bluuebunny/crossref_metadata_2025 huggingface dataset:
Substratos e temperaturas para o teste de germinação de sementes de Chorisia glaziovii (O. Kuntze)
Authors: Guedes Roberta Sales , Alves Edna Ursulino
Published: September 2014

Chorisia glaziovii O. Kuntze é uma espécie nativa do Nordeste brasileiro, pertencente à família Bombacaceae que apresenta usos diversificados na medicina popular, na recomposição de áreas degradadas e na indústria de estofados. Com este trabalho, objetivou-se indicar substratos e temperaturas adequados para condução do teste de germinação das sementes de C. glaziovii. O experimento foi realizado no Laboratório de Análise de Sementes (CCA - UFPB), Areia - PB, em delineamento inteiramente ao acaso, com os tratamentos distribuídos em esquema fatorial 4 x 4 (temperaturas 25, 30, 35 e 20-30ºC e substratos papel toalha, sobre papel mata-borrão, entre areia e entre vermiculita). Foram analisadas as seguintes características: porcentagem, primeira contagem e índice de velocidade de germinação, e comprimento de plântulas. A temperatura de 35ºC mostrou-se inadequada para a condução dos testes de germinação e vigor de sementes de C. glaziovii, independentemente do substrato utilizado. Recomendam-se, para a condução dos testes de germinação e vigor das sementes de C. glaziovii, os substratos entre areia ou papel toalha, nas temperaturas de 25 e 20-30ºC.
Modelos não lineares generalizados aplicados na predição da área basal e volume de Eucalyptus clonal
Authors: Carvalho Samuel de Pádua Chaves e , Calegario Natalino , Silva Fabyano Fonseca e , Borges Luís Antônio Coimbra , Mendonça Adriano Ribeiro de , Lima Mariana Peres de
Published: September 2014

Neste trabalho, objetivou-se propor o uso de modelos não lineares generalizados na predição da área basal e do crescimento e produção em volume total do híbrido Eucalyptus urocamaldulensis, em um plantio localizado na região central do estado de Minas Gerais, pertencente à V& M Florestal. A metodologia proposta permite trabalhar com os dados na sua forma original sem a necessidade de transformações de variáveis, e gerar modelos mais precisos. Para a avaliação da qualidade de ajuste dos modelos propostos, foram utilizados os critérios de informação Bayesiano, de Akaike e o teste de razão da máxima verossimilhança, além do erro padrão residual e percentual, e dos gráficos de resíduos. Os modelos se mostraram com uma boa performance, altamente precisos e parcimoniosos nas estimativas das variáveis propostas, com erros reduzidos para 12% em área basal e 4% para predição volumétrica.
Sobrevivência e crescimento de mudas clonais de eucalipto em resposta à aplicação de fertilizante orgânico
Authors: Fernandes Sula Janaína de Oliveira , Titon Miranda , Santana Reynaldo Campos , Antonini Lucas Guimarães , Nogueira Gilciano Saraiva , Barros Filho Nairam Félix de
Published: September 2014

Conduziu-se este trabalho, com o objetivo de avaliar o efeito da aplicação de Fert-Bokashi® sobre a sobrevivência e crescimento de mudas de dois clones de Eucalyptus urophylla propagados pela técnica de miniestaquia. O experimento foi conduzido por um período de 28 dias, utilizando um delineamento experimental em blocos casualizados com três repetições, no esquema fatorial 6 x 2, sendo seis concentrações de Fert- Bokashi® (0,0%, 0,1%; 0,3%: 0,5%; 0,7% e 0,9%) e dois clones. Avaliou-se a sobrevivência das mudas, o crescimento em altura e a matéria seca da parte aérea, das raízes e total. Os resultados obtidos demonstraram que o Fert-Bokashi® não exerceu efeito significativo sobre a sobrevivência e o crescimento das mudas dos dois clones de Eucalyptus urophylla.
Molecular characterization of Eurytrema coelomaticum in cattle from Paraná, Brazil
Authors: Figueira Gustavo Freire , Oliveira Victor Henrique Silva de , Taroda Alessandra , Alfieri Amauri Alcindo , Headley Selwyn Arlington
Published: September 2014

This study investigated the occurrence of Eurytremaspp. in cattle by analysis of the partial 18S rRNA gene sequence. Trematodes from 44 bovine pancreas were collected and classified based on typical morphological features. PCR assay and sequence analyses of amplified products confirmed that the trematodes classified as Eurytrema coelomaticum were phylogenetically distinct from those identified as E. pancreaticum. The results of this study represent the first molecular characterization of E. coelomaticum within the Americas, and provide an efficient method to differentiate digenean trematodes of domestic animals.
Frequency of Toxoplasma gondii antibodies in bovines in the state of Pernambuco, Brazil
Authors: Guerra Neurisvan Ramos , Alves Bruno Henrique Leal e Silva , Farias Márcia Paula Oliveira , Mota Rinaldo Aparecido , Alves Leucio Câmara
Published: September 2014

