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Karsten Pruess - One of the best experts on this subject based on the ideXlab platform.
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eco2n v2 0 a tough2 Fluid Property module for modeling co2 h2o nacl systems to elevated temperatures of up to 300 c
Greenhouse Gases-Science and Technology, 2017Co-Authors: Lehua Pan, Nicolas Spycher, Christine Doughty, Karsten PruessAbstract:We have improved ECO2N, the TOUGH2 Fluid Property module of the CO2-H2O-NaCl system. The major enhancements include: (i) the upper temperature limit is increased from 110 to about 300°C; (ii) the thermophysical properties of the CO2-rich phase are more accurately calculated as a non-ideal mixture of CO2 and H2O; (iii) the approach to calculate the specific enthalpy of dissolved CO2 has been improved to make the code more robust in modeling phase transitions under non-isothermal conditions; and (iv) more sophisticated models for effective heat conductivity of formations saturated with supercritical CO2 have been provided. The new module includes a comprehensive description of the thermodynamic and thermophysical properties of H2ONaClCO2 mixtures, that reproduces Fluid properties largely within experimental error for the temperature, pressure and salinity conditions 10°C < T < 300°C, P < 600 bar, and salinity up to halite saturation. This includes density, viscosity, and specific enthalpy of Fluid phases as functions of temperature, pressure, and composition, as well as partitioning of mass components H2O, NaCl and CO2 among the different phases. ECO2N with the TOUGH2 reservoir simulator can be applied to a wide range of problems in geologic sequestration of CO2 in saline aquifers, and in enhanced geothermal reservoirs. ECO2N can describe both sub- and supercritical states of CO2, but applications that involve subcritical conditions are limited to systems in which there is no change of phase between liquid and gaseous CO2, and in which no mixtures of liquid and gaseous CO2 occur. © 2016 Society of Chemical Industry and John Wiley & Sons, Ltd.
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eco2m a tough2 Fluid Property module for mixtures of water nacl and co2 including super and sub critical conditions and phase change between liquid and gaseous co2
Lawrence Berkeley National Laboratory, 2011Co-Authors: Karsten PruessAbstract:LBNL-4590E ECO2M: A TOUGH2 Fluid Property Module for Mixtures of Water, NaCl, and CO 2 , Including Super- and Sub-Critical Conditions, and Phase Change Between Liquid and Gaseous CO 2 Karsten Pruess Earth Sciences Division, Lawrence Berkeley National Laboratory University of California, Berkeley, CA 94720 April 2011 This work was supported by the U.S. Department of Energy under Contract No. DE-AC02-05CH11231 with the Lawrence Berkeley National Laboratory.
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eco2n a Fluid Property module for the tough2 code for studies of co2 storage in saline aquifers
Energy Conversion and Management, 2007Co-Authors: Karsten Pruess, Nicolas SpycherAbstract:ECO2N is a Fluid Property module for the TOUGH2 simulator (Version 2.0) that was designed for applications involving geologic storage of CO 2 in saline aquifers. It includes a comprehensive description of the thermodynamics and thermophysical properties of H 2 O-NaCl-CO 2 mixtures, that reproduces Fluid properties largely within experimental error for the temperature, pressure and salinity conditions of interest (10 °C ≤ T ≤ 110 °C; P ≤ 600 bar; salinity up to full halite saturation). Flow processes can be modeled isothermally or non-isothermally, and phase conditions represented may include a single (aqueous or CO 2 -rich) phase, as well as two-phase mixtures. Fluid phases may appear or disappear in the course of a simulation, and solid salt may precipitate or dissolve. ECO2N can model super-as well as sub-critical conditions, but it does not make a distinction between liquid and gaseous CO 2 and hence is not applicable for processes that involve two CO 2 -rich phases. This paper highlights significant features of ECO2N, and presents illustrative applications.
