# Compressibility

## Definition - What does Compressibility mean?

Compressibility is the measure of a liquid’s relative volume change when the pressure acting on it changes. Compressibility is related to thermodynamics and fluid mechanics. It is denoted by beta “B”. The Compressibility of a fluid depends on adiabatic or isothermal process. It can be represented in the formula below.

Where

B = compressibility

V = Volume

P = Pressure

## Petropedia explains Compressibility

The compressibility of oil, gas and water depends on the volumetric and pressure conditions in a given temperature. There are two types of compressibility:

1. ** Isothermal Compressibility** – It is the compressibility in which fluids are compressed at a constant pressure. This type of entropy is expressed as:

Where, T represents constant temperature.

2. ** Isentropic Compressibility** - It is the compressibility in which the volume of the fluid reduces with the increase in pressure. This type of entropy is expressed as:

Where, S represents Entropy.