Download or read book In Depth Study of in Situ Combustion Kinetics and Coupling to Flow written by Kuy Hun Koh Yoo and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis furthers understanding of three topics that are critical to In Situ Combustion (ISC) processes: crude oil kinetics, the tools used to model accurately and practically complex kinetic behavior and how oil kinetics couples with flow, especifically in systems with complex permeability distributions. On kinetics, we study the effects of pressure on crude oil kinetics for a large range of pressures and heating rates (1.5, 2.0, 5.0, 7.5, 8.0, 10.0, 15.0, 20.0, and 30.0 °C/min. Our results show that the activation energy of global reactions is not affected by changes in both partial pressure (21, 42, 50, 84, 209, and 250 psi) and absolute pressure (100-2000 psi) with values ranging 50 and 60 kJ/mol for the LTO regime and 90-100 kJ/mol for the HTO regime. Three different crude oils were tested. For one of the crude oils, we observe an increasing trend in oxygen consumption as absolute pressure is increased up to a critical pressure (~500 psi), after which it remains constant. This is associated to light component evaporation at low pressures, decreasing the amount of oil available for fuel generation. Total oxygen consumption starts to decrease again at very large pressures (> 1500 psi) and we associate it to water phase behavior at these conditions. We then propose a workflow and construct the corresponding tools to match Arrhenius-based reaction models for lab-scale numerical simulation models. The workflow is validated by matching multiple reaction models to experimental data obtained for a large range of heating rates (1.5-30 °C/min). On flow, we study instabilities that have been observed during combustion tube experiments by analyzing simple analogous problems and performing perturbation analysis from which we derive a new stability parameter. Finally, we propose and test a new experimental approach to observe directly how oil kinetics evolve under flow conditions by using thermal imaging and combining images with ramped temperature oxidation (RTO) experimental data. Results show that the reaction zone in lab conditions is in the order of centimeters. Reaction zone thicknesses range between 10-30 cm for the LTO zone and 10-50 cm for the HTO zone. Furthermore, we show how the new approach can help investigate complex systems and behaviors, such as oscillations, that could not otherwise be studied with conventional experiments.
Download or read book Kinetics of In situ Combustion written by Daulat D. Mamora and published by . This book was released on 1993 with total page 614 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Investigation of In situ Combustion Kinetics Using the Isoconversional Principle written by Bo Chen and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In-situ combustion (ISC) is the most energy efficient thermal enhanced oil recovery (EOR) method implemented in crude-oil reservoirs. The worldwide implementation of ISC in commercial field projects reached a maximum of 19 during the period of 1970's to 1990's, but it has declined to 4 active operations nowadays. Many failed projects are due to incorrect operations. Understanding the complicated combustion kinetics during the ISC process is essential and significantly important to optimize field operation. The combination of the experimental tool, ramped temperature oxidation (RTO), and the measured data interpretation method, isoconversional principle, provides a workflow to unlock the complicated characteristics of ISC kinetics. Conducting reliable or repeatable RTO experiments for isoconversional interpretation is the baseline for the workflow. Simulations coupled with a synthetic reaction model in an in-house virtual kinetic cell (VKC) simulator show that reducing temperature deviation caused by exothermic reactions is critical to carry out consistent RTO experiments. The argument is supported by a series of RTO experiments of the same crude-oil mixture, but different working conditions with respect to the kinetic cell design, the volumetric flow rate of air injection and the size of the sample mixture. Furthermore, the consistent RTO experimental results prove the model-free nature of the isoconversional principle and its applicability in the investigation of ISC kinetics. An attempt to combine the isoconversional principle and the conventional interpretation method is proposed to interpret kinetic parameters including apparent activation energy, pre-exponential factor and reaction orders for both fuel and oxygen partial pressure. Simulations in the VKC were carried out to test the proposed method for a unit and a non-unit reaction order case. The result showed good matches in the kinetic parameters between the interpretation and the simulations. A three-reaction scheme is proposed for two crude-oil mixtures, Alaska crude-oil and Karamay crude-oil, based on the observation and analysis of the activation energy fingerprints and the effluent data. The stoichiometry and the kinetic parameters for the reaction model are interpreted by the proposed method. The combustion models are verified in the commercial reservoir simulator CMG-STARS regarding the temperature histories, the effluent data from RTO experiments, and the isoconversional fingerprints. Further application of the isoconversional principle to analyze the crude-oil combustion includes investigating the sand and clay surface effect on the reaction paths together with X-ray photoelectron spectroscopy (XPS) to study the coke formation characteristics and their reaction kinetics. Screening the ISC candidates with respect to different crude-oil/sand-matrix pairs is also discussed. Lastly, the development of a microwave heating system is discussed to replace the conventional electric furnace system to carry out RTO experiments. Three generations of the microwave heating system are developed and discussed.
