Definition - What does Formation Pressure mean?
Formation Pressure, also known as Reservoir Pressure or hydrostatic pressure is the pressure of the fluids present in a hydrocarbon reservoir. It can also be stated as the pressure which is exerted by column of water on sea level from the depth of a hydrocarbon reservoir inside the earth's surface. Formation Pressure data is helpful in volumetric calculations.
Petropedia explains Formation Pressure
In order to calculate Formation Pressure, bottom hole pressure measuring instruments are used to measure the fluid pressure in the pores of the reservoir. Usually, the pressure inside the reservoir always keeps changing when fluids are produced hence Formation Pressure is measured at a specific time and is referred to as initial reservoir pressure. When the fluids flow from the reservoir, the pressure distribution can be in a steady state flow, pseudosteady state flow or transient flow. Optical Fiber technology is considered to be advantageous in measuring the pressure and temperature of the reservoir.