The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform
Bao-zhu Guo - One of the best experts on this subject based on the ideXlab platform.
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On the stability of swelling porous elastic soils with Fluid Saturation by one internal damping
IMA Journal of Applied Mathematics, 2006Co-Authors: Jun-min Wang, Bao-zhu GuoAbstract:This article addressed the stabilization of a system of 1D swelling porous elastic soils with Fluid Saturation. The system is described by strongly coupled vibrating Fluid and solid elastic materials. Using Riesz basis approach, we show that the whole system can be exponentially stabilized by only one internal viscous damping with variable feedback gain imposed in the Fluid part, which is sharp contrast with the same effect by two dampings in existing literature. Moreover, the explicit asymptotic expressions of high eigenfrequencies exhibit clearly how this one damping can affect the another part of solid vibration.
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Stabilization of swelling porous elastic soils with Fluid Saturation by one internal damping
Proceedings of the 44th IEEE Conference on Decision and Control, 1Co-Authors: Jun-min Wang, Bao-zhu GuoAbstract:This article considers the stabilization of a system of one-dimensional swelling porous elastic soils with Fluid Saturation. This system is strongly coupled by vibrations of both Fluid and solid elastic materials. Using Riesz basis approach, it is shown that the system can be exponentially stabilized by one internal damping with variable feedback gain imposed in the Fluid equation. The result improved greatly at the first time the previous results in literature where two dampings are needed to get the same result.
Guilherme A. R. Gualda - One of the best experts on this subject based on the ideXlab platform.
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An H_2O–CO_2 mixed Fluid Saturation model compatible with rhyolite-MELTS
Contributions to Mineralogy and Petrology, 2015Co-Authors: Mark S. Ghiorso, Guilherme A. R. GualdaAbstract:A thermodynamic model for estimating the Saturation conditions of H_2O–CO_2 mixed Fluids in multicomponent silicate liquids is described. The model extends the capabilities of rhyolite-MELTS (Gualda et al. in J Petrol 53:875–890, 2012a ) and augments the water Saturation model in MELTS (Ghiorso and Sack in Contrib Mineral Petrol 119:197–212, 1995 ). The model is internally consistent with the Fluid-phase thermodynamic model of Duan and Zhang (Geochim Cosmochim Acta 70:2311–2324, 2006 ). It may be used independently of rhyolite-MELTS to estimate intensive variables and Fluid Saturation conditions from glass inclusions trapped in phenocrysts. The model is calibrated from published experimental data on water and carbon dioxide solubility, and mixed Fluid Saturation in silicate liquids. The model is constructed on the assumption that water dissolves to form a hydroxyl melt species, and that carbon dioxide both a molecular species and a carbonate ion, the latter complexed with calcium. Excess enthalpy interaction terms in part compensate for these simplistic assumptions regarding speciation. The model is restricted to natural composition liquids over the pressure range 0–3 GPa. One characteristic of the model is that Fluid Saturation isobars at pressures greater than ~100 MPa always display a maximum in melt CO_2 at nonzero H_2O melt concentrations, regardless of bulk composition. This feature is universal and can be attributed to the dominance of hydroxyl speciation at low water concentrations. The model is applied to four examples. The first involves estimation of pressures from H_2O–CO_2-bearing glass inclusions found in quartz phenocrysts of the Bishop Tuff. The second illustrates H_2O and CO_2 partitioning between melt and Fluid during Fluid-saturated equilibrium and fractional crystallization of MORB. The third example demonstrates that the position of the quartz–feldspar cotectic surface is insensitive to melt CO_2 contents, which facilitates geobarometry using phase equilibria. The final example shows the effect of H_2O and CO_2 on the crystallization paths of a high-silica rhyolite composition representative of the late-erupted Bishop Tuff. Software that implements the model is available at ofm-research.org, and the model is incorporated into the latest version (1.1+) of rhyolite-MELTS.
