bluuebunny/crossref_metadata_2025_split huggingface dataset:
New Test for Material Resistance against Microbiologically Influenced Corrosion
Authors: Jensen Jeppe , Sorensen Ketil Bernt , Juhler Susanne , Lundgaard Thomas 
Published: May 2012

Abstract
A material test for microbiologically influenced corrosion (MIC) is presented. This laboratory based test evaluates the material resistance to MIC caused by corrosive, methane-producing microorganisms. Material testing and corrosion modeling is a natural and important step to ensure material integrity during oil production. Currently, good models for physical and chemical parameters exist, but MIC remains very hard to predict in spite of many years of research, and failures continue to occur prematurely.
MIC can to some degree be mitigated by biocide treatment. However, the effect can be limited because responsible microorganisms are part of a protective biofilm of the metal surface. Parts of the biofilms often survive even the best biocide program, and the surviving microorganisms will quickly re-establish their activity in the system. Metal alloys react differently to these biofilms, and the choice of material is a crucial parameter in minimizing MIC.
Biofilms formed by methane-producing microorganisms are known to cause MIC. These microorganisms are not detected in standard monitoring tests, such as bottle incubations, widely used by the industry. However, several recent studies employing Molecular Microbiology Methods (MMM) have shown that these microorganisms are numerous, widespread, and highly corrosive in off- as well as on-shore oil fields. The new material test described in this paper uses methane-producing microorganisms to test the MIC resistance of metal alloys. This enables petroleum companies to choose a suitable material for an environment with high MIC potential and to predict the corrosion rate at close to in situ conditions.
Sustainable Production of Biochemicals and Biofuels Based on Biofixation of Carbon Dioxide by Microalgae
Authors: van den Bos W. A. , Jahn J.. , van den Broeke L. J. 
Published: May 2012

Abstract
For the further development of CCS (Carbon Capture and Storage) an integrated approach is needed to optimize the full chain from capture, via transport to application. It is to be expected that in the near future carbon dioxide will be one of the largest commodities. Besides storage as the main option to discard the captured CO2 more sustainable option are emerging where CO2 is used as a feedstock.
A number of options for CO2 utilization are evaluated, and one of the most promising options, biofixation of CO2 by microalgae, is discussed in detail. One of the main aspects of mirco-algae is the scale-ability, both small-scale and relatively large-scale applications can be envisaged. Results for the growth of different microalgae in the presence of CO2 and the extraction of valuable components from the algae biomass are presented.
Study of Particle Straining Effect on Produced Water Management and Injectivity Enhancement
Authors: Aji K.. , You Z.. , Badalyan A.. , Bedrikovetsky P.. 
Published: May 2012

Abstract
Theoretical and laboratory studies are performed aiming at the development of a predictive model for transport and retention of particles from produced water and crude oil/gas based on grain size distribution and particle sizes only. The particle capture by straining is thoroughly investigated. In the laboratory, injections of different sized particles suspended in fluid with different salinity and pH values have been carried out into the newly designed porous media holder with single-layer grains and into the column packed engineering porous media. The retained particles are filmed using microscope; their breakthrough concentrations are measured by particle counter. A new mathematical model accounting for pore connectivity and triangular pore throat shape is derived and applied to the experimental conditions. Agreement between test data and modelling results supports application of the model to the evaluation of straining effect on the produced water management and injectivity enhancement.
Optimizing Hydraulic Fracturing Design for Shale Gas Production through Numerical Simulations
Authors: Li Y.. , Wei C.. , Qin G.. , Lu Y.. , Luo K.. 
Published: May 2012