Toxoplasmosis is a parasitic disease caused by Toxoplasma gondii that affects homeothermic animals, including humans. Felines are considered the definitive host of this parasite, while other animals act as intermediate hosts. The purpose of this study was to assess the frequency of anti-T. gondii IgG antibodies in bovines in the state of Pernambuco, Brazil. Serum samples (n = 427) from animals in 13 municipalities of the coastal forest/plantation region of the state were analyzed using the immunofluorescent antibody test (IFAT). The overall results revealed a prevalence rate of 16.63% (27/427). High percentages of positivity were found among animals aged 25 to 36 months (28.57%; 30/42) and in males (22.22%; 2/9). The present findings suggest that bovine toxoplasmosis is endemic in the area under study.
Gastrointestinal nematode infections in sheep raised in Botucatu, state of São Paulo, Brazil
Authors: Wilmsen Maurício Orlando , Silva Bruna Fernanda , Bassetto César Cristiano , Amarante Alessandro Francisco Talamini do
Published: September 2014

Gastrointestinal nematode infections were evaluated in sheep raised in Botucatu, state of São Paulo, Brazil between April 2008 and March 2011. Every month, two tracer lambs grazing with a flock of sheep were exposed to natural infection with gastrointestinal nematodes for 28 consecutive days. At the end of this period, the lambs were sacrificed for worm counts. Haemonchus contortus presented 100% of prevalence. The seasons exerted no significant influence on the mean intensity of H. contortus, which ranged from 315 worms in November 2010 to 2,5205 worms in January 2011. The prevalence of Trichostrongylus colubriformis was also 100%, with the lowest mean intensity (15 worms) recorded in February 2011 and the highest (9,760 worms) in October 2009. In the case of T. colubriformis, a significant correlation coefficient was found between worm counts vs. rainfall (r = −0.32; P <0.05). Three other nematodes species were found in tracer lambs, albeit in small numbers. Their prevalence and mean intensity (in parenthesis) were as follows: Oesophagostomum columbianum 28% (25.2), Cooperia curticei 7% (4.5) and Trichuris spp. 2% (1). In conclusion, the environmental conditions of the area proved to be highly favorable for the year-round transmission of H. contortus and T. colubriformis.
Rhipicephalus (Boophilus) microplus in the western-central region of Rio Grande do Sul, Brazil: multiresistant tick
Authors: Machado Fabrício Amadori , Pivoto Felipe Lamberti , Ferreira Maiara Sanitá Tafner , Gregorio Fabiano de Vargas , Vogel Fernanda Silveira Flores , Sangioni Luís Antônio
Published: September 2014

The aim of the present study was to assess the acaricide resistance of tick populations in the western-central region of Rio Grande do Sul (Brazil), which has not previously been reported. Fifty-four cattle farms were visited and specimens of Rhipicephalus (Boophilus) microplus were collected and subjected to the adult immersion test, using nine commercial acaricides in the amidine, pyrethroid and organophosphate groups. Climatic data, including monthly precipitation, were recorded. The results from the present study demonstrated that seven of the acaricides analyzed presented mean efficacy values of less than 95%, with large differences among the products tested. Nine of them exhibited satisfactory and unsatisfactory acaricide results on at least one farm. In conclusion, the farms located in the western-central region of Rio Grande do Sul, Brazil, exhibited populations of R. (Boophilus) microplus with variable degrees of susceptibility to different acaricides, thus suggesting that resistance to the active compounds exists. It is suggested that treatment protocols should be implemented at the beginning of winter and summer, using the acaricides that showed efficacy in the adult immersion test.
Ecology of Lutzomyia longipalpis and Lutzomyia migonei in an endemic area for visceral leishmaniasis
Authors: Silva Rafaella Albuquerque , Santos Fabricio Kassio Moura , Sousa Lindemberg Caranha de , Rangel Elizabeth Ferreira , Bevilaqua Claudia Maria Leal
Published: September 2014

The main vector for visceral leishmaniasis (VL) in Brazil is Lutzomyia longipalpis. However, the absence of L. longipalpis in a region of autochthonous VL demonstrates the participation of other species in the transmission of the parasite. Studies conducted in La Banda, Argentina, and São Vicente Férrer, Pernambuco State, Brazil, have correlated the absence of L. longipalpisand the presence of L. migonei with autochthonous cases of VL. In São Vicente Férrer, Pernambuco, there was evidence for the natural infection of L. migonei with Leishmania infantum chagasi. Thus, the objective of this work was to assess the ecology of the sand flies L. longipalpis and L. migonei in Fortaleza, an endemic area for VL. Insect capture was conducted at 22 sampling points distributed across four regions of Fortaleza. In total, 32,403 sand flies were captured; of these, 18,166 (56%) were identified as L. longipalpis and 14,237 (44%) as L. migonei. There were significant density differences found between the vectors at each sampling site (indoors and outdoors) (p <0.0001). These findings confirm that L. migonei and L. longipalpis are distributed throughout Fortaleza, where they have adapted to an indoor environment, and suggest that L. migonei may share the role as a vector with L. longipalpis in the transmission of VL in Fortaleza.
First study on parasites of Hemibrycon surinamensis (Characidae), a host from the eastern Amazon region
Authors: Hoshino Maria Danielle Figueiredo Guimarães , Hoshino Érico Melo , Tavares-Dias Marcos
Published: September 2014