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an h2o co2 mixed Fluid Saturation model compatible with rhyolite melts
Contributions to Mineralogy and Petrology, 2015Co-Authors: Mark S. Ghiorso, Guilherme A. R. GualdaAbstract:A thermodynamic model for estimating the Saturation conditions of H2O–CO2 mixed Fluids in multicomponent silicate liquids is described. The model extends the capabilities of rhyolite-MELTS (Gualda et al. in J Petrol 53:875–890, 2012a) and augments the water Saturation model in MELTS (Ghiorso and Sack in Contrib Mineral Petrol 119:197–212, 1995). The model is internally consistent with the Fluid-phase thermodynamic model of Duan and Zhang (Geochim Cosmochim Acta 70:2311–2324, 2006). It may be used independently of rhyolite-MELTS to estimate intensive variables and Fluid Saturation conditions from glass inclusions trapped in phenocrysts. The model is calibrated from published experimental data on water and carbon dioxide solubility, and mixed Fluid Saturation in silicate liquids. The model is constructed on the assumption that water dissolves to form a hydroxyl melt species, and that carbon dioxide both a molecular species and a carbonate ion, the latter complexed with calcium. Excess enthalpy interaction terms in part compensate for these simplistic assumptions regarding speciation. The model is restricted to natural composition liquids over the pressure range 0–3 GPa. One characteristic of the model is that Fluid Saturation isobars at pressures greater than ~100 MPa always display a maximum in melt CO2 at nonzero H2O melt concentrations, regardless of bulk composition. This feature is universal and can be attributed to the dominance of hydroxyl speciation at low water concentrations. The model is applied to four examples. The first involves estimation of pressures from H2O–CO2-bearing glass inclusions found in quartz phenocrysts of the Bishop Tuff. The second illustrates H2O and CO2 partitioning between melt and Fluid during Fluid-saturated equilibrium and fractional crystallization of MORB. The third example demonstrates that the position of the quartz–feldspar cotectic surface is insensitive to melt CO2 contents, which facilitates geobarometry using phase equilibria. The final example shows the effect of H2O and CO2 on the crystallization paths of a high-silica rhyolite composition representative of the late-erupted Bishop Tuff. Software that implements the model is available at ofm-research.org, and the model is incorporated into the latest version (1.1+) of rhyolite-MELTS.
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An H2O–CO2 mixed Fluid Saturation model compatible with rhyolite-MELTS
Contributions to Mineralogy and Petrology, 2015Co-Authors: Mark S. Ghiorso, Guilherme A. R. GualdaAbstract:A thermodynamic model for estimating the Saturation conditions of H2O–CO2 mixed Fluids in multicomponent silicate liquids is described. The model extends the capabilities of rhyolite-MELTS (Gualda et al. in J Petrol 53:875–890, 2012a) and augments the water Saturation model in MELTS (Ghiorso and Sack in Contrib Mineral Petrol 119:197–212, 1995). The model is internally consistent with the Fluid-phase thermodynamic model of Duan and Zhang (Geochim Cosmochim Acta 70:2311–2324, 2006). It may be used independently of rhyolite-MELTS to estimate intensive variables and Fluid Saturation conditions from glass inclusions trapped in phenocrysts. The model is calibrated from published experimental data on water and carbon dioxide solubility, and mixed Fluid Saturation in silicate liquids. The model is constructed on the assumption that water dissolves to form a hydroxyl melt species, and that carbon dioxide both a molecular species and a carbonate ion, the latter complexed with calcium. Excess enthalpy interaction terms in part compensate for these simplistic assumptions regarding speciation. The model is restricted to natural composition liquids over the pressure range 0–3 GPa. One characteristic of the model is that Fluid Saturation isobars at pressures greater than ~100 MPa always display a maximum in melt CO2 at nonzero H2O melt concentrations, regardless of bulk composition. This feature is universal and can be attributed to the dominance of hydroxyl speciation at low water concentrations. The model is applied to four examples. The first involves estimation of pressures from H2O–CO2-bearing glass inclusions found in quartz phenocrysts of the Bishop Tuff. The second illustrates H2O and CO2 partitioning between melt and Fluid during Fluid-saturated equilibrium and fractional crystallization of MORB. The third example demonstrates that the position of the quartz–feldspar cotectic surface is insensitive to melt CO2 contents, which facilitates geobarometry using phase equilibria. The final example shows the effect of H2O and CO2 on the crystallization paths of a high-silica rhyolite composition representative of the late-erupted Bishop Tuff. Software that implements the model is available at ofm-research.org, and the model is incorporated into the latest version (1.1+) of rhyolite-MELTS.
Jun-min Wang - One of the best experts on this subject based on the ideXlab platform.
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On the stability of swelling porous elastic soils with Fluid Saturation by one internal damping
IMA Journal of Applied Mathematics, 2006Co-Authors: Jun-min Wang, Bao-zhu GuoAbstract:This article addressed the stabilization of a system of 1D swelling porous elastic soils with Fluid Saturation. The system is described by strongly coupled vibrating Fluid and solid elastic materials. Using Riesz basis approach, we show that the whole system can be exponentially stabilized by only one internal viscous damping with variable feedback gain imposed in the Fluid part, which is sharp contrast with the same effect by two dampings in existing literature. Moreover, the explicit asymptotic expressions of high eigenfrequencies exhibit clearly how this one damping can affect the another part of solid vibration.
-
Stabilization of swelling porous elastic soils with Fluid Saturation by one internal damping
Proceedings of the 44th IEEE Conference on Decision and Control, 1Co-Authors: Jun-min Wang, Bao-zhu GuoAbstract:This article considers the stabilization of a system of one-dimensional swelling porous elastic soils with Fluid Saturation. This system is strongly coupled by vibrations of both Fluid and solid elastic materials. Using Riesz basis approach, it is shown that the system can be exponentially stabilized by one internal damping with variable feedback gain imposed in the Fluid equation. The result improved greatly at the first time the previous results in literature where two dampings are needed to get the same result.
Mark S. Ghiorso - One of the best experts on this subject based on the ideXlab platform.
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An H_2O–CO_2 mixed Fluid Saturation model compatible with rhyolite-MELTS
Contributions to Mineralogy and Petrology, 2015Co-Authors: Mark S. Ghiorso, Guilherme A. R. GualdaAbstract:A thermodynamic model for estimating the Saturation conditions of H_2O–CO_2 mixed Fluids in multicomponent silicate liquids is described. The model extends the capabilities of rhyolite-MELTS (Gualda et al. in J Petrol 53:875–890, 2012a ) and augments the water Saturation model in MELTS (Ghiorso and Sack in Contrib Mineral Petrol 119:197–212, 1995 ). The model is internally consistent with the Fluid-phase thermodynamic model of Duan and Zhang (Geochim Cosmochim Acta 70:2311–2324, 2006 ). It may be used independently of rhyolite-MELTS to estimate intensive variables and Fluid Saturation conditions from glass inclusions trapped in phenocrysts. The model is calibrated from published experimental data on water and carbon dioxide solubility, and mixed Fluid Saturation in silicate liquids. The model is constructed on the assumption that water dissolves to form a hydroxyl melt species, and that carbon dioxide both a molecular species and a carbonate ion, the latter complexed with calcium. Excess enthalpy interaction terms in part compensate for these simplistic assumptions regarding speciation. The model is restricted to natural composition liquids over the pressure range 0–3 GPa. One characteristic of the model is that Fluid Saturation isobars at pressures greater than ~100 MPa always display a maximum in melt CO_2 at nonzero H_2O melt concentrations, regardless of bulk composition. This feature is universal and can be attributed to the dominance of hydroxyl speciation at low water concentrations. The model is applied to four examples. The first involves estimation of pressures from H_2O–CO_2-bearing glass inclusions found in quartz phenocrysts of the Bishop Tuff. The second illustrates H_2O and CO_2 partitioning between melt and Fluid during Fluid-saturated equilibrium and fractional crystallization of MORB. The third example demonstrates that the position of the quartz–feldspar cotectic surface is insensitive to melt CO_2 contents, which facilitates geobarometry using phase equilibria. The final example shows the effect of H_2O and CO_2 on the crystallization paths of a high-silica rhyolite composition representative of the late-erupted Bishop Tuff. Software that implements the model is available at ofm-research.org, and the model is incorporated into the latest version (1.1+) of rhyolite-MELTS.
-
an h2o co2 mixed Fluid Saturation model compatible with rhyolite melts
Contributions to Mineralogy and Petrology, 2015Co-Authors: Mark S. Ghiorso, Guilherme A. R. GualdaAbstract:A thermodynamic model for estimating the Saturation conditions of H2O–CO2 mixed Fluids in multicomponent silicate liquids is described. The model extends the capabilities of rhyolite-MELTS (Gualda et al. in J Petrol 53:875–890, 2012a) and augments the water Saturation model in MELTS (Ghiorso and Sack in Contrib Mineral Petrol 119:197–212, 1995). The model is internally consistent with the Fluid-phase thermodynamic model of Duan and Zhang (Geochim Cosmochim Acta 70:2311–2324, 2006). It may be used independently of rhyolite-MELTS to estimate intensive variables and Fluid Saturation conditions from glass inclusions trapped in phenocrysts. The model is calibrated from published experimental data on water and carbon dioxide solubility, and mixed Fluid Saturation in silicate liquids. The model is constructed on the assumption that water dissolves to form a hydroxyl melt species, and that carbon dioxide both a molecular species and a carbonate ion, the latter complexed with calcium. Excess enthalpy interaction terms in part compensate for these simplistic assumptions regarding speciation. The model is restricted to natural composition liquids over the pressure range 0–3 GPa. One characteristic of the model is that Fluid Saturation isobars at pressures greater than ~100 MPa always display a maximum in melt CO2 at nonzero H2O melt concentrations, regardless of bulk composition. This feature is universal and can be attributed to the dominance of hydroxyl speciation at low water concentrations. The model is applied to four examples. The first involves estimation of pressures from H2O–CO2-bearing glass inclusions found in quartz phenocrysts of the Bishop Tuff. The second illustrates H2O and CO2 partitioning between melt and Fluid during Fluid-saturated equilibrium and fractional crystallization of MORB. The third example demonstrates that the position of the quartz–feldspar cotectic surface is insensitive to melt CO2 contents, which facilitates geobarometry using phase equilibria. The final example shows the effect of H2O and CO2 on the crystallization paths of a high-silica rhyolite composition representative of the late-erupted Bishop Tuff. Software that implements the model is available at ofm-research.org, and the model is incorporated into the latest version (1.1+) of rhyolite-MELTS.
-
An H2O–CO2 mixed Fluid Saturation model compatible with rhyolite-MELTS
Contributions to Mineralogy and Petrology, 2015Co-Authors: Mark S. Ghiorso, Guilherme A. R. GualdaAbstract:A thermodynamic model for estimating the Saturation conditions of H2O–CO2 mixed Fluids in multicomponent silicate liquids is described. The model extends the capabilities of rhyolite-MELTS (Gualda et al. in J Petrol 53:875–890, 2012a) and augments the water Saturation model in MELTS (Ghiorso and Sack in Contrib Mineral Petrol 119:197–212, 1995). The model is internally consistent with the Fluid-phase thermodynamic model of Duan and Zhang (Geochim Cosmochim Acta 70:2311–2324, 2006). It may be used independently of rhyolite-MELTS to estimate intensive variables and Fluid Saturation conditions from glass inclusions trapped in phenocrysts. The model is calibrated from published experimental data on water and carbon dioxide solubility, and mixed Fluid Saturation in silicate liquids. The model is constructed on the assumption that water dissolves to form a hydroxyl melt species, and that carbon dioxide both a molecular species and a carbonate ion, the latter complexed with calcium. Excess enthalpy interaction terms in part compensate for these simplistic assumptions regarding speciation. The model is restricted to natural composition liquids over the pressure range 0–3 GPa. One characteristic of the model is that Fluid Saturation isobars at pressures greater than ~100 MPa always display a maximum in melt CO2 at nonzero H2O melt concentrations, regardless of bulk composition. This feature is universal and can be attributed to the dominance of hydroxyl speciation at low water concentrations. The model is applied to four examples. The first involves estimation of pressures from H2O–CO2-bearing glass inclusions found in quartz phenocrysts of the Bishop Tuff. The second illustrates H2O and CO2 partitioning between melt and Fluid during Fluid-saturated equilibrium and fractional crystallization of MORB. The third example demonstrates that the position of the quartz–feldspar cotectic surface is insensitive to melt CO2 contents, which facilitates geobarometry using phase equilibria. The final example shows the effect of H2O and CO2 on the crystallization paths of a high-silica rhyolite composition representative of the late-erupted Bishop Tuff. Software that implements the model is available at ofm-research.org, and the model is incorporated into the latest version (1.1+) of rhyolite-MELTS.
Arne Graue - One of the best experts on this subject based on the ideXlab platform.
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In-Situ Phase Pressures and Fluid Saturation Dynamics Measured in Waterfloods at Various Wettability Conditions
SPE Reservoir Evaluation & Engineering, 2010Co-Authors: Amund Brautaset, Geir Ersland, Arne GraueAbstract:Summary During waterfloods of six outcrop chalk core-plug samples prepared at various wettabilities, simultaneous local pressures and in-situ Fluid Saturations were measured. Using high-spatial-resolution magnetic-resonance imaging (MRI) to image Fluid Saturations and pressure taps with semipermeable disks to measure individual phase pressures allowed calculations of relative permeabilities and the dynamic capillary pressure curves for the imbibition processes. A second objective was to identify individual-Fluid Saturation changes caused by spontaneous imbibition and viscous displacement to determine the local recovery mechanism and to calculate local recovery factors and in-situ Amott-Harvey indices. The obtained results contribute to improved description and understanding of multiphase-Fluid flow in porous media, including in situ measurements of relative permeabilities, dynamic capillary pressure curves, Amott-Harvey Indices, and local oil-recovery mechanisms.
