This paper presents some simple methodologies in generating the most effective design possible from provided data.

Establishing clear communication, gathering as much data as possible (including structural maps), and using proper models and simulators are key to optimizing advanced completion designs, particularly when utilizing AICDs in heavy oil.
Investigation of Post-Breakthrough Heavy Oil Recovery by Water and Chemical Additives Using Hele-Shaw Cell
Authors: Voroniak A.. , Bryan J. L. , Taheri S.. , Hejazi H.. , Kantzas A..
Published: September 2016

There has been a large number of laboratory tests run in the past, looking at recovery of heavy oil by chemical flooding (polymer, surfactant and SP or ASP systems). These tests have all shown a potential for significant incremental oil recovery from chemical injection compared to water alone. The higher oil recovery was generally achieved under high pressure gradients that were generated during chemical injection. As such, the mechanism proposed in all of these studies is that of water channel blockage and improved sweep from chemical injection. In actual reservoir applications of chemical flooding, the impact of these water pathway blockages may be much less important than what is observed in the linear laboratory scale tests, so the actual mechanisms of chemical flooding in real systems may not be properly represented.

In this project, an experimental investigation is performed using a 2D visual Hele-Shaw cell, to visualize production mechanisms during the chemical flooding process. The 2D nature of the system allows for an understanding of whether chemicals sweep incremental oil from along the same channels as the pre-formed water or if new displacement channels are formed. The flow of a fluid in such models also represents flow without any pore-scale trapping, so observations can be made regarding whether trapping and fluid re-diversion are the only ways that these chemicals can yield improved oil recovery, or if simple alteration of the mobility ratio without additional trapping will already lead to incremental oil.
A Calculation Model for Steam Property Variation Along Wellbore Trajectory in SAGD Processes
Authors: Ju Ning , Zhao Gang
Published: September 2016

Steam properties such as steam pressure and steam quality are critical parameters to form integrated steam chamber and control steam consumption cost during SAGD process. However, steam property variation along steam injection well was not well understood yet. In this paper, a model describing steam flow behavior in steam injection wellbore was built and solved; accordingly steam property variation along steam injection wellbore can be calculated. In our model, both vertical and horizontal wellbores were further divided into several segments. Mass, momentum and energy balance equations have been applied to steam flow inside each segment. During the derivation of these equations, a void fraction correlation that is based on flow-pattern-independent drift-flux model was applied to describe steam flow in a non-uniform manner.

This model was validated by several sets of published field data and a series of general cases were studied to investigate the steam property variation inside wellbore. The computational results indicated that steam property distribution along vertical and horizontal wellbore portions have similar characteristics: steam pressure and steam quality tend to decrease along with wellbore trajectory in both vertical and horizontal wellbore portions during SAGD process; With the increase of steam injection pressure, steam quality decreases faster; with the increase of steam quality during injection, steam pressure decreases faster; With the increase of steam injection rate, steam pressure decrease faster while steam quality decrease slower. For horizontal wellbore, the increase of reservoir permeability tends to slow down the steam pressure decrease but accelerates steam quality deterioration; the increase of oil viscosity tends to slow down the steam quality deterioration but accelerate steam pressure decrease. The results from this study show the effects of steam properties varying along wellbore trajectory under different steam injection conditions and can be used as a design guidance to optimize the steam injection practice in SAGD process.
State of the Art Review of the Steam Foam Process
Authors: Delamaide Eric , Cuenca Amandine , Chabert Max
Published: September 2016

Foam has been used to improve the efficiency of steam injection since the late 1970s and the process has been applied successfully in several fields in particular in California but interest sagged at the end of the 1990s due to low oil prices and little activity took place for several years. The topic has however become more popular in the recent years due to higher oil prices. Foam is generated by the introduction of surfactant along with the steam into the reservoir and reduces its mobility, thus improving the sweep efficiency and reducing heat losses.

There has been no review of the process since the classical work by Hirasaki (Hirasaki 1989) and this paper proposes to remedy the situation and present a state of the art of the process.

The paper will revisit the field tests from the 1980 and then focus on the recent developments in the laboratory where researchers are attempting to develop new workflows and improved surfactant formulations for better performances; in the field with some recent pilot tests; and in terms of reservoir simulations.

This paper will allow engineers to get a complete and up to date understanding of the characteristics and limitations of the process and some guidance as to whether foam could help improve the performances of their steam injection projects.
Optimization of Production in Reservoirs with Temperature-Dependent Asphaltene Precipitation and Irreversible Flocculation
Authors: Temizel Cenk , Zhang Ming , Balaji Karthik , Ranjith Rahul , Zheng Wei
Published: September 2016

Asphaltene precipitation is caused by numerous factors such as changes in pressure, temperature, and composition. Drilling, completion, acid stimulation, and hydraulic fracturing activities can also induce precipitation in the near-wellbore region. Heavier crudes that contain a larger amount of asphaltene have very few asphaltene precipitation problems because they can dissolve more asphaltene. Thus, it is crucial to understand the significance of each uncertainty and control variables not only theoretically, but also with application to real-life examples such as with this model that uses a 32-degree API South American oil to demonstrate the importance of each variable to shed light in order to efficiently manage such reservoirs.

