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Comparison of computation methods for CBM production performanceMora, Carlos A. 02 June 2009 (has links)
Coalbed methane (CBM) reservoirs have become a very important natural resource around the world. Because of their complexity, calculating original gas in place and analyzing production performance require consideration of special features. Coalbed methane production is somewhat complicated and has led to numerous methods of approximating production performance. Many CBM reservoirs go through a dewatering period before significant gas production occurs. With dewatering, desorption of gas in the matrix, and molecular diffusion within the matrix, the production process can be difficult to model. Several authors have presented different approaches involving the complex features related to adsorption and diffusion to describe the production performance for coalbed methane wells. Various programs are now commercially available to model production performance for CBM wells, including reservoir simulation, semi-analytic, and empirical approaches. Programs differ in their input data, description of the physical problem, and calculation techniques. This study will compare different tools available in the gas industry for CBM reservoir analysis, such as numerical reservoir simulators and semi-analytical software programs, to understand the differences in production performance when standard input data is used. Also, this study will analyze how sorption time (for modeling the diffusion process) influences the gas production performance for CBM wells.
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Comparison of computation methods for CBM production performanceMora, Carlos A. 02 June 2009 (has links)
Coalbed methane (CBM) reservoirs have become a very important natural resource around the world. Because of their complexity, calculating original gas in place and analyzing production performance require consideration of special features. Coalbed methane production is somewhat complicated and has led to numerous methods of approximating production performance. Many CBM reservoirs go through a dewatering period before significant gas production occurs. With dewatering, desorption of gas in the matrix, and molecular diffusion within the matrix, the production process can be difficult to model. Several authors have presented different approaches involving the complex features related to adsorption and diffusion to describe the production performance for coalbed methane wells. Various programs are now commercially available to model production performance for CBM wells, including reservoir simulation, semi-analytic, and empirical approaches. Programs differ in their input data, description of the physical problem, and calculation techniques. This study will compare different tools available in the gas industry for CBM reservoir analysis, such as numerical reservoir simulators and semi-analytical software programs, to understand the differences in production performance when standard input data is used. Also, this study will analyze how sorption time (for modeling the diffusion process) influences the gas production performance for CBM wells.
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Couplage diagnostic pronostic pour la maintenance prévisionnelle des systèmes photovoltaïquesHassan Ali, Mohamed 16 March 2018 (has links)
Dans ce travail, nous avons développé une méthode de couplage d'un processus de diagnostic à base de modèle avec un processus de prognostic issu de l'expérience au moyen d'une architecture OSA-CBM (Open System Architecture for Condition Based Maintenance). Pour cela, le modèle 2M7P de la cellule photovoltaïque est optimisé par la mise en œuvre d'une méthode métaheuristique d'extraction des sept paramètres, FodPSO. Cette optimisation permet de mieux reproduire la performance de la cellule surtout en conditions réelles de fonctionnement. L'approche du diagnostic est traitée par la quantification du résidu différentiel au moyen de la distance euclidienne en vue de caractériser la signature électrique des cinq défauts ciblés. La connaissance de la signature des défauts permet la détection puis la discrimination. La partie pronostic évolue depuis une première approche issue des modèles de dégradation de Pan et Monroe d'une part et de Vazquez et al. d'autre part vers une approche par analyse de fiabilité basée sur l'expérience. Le couplage proposé dans ce travail, consiste en un échange d'information entre les deux processus de diagnostic et de pronostic pour l'aide à la décision selon une architecture où les décisions sont faites grâce à un test de seuil sur l'indicateur choisi, le Corrected Performance Ration. Les informations sont restituées à l'utilisateur sur la dernière couche de l'architecture. L'ensemble des approches ont été validées avec les données expérimentales issues de différentes centrales solaires (UPJV, Catania Univ…). / In this work, we have developed a method of coupling a model-based diagnostic process with a prognostic process derived from the experience using an OSA-CBM (Open System Architecture for Condition Based Maintenance) architecture. For that, the 2M7P model of the photovoltaic cell is optimized by the implementation of a metaheuristic method of extraction of seven parameters, FodPSO. This optimization makes it possible to better reproduce cell's performance, especially under actual operating conditions. The diagnostic approach is treated by quantifying the differential residual using Euclidean distance in order to characterize electrical signatures of five targeted faults. The knowledge of faults signatures allows detection and discrimination. The prognostic part evolves since a first approach resulting from models of degradation of Pan and Monroe on the one hand and Vazquez et al. on the other hand towards a reliability analysis approach based on experience. The coupling proposed in this work consists of an exchange of information between the two diagnostic and prognostic processes for decision support according to an architecture where decisions are made by means of a threshold test on the selected indicator, the Corrected performance Ratio. Information is returned to the user on last layer of the OSA-CBM architecture. All approaches have been validated with experimental data from different plants (UPJV Platform, Catania University…).
