Work out hydrostatic pressure in well instantly with clear inputs, formula shown and shareable results.
Hydrostatic pressure is 0.052 x mud weight in ppg x true vertical depth in feet. Only vertical depth counts — measured depth along a deviated hole does not add pressure. While circulating, annular friction adds to bottom hole pressure, expressed as equivalent circulating density.
Hydrostatic pressure
P (psi) = 0.052 x mud weight (ppg) x TVD (ft)
Equivalent circulating density
ECD (ppg) = (hydrostatic + annular losses) / (0.052 x TVD)
Well control calculations must use verified true vertical depth and fluid density. Errors in hydrostatic pressure can cause blowouts or lost circulation.
Pressure depends on the vertical column of fluid. A horizontal section adds length and friction but no hydrostatic head, which is why TVD and MD must never be confused in well control.
It can exceed the fracture gradient during circulation even when static mud weight is safe, causing losses. Narrow-margin wells often have to reduce pump rate to manage ECD.