A commercial optimization and uncertainty tool is coupled with a full-physics commercial simulator that models the phenomenon in order to investigate the significance of major parameters on performance of wells in temperature-dependent asphaltene precipitation and irreversible flocculation. Temperature-dependent asphaltene precipitation and irreversible flocculation are modelled where no precipitation occurs at the original reservoir temperature, and flocculated asphaltene is allowed to deposit via surface adsorption and pore throat plugging. The exponent in the power law relating porosity reduction to the permeability resistance factor is modified to change the effect of asphaltene deposition on permeability reduction.

Lower temperatures are specified around the wellbore causing asphaltene precipitation. Sensitivity and optimization have been done on major reservoir parameters, such as, fluid and rock properties and well operational parameters, and significance of each has been illustrated in tornado diagrams. It is observed that a robust approach on handling of uncertainties in reservoir are as important as management of well operational parameters in the scope of reservoir management.

This study provides an in-depth optimization and uncertainty analysis to outline the significance of each major parameter involved in production performance and ultimately the recovery efficiency in reservoirs with temperature-dependent asphaltene precipitation and irreversible flocculation.
Retrieval of Solvent Injected During Heavy-Oil Recovery from Water - and Oil-Wet Reservoirs: Pore Scale Analysis at Variable Temperature Conditions
Authors: Cui Jingwen , Babadagli Tayfun
Published: September 2016

Solvent injection has been given attention to enhance oil recovery by sole use or in combination with a thermal method to develop light, medium, and heavy-oil fields. To make this process efficient, retrieval of expensive solvent efficiently is required. This can be achieved by alternative injection of water (WAG) if the reservoir is homogeneous. In case of heterogeneous reservoirs (fractured carbonates or sands with wormholes), one needs to develop techniques other than viscous displacement to retrieve the solvent diffused into less permeable matrix portion. A method of injecting steam/hot water to heat the solvent to vaporize and retrieve it was introduced recently (steam-over-solvent injection in fractured reservoirs) and tested through core experiments. Although these tests provide valuable data to design the optimal temperature of injected water to make the process viable, the mechanics of the nucleation of the solvent vapor and its entrapment in the pores at the micro scale requires further research.

A series of experiments using a 2-D etched glass micromodel (sandstone replica with a fracture) were carried out to investigate the mechanics of solvent retrieval and entrapment at variable temperature conditions. The micromodel was saturated with dyed processed oils and different solvents were injected through fracture. After the solvent was diffused into matrix completely to recover the oil, the model was heated mimicking a thermal method to reach the boiling point of the solvent and retrieve it. The wettability of the micromodel was also altered to achieve water-wet and oil-wet conditions as wettability dictates the phase distribution in the pores. Following the heating phase, water was injected to retrieve the remaining solvent in the liquid or vapor phase.

Visual observations of solvent diffusion/dispersion into matrix and its retrieval from the matrix clarified the miscibility process in the presence of an immiscible phase, interaction between different phases in a complex heterogeneous system, and phase distributions as a function of temperature. This information can be used to determine the efficiency of solvent retrieval process and optimal application conditions for EOR applications in heterogeneous sands and carbonates.
The Concept of the Sustainable Oil Field Development Applied to Heavy and Extra Heavy Oil Fields
Authors: Armacanqui J. Samuel
Published: September 2016

The Concept of the Sustainable Oil and Gas Field involves a Preventive Approach and the use of New Technologies, Innovations and Best Practices to avoid or reduce the risks of occurrence of environmental incidents and accidents achieved in a cost effective manner. This novel approach focuses on the root causes of the current gaps proposing a practical solution demonstrated on real example cases. Further it contributes to bridge the gap between non Oil and Gas Professionals evaluating the potential impact on the Environment of the core business processes related to the Exploration, Development and Field Abandonment of Oil and Gas fields.

In the present Paper a method is described that supports a sustainable development and operation of Oil and Gas Fields. Further the most common reasons for the current dysfunctional procedures are analyzed as well as practical examples of the proposed approach are shown on executed projects in four continents. The proposed method builds on a preventive approach that starts with the focus of the Environmental Impact Assessment of the activities foreseen for the early project phase, as it is at this stage where the entire project can more effectively be influenced. Further the Use of fit for purpose Innovations, Technologies and Best Practices that strive to remove the risk before it happens, supports a preventive approach. The involved technologies deliver the same outcome than traditional means in a more efficient way. The mindset that the use of those Technologies comes at a higher price is challenged by the latest developments showing that those enable both an environmental friendly workflow and economical advantages to the E & P Companies. Further the above Technologies can be applied at any stage of the field life, be it at the early field development, the operational plateau or later on at the decline and abandonment phase.