Download or read book Combustion written by Jürgen Warnatz and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: Combustion is an old technology, which at present provides about 90% of our worldwide energy support. Combustion research in the past used fluid mechanics with global heat release by chemical reactions described with thermodynamics, assuming infinitely fast reactions. This approach was useful for stationary combustion processes, but it is not sufficient for transient processes like ignition and quenching or for pollutant formation. Yet pollutant formation during combustion of fossil fuels is a central topic and will continue to be so in future. This book provides a detailed and rigorous treatment of the coupling of chemical reactions and fluid flow. Also, combustion-specific topics of chemistry and fluid mechanics are considered, and tools described for the simulation of combustion processes.
Download or read book Combustion written by Jürgen Warnatz and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 309 pages. Available in PDF, EPUB and Kindle. Book excerpt: Combustion is an old technology, which at present provides about 90% of our worldwide energy support. Combustion research in the past used fluid mechanics with global heat release by chemical reactions described with thermodynamics, assuming infinitely fast reactions. This approach was useful for stationary combustion processes, but it is not sufficient for transient processes like ignition and quenching or for pollutant formation. Yet pollutant formation during combustion of fossil fuels is a central topic and will continue to be so in future. This book provides a detailed and rigorous treatment of the coupling of chemical reactions and fluid flow. Also, combustion-specific topics of chemistry and fluid mechanics are considered, and tools described for the simulation of combustion processes. For the 2nd edition, the parts dealing with experiments, spray combustion, and soot were thoroughly revised.
Download or read book A High Pressure Kinetic Study of the In situ Combustion Process for Oil Recovery written by Rafiq Akhtar Kazi and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Kinetic Study of the In situ Combustion Process Using Thermal Analysis Technique written by Youssef M. T. El-Shoubary and published by . This book was released on 1986 with total page 1202 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Detailed and Reduced Kinetic Mechanisms in Low Emission Combustion Processes written by Sylvie Honnet and published by Cuvillier Verlag. This book was released on 2007-10-11 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this work is the application of the Representative Interactive Flamelet (RIF) model with detailed and reduced kinetics to describe the combustion processes with low-emission. Chemical kinetic reaction mechanisms are developed. Regarding the application of these mechanisms in the numerical simulation of combustion processes, the description of the formation of nitrous oxide is particularly taken into account. After the introduction in the topic, chapter 2 presents the conservation equations and the description of the turbulent flow and mixing field. The flamelet model and the RIF-concept are described: the chemical reaction kinetics is separately considered from the flow dynamics. This is possible due to the assumption of the existence of a very thin flame layer, in which the chemical processes take place. This flame layer, also considered as laminar in turbulent flows, is called flamelet. The calculation of the ignition, heat release and formation of nitrogen oxide with detailed kinetics is then possible. In chapter 3, a model for the calculation of three-dimensional combustion processes is presented. It is based on the flamelet model. To describe the formation of nitrous oxide, the consideration of the combustion as an unsteady process is very important. This is possible thanks to the use of unsteady flamelets. The flamelets are calculated interactive with the flow solver, each representative for a pathway of particle through the combustion chamber. The statistical way of fluid particle through the combustion chamber is described by the eulerian transport equations. In chapter 4, a chemical reaction mechanism is developed and validated with comparison with experimental results. Special attention is paid to the methane mechanism with consideration of nitrous oxide formation. This mechanism is reduced with steady-state assumptions. Furthermore, a pyrolysis and burnout model are presented, which are used for the simulation of the coal combustion in chapter 5. In chapter 5, simulation results for two different configurations are compared to experimental data. In the MILD combustion chamber, the formation of nitrous oxide is investigated with the use of the detailed and reduced kinetics presented in chapter 4. The Eulerian Particle Flamelet model is completed and used for the simulation of the gaseous phase during the coal combustion. Based on the results, it is shown that the flamelet model, coupled with the detailed and the reduced kinetics, is able to model low-emission combustion processes.
