Enter the hydrostatic pressure of the mud in the annulus (psi), the hydrostatic pressure of the influx (psi), and the shut-in casing pressure (psi) into the Formation Pressure Calculator. The calculator will evaluate the Formation Pressure.

- TFA – Total Flow Area Calculator
- EMW (Equivalent Mud Weight) Calculator
- Casing Capacity (Annular Volume) Calculator
- Oil Formation Volume Factor Calculator

## Formation Pressure Formula

The following formula is used to calculate the Formation Pressure.

FP = HSPM + HSPI + SICP

Variables:

- FP is the Formation Pressure (psi)
- HSPM is the hydrostatic pressure of the mud in the annulus (psi)
- HSPI is the hydrostatic pressure of the influx (psi)
- SICP is the shut-in casing pressure (psi)

## How to Calculate Formation Pressure?

The following steps outline how to calculate the Formation Pressure.

- First, determine the hydrostatic pressure of the mud in the annulus (psi).
- Next, determine the hydrostatic pressure of the influx (psi).
- Next, determine the shut-in casing pressure (psi).
- Next, gather the formula from above = FP = HSPM + HSPI + SICP.
- Finally, calculate the Formation Pressure.
- After inserting the variables and calculating the result, check your answer with the calculator above.

**Example Problem:**

Use the following variables as an example problem to test your knowledge.

hydrostatic pressure of the mud in the annulus (psi) = 100

hydrostatic pressure of the influx (psi) = 230

shut-in casing pressure (psi) = 10

FP = HSPM + HSPI + SICP =** ** ?