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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Estimation of static and dynamic petrophysical properties from well logs in multi-layer formations

Heidari, Zoya 26 October 2011 (has links)
Reliable assessment of static and dynamic petrophysical properties of hydrocarbon-bearing reservoirs is critical for estimating hydrocarbon reserves, identifying good production zones, and planning hydro-fracturing jobs. Conventional well-log interpretation methods are adequate to estimate static petrophysical properties (i.e., porosity and water saturation) in formations consisting of thick beds. However, they are not as reliable when estimating dynamic petrophysical properties such as absolute permeability, movable hydrocarbon saturation, and saturation-dependent capillary pressure and relative permeability. Additionally, conventional well-log interpretation methods do not take into account shoulder-bed effects, radial distribution of fluid saturations due to mud-filtrate invasion, and differences in the volume of investigation of the various measurements involved in the calculations. This dissertation introduces new quantitative methods for petrophysical and compositional evaluation of water- and hydrocarbon-bearing formations based on the combined numerical simulation and nonlinear joint inversion of conventional well logs. Specific interpretation problems considered are those associated with (a) complex mineral compositions, (b) mud-filtrate invasion, and (c) shoulder-bed effects. Conventional well logs considered in the study include density, photoelectric factor (PEF), neutron porosity, gamma-ray (GR), and electrical resistivity. Depending on the application, estimations yield static petrophysical properties, dynamic petrophysical properties, and volumetric/weight concentrations of mineral constituents. Assessment of total organic carbon (TOC) is also possible in the case of hydrocarbon-bearing shale. Interpretation methods introduced in this dissertation start with the detection of bed boundaries and population of multi-layer petrophysical properties with conventional petrophysical interpretation results or core/X-Ray Diffraction (XRD) data. Differences between well logs and their numerical simulations are minimized to estimate final layer-by-layer formation properties. In doing so, the interpretation explicitly takes into account (a) differences in the volume of investigation of the various well logs involved, (b) the process of mud-filtrate invasion, and (c) the assumed rock-physics model. Synthetic examples verify the accuracy and reliability of the introduced interpretation methods and quantify the uncertainty of estimated properties due to noisy data and incorrect bed boundaries. Several field examples describe the successful application of the methods on (a) the assessment of residual hydrocarbon saturation in a tight-gas sand formation invaded with water-base mud (WBM) and a hydrocarbon-bearing siliciclastic formation invaded with oil-base mud (OBM), (b) estimation of dynamic petrophysical properties of water-bearing sands invaded with OBM, (c) estimation of porosity and volumetric concentrations of mineral and fluid constituents in carbonate formations, and (d) estimation of TOC, total porosity, total water saturation, and volumetric concentrations of mineral constituents in the Haynesville shale-gas formation. Comparison of results against those obtained with conventional petrophysical interpretation methods, commercial multi-mineral solvers, and core/XRD data confirm the advantages and flexibility of the new interpretation techniques introduced in this dissertation for the quantification of petrophysical and compositional properties in a variety of rock formations. / text
12

Determina??o das propriedades da torta de filtra??o de fluido de perfura??o e estima??o de par?metros / Determination of filter-cake properties of drilling fluid and parameter estimation