This study was the first investigation of communities and infracommunities of parasites of Hemibrycon surinamensis. All the fish collected in a tributary of the Amazon river were parasitized by one or more parasite species. The Brillouin diversity index (HB) was 0.46 ± 0.28 and the mean species richness was 3.5 ± 1.2 parasites per host. A total of 14,734 parasites were collected, including Ichthyophthirius multifiliis and Piscinoodinium pillulare (Protozoa); Jainus hexops and Tereancistrum sp. (Monogenoidea); Ergasilus turucuyus and Argulus sp. (Crustacea); metacercariae of Derogenidae gen. sp.; metacercariae and adults of Genarchella genarchella (Digenea); and Cucullanus larvae and Contracaecum larvae (Nematoda). The dominant parasite was I. multifiliis, followed by P. pillulare. The parasites showed aggregated dispersion, except for E. turucuyus, which had random dispersion. The condition factor (Kn) indicated that the parasitism levels had not affected host body condition. The high levels of infection observed were due to host behavior, and this was discussed. This was the first report of I. multifiliis, P. pillulare, Argulus sp., E. turucuyus, G. genarchella, J. hexops and Tereancistrum sp. in H. surinamensis, and it expanded the occurrence of E. turucuyus and G. genarchella to the eastern Amazon region.
Species‐abundance–seed‐size patterns within a plant community affected by grazing disturbance
Authors: Wu Gao-Lin , Shang Zhan-Huan , Zhu Yuan-Jun , Ding Lu-Ming , Wang Dong
Published: September 2014

Seed size has been advanced as a key factor that influences the dynamics of plant communities, but there are few empirical or theoretical predictions of how community dynamics progress based on seed size patterns. Information on the abundance of adults, seedlings, soil seed banks, seed rains, and the seed mass of 96 species was collected in alpine meadows of the Qinghai‐Tibetan Plateau (China), which had different levels of grazing disturbance. The relationships between seed‐mass–abundance patterns for adults, seedlings, the soil seed bank, and seed rain in the plant community were evaluated using regression models. Results showed that grazing levels affected the relationship between seed size and abundance properties of adult species, seedlings, and the soil seed bank, suggesting that there is a shift in seed‐size–species‐abundance relationships as a response to the grazing gradient. Grazing had no effect on the pattern of seed‐size–seed‐rain‐abundance at four grazing levels. Grazing also had little effect on the pattern of seed‐size–species‐abundance and pattern of seed‐size–soil‐seed‐bank‐abundance in meadows with no grazing, light grazing, and moderate grazing), but there was a significant negative effect in meadows with heavy grazing. Grazing had little effect on the pattern of seed‐size–seedling‐abundance with no grazing, but had significant negative effects with light, moderate, and heavy grazing, and the |r| values increased with grazing levels. This indicated that increasing grazing pressure enhanced the advantage of smaller‐seeded species in terms of the abundances of adult species, seedlings, and soil seed banks, whereas only the light grazing level promoted the seed rain abundance of larger‐seeded species in the plant communities. This study suggests that grazing disturbances are favorable for increasing the species abundance for smaller‐seeded species but not for the larger‐seeded species in an alpine meadow community. Hence, there is a clear advantage of the smaller‐seeded species over the larger‐seeded species with increases in the grazing level.
An Innovative ES-PCP Technology and Key Learnings from Field Trials in the Kern River Field, Bakersfield, CA
Authors: Franks Spencer , Cochran Jamie
Published: September 2014

An estimated 90% of wells worldwide use some method of artificial lift to assist in the production of reservoir fluids. The type of artificial lift employed has a direct impact on an operator's ability to realize maximum potential from developing an oil or gas field. This paper will outline the development, field trials and path forward of an innovative artificial lift system at the Kern River Field in Bakersfield, CA. This artificial lift system combines an electric submersible permanent magnet motor and drivetrain (ES) with a progressive cavity pump (PCP). This ES-PCP allows for significant benefits over other methods of artificial lift in terms of system efficiency, pump placement, reduced power consumption, use in deviated or horizontal wells, and its ability to handle produced solids. Additionally, this ES-PCP system allows for a smaller footprint and environmental benefits as compared to other artificial lift systems. In 2013 a pilot was conducted for the first field trial of this artificial lift system at the Kern River Field. This paper will elaborate on the key learnings derived from these field trials.
An approach to account ESP head degradation in gassy well for ESP frequency optimization
Authors: Krasnov V. A. , Litvinenko K. V. , Khabibullin R. A.
Published: September 2014

The majority of Western Siberia oil wells in Russia equipped by electric submersible pumps (ESP). Nowadays the common practice is to operate oil well with ESP as close to its production potential as possible. This strategy allows achieving maximum oil rates and economic efficiency according to Vogel's inflow relationship.