Download or read book Flow Reactor Studies of Non equilibrium Plasma Assisted Combustion Kinetics written by Nicholas Tsolas and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A new experimental facility was developed to study the reactive chemical kinetics associated with plasma-assisted combustion (PAC). Experiments were performed in a nearly isothermal plasma flow reactor (PFR), using reactant mixtures highly diluted in an inert gas (e.g., Ar, He, or N2) to minimize temperature changes from chemical reactions. At the end of the isothermal reaction zone, the gas temperature was rapidly lowered to terminate any continuation in reaction. Product composition as a result of any observed reaction was then determined using ex situ techniques, including non-dispersive infrared (NDIR), and by sample extraction and storage into a multi-position valve for subsequent analysis by gas chromatography (GC). Hydroxyl radical concentrations were measured in situ, using the laser induced fluorescence (LIF) technique. Reactivity maps for a given fuel system were achieved by fixing the flow rate or residence time of the reactant mixture through the PFR and varying the isothermal temperature. Fuels studied were hydrogen, ethylene and C1 to C7 alkane hydrocarbons, to examine pyrolysis and oxidation kinetics with and without the effects of a high-voltage nanosecond pulse duration plasma discharge, at atmospheric pressure from 420 K to 1250 K. In select instances, experimental studies were complimented with detailed chemical kinetic modeling analysis to determine the dominant and rate-controlling mechanisms, while elucidating the influence of the plasma chemistry on the thermal (neutral) chemistry.In the hydrogen oxidation system, no thermal reaction was observed until 860 K, consistent with the second explosion limit at atmospheric pressure, at which point all the hydrogen was rapidly consumed within the residence time of the reactor. With the plasma discharge, oxidation occurred at all temperatures examined, exhibiting a steady increase in the rate of oxidation starting from 470 K, and eventually consuming all the initial hydrogen by 840 K. For ethylene, kinetic results with the discharge indicated that pyrolysis type reactions were nearly as important as oxidative reactions in consuming ethylene below 750 K. Above 750 K, the thermal reactions coupled to the plasma reactions to further enhance the high temperature fuel consuming chemistry. Modeling analysis of plasma-assisted pyrolysis revealed that ethylene dissociation by collisional quenching with electronically-excited argon atoms formed in the presence of the plasma, resulted in the direct formation of acetylene and larger hydrocarbons by way of the ethyl radical. Similarly, during plasma-assisted oxidation, excited argon was able to directly dissociate the initial oxidizer to further enhance fuel consumption, but also facilitate low temperature oxidative chemistry due to the effective production of oxygenated species controlled by R+O2 chemistry. At the highest temperatures, the radical production by neutral thermal reactions became competitive and the effectiveness associated with the plasma coupled chemistry decreased. Under the effects of the plasma, alkane fuels exhibited extended limits of oxidation over the entire temperature range considered, compared to that of the thermal reactions alone. At atmospheric pressure, propane and butane exhibited cool flame chemistry between 420 K to 700 K, which normally occurs at higher pressures (P > 1 atm) for thermally constrained systems. This chemistry is characterized by the alkylperoxy radical formation, isomerization to the hydroperoxyalkyl radical, followed by dissociation to form aldehydes and ketones. Whereas, intermediate temperature chemistry between 700 K to 950 K, is characterized by beta-scission of the initial alkyl radical to form alkenes and smaller alkanes. The culmination of these studies demonstrate new insight into the kinetics governing PAC and provides a new experimental database to facilitate the development and validation of PAC-specific kinetic mechanisms.
Download or read book The Role of Kinetics in the Numerical Simulation of In situ Combustion written by Douglas W. Bennion and published by . This book was released on 1982 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Kinetics of Crude oil Combustion in Porous Media Interpreted Using Isoconversional Methods written by Murat Cinar and published by Stanford University. This book was released on 2011 with total page 377 pages. Available in PDF, EPUB and Kindle. Book excerpt: One method to access unconventional, heavy-oil and natural bitumen resources as well as waterflood residual oil is to apply in situ combustion (ISC) to oxidize in place a small fraction of the hydrocarbon thereby providing heat to reduce oil viscosity and pressure that enhances recovery. ISC is also attractive because it provides the opportunity to upgrade oil in-situ by increasing the API gravity and decreasing, for instance, sulfur content. Experimental analysis of crude-oil oxidation kinetics provides parameters, such as activation energy, for modeling and optimization of ISC processes. The complex nature of petroleum as a multi-component mixture and multi-step character of oxidation reactions complicates substantially the kinetic analysis of crude-oil. Isoconversional techniques provide model-free methods for estimating activation energy and naturally deconvolve multi-step reactions. In addition, isoconversional methods are also useful as a screening tool to recognize the burning characteristics of different oils. By using experimentally determined combustion kinetics of different oil samples along with combustion tube results, we show that isoconversional analysis of ramped temperature oxidation data is useful to predict combustion-front propagation. It also provides new insight into the nature of the reactions occurring during ISC. Ramped temperature oxidation (RTO) tests with effluent gas analysis are conducted to probe ISC reaction kinetics along with isothermal coke formation experiments. The role of oxygen during coke formation reactions (i.e., fuel formation for ISC) is investigated using X-ray photoelectron spectroscopy (XPS) of intermediate reaction products. The XPS data is analyzed along with companion RTO experiments to obtain a simplified multi-step reaction scheme. Synthetic cases illustrate the connection between a proposed reaction scheme for oil/matrix pairs and one-dimensional combustion front propagation. Analysis of experimental results illustrate that the reaction scheme is capable of reproducing experimental results including the basic trends in oxygen consumption and carbon oxides production for RTO experiments as a function of heating rate for both good and poor ISC candidates. The combination of XPS and RTO studies indicates that the quality (or reactivity) of coke formed during the process is a function of oxygen presence/absence.