Abstract
Hydraulic fracturing stimulation is one of the key technologies for shale gas development. The recent advances in micro-seismic data acquisition and processing suggest that hydraulic fracturing stimulation has often resulted in complex fracture network due to the pre-existing natural fractures. Modeling hydraulic fracturing processes needs to couple in-situ stress response and flow of engineered fluid that includes water, proppant and other chemicals. Moreover, the high Reynolds number indicates that the flow in the hydraulic fracturing processes is either in transition or turbulent flow regime. Consequently, the resulting mathematical model is complex and needs to be numerically solved.
In this paper, we have developed a hydraulic fracturing model considering the in-situ stress response to turbulent flow process. The mixed finite element method is employed for numerical solution of the resulting system of coupled nonlinear partial different equations. The proposed model has been validated with bi-wing hydraulic fracture model through regression tests. The preliminary numerical results show the significant differences in hydraulic fracture growth in comparison with the models that assume laminar flow in hydraulic fracturing processes. We have also integrated proposed hydraulic fracturing model into a numerical reservoir simulator and are currently conducting field-scale numerical simulation studies. The preliminary results also suggest that the proposed model is also capable of modeling the interactions between the hydraulic fracture and pre-existing natural fractures based on initial fracture mapping.
The proposed model provides an opportunity to optimize hydraulic fracturing stimulation design through numerical simulations, which is vital in unconventional reservoir production.
Application of IPM Modeling for Production Surveillance, Allocation and Optimization
Authors: Orioha Herbert , Gruba Chris , Muoneke Gabriel , Ezuka Ifeanyi 
Published: May 2012

AbstractIn order to make effective decisions for oil field management, well and reservoir surveillance data needs to be utilized to better understand how the subsurface and surface systems in a field interact. This can be done at the reservoir, well and surface facility level, but is most effective when considering the entire production or injection system. IPM (Integrated Production Modeling) is now being used more often and, has demonstrated its usefulness in many oil and gas field applications.The use of integrated production modeling methodologies for improving production, identifying and eliminating bottlenecks and improving production allocation for wells from multiple reservoirs from both onshore and offshore oil fields are presented. Methods for coupling the surface and subsurface are reviewed and its usefulness for identifying bottlenecks at both the well and surface facility level are demonstrated. Field examples are presented where issues were identified and overcome by operational means and, found to increase production. Prioritization of wells and production intervals can also be incorporated to improve production/system uptime and field life.The use of artificial lift for oil wells and additional compression for gas wells can be effectively modeled by reasonably calibrated IPM models. Without proper calibration, these models can yield results that lead to inadequate decisions that have a significant impact on project economics. The use of IPM models as a tool to better allocate field production data has proved to be very reliable and has resulted in better field management. This approach requires both reservoir and surface facility information gathered on a regular basis in order to be reliable and accurate. Reservoir, well and surface models require occasional calibration or updates of inflow type curves. Application of these methods are discussed and presented for some field cases for oil reservoirs some under waterflood and others with active water drive.
Modeling of Proppant Embedment: Elastic Deformation and Creep Deformation
Authors: Guo Jianchun , Liu Yuxuan 
Published: May 2012

Abstract
Unconventional reservoir has become the hotspot of development in petroleum industry. In shale reservoir, some fracture is only propped by a monolayer 100mesh proppant. Fracture width is very small and under the condition of low rock hardness and high effective closure stress, the fracture will heal after a period of time, especially after the rock has been exposed to the fracturing fluids, causing weakening of the rock frame. In these reservoirs, proppant embedment becomes more serious. This paper purposes two embedment mechanisms, elastic deformation and creep deformation, and develops the corresponding models by combining simplified physical processes with elastic theory. Then with time integral, pressure dependent embedment depth is achieved. This paper provides a more reasonable method for calculating embedment. For fracturing engineer, it will give them a way to know how worse the matter will be. Finally, the model could couple with fracture propagation model and production prediction model to get a better result.
According to the results of analysis in the paper, in shale formation, proppant will cause creep deformation of rock, which will decrease fracture width with time. Optimization of fracturing fluid and treatment procedure are required to reduce the influence of creep deformation. Poisson's Ratio do have an effect on proppant embedment but very little. The mechanisms described in the paper provide a new understanding about embedment. It provides us a tool to determine how much the degree will be.
Propellant Treatment to Clean Out Gravel-Pack Wells
Authors: Hamdan V. H. , Jumaat M. S. , Samsu M.. , Trebolle R.. 
Published: May 2012

Abstract
A mature offshore field in Malaysia consists of wells that are over 20 years old and completed with dual-strings and multiple packers to produce from different sand layers. Due to the unconsolidated formation, most of the wells were completed with a gravel pack. After many years of production, the water cut has increased and fines migration has gradually plugged the gravel packs and screens. This has resulted in closing in these wells, leaving stranded potential oil behind. Continuing to produce through the plugged screens would require higher drawdown, which in turn induces greater sanding from the nearby reservoir rock and higher water cut. However, working over these wells was often noneconomical.
Initially, several wells were treated with acid but were reported to produce sand after the treatment. This was attributed to screen damage and gravel-pack failure requiring costly repair. Additionally, the acid used to remove the plugging caused by the fines migration weakened the matrix, increasing the sanding tendency.
This paper presents a case history of propellent stimulation treatment performed in two wells at this field. The gravel-packed wells were rejuvenated by applying a propellent treatment instead of acid treatments to clean the plugging in the gravel packs and screens over selected intervals that are known to be oil-bearing. Zones that could be producing water because of movement of the oil/water-contact can be left untreated so that the plugging in the screens helps in delaying water production.
Propellant has been used in the oil industry for many years, but its application has been mainly for minifracturing of consolidated rock in standard cased and perforated wells. Its application to clean gravel pack is not well known and knowledge in this domain is limited. As such, the case study started with candidate selection and proceeded through the proposed solution, conceptual job design, execution, and finally the results of the application.
A New Approach of Applying Analytical Inflow Model for Horizontal Well Performance of Non-Fully Penetrated Wells
Authors: Lin Jiajing , Zhu Ding 
Published: May 2012

AbstractHorizontal wells and multilateral wells have been applied in conventional and unconventional resource to improve recovery of hydrocarbon by increasing the contact of wellbores with reservoirs. In order to estimate production rate, many analytical models have been developed in the past years. One of the commonly used models is the Babu and Odeh's model which introduces a concept of partial penetration skin factor to transfer an analytical model for vertical wells to horizontal well mode. The partial penetration skin, SR, which accounts for the deviation of production for a partially-penetrated well in a reservoir (more likely in horizontal well scenarios) from a fully-penetrated well, is estimated by a correlation based on the reservoir simulation results. The correlation is one of the key elements in the Babu and Odeh's model, and it made the model flexible and convenient to use. The limit of the correlation is that the error of the calculation is increasing as the ratio of wellbore length to reservoir dimension decreases. Meanwhile, to consider the influence of permeability heterogeneity and wellbore pressure drop on well performance in these models, a segment approach is also commonly used for a horizontal well which divides the entire wellbore into smaller piece while calculating the pressure and flow relationship. When a well is segmented, the segmented well length is most likely lower than the limit of the partial penetration skin correlation applies. This raises a question of how the partial penetration skin should be distributed for different segments. The conventional method is to only apply the SR to the toe and heel segments when segment a wellbore, since the centered segments are considered fully-penetrated. This sometimes results in unreasonably low flow rate in these two segments compared to the segments in the middle. The toe and the heel segments should have high flow rate because of the larger drainage area contacted at these segments compared with the center segments in partial-penetrated wells. A new approach to distribute the partial penetration skin is needed to solve this problem.In this work, we discuss several approaches to reasonably distribute the total partial penetration skin over different segments. A new approaches is proposed to take into account of the effect of contact area, location of segments, as well as the drainage area on inflow performance. The result shows a more reasonable flow rate distribution for different segments of the new approach when compared with reservoir simulation results. This modification to the conventional approach for the segmented horizontal inflow model makes the analytical model more reasonable and applicable. Examples in the paper illustrate how to use the new approach to estimate horizontal well inflow performance.
An Innovative Integrated Asset Modeling for an Offshore-Onshore Field Development. Tomoporo Field Case
Authors: Pérez Fernando , Tillero Edwin , Pérez Ender , Nino Pedro , Rojas José , Araujo Juan , Marrocchi Milciades , Montero Marisabel , Piña Maikely 
Published: May 2012