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eco2n a tough2 Fluid Property module for mixtures of water nacl and co2
2005Co-Authors: Karsten PruessAbstract:ECO2N is a Fluid Property module for the TOUGH2 simulator (Version 2.0) that was designed for applications to geologic sequestration of CO{sub 2} in saline aquifers. It includes a comprehensive description of the thermodynamics and thermophysical properties of H{sub 2}O-NaCl-CO{sub 2} mixtures, that reproduces Fluid properties largely within experimental error for the temperature, pressure and salinity conditions of interest (10 C {le} T {le} 110 C; P {le} 476 bar; salinity up to full halite saturation). Flow processes can be modeled isothermally or non-isothermally, and phase conditions represented may include a single (aqueous or CO{sub 2}-rich) phase, as well as two-phase mixtures. Fluid phases may appear or disappear in the course of a simulation, and solid salt may precipitate or dissolve. This report gives technical specifications of ECO2N and includes instructions for preparing input data. Code applications are illustrated by means of several sample problems, including problems that had been previously investigated in a code intercomparison study.
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A Fluid Property module for the TOUGH2 simulator for saline brines with non-condensible gas
1993Co-Authors: Alfredo Battistelli, C. Calore, Karsten PruessAbstract:A new equation-of-state module has been developed for the TOUGH2 simulator, belonging to the MULKOM family of computer codes developed at LBL. This EOS module is able to handle three-component mixtures of water, sodium chloride, and a non-condensible gas. It can describe liquid and gas phases, and includes precipitation and dissolution of solid salt. The dependence of density, viscosity, enthalpy, and vapor pressure of brine on salt concentration is taken into account, as well as the effects of salinity on gas solubility in the liquid phase and related heat of solution. The main assumptions made in developing this EOS module are discussed, together with the correlations employed to calculate the thermophysical properties of multiphase multicomponent mixtures. At present the non-condensible gas can be chosen to be air, CO2, CH4, H2, or N2. This paper focuses on H2O-NaCI-CO2 mixtures and describes new correlations obtained from fitting of published experimental data. Illustrative results for geothermal reservoir depletion in the presence of salinity and non-condensible gas are presented. We demonstrate and analyze effects of vapor pressure lowering and gas solubility decrease from salinity, and loss of reservoir porosity and permeability from salt precipitation during boiling of brines.
Nicolas Spycher - One of the best experts on this subject based on the ideXlab platform.
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eco2n v2 0 a tough2 Fluid Property module for modeling co2 h2o nacl systems to elevated temperatures of up to 300 c
Greenhouse Gases-Science and Technology, 2017Co-Authors: Lehua Pan, Nicolas Spycher, Christine Doughty, Karsten PruessAbstract:We have improved ECO2N, the TOUGH2 Fluid Property module of the CO2-H2O-NaCl system. The major enhancements include: (i) the upper temperature limit is increased from 110 to about 300°C; (ii) the thermophysical properties of the CO2-rich phase are more accurately calculated as a non-ideal mixture of CO2 and H2O; (iii) the approach to calculate the specific enthalpy of dissolved CO2 has been improved to make the code more robust in modeling phase transitions under non-isothermal conditions; and (iv) more sophisticated models for effective heat conductivity of formations saturated with supercritical CO2 have been provided. The new module includes a comprehensive description of the thermodynamic and thermophysical properties of H2ONaClCO2 mixtures, that reproduces Fluid properties largely within experimental error for the temperature, pressure and salinity conditions 10°C < T < 300°C, P < 600 bar, and salinity up to halite saturation. This includes density, viscosity, and specific enthalpy of Fluid phases as functions of temperature, pressure, and composition, as well as partitioning of mass components H2O, NaCl and CO2 among the different phases. ECO2N with the TOUGH2 reservoir simulator can be applied to a wide range of problems in geologic sequestration of CO2 in saline aquifers, and in enhanced geothermal reservoirs. ECO2N can describe both sub- and supercritical states of CO2, but applications that involve subcritical conditions are limited to systems in which there is no change of phase between liquid and gaseous CO2, and in which no mixtures of liquid and gaseous CO2 occur. © 2016 Society of Chemical Industry and John Wiley & Sons, Ltd.
