## What is the relationship between capillary pressure and water saturation?

As is typical of mixed-wet samples, the water saturation increases rapidly during imbibition for decreasing capillary pressure in the vicinity of zero. Similarly, water saturation decreases rapidly during the secondary-drainage cycle for increasing capillary pressure just above zero.

How do you calculate pressure in a capillary tube?

Capillary pressure (Pc) is the difference in pressure measured across the interface in the capillary (Pc = Pnw – Pw). This pressure results from the contrast in pressure gradients caused by the different densities of the nonwetting (ρnw) and wetting (ρw) phases (right).

### 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.

How does venous pressure affect capillary pressure?

An increase in small artery, arteriolar, or venous pressure will increase the capillary hydrostatic pressure favoring filtration. A reduction of these pressures will have the opposite effect.

## What is the pressure of capillaries?

Capillary pressure physiology 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).

What is capillary tube pressure?

In fluid statics, capillary pressure ( ) is the pressure between two immiscible fluids in a thin tube (see capillary action), resulting from the interactions of forces between the fluids and solid walls of the tube.

### How do you calculate capillary water?

Capillary Action Formula

1. The rise of a column of liquid within a narrow capillary tube is also because of the surface tension. The formula for capillary rise (h)=2Trρg.
2. Capillary rise (h)=2Tcosθrρg.
3. Capillary rise (h)=2Trρg.
4. Using the capillary action formula: h=2Trρg.
5. Radius of tube r=2Thρg.

What is capillary rise of water?

DEFINITION: A rise in a liquid above the level of zero pressure due to a net upward force produced by the attraction of the water molecules to a solid surface, e.g. glass, soil (for those cases where the adhesion of the liquid to the solid is greater than the cohesion of the liquid to itself)

## What is connate water saturation?

Connate water saturation is the amount of the water which adsorbs on the surface of the grains of the rock or on the walls of the porous pore channels (immobile with the traditional displacement methods) divided by the pore volume.

What pressure pulls water into capillaries?

Hydrostatic pressure pushes water out of the capillary and colloid osmotic pressure pulls water into the capillary. The difference between these gradients is the net filtration pressure (NFP). At the capillary’s arteriolar end, the NFP is? 13 mm Hg.

### How do you calculate oncotic pressure?

Osmotic pressure = n x (c/M) x RT n is the number of particles into which the substance dissociates ( n = 1 for plasma proteins) c is the concentration in G/l. M is the MW of the molecules. c/M is thus the molar concentration of the substance (mol/l)

How do you find the capillary pressure between gas and water?

Fig. 1 shows a sketch of a typical capillary pressure relationship for gas invading a porous medium that is initially saturated with water; the gas/water capillary pressure is defined as Pcgw = pg – pw. For this example, water is the wetting phase, and gas is the nonwetting phase.

## What is the relationship between water saturation and capillary pressure?

As is typical of mixed-wet samples, the water saturation increases rapidly during imbibition for decreasing capillary pressure in the vicinity of zero. Similarly, water saturation decreases rapidly during the secondary-drainage cycle for increasing capillary pressure just above zero.

What is the relationship between capillary size and capillary pressure?

θ= contact angle between the fluids and the capillary tube rc= radius of the capillary These equations show that capillary pressure increases with greater height above the free surface and with smaller capillary size.

### What is the capillary pressure for an oil water system?

Capillary pressure for an oil–water system is Capillary pressure increases with height above the oil–water contact (OWC) as water saturation decreases. In gas–oil systems, gas usually behaves as the nonwetting phase and oil as the wetting phase.