Abstract
A reliable future development plan of an oilfield would require that all of the elements in the petroleum system are modeled in an integrated manner if a timely response, a more realistic economical evaluation, and risk analysis are needed for better decisions making.
The main goal for future development of Tomoporo field is to change the traditional focus (petroleum system elements by separated) by enabling to multidisciplinary team members to take advantage of their expertises within a collaborative environment based on interaction among petroleum system components.
The Tomoporo field's hydrocarbon reserves have been largely developed in offshore, but barely in onshore. It has been planned to increase production twice through new producing wells in onshore area which presents several limitations for handling production. Also a plan for pressure support, and improved oil recovery have been considered by implementing a waterflooding project.
This paper shows an innovative integrated asset methodology, applied for forecasting scenarios where reservoir, surface network, geographic location aspects, economy, risk, and uncertainty analysis were considered. The evaluation of forecasting scenarios was performed by implementing an integrated asset modeling (IAM) where all of simulation scenarios were coupled with a surface network model. Such network modeling included itself three integration levels to address complexity of surface facility needed for future offshore-onshore field development. In addition, an innovative link from reservoir-surface network models to the economic model was developed for a fully assisted asset modeling, resulting in faster and more reliable scenarios evaluation.
The IAM for Tomoporo field provided valuable information for all team members of the production stream, maximizing benefits from decision making based on a fully coupled asset model. This integrated approach determined that greater recovery factor and less reservoir pressure drop are achieved if an onshore flow station is added for new onshore wells in spite of existing capabilities in offshore surface facilities.
The IAM approach triggered warnings about future needs (investment, expenses), and also to be alert in minimizing bottlenecks in order to ensure no violation of surface capacity constraints. In addition, it allowed to define operating limits of water injection plants, enabling that optimum operation conditions are set, and the added value of the Tomoporo field development be maximized.
Development of modified diagnostic criteria for bacterial vaginosis at peripheral health centres in developing countries
Authors: Mittal Vineeta , Jain Amita , Pradeep Yashodhara 
Published: May 2012

Introduction: Bacterial vaginosis (BV) is the commonest cause of abnormal vaginal discharge in women of child-bearing age and is associated with increased susceptibility to HIV-AIDS and sexually transmitted diseases. In obstetrics, BV has been implicated in causing various complications. In clinical practice, BV is diagnosed using Amsel criteria and Nugent scoring. Using modified Amsel criteria, we determined that the fulfilling of any two instead of three criteria can be diagnostic of BV. Methodology: This prospective cross-sectional study involved pregnant females complaining of excessive vaginal discharge admitted in a tertiary health centre in central India. Four vaginal swabs were collected for the diagnosis of BV by Amsel criteria, modified Amsel criteria, and Nugent scoring on Gram stain. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy of each individual criterion and combinations of criteria were calculated by using Nugent scoring as the gold standard and by chi square test. Results: In the present study overall prevalence of BV was 12%. The sensitivity of individual or a combination of two criteria was almost same or higher than that of Amsel criteria. Specificity of each combination of criteria was comparable to that of Amsel criteria. However, a combination of high pH and amine odor test had the highest sensitivity (88%) and highest PPV (62%). Diagnostic accuracy of all combinations in our study was equal to or slightly higher than that of Amsel criteria. Conclusion: Diagnostic accuracy of new modified Amsel criteria is as reliable as that of Amsel criteria.
Detection of carbapenem-resistant Escherichia coli and Klebsiella pneumoniae producing NDM-1 in Lebanon
Authors: El-Herte Rima I , Araj George F , Matar Ghassan M , Baroud Maysa , Kanafani Zeina A , Kanj Souha S 
Published: May 2012

