What is a capillary pressure curve?
Capillary pressure (Pc) curves are a rock property measurement that relates the volume of pore space controlled by pore throats of a given size (usually given in microns) to a given capillary pressure.
How do you calculate capillary pressure?
Capillary pressure is defined as Pc=Pnw−Pw and for water saturation decreasing, Pnw outside the pore throat is greater than Pw inside the pore throat, resulting in a positive pressure.
How is capillary pressure curve used to determine the initial distribution of fluids in a reservoir?
If you know the rock quality, namely porosity and permeability of the rock at a certain depth in the reservoir, you can use the capillary pressure (determined from the difference in densities between water and hydrocarbon and the height above the Free Water Level) to determine the initial water saturation of the …
How are capillary pressure and permeability related?
Capillary pressure and relative permeability both depend on the same fluid-fluid and rock-fluid interaction energies. If the capillary pressure vanishes, the residual saturations approach zero and the relative permeability of a phase becomes equal to its saturation.
What is normal capillary pressure?
Normal capillary pressure, measured at the apex of the capillary loop with the capillary at heart level, ranges from 10.5 to 22.5 mmHg (Figure 4). It is lower in premenopausal women than in postmenopausal women or in men and does not correlate with brachial artery blood pressure.
Is capillary pressure positive?
A positive capillary pressure represents a valve on the fluid flow while a negative pressure represents the fluid being pulled into the microchannel.
What causes capillary pressure?
What Causes Capillary Pressure? Capillary pressure is as a result of the interfacial tension existing at the interface separating two immiscible fluids. The interfacial tension itself is caused by the imbalance in the molecular forces of attraction experienced by the molecules at the surface as shown below.
How can capillary pressure be reduced?
Surfactants can reduce capillary pressure in the matrix by reducing surface tension and/or by changing the wettability of the rock surface when they adsorb on a surface.
What is Bubblepoint test?
Bubble Point Test The test is based on the fact that for a given fluid and membrane pore size and constant wetting the pressure required to force an air bubble through a pore is inversely proportional to the size of the pore or hole.
What is dew point and bubble point?
Bubble point: Liquid refrigerant starts to boil at this pressure and temperature in the evaporator. Mid point: Half of the liquid refrigerant has boiled away to a gas. Dew point: The last of the liquid refrigerant boils away.
What increases capillary pressure?
Distension, as recruitment, is an adaptation to the increase in capillary pressure. By increasing diameter and volume, resistance of the capillary is reduced, and tt is prolonged, thus giving more time for O2 pressure in the blood to equilibrate with Pa.