Main limiting factor to decrease BHP and increase well's oil production is an ability of ESP to work with high free gas fraction at pump intake. It is well known that ESP fails to generate pressure drop with high gas fraction at pump intake. However, there is no appropriate mathematical model to account it in ESP design properly.

It is often assumed that ESP works well with gas fraction at pump intake below critical and cannot operate with gas fraction at pump intake above critical. Critical gas fraction varies for different ESP types and manufactures from 25% to 35% and even 50% for ESP with gas handling devices like MVP from Centrilift, AGH or Poseidon from Schlumberger. Using this assumption one can conclude that affinity law should work well for ESP with gas fraction below critical. Nevertheless, it is often observed on wells with high gas fraction that increasing of ESP rotating frequency does not affect BHP and production as it predicted by affinity law.

This paper discusses an approach to describe an abnormal well behavior after frequency change. It shows that correlation for ESP head degradation as in SPE 117414 combined with nodal analysis technique allows to predict well behavior with high free gas fraction. It also allows optimizing energy consumption by ESP by varying ESP rotating frequency. Field cases discussed.
PCP Application for Development of Waxy Bhagyam Field In Onshore India
Authors: Karthik N. R. , Jha Mihir , Kumar Amit , Kumar Piyush , Aggarwal Shubham
Published: September 2014

Bhagyam field is an onshore, shallow field containing light sweet oil (27° API) with low Gas Oil Ratio (GOR) (~100 scf/stb). The crude has ~30% wax content with moderate insitu oil viscosity of ~ 50–250 centipoise (cP) with wax appearance temperature (WAT) ~2° C lower than the reservoir temperature of 53° C. With water production, it was initially expected that viscosity of production fluid will rise upto 3000 cP due to emulsification.

Rod driven Progressing Cavity Pump (PCP) system was selected as artificial lift for the field development considering low GOR and relatively high fluid viscosity. To ensure flow assurance of the high WAT crude, various methods such as annular hot water circulation, heater cable, vacuum insulated tubing (VIT) etc were considered. Based on the analogue Mangala field, which is located in the same license area, it was decided to utilize annular hot water circulation as the downhole heating methodology as it provided a significant completion design similarity with previous installation and operational experience. This completion involves running Colied Tubing (CT) clamped to the main production tubing as a secondary string. The main production tubing with PCP stator is stabbed in a production packer for downhole isolation.Hot water is circulated at 85° C down the coil taking returns through the annulus. This arrangement ensures temperature of the fluid inside the main production tubing is maintained higher than the WAT at all times.

In the 1st phase of field development, wells completed with PCP and have been successfully operating for ~ 2 years meeting requirement of flow assurance & PCP run life. However, PCP efficiency was lower in high GOR wells, as downhole gas separation was not possible. For the 2nd phase of development, alternate completion designs which can mitigate the downhole flow assurance challenges and at the same time open up the annulus similar to a conventional PCP application were considered and finally hollow rod driven PCP design was selected as the most suitable method.

The paper details PCP application in Bhagyam field during the first two phases of development, installation & operating practices, lessons learnt & overall system performance.
Optimization Design of Progressive Cavity Pumps via Finite Element Simulations with a Fluid-Solid Interaction Model
Authors: Chen Jie , Wu HengAn , Liu He , Wang FengShan , Shi GuoCheng , Cao Gang , Sun YanAn , Sun ChunLong , He Yan , Ge WeiTao
Published: September 2014

Progressive cavity pumps (PCPs) have been widely used as an artificial lifting device in various oilfield productions due to their numerous advantages. However, some problems still exist during practical applications. In order to improve the performance and promote the application, it is of great significance to optimize the design of PCPs.

In this study, we established a finite element model of PCP, which consists of the stator, the rotor, the lifted fluid and the fluid-solid interaction. The controlling equations of solid deformation and fluid dynamics are solved using different solvers for solid domain and fluid domain respectively, and their results are exchanged through the fluid-solid interface. Partitioned solution algorithm is employed to tackle the problem of this two-way fluid-solid interaction.

For specified design parameters, our computed laden torque and volumetric efficiency of PCP agree well with experimental results of laboratory test, which can verify our model and simulation method. Furthermore, the developed model is used to optimize the design parameters of PCPs, which primarily include interference, stator thickness, elastic modulus and Poisson's ratio of stator. The goal is to choose the appropriate parameters to make the best performance of PCPs. We studied the influence of these parameters on the main performance of PCPs such as laden torque, volumetric efficiency. According to the simulation results, the interference and stator thickness are found to be the two main factors influencing the performance. The influencing rules are summarized, and a comprehensive optimization system of the design parameters is established. Based on these results, we can choose the appropriate parameters and optimize the design of PCPs. Our work can be of great significance for guiding the design and optimization of new PCPs.
Component Analysis With Competing Risks: How Re-Use of Individual Components of an ESP Impacts Reliability
Authors: Bailey William J. , Couet Benoît , Weir Iain S.
Published: September 2014

A rigorous statistical study using a semi-parametric survival analysis approach was applied to an analysis of individual components, with competing risks, of an ESP system.