Several specific examples from executed Oil and Gas Projects following key elements of the presented Concept of the Sustainable Oil and Gas Field carried out in four continents are provided, showing that operating Oil and Gas fields with Zero Gas Flare, Zero Oil Spill, small footprint, no process effluents to the environment and energy efficiency can be reflected in low oil/gas unit production costs, technical and operational excellence as well as full environmental compliance.

In the present paper a preventive approach to avoid and reduce environmental incidents and accidents by means of an Environmental Impact Assessment that focuses on the early project phases and the aid of fit for purpose Technical Innovations, Technologies and Best Practices is presented. This supports the goal of achieving a more Sustainable Oil and Gas Field to safely achieve production peak and increase recoverable Reserves.
Robust Characterization of Naturally Fractured Carbonate Reservoirs Through Sensitivity Analysis and Noise Propagation Reduction
Authors: Minutti C.. , Ramos G.. , Gomez S.. , Camacho R.. , Vázquez M.. , Castillo N. del
Published: September 2016

Well testing is today a main procedure for verifying reservoir, well and fluid properties such as permeability, skin effect, average reservoir pressure, heterogeneities, boundaries and hydraulic connectivity. We present in this work a methodology based on numerical optimization and statistical methods to get an accurate and reliable Naturally Fractured Carbonate Vuggy Reservoir Characterization, using a Triple Porosity-Double Permeability Model. A sensitivity analysis is performed to identify the effect and magnitude on the pressure of each parameter involved in the model to reduce the error estimation and to eliminate multiple interpretations due to numerical precision. We also introduce a robust regularization method to control noise propagation contained in pressure data for improving well test analysis. The efficiency and accuracy of the proposed approach is demonstrated by implementing the triple porosity-double permeability model as compared with the traditional double-porosity model used in commercial software. Furthermore, not only the accuracy of the fit is compared but also the amount of reservoir information obtained when using the Triple Porosity-Double Permeability model, as we identify nine parameters in the case of totally penetrated wells and eleven parameters in the case of partially penetrated wells. Results are illustrated with transient well tests of real carbonate fractured vuggy reservoirs from Mexico.
Pore-Level Simulation of Heavy Oil Reservoirs; Competition of Capillary, Viscous, and Gravity Forces
Authors: Goudarzi B.. , Mohammadmoradi P.. , Kantzas A..
Published: September 2016

The advancing high resolution scanning technology has formed a concrete basis for simulation of pore events within microstructures. Interactions between capillary, gravity, and viscous forces result in complex flow phenomena affecting pore-scale physics and phase distributions during different displacement scenarios. Consequently, a myriad of techniques has been proposed to deal with all effective forces and dynamically simulate pore scale multi-phase flow physics. In this regard, the significance of each force, particularly viscous forces, on pore-level flow morphology is not yet well studied. Here, the Navier-Stokes equation along with a VOF volume tracking advection equation is applied for simulation of two-phase displacement scenarios considering gravity, capillary, and viscous forces. A pore-throat pair is used as a simple pore-level geometry to conduct a comprehensive sensitivity analysis and investigate the effect of viscosity, IFT, contact angle and velocity on the trapping amount of non-wetting phase. The results are in good agreement with available experimental data and confirm that in pore-level transport phenomena, the amount of residual trapping is a function of pore-throat geometry and wettability and is not affected greatly by interfacial tension or differences of viscosity. The analysis also demonstrates that within microscale porous media images the gravity role is negligible due to low Bond number values. A pore morphology-based quasi-static approach is then applied to a multi-pore micro-tomographic sandstone image to simulate drainage, and imbibition processes and investigate the effect of geometry, contact angle, and IFT on the amount of heavy oil residual trapping.
Evaluation of Heavy Oil Recovery Factor by Water Flooding and Polymer Flooding at Different Temperatures
Authors: Bento Hernandes de , Moreno Rosângela Barros
Published: September 2016

This paper compares the effiency of heavy oil recovery factor by water and polymer flooding under different level of temperature (26°, 50° and 75°C). The performances of both methods were assessed by analyzing the fractional flow curves and the oil recovery factor (%OOIP) for the same temperature. Rheological measurements were carried out to characterize and to select the fluids. Buckley-Leverett model was applied to evalute the effectiveness of the recovery method after the injected fluid breakthrough. Due to the high oil viscosity, the displacement for water flooding is unfavarable. However, the polymer addition improves the viscosity ratio injected/displaced fluids, making the displacement front more sharp. The fractional flow curves showed that the polymer flooding reduces the amount of the remaining oil more than water flooding and the oil recovery are greatly influenced by the test temperature. As the temperature increases, the oil recovery increases, for both methods. At the same temperature, the final oil recovery is equal for water and polymer flooding, showing that the used polymer has not affected the residual oil saturation. However, the polymer flooding was able to anticipate the oil production and the anticipation was more pronounced for higher temperatures. The mobility ratio reduction with temperature rising turned the displacement more piston-like, highlighting the anticipation of the produced oil by polymer flooding.