scholarly journals Two-step explicit procedure formulation for fast decompression of two-phase water/steam mixture. [LMFBR]

1976 ◽  
Author(s):  
Y.W. Shin
2018 ◽  
Vol 31 (4) ◽  
pp. 317-333
Author(s):  
G. Tymen ◽  
N. Allanic ◽  
A. Sarda ◽  
P. Mousseau ◽  
C. Plot ◽  
...  

1980 ◽  
Vol 20 (03) ◽  
pp. 206-214 ◽  
Author(s):  
S.K. Garg

Pressure Transient Analysis for Two-Phase Pressure Transient Analysis for Two-Phase (Water/Steam) Geothermal Reservoirs Abstract A new diffusivity equation for two-phase (water/steam) flow in geothermal reservoirs is derived. The geothermal reservoir may be initially two-phase or may evolve into a two-phase system during production. Solutions of the diffusivity equation for a continuous line source are presented; the solutions imply that the plot of bottomhole pressure vs. loglot (t=time) should be a straight pressure vs. loglot (t=time) should be a straight line. The slope of the straight line is inversely proportional to the total kinematic mobility. proportional to the total kinematic mobility. Comparison of the theory with a limited number of computer-simulated drawdown histories shows excellent agreement. Introduction In petroleum engineering and groundwater hydrology, well tests are conducted routinely to diagnose the well's condition and to estimate formation properties. Well test data may be analyzed to yield quantitative information regarding (1) formation permeability, storativity, and porosity, (2) the presence of barriers and leaky boundaries, (3) the condition of the well (i.e., damaged or stimulated), (4) the presence of major fractures close to the well, and (5) the mean formation pressure. Well testing procedures (and the quality of information obtained) procedures (and the quality of information obtained) depend on the age of the well. During temporary completion, testing involves producing the reservoir using a temporary plumbing system (e.g., drillstem testing), and the estimates obtained for the formation parameters are not very accurate. After completion, parameters are not very accurate. After completion, testing usually is performed in the hydraulic mode. In hydraulic testing, one or more wells are produced at controlled rates, and pressure changes within the producing well itself or nearby observation wells producing well itself or nearby observation wells (interference tests) are monitored.A major concern of well testing is the interpretation of pressure transient data. Much of the existing literature deals with isothermal single-phase (water/oil) and isothermal two-phase (oil with gas in solution, free gas) systems. In general, there is a lack of methodology for analyzing nonisothermal reservoir systems, either single- or two-phase (water/steam). Geothermal reservoirs commonly involve nonisothermal two-phase flow during well testing. This paper presents a theoretical framework for analyzing multiphase pressure transient data in geothermal systems. Two-Phase Flow in Geothermal Systems Consider a fully penetrating well located in an infinite reservoir of thickness h. We neglect any variations in either formation or fluid properties in the vertical direction. (This is a common assumption in pressure transient analysis.) The geothermal system may be two-phase before production or may evolve into a two-phase system as a result of fluid production. In the latter case, a boiling front will production. In the latter case, a boiling front will propagate outward from the wellbore. The boiling propagate outward from the wellbore. The boiling front may be treated as a constant-pressure boundary (p=saturation pressure corresponding to the local reservoir temperature).For the sake of simplicity, consider a reservoir that is initially two-phase everywhere. Furthermore, it is convenient to assume that the pressure (and, hence, temperature) is uniform throughout the system. In radial geometry, the pressure response is governed by the following diffusivity equation (see Appendix for a derivation of Eq. 1). (1) SPEJ P. 206


1986 ◽  
Vol 108 (1) ◽  
pp. 76-83 ◽  
Author(s):  
F. N. Vafaie ◽  
J. R. Dunn

The heat transfer characteristics of a single-tube, helically coiled receiver for a concentrating solar collector are presented. Heat transfer coefficients were measured for single and two-phase water-steam flow in a helical coil subjected to radiant heating for a range of flow conditions and radiant flux levels. Results are presented for both the local and average heat transfer coefficients in several flow regimes.


2001 ◽  
pp. 677-683
Author(s):  
H. Paillere ◽  
A. Kumbaro ◽  
C. Viozat ◽  
S. Clerc ◽  
A. Broquet ◽  
...  
Keyword(s):  

2021 ◽  
Vol 655 (1) ◽  
pp. 012024
Author(s):  
O.H. Ajesi ◽  
M.B. Latif ◽  
S.T. Gbenu ◽  
C. A. Onumejor ◽  
M. K. Fasasi ◽  
...  

2021 ◽  
Author(s):  
Filipe Smith Buarque ◽  
Cleide Mara Faria Soares ◽  
Ranyere Lucena de Souza ◽  
Matheus Mendonça Pereira ◽  
Álvaro Silva Lima

Two-phase water-free systems containing high ethanol content in the coexisting phases can selectively partition hydrophobic molecules from natural biomass.


1983 ◽  
Vol 105 (3) ◽  
pp. 485-492 ◽  
Author(s):  
K. S. Udell

Heat and mass transfer characteristics of a sand-water-steam system heated at the top and cooled at the bottom were studied. It was found that at steady-state conditions the system segregated into three regions. The top region was conduction-dominated with the voids containing a stationary superheated steam. The middle region was convection-dominated, nearly isothermal, and exhibited an upward flow of the liquid by capillary forces and a downward flow of steam due to a slight pressure gradient. The bottom portion contained a stationary compressed liquid and was also conduction dominated. The length of the two-phase convection zone was evaluated through the application of Darcy’s equations for two-phase flow and correlations of relative permeabilities and capillary pressure data. The model was in excellent agreement with the observed results, predicting a decreasing two-phase zone length with increasing heat flux. The thermodynamics of the two-phase zone were also analyzed. It was found that the vapor phase was in a superheated state as described by the Kelvin equation for vapor pressure lowering. Also, it was evident that the liquid must also be superheated for thermodynamic equilibrium to result. A stability analysis demonstrated that the superheated liquid can exist in an unconditionally stable state under conditions typical of porous systems. The degree of liquid superheat within the two-phase zone of these experiments was obtained.


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