Since its proposal in 1972, Cox's Proportional Hazards (CPH) semi-parametric model has become a primary tool for regression analysis of censored data in medical studies and in the aerospace industry. However, Cox's model assumes that observations are time-independent. This is not the case with ESP components as observations involving these, in the same installation, are naturally related and the multiple observations of an individual component through its re-use are also related and time-dependent. In this paper, we utilize some of recent extensions of standard Cox formulation to analyze components of ESP systems where multiple competing risks from individual components exist (intra-component correlations, intra-installation correlations and time-dependent explanatory variables). These model extensions utilize a more involved analysis undertaking and demand some careful preliminary data treatment. The work illustrates the concept of time-dependent competing risks with an example of an individual component, in our case a specific motor, from its first deployment and subsequent re-deployments in different ESP systems in a systematic and unbiased manner.
Optimizing Gas Lift Operations Using Disintegrable Gas Lift Valve Plugs
Authors: Salinas Bobby J. , Xu Zhiyue , Richard Bennett M.
Published: September 2014

Artificial lift encompasses approximately 96% of the US oil well market. Of the wells that use artificial lift, 10% use gas lift for production. As gas is injected into the well, the viscosity of the fluid and pressure is reduced, promoting flow to the surface. In typical gas lift valve systems, dummy valves are installed in side-pocket mandrels to isolate the annulus from the tubing where pressurization is required to test the tubing, test the annulus, set a hydraulic packer, or activate an isolation device. Then intervention would be required to remove the dummy valves and install a live gas lift system. This can be a time-consuming process and can pose risks to existing infrastructure while hindering production time.

This paper presents a newly developed nano-engineered disintegrable composite (DNEC) and its use in gas lift valves. The DNEC gives gas lift valves the flexibility to be installed as dummy valves, but switching to a live valve without intervention. The switch from a dummy valve to a live valve occurs through an in-situ disintegration of the DNEC plug. This eliminates multiple intervention trips and enables immediate production of these wells under optimized gas lift conditions.

The nano-engineered composite plug is lighter than aluminum, but as strong as some mild steel. The DNEC plug has pressure rating of 5,000 psi and will disintegrate in brine during the cleanup process, within 12 to 50 hours, making it an ideal tool for offshore gas lift valve applications. To date, more than 1,000 gas lift valves equipped with DNEC plugs have been successfully installed. The nanostructured composite material, the valve design, the lab test data and a successful case history will be presented.
Hyperbolic Decline Parameters During and After Linear Flow: Field Example from the Barnett Shale Using Public Data
Authors: Pratikno H. , Reese D. E. , Summers L. E.
Published: September 2014

The Barnett Shale is one of the first unconventional shale plays developed with multistaged, fracture-stimulated horizontal wells in the world. It is located in North Central Texas near Fort Worth. At the end of 2013, the Barnett Shale had over 14,000 multistaged hydraulically fractured horizontal wells (MFHW) with approximately 7,600 of these wells with over five years of production history. In addition to these MFHW, there are approximately 4,000 vertical wells.

Production forecasting for unconventional reservoirs with MFHW is a topic with a great amount of interest. The question is what are the appropriate decline parameters to be used in the forecast? Are multisegment forecasts with their own decline parameters necessary?

Currently, production forecasting using a modified hyperbolic Arps equation is still widely accepted. This work provides analysis in characterizing decline parameters during and after linear flow for horizontal wells in the Barnett Shale using public data. There will be examples of MFHWs from the Barnett where the hyperbolic b-exponent will be calculated for each month of production and shown to vary with time as flow regimes change.

Single well simulation will be used to characterize the different flow regimes and their effect on decline parameters. Simulation of wells with and without volume outside of fracture tips and their effect on decline parameters will be shown. The decline parameters were in an Arps forecast to match our single well simulation forecast. Uncertainty analysis of production forecast using simulation models is also presented in this work.
A Methodology to Quantify the Impact of Well Interference and Optimize Well Spacing in the Marcellus Shale
Authors: Yaich E. , Diaz de Souza O. C. , Foster R. A. , Abou-Sayed I.
Published: September 2014

While well interference is a known phenomenon in shale gas plays, it is often overlooked or only considered when its effects are readily apparent. Spacing tests are often performed when starting to appraise or develop a new area where a qualitative evaluation of interference between drilled wells will determine the appropriate well spacing.

While numerical reservoir modelling and build-up analysis can be applied in the Marcellus shale play they are not appropriate for determining optimal spacing due to very low, nano-darcy reservoir permeabilities and uncertainty over hydraulic fracture geometry. The challenge was to develop a new approach to measure and estimate the impact of interference on gas recovery and optimize well spacing.

The impact of interference was initially evaluated by assessing the change in the productivity index of wells due to offset wells being added, put on production or shut/in. In order to have a more meaningful way of estimating its impacts on economics, interference was also quantified based on projected future five year cumulative production using Arps decline curve, Rate Transient Analysis and Pressure Normalized Rate methods. Results were compared and a statistical workflow was used to estimate optimal spacing.

