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Bullheading Initial Hydrostatic Pressure from Formation Pressure Formula

Ph,init=PformSITPP_{h,init}=P_{form}-SITP

Bullheading Initial Hydrostatic Pressure from Formation Pressure calculates initial hydrostatic pressure for well control workflows in drilling engineering.

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How engineers use this formula

Use this formula when the listed inputs (P_form, SITP) are known and the assumptions behind the cited well control relationship match the engineering case being checked.

Assumptions

  • Input values are representative for the well, reservoir, fluid, or equipment case being evaluated.
  • The declared units match the field-unit constants used in the formula.
  • The cited formula applies to the selected petroleum engineering workflow.

Limitations

  • The calculation does not replace a full engineering model or operating procedure.
  • Accuracy depends on the source correlation, assumptions, input quality, and unit consistency.

Common mistakes

  • Mixing unit systems without converting the inputs.
  • Using default example values as field recommendations.
  • Applying the formula outside the source assumptions.

Default example

Using the default inputs, P_h_init equals 3,800 psi.

P_formpsi

5000

SITPpsi

1200

Inputs

P_form

psi

Formation Pressure

SITP

psi

Shut-In Tubing Pressure

Outputs

P_h_init

psi

Initial Hydrostatic Pressure

P_form

psi

Formation Pressure

SITP

psi

Shut-In Tubing Pressure

Source and review

reviewed

IADC WellSharp Formula Sheet, field units, well completion/workover bullheading formulae.

Source

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