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eco2n a Fluid Property module for the tough2 code for studies of co2 storage in saline aquifers
Energy Conversion and Management, 2007Co-Authors: Karsten Pruess, Nicolas SpycherAbstract:ECO2N is a Fluid Property module for the TOUGH2 simulator (Version 2.0) that was designed for applications involving geologic storage of CO 2 in saline aquifers. It includes a comprehensive description of the thermodynamics and thermophysical properties of H 2 O-NaCl-CO 2 mixtures, that reproduces Fluid properties largely within experimental error for the temperature, pressure and salinity conditions of interest (10 °C ≤ T ≤ 110 °C; P ≤ 600 bar; salinity up to full halite saturation). Flow processes can be modeled isothermally or non-isothermally, and phase conditions represented may include a single (aqueous or CO 2 -rich) phase, as well as two-phase mixtures. Fluid phases may appear or disappear in the course of a simulation, and solid salt may precipitate or dissolve. ECO2N can model super-as well as sub-critical conditions, but it does not make a distinction between liquid and gaseous CO 2 and hence is not applicable for processes that involve two CO 2 -rich phases. This paper highlights significant features of ECO2N, and presents illustrative applications.
Martin Fowler - One of the best experts on this subject based on the ideXlab platform.
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The controls on the composition of biodegraded oils in the deep subsurface: Part II - Geological controls on subsurface biodegradation fluxes and constraints on reservoir-Fluid Property prediction
AAPG Bulletin, 2006Co-Authors: Steve Larter, Olufemi Jokanola, Thomas Oldenburg, Ian Head, Cindy Riediger, B Bennett, Jennifer Adams, Martin Jones, Haiping Huang, Martin FowlerAbstract:The principal controls on the Fluid properties of biodegraded oil systems have been determined by a combination of petroleum geochemistry, numerical modeling of oil biodegradation in reservoirs, and analysis of oil Property data sets from a variety of geological settings. Petroleum biodegradation proceeds under anaerobic conditions in any reservoir that has a water leg and has not been heated to temperatures more than 80C. In most reservoirs with low concentrations of aqueous sulfate, methanogenic degradation is a primary mechanism of petroleum degradation, whereas in waters containing abundant sulfate, sulfate reduction and sulfide production may dominate. Net degradation of petroleum fractions in reservoirs is primarily controlled by the reservoir temperature, the chemical compounds being degraded, and relationships between the oil-water contact (OWC) area and oil volume. The relative volumes of water leg to oil leg, prior level of oil biodegradation, and reservoir water salinity act as second-order controls on the process. Typically, degradation fluxes (kilograms of petroleum destroyed per square meter of oil-water contact area per year or kg petroleum m2 OWC yr1) for fresh petroleum in clastic reservoirs are in the range of 103104 kg petroleum m2 OWC yr1 and increase with decreasing reservoir temperature, from zero near 80C, to a maximum flux at the OWC of less than 103 kg petroleum m2 OWC yr1 at a temperature less than 40C. At very low reservoir temperatures and with severely degraded oils, such as are seen in the near-surface Canadian tar sands at the present day, the net degradation fluxes are much less than maximum values. Nutrient supply from the aquifer and adjacent shales, mostly buffered by mineral dissolution, probably provides the ultimate control on the range of degradation flux values.Oil compositional gradients and resulting oil viscosity variations are common on both reservoir thickness and field scales in biodegraded oil reservoirs and are a defining characteristic of heavy oil fields produced by crude-oil biodegradation. Continuous vertical gradients in the oil columns document episodic degradation for many millions of years, suggesting that the time scales of oil-field degradation and petroleum charging are similar. The flux-temperature relationship we have derived, coupled with typical reservoir charge histories, defines the range of variation of Fluid properties seen in many biodegraded oil provinces and identifies oil charge, mixing of biodegraded and fresh oils, and reservoir-temperature history as the primary controls on Fluid properties. These flux-temperature relationships are easily integrated into prospect charge modeling procedures; sensitivity analyses show that the limiting factor in Fluid Property predictions, using even this first-level approach, are ultimately constrained by the accuracy of current oil-charge modeling estimates. The absence today of any functional geochemical proxies for assessing oil-residence time in oil fields and the substantial uncertainty in petroleum-charging times estimated by forward basin modeling is a major obstacle to more accurate Fluid-Property predictions that needs to be addressed.
Steve Larter - One of the best experts on this subject based on the ideXlab platform.
