Hydrostatic Pressure Calculator - Mud Weight and TVD
Calculate hydrostatic and bottomhole pressure instantly. Enter mud weight in ppg and true vertical depth in feet to return hydrostatic pressure in psi.
Calculate hydrostatic and bottomhole pressure instantly. Enter mud weight in ppg and true vertical depth in feet to return hydrostatic pressure in psi.
Published by PetroCalcHub Team. Linked workflow tools and revision log.
Calculation context and source notes
Hydrostatic pressure from mud weight calculates the pressure exerted by a drilling-fluid column at true vertical depth using the standard oilfield 0.052 conversion factor.
Use it for well-control checks, bottomhole pressure estimates, equivalent mud weight comparisons, and quick pressure-balance calculations in US field units.
IADC field-unit worksheet: pressure gradient and hydrostatic pressureSolves for
HP (psi)
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Formula, variables, and sourceConvert mud weight to pressure gradient
For the field-unit relationship, gradient in psi/ft is 0.052 times mud weight in ppg. Multiply that gradient by true vertical depth in feet to obtain the hydrostatic pressure increment. The 0.052 constant is tied to these units; it is not a multiplier for density entered directly in kg/m3.
The default 10 ppg column at 10,000 ft TVD gives 0.52 psi/ft x 10,000 ft = 5,200 psi. The following values are synthetic arithmetic checks, not recommended mud weights.
| Mud weight (ppg) | Gradient (psi/ft) | Pressure at 10,000 ft TVD (psi) |
|---|---|---|
| 8.4 | 0.4368 | 4,368 |
| 10 | 0.52 | 5,200 |
| 12 | 0.624 | 6,240 |
TVD, surface pressure and circulating pressure
Hydrostatic head follows vertical elevation change, not the length of the well path. For 10 ppg mud at 10,000 ft TVD, the result remains 5,200 psi even if the measured well length is 12,000 ft; substituting that measured length would incorrectly return 6,240 psi.
This result represents the mud-column contribution. Applied surface pressure is a separate contribution, while annular friction adds a circulating contribution. Use the surface-pressure EMW calculator or linked ECD workflow for the appropriate question instead of treating static hydrostatic pressure as the complete bottomhole pressure.
When a single mud weight is insufficient
The calculation assumes one representative density over the full vertical column. Separate fluid segments, changes in density with conditions, or a gas-bearing column need a model appropriate to those conditions rather than one unqualified average mud weight.
Keep the selected depth and pressure datum explicit when comparing the result with other measurements. Converting ppg to specific gravity changes density units; it does not add surface pressure, predict friction, or establish an allowable formation-pressure limit.
Compare compatible calculations
Linked Drilling Hydraulics CalculatorLearn, compare and practice
Worked explanations, controlled studies and printable exercises connected to this calculation.
Formula, variables, and default calculation
Reproducible default result
With the default values shown below, the calculation returns HP = 5,200 psi. Defaults demonstrate the implementation; they are not recommended field values.
10
10000
Input definitions
MW
ppgMud Weight
TVD
ftTrue Vertical Depth
Output definitions
HP
Hydrostatic Pressure
MW
Mud Weight
TVD
True Vertical Depth
Engineering use, assumptions, and limits
Use it for well-control checks, bottomhole pressure estimates, equivalent mud weight comparisons, and quick pressure-balance calculations in US field units.
Assumptions
- Mud weight is uniform over the measured fluid column.
- Depth is true vertical depth, not measured depth.
- The 0.052 factor is used for ppg, ft, and psi field units.
Limitations
- Does not include surface pressure, friction losses, swab/surge effects, or gas-cut mud.
- Not a full well-control kill-sheet calculation.
Common mistakes
- Using measured depth instead of true vertical depth.
- Mixing SI and field units with the 0.052 constant.
- Applying the result without adding or subtracting surface pressure where required.
Frequently asked questions
What inputs does the Hydrostatic Pressure from Mud Weight calculator need?
The calculation uses Mud Weight (MW), True Vertical Depth (TVD). Enter values on the units shown beside each field.
What result does this calculator return?
The primary result is hydrostatic pressure in psi. The formula section shows the declared relationship, variables, and a reproducible default calculation.
What should I check before using the result?
Confirm the unit basis, source applicability, and input quality. Does not include surface pressure, friction losses, swab/surge effects, or gas-cut mud. Using measured depth instead of true vertical depth.
Source and record status
Source metadata identifies the relationship implemented by the calculator. Check the cited edition, unit basis, and scope against the engineering case before operational use.
SLB Energy Glossary. Hydrostatic pressure.
Open source reference