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Tillståndsbaserat underhåll till sjöss : Vad föranleder den begränsade användningen av tillståndsbaserat underhåll (CBM) till sjöss?Rosén, Joel, Olsson, Magnus January 2013 (has links)
Today, maintenance is a big part of the daily life on board ships. It is also one of the bigger expenses a shipping company has and without any loss of quality tries to run as economically advantageous as possible. In the hunt for economical savings the shore-based industry has subsequently applied the use of condition based maintenance, CBM, were a component is maintained according to its actual state. This leads to a reduction of maintenance costs since no parts are unnecessarily replaced. However, within the maritime sector a periodical maintenance is still the most commonly used maintenance system.The purpose of this paper is to chart the factors that are the reason for the low implementation of CBM on board the Swedish merchant fleet's ships. The investigation was carried out according to the qualitative method. Three shipping companies were interviewed, all carrying slow speed, two-stroke crosshead engines.The result from the interviews were evaluated and analyzed and the contributing factors of the low implementation of CBM on board has been identified.The result of this paper shows that the unique conditions on board ships reduces the advantages, normally received in the shore-based industry by using CBM. / Underhåll är en stor del av vardagen till sjöss. Det är även en av de stora utgiftsposterna för ett rederi och utan att tumma på kvaliteten vill man bedriva detta så ekonomiskt fördelaktigt som möjligt. I jakten på besparingar har den landbaserade industrin mer och mer övergått till ett tillståndsbaserat underhåll, s.k. condition based maintenance - CBM. Då bedrivs underhållet utifrån en komponents faktiska tillstånd. Detta leder till minskade underhållskostnader eftersom komponenter inte utbytes i onödan. Inom sjöfarten är dock det periodiskt baserade underhållet fortfarande dominerande.Syftet med denna undersökning är att kartlägga de faktorer som ligger till grund för den ringa utsträckningen av tillståndsbaserat underhåll, CBM på den Svenska handelsflottans fartyg. Undersökningen utfördes enligt den kvalitativa metoden. Tre rederier intervjuades, samtliga med fartyg i oceantrafik där framdrivningsmaskineriet består av långsamtgående, 2-takts tvärstycksmaskiner. Intervjuerna utvärderades och analyserades varpå de bidragande faktorerna till den begränsade användningen identifierades.Resultatet av undersökningen visar på att de unika förutsättningar som råder på ett fartyg minskar fördelarna, som man normalt erhåller med CBM inom den landbaserade industrin.
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Selection of best drilling, completion and stimulation method for coalbed methane reservoirsRamaswamy, Sunil 15 May 2009 (has links)
Over the past three decades, coalbed methane (CBM) has moved from a mining
hazard and novel unconventional resource to an important fossil fuel that
accounts for approximately 10% of the U.S. natural gas production and reserves.
The expansion of this industry required development of different drilling,
completion and stimulation practices for CBM in specific North American basins,
owing to the complex combinations of geologic settings and reservoir parameters
encountered. These challenges led to many technology advances and to
development of CBM drilling, completion and stimulation technology for specific
geologic settings.
The objectives of this study were to (1) determine which geologic parameters
affect CBM drilling, completion and stimulation decisions, (2) identify to the
engineering best practices for specific geologic settings, and (3) present these findings in decision charts or advisory systems that could be applied by industry
professionals.
To determine best drilling, completion and stimulation practices for CBM
reservoirs, I reviewed literature and solicited opinions of industry experts through
responses to a questionnaire. I identified thirteen geologic parameters (and their
ranges of values) that are assessed when selecting CBM drilling, completion and
stimulating applications. These are coal thickness, number of seams, areal
extent, dip, depth, rank, gas content, formation pressure, permeability, water
saturation, and compressive strength, as well as the vertical distribution of coal
beds and distance from coal reservoirs to fracture barriers or aquifers. Next, I
identified the optimum CBM drilling, completion and stimulating practices for
specific combinations of these geologic parameters. The engineering best
practices identified in this project may be applied to new or existing fields, to
optimize gas reserves and project economics.
I identified the best engineering practices for the different CBM basins in N.A and
combined these results in the form of two decision charts that engineers may use
to select best drilling and completion practices, as well as the optimal stimulation
methods and fluids for specific geologic settings. The decision charts are
presented in a Visual Basic Application software program to facilitate their use by
engineers.
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Selection of best drilling, completion and stimulation method for coalbed methane reservoirsRamaswamy, Sunil 10 October 2008 (has links)
Over the past three decades, coalbed methane (CBM) has moved from a mining
hazard and novel unconventional resource to an important fossil fuel that
accounts for approximately 10% of the U.S. natural gas production and reserves.