Download or read book The Reaction Kinetics of Fuel Formation for In situ Combustion written by Sidqi Abu-Khamsin and published by . This book was released on 1984 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of In situ Combustion Reaction Kinetics with High Fidelity and Consistent Reaction Upscaling for Reservoir Simulation written by Mohammad Bazargan and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy Research Abstracts written by and published by . This book was released on 1993 with total page 490 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Efficient Simulation of Thermal Enhanced Oil Recovery Processes written by Zhouyuan Zhu and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Simulating thermal processes is usually computationally expensive because of the complexity of the problem and strong nonlinearities encountered. In this work, we explore novel and efficient simulation techniques to solve thermal enhanced oil recovery problems. We focus on two major topics: the extension of streamline simulation for thermal enhanced oil recovery and the efficient simulation of chemical reaction kinetics as applied to the in-situ combustion process. For thermal streamline simulation, we first study the extension to hot water flood processes, in which we have temperature induced viscosity changes and thermal volume changes. We first compute the pressure field on an Eulerian grid. We then solve for the advective parts of the mass balance and energy equations along the individual streamlines, accounting for the compressibility effects. At the end of each global time step, we account for the nonadvective terms on the Eulerian grid along with gravity using operator splitting. We test our streamline simulator and compare the results with a commercial thermal simulator. Sensitivity studies for compressibility, gravity and thermal conduction effects are presented. We further extended our thermal streamline simulation to steam flooding. Steam flooding exhibits large volume changes and compressibility associated with the phase behavior of steam, strong gravity segregation and override, and highly coupled energy and mass transport. To overcome these challenges we implement a novel pressure update along the streamlines, a Glowinski scheme operator splitting and a preliminary streamline/finite volume hybrid approach. We tested our streamline simulator on a series of test cases. We compared our thermal streamline results with those computed by a commercial thermal simulator for both accuracy and efficiency. For the cases investigated, we are able to retain solution accuracy, while reducing computational cost and gaining connectivity information from the streamlines. These aspects are useful for reservoir engineering purposes. In traditional thermal reactive reservoir simulation, mass and energy balance equations are solved numerically on discretized reservoir grid blocks. The reaction terms are calculated through Arrhenius kinetics using cell-averaged properties, such as averaged temperature and reactant concentrations. For the in-situ combustion process, the chemical reaction front is physically very narrow, typically a few inches thick. To capture accurately this front, centimeter-sized grids are required that are orders of magnitude smaller than the affordable grid block sizes for full field reservoir models. To solve this grid size effect problem, we propose a new method based on a non-Arrhenius reaction upscaling approach. We do not resolve the combustion front on the grid, but instead use a subgrid-scale model that captures the overall effects of the combustion reactions on flow and transport, i.e. the amount of heat released, the amount of oil burned and the reaction products generated. The subgrid-scale model is calibrated using fine-scale highly accurate numerical simulation and laboratory experiments. This approach significantly improves the computational speed of in-situ combustion simulation as compared to traditional methods. We propose the detailed procedures to implement this methodology in a field-scale simulator. Test cases illustrate the solution consistency when scaling up the grid sizes in multidimensional heterogeneous problems. The methodology is also applicable to other subsurface reactive flow modeling problems with fast chemical reactions and sharp fronts. Displacement front stability is a major concern in the design of all the enhanced oil recovery processes. Historically, premature combustion front break through has been an issue for field operations of in-situ combustion. In this work, we perform detailed analysis based on both analytical methods and numerical simulation. We identify the different flow regimes and several driving fronts in a typical 1D ISC process. For the ISC process in a conventional mobile heavy oil reservoir, we identify the most critical front as the front of steam plateau driving the cold oil bank. We discuss the five main contributors for this front stability/instability: viscous force, condensation, heat conduction, coke plugging and gravity. Detailed numerical tests are performed to test and rank the relative importance of all these different effects.
Download or read book Publications of the National Institute of Standards and Technology Catalog written by National Institute of Standards and Technology (U.S.) and published by . This book was released on 1994 with total page 1162 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book ERDA Energy Research Abstracts written by United States. Energy Research and Development Administration and published by . This book was released on 1977 with total page 818 pages. Available in PDF, EPUB and Kindle. Book excerpt:
