The Experts below are selected from a list of 96 Experts worldwide ranked by ideXlab platform

Russell T. Johns - One of the best experts on this subject based on the ideXlab platform.

  • extrapolation of black and volatile oil fluid properties with application to immiscible miscible gas injection
    Journal of Natural Gas Science and Engineering, 2016
    Co-Authors: Bahareh Nojabaei, Russell T. Johns
    Abstract:

    Abstract Black-oil fluid properties are determined by lab measurements or can be calculated through flash calculations of the reservoir fluid. Allowing for variable bubble-point Pressures in black- or volatile-oil models requires a table of fluid properties be extended above the original bubble-point. Reservoir simulation accuracy, however, may be affected by discontinuities in the input data and poor predictions of extrapolated fluid properties. Common practice is to add surface gas to the original oil in the lab and increase the Pressure to reach a new bubble-point. Another approach is to use linear extrapolation of oil and gas K -values with Pressure on a log-log plot, where K -values are equal to 1.0 at a pseudo-critical or Convergence Pressure. The latter approach results in discontinuities in the phase behavior. We calculate continuous black-oil fluid properties above the original bubble-point by adding a fraction of the equilibrium gas at one bubble-point Pressure to achieve a larger bubble-point Pressure. This procedure continues until a critical point is reached at the top of the pseudocomponent Pressure-composition diagram. Unlike other methods commonly used or recently proposed, the approach provides a smooth and continuous Pressure-composition curve to the critical point. The model further allows for reinjection of produced gas, methane, or CO 2 to increase oil recovery for both volatile and black oils. Further, the approach allows the use of black-oil or volatile-oil properties for tight rocks where capillary Pressure alters the saturation Pressures by decreasing the bubble-point Pressure or increasing the dew-point Pressure. Bubble-point Pressure in the new model is a function of both capillary Pressure (effective pore radius) and gas content. The phase behavior is illustrated using ternary diagrams for up to four components (water, oil, gas, and CO 2 or CH 4 ) and three phases (aqueous, oleic, gaseous) to allow for miscible and immiscible injection of various gases. The new phase behavior could be easily incorporated in a compositionally-extended black- or volatile-oil simulator. The approach could also be used to model gas condensate reservoirs with or without gas injection and capillary Pressure. Finally, 1-D slim-tube simulations are made with the extrapolated black oil fluid properties to estimate minimum miscibility Pressure (MMP) to demonstrate the applicability of the approach. Shocks occur in the 1-D displacement consistent with a compositional simulator.

  • Extrapolation of black- and volatile-oil fluid properties with application to immiscible/miscible gas injection
    Journal of Natural Gas Science and Engineering, 2016
    Co-Authors: Bahareh Nojabaei, Russell T. Johns
    Abstract:

    Abstract Black-oil fluid properties are determined by lab measurements or can be calculated through flash calculations of the reservoir fluid. Allowing for variable bubble-point Pressures in black- or volatile-oil models requires a table of fluid properties be extended above the original bubble-point. Reservoir simulation accuracy, however, may be affected by discontinuities in the input data and poor predictions of extrapolated fluid properties. Common practice is to add surface gas to the original oil in the lab and increase the Pressure to reach a new bubble-point. Another approach is to use linear extrapolation of oil and gas K -values with Pressure on a log-log plot, where K -values are equal to 1.0 at a pseudo-critical or Convergence Pressure. The latter approach results in discontinuities in the phase behavior. We calculate continuous black-oil fluid properties above the original bubble-point by adding a fraction of the equilibrium gas at one bubble-point Pressure to achieve a larger bubble-point Pressure. This procedure continues until a critical point is reached at the top of the pseudocomponent Pressure-composition diagram. Unlike other methods commonly used or recently proposed, the approach provides a smooth and continuous Pressure-composition curve to the critical point. The model further allows for reinjection of produced gas, methane, or CO 2 to increase oil recovery for both volatile and black oils. Further, the approach allows the use of black-oil or volatile-oil properties for tight rocks where capillary Pressure alters the saturation Pressures by decreasing the bubble-point Pressure or increasing the dew-point Pressure. Bubble-point Pressure in the new model is a function of both capillary Pressure (effective pore radius) and gas content. The phase behavior is illustrated using ternary diagrams for up to four components (water, oil, gas, and CO 2 or CH 4 ) and three phases (aqueous, oleic, gaseous) to allow for miscible and immiscible injection of various gases. The new phase behavior could be easily incorporated in a compositionally-extended black- or volatile-oil simulator. The approach could also be used to model gas condensate reservoirs with or without gas injection and capillary Pressure. Finally, 1-D slim-tube simulations are made with the extrapolated black oil fluid properties to estimate minimum miscibility Pressure (MMP) to demonstrate the applicability of the approach. Shocks occur in the 1-D displacement consistent with a compositional simulator.

Bahareh Nojabaei - One of the best experts on this subject based on the ideXlab platform.

  • extrapolation of black and volatile oil fluid properties with application to immiscible miscible gas injection
    Journal of Natural Gas Science and Engineering, 2016
    Co-Authors: Bahareh Nojabaei, Russell T. Johns
    Abstract:

    Abstract Black-oil fluid properties are determined by lab measurements or can be calculated through flash calculations of the reservoir fluid. Allowing for variable bubble-point Pressures in black- or volatile-oil models requires a table of fluid properties be extended above the original bubble-point. Reservoir simulation accuracy, however, may be affected by discontinuities in the input data and poor predictions of extrapolated fluid properties. Common practice is to add surface gas to the original oil in the lab and increase the Pressure to reach a new bubble-point. Another approach is to use linear extrapolation of oil and gas K -values with Pressure on a log-log plot, where K -values are equal to 1.0 at a pseudo-critical or Convergence Pressure. The latter approach results in discontinuities in the phase behavior. We calculate continuous black-oil fluid properties above the original bubble-point by adding a fraction of the equilibrium gas at one bubble-point Pressure to achieve a larger bubble-point Pressure. This procedure continues until a critical point is reached at the top of the pseudocomponent Pressure-composition diagram. Unlike other methods commonly used or recently proposed, the approach provides a smooth and continuous Pressure-composition curve to the critical point. The model further allows for reinjection of produced gas, methane, or CO 2 to increase oil recovery for both volatile and black oils. Further, the approach allows the use of black-oil or volatile-oil properties for tight rocks where capillary Pressure alters the saturation Pressures by decreasing the bubble-point Pressure or increasing the dew-point Pressure. Bubble-point Pressure in the new model is a function of both capillary Pressure (effective pore radius) and gas content. The phase behavior is illustrated using ternary diagrams for up to four components (water, oil, gas, and CO 2 or CH 4 ) and three phases (aqueous, oleic, gaseous) to allow for miscible and immiscible injection of various gases. The new phase behavior could be easily incorporated in a compositionally-extended black- or volatile-oil simulator. The approach could also be used to model gas condensate reservoirs with or without gas injection and capillary Pressure. Finally, 1-D slim-tube simulations are made with the extrapolated black oil fluid properties to estimate minimum miscibility Pressure (MMP) to demonstrate the applicability of the approach. Shocks occur in the 1-D displacement consistent with a compositional simulator.

  • Extrapolation of black- and volatile-oil fluid properties with application to immiscible/miscible gas injection
    Journal of Natural Gas Science and Engineering, 2016
    Co-Authors: Bahareh Nojabaei, Russell T. Johns
    Abstract:

    Abstract Black-oil fluid properties are determined by lab measurements or can be calculated through flash calculations of the reservoir fluid. Allowing for variable bubble-point Pressures in black- or volatile-oil models requires a table of fluid properties be extended above the original bubble-point. Reservoir simulation accuracy, however, may be affected by discontinuities in the input data and poor predictions of extrapolated fluid properties. Common practice is to add surface gas to the original oil in the lab and increase the Pressure to reach a new bubble-point. Another approach is to use linear extrapolation of oil and gas K -values with Pressure on a log-log plot, where K -values are equal to 1.0 at a pseudo-critical or Convergence Pressure. The latter approach results in discontinuities in the phase behavior. We calculate continuous black-oil fluid properties above the original bubble-point by adding a fraction of the equilibrium gas at one bubble-point Pressure to achieve a larger bubble-point Pressure. This procedure continues until a critical point is reached at the top of the pseudocomponent Pressure-composition diagram. Unlike other methods commonly used or recently proposed, the approach provides a smooth and continuous Pressure-composition curve to the critical point. The model further allows for reinjection of produced gas, methane, or CO 2 to increase oil recovery for both volatile and black oils. Further, the approach allows the use of black-oil or volatile-oil properties for tight rocks where capillary Pressure alters the saturation Pressures by decreasing the bubble-point Pressure or increasing the dew-point Pressure. Bubble-point Pressure in the new model is a function of both capillary Pressure (effective pore radius) and gas content. The phase behavior is illustrated using ternary diagrams for up to four components (water, oil, gas, and CO 2 or CH 4 ) and three phases (aqueous, oleic, gaseous) to allow for miscible and immiscible injection of various gases. The new phase behavior could be easily incorporated in a compositionally-extended black- or volatile-oil simulator. The approach could also be used to model gas condensate reservoirs with or without gas injection and capillary Pressure. Finally, 1-D slim-tube simulations are made with the extrapolated black oil fluid properties to estimate minimum miscibility Pressure (MMP) to demonstrate the applicability of the approach. Shocks occur in the 1-D displacement consistent with a compositional simulator.

François Montel - One of the best experts on this subject based on the ideXlab platform.

  • Calculation of Convergence Pressure/temperature and stability test limit loci of mixtures with cubic equations of state
    Fluid Phase Equilibria, 2007
    Co-Authors: Dan Vladimir Nichita, Daniel Broseta, François Montel
    Abstract:

    The Convergence locus (CL) and stability test limit locus (STLL) are important underlying properties of multicomponent system phase diagrams. In the Pressure–temperature plane, the CL separates the region where the negative flash has non-trivial solutions. The mathematical domain of flash calculations is significantly wider than the physical domain; if a negative flash is performed, the equilibrium constants are continuously derivable when a phase boundary is crossed. Criticality criteria are met for the phase compositions resulting from the negative flash and the minimum eigenvalue of a quadratic form evaluated with these compositions (which are intrinsically stable) is used to locate the CL. An efficient negative flash procedure is also proposed. The STLL is important because in its vicinity the number of iterations for phase stability testing increases dramatically and divergence may occur. Outside the STLL the tangent plane distance function has only a trivial solution; between STLL and the phase boundary, there is a non-trivial positive solution. The spinodal criterion is met at the STLL for trial phase compositions. The CL and STLL are located at given Pressure or temperature based on rigorous thermodynamic criteria in only few Newton iterations. The proposed method avoids repeated expensive negative flash calculations in the vicinity of the CL and phase stability calculations in the vicinity of the STLL. Results are presented for representative hydrocarbon mixtures with different amounts of classical contaminants and different shapes of phase envelopes.

  • calculation of Convergence Pressure temperature and stability test limit loci of mixtures with cubic equations of state
    Fluid Phase Equilibria, 2007
    Co-Authors: Dan Vladimir Nichita, Daniel Broseta, François Montel
    Abstract:

    The Convergence locus (CL) and stability test limit locus (STLL) are important underlying properties of multicomponent system phase diagrams. In the Pressure–temperature plane, the CL separates the region where the negative flash has non-trivial solutions. The mathematical domain of flash calculations is significantly wider than the physical domain; if a negative flash is performed, the equilibrium constants are continuously derivable when a phase boundary is crossed. Criticality criteria are met for the phase compositions resulting from the negative flash and the minimum eigenvalue of a quadratic form evaluated with these compositions (which are intrinsically stable) is used to locate the CL. An efficient negative flash procedure is also proposed. The STLL is important because in its vicinity the number of iterations for phase stability testing increases dramatically and divergence may occur. Outside the STLL the tangent plane distance function has only a trivial solution; between STLL and the phase boundary, there is a non-trivial positive solution. The spinodal criterion is met at the STLL for trial phase compositions. The CL and STLL are located at given Pressure or temperature based on rigorous thermodynamic criteria in only few Newton iterations. The proposed method avoids repeated expensive negative flash calculations in the vicinity of the CL and phase stability calculations in the vicinity of the STLL. Results are presented for representative hydrocarbon mixtures with different amounts of classical contaminants and different shapes of phase envelopes.

  • Calculation of Convergence Pressure/temperature and stability test limit loci of mixtures with cubic equations of state
    Fluid Phase Equilibria, 2007
    Co-Authors: Dan Vladimir Nichita, Daniel Broseta, François Montel
    Abstract:

    International audienceThe Convergence locus (CL) and stability test limit locus (STLL) are important underlying properties of multicomponent system phase diagrams. In the Pressure–temperature plane, the CL separates the region where the negative flash has non-trivial solutions. The mathematical domain of flash calculations is significantly wider than the physical domain; if a negative flash is performed, the equilibrium constants are continuously derivable when a phase boundary is crossed. Criticality criteria are met for the phase compositions resulting from the negative flash and the minimum eigenvalue of a quadratic form evaluated with these compositions (which are intrinsically stable) is used to locate the CL. An efficient negative flash procedure is also proposed. The STLL is important because in its vicinity the number of iterations for phase stability testing increases dramatically and divergence may occur. Outside the STLL the tangent plane distance function has only a trivial solution; between STLL and the phase boundary, there is a non-trivial positive solution. The spinodal criterion is met at the STLL for trial phase compositions. The CL and STLL are located at given Pressure or temperature based on rigorous thermodynamic criteria in only few Newton iterations. The proposed method avoids repeated expensive negative flash calculations in the vicinity of the CL and phase stability calculations in the vicinity of the STLL. Results are presented for representative hydrocarbon mixtures with different amounts of classical contaminants and different shapes of phase envelopes

Dan Vladimir Nichita - One of the best experts on this subject based on the ideXlab platform.

  • Calculation of Convergence Pressure/temperature and stability test limit loci of mixtures with cubic equations of state
    Fluid Phase Equilibria, 2007
    Co-Authors: Dan Vladimir Nichita, Daniel Broseta, François Montel
    Abstract:

    The Convergence locus (CL) and stability test limit locus (STLL) are important underlying properties of multicomponent system phase diagrams. In the Pressure–temperature plane, the CL separates the region where the negative flash has non-trivial solutions. The mathematical domain of flash calculations is significantly wider than the physical domain; if a negative flash is performed, the equilibrium constants are continuously derivable when a phase boundary is crossed. Criticality criteria are met for the phase compositions resulting from the negative flash and the minimum eigenvalue of a quadratic form evaluated with these compositions (which are intrinsically stable) is used to locate the CL. An efficient negative flash procedure is also proposed. The STLL is important because in its vicinity the number of iterations for phase stability testing increases dramatically and divergence may occur. Outside the STLL the tangent plane distance function has only a trivial solution; between STLL and the phase boundary, there is a non-trivial positive solution. The spinodal criterion is met at the STLL for trial phase compositions. The CL and STLL are located at given Pressure or temperature based on rigorous thermodynamic criteria in only few Newton iterations. The proposed method avoids repeated expensive negative flash calculations in the vicinity of the CL and phase stability calculations in the vicinity of the STLL. Results are presented for representative hydrocarbon mixtures with different amounts of classical contaminants and different shapes of phase envelopes.

  • calculation of Convergence Pressure temperature and stability test limit loci of mixtures with cubic equations of state
    Fluid Phase Equilibria, 2007
    Co-Authors: Dan Vladimir Nichita, Daniel Broseta, François Montel
    Abstract:

    The Convergence locus (CL) and stability test limit locus (STLL) are important underlying properties of multicomponent system phase diagrams. In the Pressure–temperature plane, the CL separates the region where the negative flash has non-trivial solutions. The mathematical domain of flash calculations is significantly wider than the physical domain; if a negative flash is performed, the equilibrium constants are continuously derivable when a phase boundary is crossed. Criticality criteria are met for the phase compositions resulting from the negative flash and the minimum eigenvalue of a quadratic form evaluated with these compositions (which are intrinsically stable) is used to locate the CL. An efficient negative flash procedure is also proposed. The STLL is important because in its vicinity the number of iterations for phase stability testing increases dramatically and divergence may occur. Outside the STLL the tangent plane distance function has only a trivial solution; between STLL and the phase boundary, there is a non-trivial positive solution. The spinodal criterion is met at the STLL for trial phase compositions. The CL and STLL are located at given Pressure or temperature based on rigorous thermodynamic criteria in only few Newton iterations. The proposed method avoids repeated expensive negative flash calculations in the vicinity of the CL and phase stability calculations in the vicinity of the STLL. Results are presented for representative hydrocarbon mixtures with different amounts of classical contaminants and different shapes of phase envelopes.

  • Calculation of Convergence Pressure/temperature and stability test limit loci of mixtures with cubic equations of state
    Fluid Phase Equilibria, 2007
    Co-Authors: Dan Vladimir Nichita, Daniel Broseta, François Montel
    Abstract:

    International audienceThe Convergence locus (CL) and stability test limit locus (STLL) are important underlying properties of multicomponent system phase diagrams. In the Pressure–temperature plane, the CL separates the region where the negative flash has non-trivial solutions. The mathematical domain of flash calculations is significantly wider than the physical domain; if a negative flash is performed, the equilibrium constants are continuously derivable when a phase boundary is crossed. Criticality criteria are met for the phase compositions resulting from the negative flash and the minimum eigenvalue of a quadratic form evaluated with these compositions (which are intrinsically stable) is used to locate the CL. An efficient negative flash procedure is also proposed. The STLL is important because in its vicinity the number of iterations for phase stability testing increases dramatically and divergence may occur. Outside the STLL the tangent plane distance function has only a trivial solution; between STLL and the phase boundary, there is a non-trivial positive solution. The spinodal criterion is met at the STLL for trial phase compositions. The CL and STLL are located at given Pressure or temperature based on rigorous thermodynamic criteria in only few Newton iterations. The proposed method avoids repeated expensive negative flash calculations in the vicinity of the CL and phase stability calculations in the vicinity of the STLL. Results are presented for representative hydrocarbon mixtures with different amounts of classical contaminants and different shapes of phase envelopes

Daniel Broseta - One of the best experts on this subject based on the ideXlab platform.

  • Calculation of Convergence Pressure/temperature and stability test limit loci of mixtures with cubic equations of state
    Fluid Phase Equilibria, 2007
    Co-Authors: Dan Vladimir Nichita, Daniel Broseta, François Montel
    Abstract:

    The Convergence locus (CL) and stability test limit locus (STLL) are important underlying properties of multicomponent system phase diagrams. In the Pressure–temperature plane, the CL separates the region where the negative flash has non-trivial solutions. The mathematical domain of flash calculations is significantly wider than the physical domain; if a negative flash is performed, the equilibrium constants are continuously derivable when a phase boundary is crossed. Criticality criteria are met for the phase compositions resulting from the negative flash and the minimum eigenvalue of a quadratic form evaluated with these compositions (which are intrinsically stable) is used to locate the CL. An efficient negative flash procedure is also proposed. The STLL is important because in its vicinity the number of iterations for phase stability testing increases dramatically and divergence may occur. Outside the STLL the tangent plane distance function has only a trivial solution; between STLL and the phase boundary, there is a non-trivial positive solution. The spinodal criterion is met at the STLL for trial phase compositions. The CL and STLL are located at given Pressure or temperature based on rigorous thermodynamic criteria in only few Newton iterations. The proposed method avoids repeated expensive negative flash calculations in the vicinity of the CL and phase stability calculations in the vicinity of the STLL. Results are presented for representative hydrocarbon mixtures with different amounts of classical contaminants and different shapes of phase envelopes.

  • calculation of Convergence Pressure temperature and stability test limit loci of mixtures with cubic equations of state
    Fluid Phase Equilibria, 2007
    Co-Authors: Dan Vladimir Nichita, Daniel Broseta, François Montel
    Abstract:

    The Convergence locus (CL) and stability test limit locus (STLL) are important underlying properties of multicomponent system phase diagrams. In the Pressure–temperature plane, the CL separates the region where the negative flash has non-trivial solutions. The mathematical domain of flash calculations is significantly wider than the physical domain; if a negative flash is performed, the equilibrium constants are continuously derivable when a phase boundary is crossed. Criticality criteria are met for the phase compositions resulting from the negative flash and the minimum eigenvalue of a quadratic form evaluated with these compositions (which are intrinsically stable) is used to locate the CL. An efficient negative flash procedure is also proposed. The STLL is important because in its vicinity the number of iterations for phase stability testing increases dramatically and divergence may occur. Outside the STLL the tangent plane distance function has only a trivial solution; between STLL and the phase boundary, there is a non-trivial positive solution. The spinodal criterion is met at the STLL for trial phase compositions. The CL and STLL are located at given Pressure or temperature based on rigorous thermodynamic criteria in only few Newton iterations. The proposed method avoids repeated expensive negative flash calculations in the vicinity of the CL and phase stability calculations in the vicinity of the STLL. Results are presented for representative hydrocarbon mixtures with different amounts of classical contaminants and different shapes of phase envelopes.

  • Calculation of Convergence Pressure/temperature and stability test limit loci of mixtures with cubic equations of state
    Fluid Phase Equilibria, 2007
    Co-Authors: Dan Vladimir Nichita, Daniel Broseta, François Montel
    Abstract:

    International audienceThe Convergence locus (CL) and stability test limit locus (STLL) are important underlying properties of multicomponent system phase diagrams. In the Pressure–temperature plane, the CL separates the region where the negative flash has non-trivial solutions. The mathematical domain of flash calculations is significantly wider than the physical domain; if a negative flash is performed, the equilibrium constants are continuously derivable when a phase boundary is crossed. Criticality criteria are met for the phase compositions resulting from the negative flash and the minimum eigenvalue of a quadratic form evaluated with these compositions (which are intrinsically stable) is used to locate the CL. An efficient negative flash procedure is also proposed. The STLL is important because in its vicinity the number of iterations for phase stability testing increases dramatically and divergence may occur. Outside the STLL the tangent plane distance function has only a trivial solution; between STLL and the phase boundary, there is a non-trivial positive solution. The spinodal criterion is met at the STLL for trial phase compositions. The CL and STLL are located at given Pressure or temperature based on rigorous thermodynamic criteria in only few Newton iterations. The proposed method avoids repeated expensive negative flash calculations in the vicinity of the CL and phase stability calculations in the vicinity of the STLL. Results are presented for representative hydrocarbon mixtures with different amounts of classical contaminants and different shapes of phase envelopes