By relating the degree of interference with overlap between wells, the nature of interference was also investigated. Interference can be due to a Stimulated Rock Volume (SRV) overlap. This is characterized by a proportionality increasing interference with SRV overlap. The impact of natural features such as faults or high permeability streaks that can act as conductivity highways across many wells is usually not proportional to overlap.

This study in Marcellus shale play demonstrated that measurable interference occurred at wide spacing and that 1,000 ft spacing should result in an increased FYFCP (Five Year Forecasted Cumulative Production) of 10% over existing spacing assumptions, key at low gas prices. Therefore, 1,000 ft spacing has been recommended for future well placement. The workflow outlined in this paper is currently being used to evaluate well spacing for other assets and can be used by Reservoir Engineers to evaluate spacing in tight or shale gas/oil plays.
Reducing Cost and Risk with Cemented-Back Monobore Well Construction in the Cardium Formation
Authors: Lowe J. , Rey M. M. , Manuel J. J. , Kenyon M.
Published: September 2014

Operators in the Cardium formation of central Alberta are increasingly adopting a cemented-back monobore well design to reduce costs and improve operational efficiency. Extensive field data from more than 360 wells completed by an operator working in this formation demonstrates the operational advantages and substantial cost savings gained by adopting a monobore well design. This paper details the evolution of well construction for open hole horizontals in the Cardium, and provides cost and operational comparisons between drilling different wellbore sizes, running different casing sizes, and using different stage tools to cement from the heel of the well back to surface.

The operator completed 77 wells in the Cardium using 177.8 mm intermediate casing through the build section and a 159 mm open hole lateral with 114.3 mm liner before evolving to a cemented-back monobore design. Analysis of the field data determined that 171 mm vertical and build sections of the wellbore, and a 159 mm open hole lateral with 114.3 mm casing is the optimal cemented-back monobore design, allowing for easier casing installation and providing substantial cost savings by eliminating the intermediate casing.

Monobore ball-drop completion systems require a stage tool to cement from the heel of the well back to surface. By implementing a stage collar that closes mechanically rather than with a wiper plug or dart, the operator was able to reduce wellbore integrity risks and considerably lower drill-out costs before stimulating the well. The operator has completed more than 220 wells using this stage collar with 100% success.

The geology of the upper formations was managed using invert drilling mud to control wellbore stability and downhole pressure, rather than intermediate casing, to successfully adopt a cemented-back monobore well design. The steps detailed in this paper to eliminate intermediate casing from wellbore construction, identify optimal wellbore sizes and reduce drill-out costs have proven to be successful in the field and can be applied to a variety of formations around the world.
Production Forecasting in Unconventional Resources using Data Mining and Time Series Analysis
Authors: Gupta Siddhartha , Fuehrer Franz , Jeyachandra Benin Chelinsky
Published: September 2014

Production forecasting in shale reservoirs is a challenging task because of the complex influences of geology, lithology, stimulation practices, etc. The large well count makes history matching and forward simulation particularly time consuming and laborious. In such a context, it is important to consider alternative methods, and to this end, we have developed two new methods of forecasting production.

The first method uses data mining techniques, which allow the analysis of large quantities of data to discover meaningful pattern and relationships. These can subsequently be used for prediction. Some common data mining tools are neural networks (NN), genetic algorithms (GA), and self-organizing maps (SOM). Our method uses NN for predicting the future performance of a shale gas well based on historical production data of the previous year. The decline in production is captured during the NN training process and applied to the production data during the forecasting phase. The model is simple, elegant and fast and is able to forecast production in an unconventional play with reasonable tolerance.

The second method uses time series analysis. It the trend, changes in value, rate of decline, and correlation with the past to generate a rapid and accurate forecast. The stock markets use this technique, and it is safe to say that if it can predict the stock ticks, then it can yield good results on a fluctuating, but surely declining, production rate.

These methods are elegant and fast and are able to forecast production in an unconventional play with reasonable tolerance. They are not data intensive and can also be automated to be applied to a large number of wells, which makes them particularly useful in integrated operations in which a comparison of actual versus predicted behavior would enable operators to quickly identify problem wells for a more detailed investigation. The methods were applied to wells from the Barnett, Bakken, and Eagle Ford plays.
Production Forecasting in Shales: A Comparative Field Data Study Using Large Well Counts
Authors: Valentine A. P. , Brown A. , Gupta S. , Dwivedi P.
Published: September 2014

As the effort to develop unconventional reservoirs takes on a greater pace within the industry, so too does the effort to understand the way in which these unique reservoirs produce. Classical forecasting techniques such as Arps are typically not able to adapt to the characteristic "tail" exhibited by wells producing from these reservoirs. As such, a tremendous amount of investigation and research has been undertaken to better understand and therefore better predict future performance. As a result the literature is full of alternative techniques.

In this paper we explore a number of these techniques, comparing them to the classical Arps method as a form of benchmark. In addition, we take a "backcasting" approach on several large shale fields, including the Barnett, Eagle Ford, Bakken and Montney. This approach is equivalent to going back in time, hiding later production data, forecasting and comparing forecasts to what we now know production rates to have been. We also test the applicability of classical and newer forecasting techniques on big data sets by identifying changes in operating conditions and calculating decline rates for the period thereafter. As seen in this study, each method has its own "sweet spot" in which it yields accurate results.