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Capillary Pressures by Fluid Saturation Profile Measurements During Centrifuge Rotation
Transport in Porous Media, 2009Co-Authors: Martin A. Fernø, Øyvind Bull, Pål Ove Sukka, Arne GraueAbstract:A novel centrifuge technique to obtain the capillary pressure curve by measuring the local Fluid distribution in a spinning core is presented. The Nuclear Tracer Imaging Centrifuge (NTIC) method measures the Fluid Saturation profile along the length of the core to directly obtain the capillary pressure curve. The proposed method is superior to conventional centrifuge techniques because (1) the capillary pressure curve is obtained at one rotational speed, (2) core plugs are not removed from the spinning centrifuge for imaging, and (3) no mathematical solution is needed to calculate the capillary pressure curve. The literature states that the various mathematical solutions used in conventional centrifuge tests are the greatest source of error, not the uncertainty in the experimental data. By eliminating the dependence of such solutions, the NTIC represents an alternative to conventional centrifuge tests, and may be used to validate the various mathematical procedures applied in conventional centrifuge capillary pressure tests. NTIC may also confirm the applicability of other imaging techniques that rely on core plug removal for Saturation imaging, by verifying if there is no Fluid re-distribution at static conditions.
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In Situ Phase Pressures and Fluid Saturation Dynamics Measured in Waterfloods at Various Wettability Conditions
All Days, 2008Co-Authors: Amund Brautaset, Geir Ersland, Arne GraueAbstract:Abstract During waterfloods of a total of six outcrop chalk core plug samples prepared at various wettabilities, simultaneous local pressures and in situ Fluid Saturation from Magnetic Resonance Imaging (MRI) intensities were measured. Complementary use of high spatial resolution Fluid Saturation imaging and phase pressure measurements allowed calculations of the relative permeability to water and the dynamic capillary pressure curves for the imbibition process. One objective was to validate the theory for relative permeability calculations based on data from the Fluid phase pressures measured separately using semi-permeable discs and local in situ Fluid Saturation measurements. A second objective was to identify Fluid Saturation changes due to spontaneous imbibition and viscous displacement, respectively, to determine the local recovery mechanism and allowing local recovery factors and in situ Amott-Harvey indices to be measured. The analysis of the experimental data from three of the core samples shows that the presented theory only applies for the Saturation interval when the pressures are measured in the same phase. A new and improved experimental setup is therefore introduced for the remaining three cores in order to measure each of the dynamic phase pressure gradients separately using semi-permeable discs located at fixed pressure ports. The obtained data contributes to improved description and understanding of multi-phase Fluid flow in porous media, including in situ measurements of relative permeabilities, capillary pressure curves, wettability distribution and local oil recovery mechanisms. Introduction The dominant recovery mechanism in most chalk reservoirs is spontaneous imbibition. This is due to narrow pore throats, more or less water-wet conditions and low permeability (Baldwin, B. A., 2002, Viksund, B. G., 1996). In this study, simultaneous Fluid Saturation distribution and separate Fluid phase pressures are measured in situ in order toincrease knowledge of dynamic phase behavior in an immiscible displacement,identify the contributions from spontaneous and viscous displacement andto calculate in situ Amott-Harvey indices, capillary pressure and relative permeabilities. Knowledge of the relative permeabilities in multiphase flow is of vital importance to the oil industry in order to describe immiscible Fluid mechanisms and to improve oil recovery during production. Several methods for calculating relative permeabilities from experimental data have been introduced, but a satisfactory method is still not developed. Most methods (Chardaire, C, 1989, Heaviside, J., 1983, Islam, M.R., 1986, Johnson, E.F., 1959, Kerig, P.D., 1986) utilize production data and total differential pressure over a core sample as measures of average Saturation and pressure gradients, but this is a coarse approximation that neglects capillary pressure, wetting phase end effects and the rapid changes in the pressure around the displacement front. By measuring Saturations and phase pressure gradients in situ as functions of time and position, end effects are avoided, and relative permeabilities are calculated by use of an explicit method. The main objective with the experiments was to determine the dynamic properties of the local pressure gradient and relate this to the Fluid Saturation distribution to improve the understanding of oil recovery at various wettability conditions. Part of the objective was to identify the contribution from spontaneous and viscous displacement to the oil recovery at different wettabilities in chalk and to calculate in situ Amott-Harvey wettability indices, relative permeabilities and capillary pressure for the imbibition process.