The expansion of this industry required development of different drilling,
completion and stimulation practices for CBM in specific North American basins,
owing to the complex combinations of geologic settings and reservoir parameters
encountered. These challenges led to many technology advances and to
development of CBM drilling, completion and stimulation technology for specific
geologic settings.
The objectives of this study were to (1) determine which geologic parameters
affect CBM drilling, completion and stimulation decisions, (2) identify to the
engineering best practices for specific geologic settings, and (3) present these findings in decision charts or advisory systems that could be applied by industry
professionals.
To determine best drilling, completion and stimulation practices for CBM
reservoirs, I reviewed literature and solicited opinions of industry experts through
responses to a questionnaire. I identified thirteen geologic parameters (and their
ranges of values) that are assessed when selecting CBM drilling, completion and
stimulating applications. These are coal thickness, number of seams, areal
extent, dip, depth, rank, gas content, formation pressure, permeability, water
saturation, and compressive strength, as well as the vertical distribution of coal
beds and distance from coal reservoirs to fracture barriers or aquifers. Next, I
identified the optimum CBM drilling, completion and stimulating practices for
specific combinations of these geologic parameters. The engineering best
practices identified in this project may be applied to new or existing fields, to
optimize gas reserves and project economics.
I identified the best engineering practices for the different CBM basins in N.A and
combined these results in the form of two decision charts that engineers may use
to select best drilling and completion practices, as well as the optimal stimulation
methods and fluids for specific geologic settings. The decision charts are
presented in a Visual Basic Application software program to facilitate their use by
engineers.
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Lean study on the maintenance division at Sandvik Coromant : Resource utilization of work proceduresSundin, Fredric, Svensson, Victor January 2014 (has links)
Sandvik Coromant in Gimo, Sweden, is a world- leading supplier of tools and know- how for the metal cutting industry. This thesis was carried out on the maintenance division at the production plant producing tools for milling and drilling. The maintenance division is responsible for the maintenance of the machinery operating at all eight production units on the tool production plant. This thesis aims to map the value flow and non- value adding activities on the maintenance division and come up with suggestions for improvement. The study only focuses on the organizations work procedures and routines. The thesis began with a current state analysis of the maintenance division to find out how the activities, databases and service technicians interacts in daily operations. A time study showed that the proportion of non-value adding activities in some isolated cases was as low as 30%. The thesis ended in a root cause analysis, in form of a workshop, which aimed to, with help from the service technicians’ expertise and the researchers’ knowledge of lean production come up with solutions worth implementing on the maintenance division. The root cause analysis resulted in three solutions, which the researchers along with the service technicians sees as simple actions that will reduce the non-value adding time associated with the use, and handling of documentation. The analysis also resulted in sex actions seen as worth implementing, which however is more recourse demanding for the organization. / Sandvik Coromant i Gimo, Sverige, är en världsledande leverantör av verktyg och know- how för metallbearbetningsindustrin. Detta arbete utfördes på underhållsavdelningen vid fabriken för tillverkning av verktyg för borrning och fräsning. Underhållsavdelningen är ansvarig för underhållet av maskinparken på alla de åtta produktionsavsnitten vid fabriken för verktygstillverkning. Arbetet syftar till att kartlägga värdeflödet och icke värdeskapande tid vid underhållsavdelningen och komma med förbättringsförslag. Studien fokuserar enbart på organisationens arbetssätt och rutiner. Arbetet började med en nuvärdesanalys av underhållsavdelningen för att undersöka hur aktiviteter, databaser och servicetekniker fungera tillsammans i den dagliga verksamheten. En tidsstudie genomfördes för att undersöka hur mycket icke värdeskapande tid serviceteknikerna har vid en standardarbetsorder från produktionsavsnitten. Tidsstudien visade att andelen icke värdeskapande tid var så låg som 30 % i vissa isolerade fall. Arbetet avslutades i en rotorsaksanalys i form av en workshop, vilkens syfte var att med hjälp från serviceteknikerna och deras expertis tillsammans med kunskapen om lean production hos forskarna undersöka vilka lösningar som skulle minska denna siffra ytterligare. Rotorsaksanalysen resulterade i tre lösningar som forskarna tillsammans med serviceteknikerna ser som enkla åtgärder för att minska den icke värdeskapande tiden kopplad till användning och hantering av dokumentation. Analysen resulterade även i sex åtgärder som anses vara värd att implementera men som är mer resurskrävande för organisationen.