This study differs from other published studies in that our focus was not so much on obtaining Estimated Ultimate Recovery (EUR) values that matched the actual production of depleted wells, but rather was on predicting production rates in the relatively near term. While EUR estimation is a key performance indicator, it falls into the domain of the long term planners. Conversely, future production rates are of prime importance to operational personnel and to their short term decision making processes, such as timing of infill drilling and remedial activity, along with surface facility planning activities such as system upgrades or reconfiguration.

Another aspect of this study which differs from others published is that we did not preclude wells with noisy data. Rather, we embraced the challenge presented by real data sets. In this way we could ensure that our proposals could be applied universally and not simply to those wells with well-behaved production histories.
Kinematics and Force Analysis of Lifting Mechanism of Detachable Container Garbage Truck
Authors: Shanzeng Liu , Lianjie Zhang
Published: September 2014

The kinematics and force analysis of the lifting mechanism of the detachable container garbage truck is
performed in this article. First of all, the structural features and working mechanism of detachable container garbage truck
are introduced. Then, for each working condition of the DCG truck, kinematic models are established, and the force
analysis of the lifting mechanism is performed. Finally, the movement of a 20 ton DCG truck is calculated and analyzed
as an example. This study provides a theoretical basis for the optimized design of DCGgarbage truck.
Investigation on Dynamics of Mechanical System with Clearance Joint
Authors: Bai Zheng-Feng , Yang Bin-jiu , Sun Yi
Published: September 2014

In this work, the dynamic responses and vibration characteristics of mechanical system with revolute
clearance joints are investigated numerically. Considering clearance in joint, the intra-joint contact model that is generated
at clearance joints is established using a nonlinear continuous contact force model and the friction effect is considered by
using a modified Coulomb friction model. A well-known slider-crank mechanism with a revolute clearance joint is
utilized to perform the investigation. The effects of clearance on dynamics of mechanical system are analyzed by timedomain
responses and frequency domain analysis. The investigation results show that the dynamic responses of
mechanical system with clearance are obviously vibration and the amplitude increases from the mechanism without
clearance. The results also indicate that the behavior of mechanism with clearance is nonlinear.
Finite Element Analysis of Buckling of Corrugated Fiberboard
Authors: Ma Yali , Gong Zhen , Zhao Liang , Han Yue , Wang Yun
Published: September 2014

This paper investigates the relationship between mechanical behaviors and the shape of corrugated fiberboard
by means of buckling analysis, which is done by FEM (Finite Element Method). Firstly, after analyzing the structure of
corrugated fiberboard, a single-wall corrugated fiberboard model was built. The buckling load was measured in the ideal
condition by linear buckling analysis (eigenvalue buckling analysis). Subsequently, nonlinear buckling analysis based on
single-wall corrugated fiberboard was performed using the results of the eigenvalue buckling analysis. Finally, a finite
element 3-D model of four-layer and five-layer corrugated fiberboard was established using ANSYS parametric design
language (APDL) to improve mechanical properties of corrugated fiberboard based on comparing different eigenvalue
buckling loads.
Optimization Design on Triangle Plate of Auxiliary Frame of Mixer Truck
Authors: Sun Li , SunLiu Yongchen , Fu Naiji
Published: September 2014

In order to solve the question of crack of the auxiliary frame of mixer truck, especially with the life of the
triangle welding position is low, the triangle support of auxiliary frame optimization design is put forward Firstly, three
dimensional structure model of auxiliary frame is established by Pro/E and the model is imported into HyperMesh
software for meshing. The solver RADIOSS is used to calculate the maximum stress and the positions at the different full
load conditions. Including the static, left front wheel lifted up by 210 mm, the right rear wheels (double) lifted up by 210
mm and the left front and right rear wheels lifted simultaneously up by 210 mm. Then the experimental vehicle test is
performed. The test results and simulation results are compared and show a good consistency and the accuracy of the
finite element model is validated. Then the three optimization design schemes of the triangle are put forward and the
maximum stress of the optimal auxiliary frame are calculated in contrast with the original stress. The scheme 2 is found to
be the most optimal, which provides an effective method for solving the fatigue of the auxiliary frame.
Tendency Mining in Dynamic Association Rules Based on SVM Classifier
Authors: Zhang Zhonglin , Liu Zongcheng , Qiao Chongyu
Published: September 2014

A method of tendency mining in dynamic association rule based on compatibility feature vector SVM classifier
is proposed. Firstly, the class association rule set named CARs is mined by using the method of tendency mining in
dynamic association rules. Secondly, the algorithm of SVM is used to construct the classifier based on compatibility
feature vector to classify the obtained CARs taking advantage when dealing with high complex data. It uses a method
based on judging rules’ weight to construct the model. At last, the method is compared with the traditional methods with
respect to the mining accuracy. The method can solve the problem of high time complexity and have a higher accuracy
than the traditional methods which is helpful to make mining dynamic association rules more accurate and effective. By
analyzing the final results, it is proved that the method has lower complexity and higher classification accuracy.
Research on the Inner Wall of the Blind Hole Drilling Device
Authors: Zhu Lin , Huang Wei
Published: September 2014

This article describes the structure and working principle of the blind hole drilling device through application in
the production practice proving its feasibility. At present, electrical discharge machining and welding method are
commonly used to solve the problem. However, these methods have low processing efficiency, low manufacturing
precision and high cost defect. This paper developed an inner wall of the blind hole drilling device, similar to stand-alone
machine accessories and adopted the bevel gear transmission which can directly be mounted on vertical or horizontal
milling machine, completing the processing operations in few minutes. This device not only has high processing
efficiency and accuracy, but it also greatly reduces the production cost.
A Method for Railway Gearbox Faults Detection Based on Time- Frequency Feature Parameters and Genetic Algorithm Neural Network
Authors: Dechen Yao , Jia Limin , Qin Yong , Jianwei Yang
Published: September 2014

Early identification of faults in railway gearboxes is a challenging task in gearbox fault detection. There are
extensive studies, such as patents and papers have been fully developed for processing vibration signals to obtain
diagnostic information about gearbox. We have proposed a new technique for detecting faults in the railway gearbox by
applying the time frequency parameters and genetic algorithm neural network to deal with railway gearbox fault signals.
In this method, wavelet analysis and empirical mode decomposition (EMD) are carried out on gearbox vibration signals
for extracting the time-frequency feature parameters. Then genetic algorithm neural network (GNN) is used for the
classifications of the time-frequency feature parameters. The analysis results show that the effectiveness and the high
recognition rate in classifying different faults of railway gearboxes.
Behind the Numbers: Insights into Large Audit Firm Sampling Policies
Authors: Christensen Brant E. , Elder Randal J. , Glover Steven M.
Published: September 2014

SYNOPSIS

Changes in the audit industry after the Sarbanes-Oxley Act, including mandatory audits of internal control over financial reporting and PCAOB oversight and inspection of audit work, have potentially changed the nature and extent of audit sampling in the largest accounting firms. However, little academic evidence exists on these firms' current audit sampling policies (Elder, Akresh, Glover, Higgs, and Liljegren 2013). As such, we administer an extensive, open-ended survey to the national office of the Big 4 and two other international accounting firms regarding their firm's audit sampling policies. We find variation among the largest auditing firms' policies in their use of statistical and nonstatistical sampling methods and in inputs used in the sampling applications that could result in different sample sizes. Sampling experts' internal reviews indicate that projecting and resolving identified misstatements is one of the biggest difficulties that audit engagement teams face when using sampling techniques. Finally, we present evidence that some firms have significantly changed their approach to revenue testing due to PCAOB inspections. This evidence provides important insights into current sampling policies and presents opportunities for future research.

Data Availability: Please contact the authors.
The Effects of Using the Internal Audit Function as a Management Training Ground or as a Consulting Services Provider in Enhancing the Recruitment of Internal Auditors
Authors: Burton F. Greg , Starliper Matthew W. , Summers Scott L. , Wood David A.
Published: September 2014

SYNOPSIS

This paper examines factors that influence job applicants' willingness to apply for positions in internal auditing. We predict and find evidence that job applicants are dissuaded from applying for internal audit positions. In two separate experiments involving participants at seven universities, we discover that this phenomenon is most prevalent for applicants with business experience. Experienced applicants are 20 and 33 percent less willing to apply for a position if it is labeled as “internal audit” versus “accounting” in the two experiments, respectively. In addition, we find that the only experimental condition that increases interest in applying for an internal audit position for experienced applicants occurs when the position advertises the combination of (1) a short stint in internal auditing and then a move from internal audit into a management position, and (2) work primarily related to consulting services rather than assurance services. As a potential explanation for these findings, we find evidence that participants believe other business professionals have negative stereotypes of internal auditing—which likely dissuade potential job applicants from applying to work in internal audit. The results should prove informative to practitioners, internal audit professional organizations, and business professionals concerned with high-quality corporate governance.

Data Availability: Contact the authors.
The Utilization of Quantitative and Qualitative Information in Groups' Capital Investment Decisions
Authors: Ang Nicole P. , Trotman Ken T.
Published: September 2014

Organizations frequently use interactive groups to make strategic decisions, aiming to capitalize on individual members' unique knowledge. However, research shows that groups focus on information that members have in common, not unique information, resulting in suboptimal outcomes. Given that accounting systems can present information in various forms, we experimentally examine whether quantitative information results in greater information sharing and use than qualitative information. We take advantage of a rich dataset created by videoing groups making a capital investment decision. Consistent with prior research, we find that groups prefer common to unique information, regardless of whether it is quantitative or qualitative. However, individuals use quantitative information more than qualitative information before group interaction, and make more references to it during discussion. Added insights from the videos include identifying what determines greater use of quantitative cues, the importance of the numbers attached to cues, and how successful groups use quantitative cues.

Data Availability: Please contact the authors.