Carbapenem resistance has been encountered globally with poor outcome of infected patients. NDM-1 (New Delhi metallo-beta-lactamase) gene containing organisms have emerged and are now spreading in all continents. This is the first report of Iraqi patients referred to Lebanon from whom carbapenem resistant Enterobacteriaceae were recovered. The genes involved in carbapenem resistance were bla-OXA-48 and the novel NDM-1. This report highlights the alarming introduction of such resistance among Enterobacteriaecae to this country.
Logiques pastorales et de conservation de la nature : les transhumances et le Parc du W (Niger, Burkina Faso, Bénin)
Authors: Amadou Boureima , Boutrais Jean 
Published: May 2012

Résumé Comment les pasteurs, souvent considérés comme proches et même respectueux de la nature, sont-ils devenus les principaux responsables des atteintes à l’intégrité des aires protégées en Afrique soudano-sahélienne ? Les entrées illégales de transhumants dans le Parc du W ont commencé de façon exceptionnelle lors des grandes sécheresses, puis elles sont devenues habituelles. Elles renvoient à un basculement zonal des mobilités pastorales. Les modalités des transhumances sont complexes et flexibles. Les interprétations de la transhumance dans le Parc du W divergent : exaltation des valeurs pastorales versus période mal vécue. En face, la logique de conservation est affirmée au Niger par une politique nationale adossée à des conventions internationales et confortée par des accords entre États africains. De nouvelles associations d’éleveurs et des projets de développement tentent de concilier les deux logiques, mais leur influence reste faible sur les pasteurs.
Un cinéma palestinien « en mal d’archive »
Authors: Fourest Laure 
Published: May 2012

À partir de l’analyse de trois films palestiniens réalisés dans les années 2000, cet article propose d’interroger l’insertion d’images d’archives par les cinéastes dans leur montage : quelles stratégies mettent-ils en œuvre et à quelles fins ? Qu’apportent des images d’archives en plus des témoignages filmés ? Comment le recours à ces images permet-il de participer au débat historiographique qui sous-tend et détermine en partie le conflit israélo-palestinien ? Dans le contexte palestinien où il n’existe pas d’institution archivistique officielle, les archives sont porteuses d’enjeux particulièrement saillants, donnant lieu à un véritable « mal d’archive ». Celui-ci fait naître une multiplicité de stratégies cinématographiques visant à questionner cette zone d’inconfort, où le maniement des qualités émotionnelles et sensorielles de l’archive peut être un moyen de faire preuve.
CLINICAL ASPECTS OF UNCOMPLICATED AND SEVERE MALARIA
Authors: Bartoloni Alessandro , Zammarchi Lorenzo 
Published: May 2012

The first symptoms of malaria, common to all the different malaria species, are nonspecific and mimic a flu-like syndrome. Although fever represents the cardinal feature, clinical findings in malaria are extremely diverse and may range in severity from mild headache to serious complications leading to death, particularly in falciparum malaria. As the progression to these complications can be rapid, any malaria patient must be assessed and treated rapidly, and frequent observations are needed to look for early signs of systemic complications.In fact, severe malaria is a life threatening but treatable disease. The protean and nonspecific clinical findings occurring in malaria (fever, malaise, headache, myalgias, jaundice and sometimes gastrointestinal symptoms of nausea, vomiting and diarrhoea) may lead physicians who see malaria infrequently to a wrong diagnosis, such as influenza (particularly during the seasonal epidemic flu), dengue, gastroenteritis, typhoid fever, viral hepatitis, encephalitis. Physicians should be aware that malaria is not a clinical diagnosis but must be diagnosed, or excluded, by performing microscopic examination of blood films. Prompt diagnosis and appropriate treatment are then crucial to prevent morbidity and fatal outcomes. Although Plasmodium falciparum malaria is the major cause of severe malaria and death, increasing evidence has recently emerged that Plasmodium vivax and Plasmodium knowlesi can also be severe and even fatal.