Reservoir EngineeringPressure Transient Analysis
Horner Time Ratio for Pressure Buildup Test Formula
Horner Time Ratio for Pressure Buildup Test calculates horner time ratio for pressure transient analysis workflows in reservoir engineering.
How engineers use this formula
Use this formula when the listed inputs (t_p, Delta_t) are known and the assumptions behind the cited pressure transient analysis 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, H equals 11 dimensionless.
t_ph
240
Delta_th
24
Inputs
t_p
hProducing Time Before Shut-In
Delta_t
hShut-In Time Since Buildup Started
Outputs
H
dimensionless
Horner Time Ratio
t_p
h
Producing Time Before Shut-In
Delta_t
h
Shut-In Time Since Buildup Started
Source and review
reviewedAAPG Wiki, Pressure transient testing, pressure buildup test discussion after W. John Lee.
Source