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The Utility of Mathematics Curriculum-Based Measurement to Predict Student Risk Status on Standardized Academic Achievement MeasuresHancock, Kyle Max 01 May 2009 (has links)
The predictive utility of mathematics curriculum-based measurement (MCBM) to identify students who are at risk for failure on important educational measures is an emerging area of study in need of further investigation. The present study sought to identify which of four MCBM probes could be accurately used to determine students' risk status on selected subtests of three important educational measures commonly used to make educational placement decisions (WIAT-II, WJ-ACH-III, and KM 3) in grades 2 (n = 49), 4 (n = 48), and 6 (n = 47). The study also sought to determine which type of student performance measurement strategy (i.e., level, slope, or dual discrepancy) on each of the four types of MCBM probes proved to be the best method to determine student risk status. The results of the study indicated that the ability of the MCBM probes to identify students' risk status was generally poor. However, evidence indicated that MCBM probes could be used more reliably and accurately to determine students in the low risk category than those in the high risk category across all probe types and administration times. Finally, the level method generated the greatest support and the slope method generated the least support for identification of high and low risk student status on each probe or combination of probes.
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Kartläggning och analys av scanias tillsynsprogram : Ett verktyg för förbättring / Mapping and analysis of Scanias maintenanceprogram : A tool for improvementSköld, Michael, Jacob, Almbladh January 2013 (has links)
Scania intends to introduce a new maintenance program for their rolling fleet. Withthis new program Scania hopes to increase their competiveness and add furthercustomer value. This thesis report is a mapping of the current maintenance program,along with its problematic features. Furthermore the report intends to describe thenew program, Condition Based Maintenance (CBM) and the problems that Scaniamust deal with before they can implement it.The report compiles basic information on how a mapping should be performed.Further on it will describe some of the theories of LEAN and leadership. Which aretwo of the most important features in this thesis work.The work has been performed through visits in different workshops, whereinterviews have taken place. The interviews have a big impact in this report, as theycompile different people’s thoughts about the consisting work and the problems withit. All the information that has been collected has then been analyzed and discussed,to give a better understanding of the actual situation in the workshops.The field studies have been collected in a mapping report, in which the problems withimplementing CBM have been summarized. These problems have then been analyzedto generate solutions. The biggest problems in the workshops today, concernleadership and proactivity. / Scania vill införa ett nytt tillsynsprogram för sin rullande flotta. På detta sätthoppas Scania kunna stärka sin konkurrenskraft och öka kundnyttan. Dennarapport är en kartläggning av det tillsynsprogram Scania tillämpar idag, samtdess faktiska arbetssätt och problem. Vidare syftar rapporten till att beskrivadet tilltänkta programmet, Condition Based Maintenance (CBM), samt deproblemställningar som Scania måste tampas med innan implementationen.Rapporten sammanställer grundläggande information om hur ett arbete avkartläggande karaktär bör utföras. Vidare beskrivs teorier om LEAN ochledarskap. Vilket är två av de viktigaste faktorerna i detta arbete.Arbetet har utförts genom besök i verkstäder, där intervjuer har gjorts.Intervjuerna tar upp en stor del i rapporten då de sammanställer synpunkteroch brister i dagens arbetsätt. Den insamlade informationen har sedananalyserats och diskuterats, för att ge en bättre förståelse för den faktiskasituationen ute i verkstäderna.Arbetet har resulterat i en kartläggning, som samlat de problem Scania måsteåtgärda innan implementeringen av CBM. Dessa problem har sammanställtsoch analyserats för att sedan kunna generera lösningsförlag. De störstaproblemen ute i verkstäderna är ledarskap och rutiner gällande ett proaktivtarbetsätt gentemot kund.
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An examination of the equivalence of the first grade DIBELS oral reading fluency probesFan, Chung-Hau 01 December 2011 (has links)
Given the change in federal legislation allowing the consideration of a Response-To-Intervention (RTI) approach to making eligibility decisions for specific learning disabilities (IDEIA, 2004), it is crucial to establish sufficient evidence for using curriculum-based measurements (CBM) or CBM-like measures (e.g., Dynamic Indicators of Basic Early Literacy Skills; DIBELS) for monitoring students' responses to interventions as part of the identification process for Specific Learning Disabilities. One critical component in an effective RTI model is the availability of parallel measures suited for frequent progress monitoring to index student performance over time. The current study investigated the equivalence of the twenty first grade DIBELS Oral Reading Fluency (DORF) progress monitoring probes' using a one-way ANOVA for repeated-measures. Participants were 68 first grade students (36 females and 32 males) from two Midwestern elementary schools. No selection criteria other than parental consent were used. The DORF probes were given in a pseudo-counterbalanced order across four days at the end of the school year to avoid instruction and practice effects. The standard error of measurement (SEM) of the twenty first grade DORF progress monitoring probes was calculated using alternate form reliability coefficients. Results suggested that the equivalence assumption of the first grade DORF was not held. Most of the probes were significantly different in their difficulty level from each other and did not yield consistent mean levels of performance. The findings also suggested a significant magnitude of score fluctuation at the individual student level. The average SEM value was about 9 (ranging from 8 to 10), similar to previous research findings using test-retest reliability for calculation. Limitations, educational implications for CBM ORF users and researchers, and directions for future research are presented.
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