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The controls on the composition of biodegraded oils in the deep subsurface: Part II - Geological controls on subsurface biodegradation fluxes and constraints on reservoir-Fluid Property prediction
AAPG Bulletin, 2006Co-Authors: Steve Larter, Olufemi Jokanola, Thomas Oldenburg, Ian Head, Cindy Riediger, B Bennett, Jennifer Adams, Martin Jones, Haiping Huang, Martin FowlerAbstract:The principal controls on the Fluid properties of biodegraded oil systems have been determined by a combination of petroleum geochemistry, numerical modeling of oil biodegradation in reservoirs, and analysis of oil Property data sets from a variety of geological settings. Petroleum biodegradation proceeds under anaerobic conditions in any reservoir that has a water leg and has not been heated to temperatures more than 80C. In most reservoirs with low concentrations of aqueous sulfate, methanogenic degradation is a primary mechanism of petroleum degradation, whereas in waters containing abundant sulfate, sulfate reduction and sulfide production may dominate. Net degradation of petroleum fractions in reservoirs is primarily controlled by the reservoir temperature, the chemical compounds being degraded, and relationships between the oil-water contact (OWC) area and oil volume. The relative volumes of water leg to oil leg, prior level of oil biodegradation, and reservoir water salinity act as second-order controls on the process. Typically, degradation fluxes (kilograms of petroleum destroyed per square meter of oil-water contact area per year or kg petroleum m2 OWC yr1) for fresh petroleum in clastic reservoirs are in the range of 103104 kg petroleum m2 OWC yr1 and increase with decreasing reservoir temperature, from zero near 80C, to a maximum flux at the OWC of less than 103 kg petroleum m2 OWC yr1 at a temperature less than 40C. At very low reservoir temperatures and with severely degraded oils, such as are seen in the near-surface Canadian tar sands at the present day, the net degradation fluxes are much less than maximum values. Nutrient supply from the aquifer and adjacent shales, mostly buffered by mineral dissolution, probably provides the ultimate control on the range of degradation flux values.Oil compositional gradients and resulting oil viscosity variations are common on both reservoir thickness and field scales in biodegraded oil reservoirs and are a defining characteristic of heavy oil fields produced by crude-oil biodegradation. Continuous vertical gradients in the oil columns document episodic degradation for many millions of years, suggesting that the time scales of oil-field degradation and petroleum charging are similar. The flux-temperature relationship we have derived, coupled with typical reservoir charge histories, defines the range of variation of Fluid properties seen in many biodegraded oil provinces and identifies oil charge, mixing of biodegraded and fresh oils, and reservoir-temperature history as the primary controls on Fluid properties. These flux-temperature relationships are easily integrated into prospect charge modeling procedures; sensitivity analyses show that the limiting factor in Fluid Property predictions, using even this first-level approach, are ultimately constrained by the accuracy of current oil-charge modeling estimates. The absence today of any functional geochemical proxies for assessing oil-residence time in oil fields and the substantial uncertainty in petroleum-charging times estimated by forward basin modeling is a major obstacle to more accurate Fluid-Property predictions that needs to be addressed.
Xiaodong Ren - One of the best experts on this subject based on the ideXlab platform.
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Influence of the radial-inflow turbine efficiency prediction on the design and analysis of the Organic Rankine Cycle (ORC) system
Energy Conversion and Management, 2016Co-Authors: Jian Song, Xiaodong RenAbstract:Abstract The radial-inflow turbine is a common choice for the power output in the Organic Rankine Cycle (ORC) system. Its efficiency is related to the working Fluid Property and the system operating condition. Generally, the radial-inflow turbine efficiency is assumed to be a constant value in the conventional ORC system analysis. Few studies focus on the influence of the radial-inflow turbine efficiency selection on the system design and analysis. Actually, the ORC system design and the radial-inflow turbine design are coupled with each other. Different thermal parameters of the ORC system would lead to different radial-inflow turbine design and then different turbine efficiency, and vice versa. Therefore, considering the radial-inflow turbine efficiency prediction in the ORC system design can enhance its reliability and accuracy. In this paper, a one-dimensional analysis model for the radial-inflow turbine in the ORC system is presented. The radial-inflow turbine efficiency prediction in this model is based on the velocity triangle and loss models, rather than a constant efficiency assumption. The influence of the working Fluid Property and the system operating condition on the turbine performance is evaluated. The thermodynamic analysis of the ORC system with a model predicted turbine efficiency and a constant turbine efficiency is conducted and the results are compared with each other. It indicates that the turbine efficiency selection has a significant influence on the working Fluid selection and the system parameter determination.