Silva, Leandro Azevedo 25 January 2016 (has links)
Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2017-06-13T12:24:46Z No. of bitstreams: 1 2016 - Leandro Azevedo Silva.pdf: 63779080 bytes, checksum: f77d63d9585271a492573ca45c79e4b8 (MD5) / Made available in DSpace on 2017-06-13T12:24:46Z (GMT). No. of bitstreams: 1 2016 - Leandro Azevedo Silva.pdf: 63779080 bytes, checksum: f77d63d9585271a492573ca45c79e4b8 (MD5) Previous issue date: 2016-01-25 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The undesirable fluid invasion into the reservoir rock can cause irreversible damage to the rock formation. In order to avoid such problems, solid particles are used as bridging and weighting agent in drilling fluid formulations. The physico-chemical characteristics of these materials have a strong influence on cake formation and therefore on filtration rate and mud-filtrate invasion in rock formations. Thus, the control of filter-cake properties is critical in the oil well drilling process. The focus of this research was to evaluate the effect of calcium carbonate particle size and the concentration of two different types of polymeric viscosifier on static filtration tests. The experiments were performed in a HTHP cell (High Temperature, High Pressure) manufactured by OFI Testing Equipment?. This apparatus was previously used by Calabrez (2013), Martins (2013), and Ferraz (2014). The filter cake parameters evaluated were: porosity, permeability, cake thickness, filtrate volume, growth rate, and compressibility index. The particle size distribution of calcium carbonate, the viscosifier and its respective concentration influenced the rheology of the fluids and the filtration process. Equations that describe the filtration phenomenon and which allow the calculation of the filtration parameters were evaluated. Experimental data obtained in other studies were assessed in order to validate the studied model. Based on literature models, the simulation of drilling fluid filtrate invasion was performed in an oil well connecting the filtration and filtrate invasion equations. Using the simulation result of each fluid behavior it was possible to predict the characteristics of the fluid which will cause less damage to the oil well in this context. / A invas?o indesej?vel de fluido na rocha reservat?rio pode causar danos irrevers?veis ? forma??o rochosa. Com o intuito de mitigar tais problemas, part?culas s?lidas s?o utilizadas como material obturante e adensante na composi??o de fluidos de perfura??o. As caracter?sticas f?sico-qu?micas destes materiais t?m forte influ?ncia na forma??o da torta de filtra??o e consequentemente na taxa de filtra??o e invas?o de filtrado nas forma??es rochosas. Desta forma, o controle das propriedades da torta ? fundamental no processo de perfura??o de po?os de petr?leo. O objetivo deste trabalho foi avaliar o efeito do tamanho das part?culas de Carbonato de C?lcio e da concentra??o de dois tipos de viscosificantes polim?ricos distintos em testes de filtra??o est?tica. Os experimentos foram conduzidos em uma c?lula HTHP (High Temperature, High Pressure) produzida pela OFI Testing Equipments?. Os par?metros da torta avaliados foram: porosidade, permeabilidade, espessura da torta, volume de filtrado, fator de crescimento e ?ndice de compressibilidade. A distribui??o granulom?trica do carbonato de c?lcio, o viscosificante e sua respectiva concentra??o influenciaram na reologia dos fluidos e no processo de filtra??o. Foram avaliadas equa??es que descrevem o fen?meno de filtra??o e permitem o c?lculo de par?metros de filtra??o. Dados experimentais obtidos na literatura foram usados com o objetivo de validar o modelo estudado. Com base em modelos da literatura foi realizada a simula??o da invas?o de filtrado de fluido de perfura??o em um po?o de petr?leo conectando as equa??es de filtra??o e invas?o. Com o resultado da simula??o do comportamento de cada fluido pode-se prever quais as caracter?sticas do fluido que causar? menor dano ao po?o.
13

Dissolvingmassa baserat på soda-AQ kokning : Potential för ökat förädlingsvärde av svensk skogsråvara / Dissolving pulp based on soda-AQ cooking : Potential for production of higher value added products

Kihlman, Martin January 2009 (has links)
<p>Detta examensarbete genomfördes från begäran av två företag, Pöyry Sweden AB, Karlstad och Kiram AB. Arbetet var uppdelat i två delar, en litteraturstudie samt en experimentell del. I litteraturstudien kartlades olika processer för framställning av dissolvingmassa och olika processer för beredning av viskosfiber. Utöver det sammanställdes även några av de ledande aktörerna av joniska vätskor samt applikationer för cellulosabaserade produkter. Fokus genom hela arbetet har legat på svavelfria processer som t.ex. användandet av joniska vätskor för upplösning av cellulosa. I den experimentella delen undersöktes det om man via en förhydrolys följt av ett soda-AQ kok, en svavelfri process, kunde producera dissolvingmassa. Utöver produktion av dissolvingmassa undersöktes också filtratet som drogs av efter förhydrolysen.</p><p>Under den experimentella delen varierades olika parametrar för att se hur det påverkade kvaliteten av massan. De parametrar som varierades vid förhydrolysförsöken var tid och antrakinon (AQ), för soda-AQ koket varierades tid, AQ och effektiv alkali (EA) halt. För ett förhydrolysförsök varierades även vätske/vedförhållandet. Vilka betingelser som skulle användas samt de mål som skulle uppnås fick man fram under litteraturstudien.</p><p>För att nå målet med ett utbyte på ca 85 % efter förhydrolysen krävdes en temperatur på 160°C och tid på 1 timme för en förhydrolys med enbart vatten. Hypotesen om att en AQ tillsats redan vid förhydrolysen skulle sänka utbytet visades inte stämma, man fick då istället ett ökat utbyte. Målet för massorna efter soda-AQ koket var ett utbyte på ca 40 %, ett kappatal runt 30 och en viskositet > 1000 ml/g. Utförde man en förhydrolys som beskrivits ovan följt av ett soda-AQ kok med dessa betingelser: temperatur 160°C, tid ≥ 2 h, EA sats > 21 % och en AQ halt ≥ 1 kg/ton, fick man en dissolvingmassa som uppfyllde kraven.</p><p>Kolhydratanalysen på filtratet visade att mestadels glukomannan brutits ner och lösts ut under förhydrolysen. Däremot skedde det ingen nedbrytning av cellulosa. Utförde man förhydrolysen på ett sådant sätt som beskrivits ovan bröt man ner en hemicellulosa mängd på ca 72 kg/ton flis. Det får ses som en ganska rejäl mängd eftersom man enbart använder vatten under förhydrolysen.</p> / <p>This project was carried out on a request from two companies, Pöyry Sweden AB, Karlstad and Kiram AB. The work was divided in two parts, one literature study and one experimental part. In the literature study different processes for production of dissolving pulp and different processes for viscose preparation were identified. Besides that, some of the lending companies of ionic liquids and some applications of cellulose based products were compiled. The main focus throughout this work has been on processes without sulfur, for an example the use of ionic liquids for dissolving cellulose. In the experimental part, dissolving pulp production by a prehydrolysis followed by a soda-AQ cooking was investigated. The filtrate gained from the prehydrolysis was also examined.</p><p>In the dissolving pulp production different parameters for the prehydrolysis and cooking stage were alternated. For the prehydrolysis the following parameters were varied: time and concentration of anthraquinone and for the cooking stage the parameters time, EA and concentration of anthraquinone. In one experiment the liquid to wood ratio was varied. The conditions that would be used and the target of the experimental work were received from the literature study.</p><p>To reach the target yield of approximately 85 % after an prehydrolysis, with water, the following conditions were required, a temperature of 160°C and a time of 1 hour. The hypothesis that an AQ additive, already in the prehydrolysis, should lowered the yield proved to be wrong. The target for the dissolving pulps after a soda-AQ cooking were a yield of ~ 40 %, a kappa number around 30 and finally a viscosity > 1000 ml/g. A soda-AQ cooking with these conditions: temperature 160°C, time ≥ 2 h, EA > 21 % and an AQ conc. ≥ 1 kg/ton, after a prehydrolysis, mentioned above, resulted in a pulp which achieved the targets.</p><p>The carbohydrate analysis on the filtrate showed that mostly glucomannan was settled out during the prehydrolysis. It also showed that no cellulose was settled out. A result after a prehydrolysis like the one mentioned above was that the amount of hemicellulose was reduced with ~ 72 kg/ton wood.</p>
14

Dissolvingmassa baserat på soda-AQ kokning : Potential för ökat förädlingsvärde av svensk skogsråvara / Dissolving pulp based on soda-AQ cooking : Potential for production of higher value added products

Kihlman, Martin January 2009 (has links)
Detta examensarbete genomfördes från begäran av två företag, Pöyry Sweden AB, Karlstad och Kiram AB. Arbetet var uppdelat i två delar, en litteraturstudie samt en experimentell del. I litteraturstudien kartlades olika processer för framställning av dissolvingmassa och olika processer för beredning av viskosfiber. Utöver det sammanställdes även några av de ledande aktörerna av joniska vätskor samt applikationer för cellulosabaserade produkter. Fokus genom hela arbetet har legat på svavelfria processer som t.ex. användandet av joniska vätskor för upplösning av cellulosa. I den experimentella delen undersöktes det om man via en förhydrolys följt av ett soda-AQ kok, en svavelfri process, kunde producera dissolvingmassa. Utöver produktion av dissolvingmassa undersöktes också filtratet som drogs av efter förhydrolysen. Under den experimentella delen varierades olika parametrar för att se hur det påverkade kvaliteten av massan. De parametrar som varierades vid förhydrolysförsöken var tid och antrakinon (AQ), för soda-AQ koket varierades tid, AQ och effektiv alkali (EA) halt. För ett förhydrolysförsök varierades även vätske/vedförhållandet. Vilka betingelser som skulle användas samt de mål som skulle uppnås fick man fram under litteraturstudien. För att nå målet med ett utbyte på ca 85 % efter förhydrolysen krävdes en temperatur på 160°C och tid på 1 timme för en förhydrolys med enbart vatten. Hypotesen om att en AQ tillsats redan vid förhydrolysen skulle sänka utbytet visades inte stämma, man fick då istället ett ökat utbyte. Målet för massorna efter soda-AQ koket var ett utbyte på ca 40 %, ett kappatal runt 30 och en viskositet &gt; 1000 ml/g. Utförde man en förhydrolys som beskrivits ovan följt av ett soda-AQ kok med dessa betingelser: temperatur 160°C, tid ≥ 2 h, EA sats &gt; 21 % och en AQ halt ≥ 1 kg/ton, fick man en dissolvingmassa som uppfyllde kraven. Kolhydratanalysen på filtratet visade att mestadels glukomannan brutits ner och lösts ut under förhydrolysen. Däremot skedde det ingen nedbrytning av cellulosa. Utförde man förhydrolysen på ett sådant sätt som beskrivits ovan bröt man ner en hemicellulosa mängd på ca 72 kg/ton flis. Det får ses som en ganska rejäl mängd eftersom man enbart använder vatten under förhydrolysen. / This project was carried out on a request from two companies, Pöyry Sweden AB, Karlstad and Kiram AB. The work was divided in two parts, one literature study and one experimental part. In the literature study different processes for production of dissolving pulp and different processes for viscose preparation were identified. Besides that, some of the lending companies of ionic liquids and some applications of cellulose based products were compiled. The main focus throughout this work has been on processes without sulfur, for an example the use of ionic liquids for dissolving cellulose. In the experimental part, dissolving pulp production by a prehydrolysis followed by a soda-AQ cooking was investigated. The filtrate gained from the prehydrolysis was also examined. In the dissolving pulp production different parameters for the prehydrolysis and cooking stage were alternated. For the prehydrolysis the following parameters were varied: time and concentration of anthraquinone and for the cooking stage the parameters time, EA and concentration of anthraquinone. In one experiment the liquid to wood ratio was varied. The conditions that would be used and the target of the experimental work were received from the literature study. To reach the target yield of approximately 85 % after an prehydrolysis, with water, the following conditions were required, a temperature of 160°C and a time of 1 hour. The hypothesis that an AQ additive, already in the prehydrolysis, should lowered the yield proved to be wrong. The target for the dissolving pulps after a soda-AQ cooking were a yield of ~ 40 %, a kappa number around 30 and finally a viscosity &gt; 1000 ml/g. A soda-AQ cooking with these conditions: temperature 160°C, time ≥ 2 h, EA &gt; 21 % and an AQ conc. ≥ 1 kg/ton, after a prehydrolysis, mentioned above, resulted in a pulp which achieved the targets. The carbohydrate analysis on the filtrate showed that mostly glucomannan was settled out during the prehydrolysis. It also showed that no cellulose was settled out. A result after a prehydrolysis like the one mentioned above was that the amount of hemicellulose was reduced with ~ 72 kg/ton wood.
15

Development and application of a 3D equation-of-state compositional fluid-flow simulator in cylindrical coordinates for near-wellbore phenomena

Abdollah Pour, Roohollah 06 February 2012 (has links)
Well logs and formation testers are routinely used for detection and quantification of hydrocarbon reserves. Overbalanced drilling causes invasion of mud filtrate into permeable rocks, hence radial displacement of in-situ saturating fluids away from the wellbore. The spatial distribution of fluids in the near-wellbore region remains affected by a multitude of petrophysical and fluid factors originating from the process of mud-filtrate invasion. Consequently, depending on the type of drilling mud (e.g. water- and oil-base muds) and the influence of mud filtrate, well logs and formation-tester measurements are sensitive to a combination of in-situ (original) fluids and mud filtrate in addition to petrophysical properties of the invaded formations. This behavior can often impair the reliable assessment of hydrocarbon saturation and formation storage/mobility. The effect of mud-filtrate invasion on well logs and formation-tester measurements acquired in vertical wells has been extensively documented in the past. Much work is still needed to understand and quantify the influence of mud-filtrate invasion on well logs acquired in horizontal and deviated wells, where the spatial distribution of fluids in the near-wellbore region is not axial-symmetric in general, and can be appreciably affected by gravity segregation, permeability anisotropy, capillary pressure, and flow barriers. This dissertation develops a general algorithm to simulate the process of mud-filtrate invasion in vertical and deviated wells for drilling conditions that involve water- and oil-base mud. The algorithm is formulated in cylindrical coordinates to take advantage of the geometrical embedding imposed by the wellbore in the spatial distribution of fluids within invaded formations. In addition, the algorithm reproduces the formation of mudcake due to invasion in permeable formations and allows the simulation of pressure and fractional flow-rate measurements acquired with dual-packer and point-probe formation testers after the onset of invasion. An equation-of-state (EOS) formulation is invoked to simulate invasion with both water- and oil-base muds into rock formations saturated with water, oil, gas, or stable combinations of the three fluids. The algorithm also allows the simulation of physical dispersion, fluid miscibility, and wettability alteration. Discretized fluid flow equations are solved with an implicit pressure and explicit concentration (IMPEC) scheme. Thermodynamic equilibrium and mass balance, together with volume constraint equations govern the time-space evolution of molar and fluid-phase concentrations. Calculations of pressure-volume-temperature (PVT) properties of the hydrocarbon phase are performed with Peng-Robinson's equation of state. A full-tensor permeability formulation is implemented with mass balance equations to accurately model fluid flow behavior in horizontal and deviated wells. The simulator is rigorously and successfully verified with both analytical solutions and commercial simulators. Numerical simulations performed over a wide range of fluid and petrophysical conditions confirm the strong influence that well deviation angle can have on the spatial distribution of fluid saturation resulting from invasion, especially in the vicinity of flow barriers. Analysis on the effect of physical dispersion on the radial distribution of salt concentration shows that electrical resistivity logs could be greatly affected by salt dispersivity when the invading fluid has lower salinity than in-situ water. The effect of emulsifiers and oil-wetting agents present in oil-base mud was studied to quantify wettability alteration and changes in residual water saturation. It was found that wettability alteration releases a fraction of otherwise irreducible water during invasion and this causes electrical resistivity logs to exhibit an abnormal trend from shallow- to deep-sensing apparent resistivity. Simulation of formation-tester measurements acquired in deviated wells indicates that (i) invasion increases the pressure drop during both drawdown and buildup regimes, (ii) bed-boundary effects increase as the wellbore deviation angle increases, and (iii) a probe facing upward around the perimeter of the wellbore achieves the fastest fluid clean-up when the density of invading fluid is larger than that of in-situ fluid. / text
16

Vliv specifické spotřeby flokulantu na odvodnitelnost čistírenského kalu / Dependence of Sludge Dewatering efficiency on amount of flocculant

Volejník, Tomáš January 2008 (has links)
The target of the first part of this diploma thesis is focused on the problems relating to the sludge production from the wastewater treatment plant and subsequent sludge treatment. Wastewater treatment plant and individual processes from the sludge management are described. The process of the sludge dewatering is described more extensively. Various methods of the dewatering and materials balance are described, too. The second part of this thesis is based on the experiment which took place on wastewater treatment plant Tetčice. The influence of the polymeric organic flocculant dosing on the sludge dewatering was monitored by this experiment. Dependence of the sludge dry matter and filtrate suspended solids content on the specific amount of flocculant was evaluated from experiment’s outputs. Using materials balance and outputs of the experiment, economical balance was made. It made possible to choose the most economic and technologically optimal way of the sludge dewatering on wastewater treatment plant Tetčice.

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