Page 311 - Principles of Applied Reservoir Simulation 2E

296 Principles of Applied Reservoir Simulation

infinity. It should be noted that these concepts apply to both hydrocarbon
components and any other distinct molecular species, such as carbon dioxide
and nitrogen.

Pressure
The average pressure on a surface is the total normal force applied to the
surface divided by the area of the surface. The normal force is the component
of the force that is acting perpendicularly to the surface.
Consider a fluid in the pore space of a rock. The pressure at any point in
the fluid is equal in all directions. If the fluid is at rest in the pore space, the
pressure is equal at all points in the fluid at the same depth. Pascal's law says
that pressure applied to an enclosed fluid will be transmitted without a change
in magnitude to every point of the fluid and to the walls of the container.

Temperature
Temperature is a measure of the average kinetic energy of a system.
Several temperature scales are in use. The most commonly used temperature
scales are the Fahrenheit and Celsius scales. The relationship between these
scales is

where T c and T F are temperatures in degrees Celsius and degrees Fahrenheit
respectively.
Applications of equations of state require the use of absolute temperature
scales. Absolute temperature may be expressed in terms of degrees Kelvin or
degrees Rankine. The Kelvin scale is related to the Celsius scale by

T K = T c + 273
where T K is temperature in degrees Kelvin. The Rankine scale is related to the
Fahrenheit scale by
= + 460
T R T F
where T R is temperature in degrees Rankine.