Reservoir EngineeringPressure Transient Analysis
Dimensionless Length for Linear Flow General Case Formula
Dimensionless Length for Linear Flow General Case calculates dimensionless linear flow length for pressure transient analysis workflows in reservoir engineering.
How engineers use this formula
Use this formula when the listed inputs (x, A) 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, x_D equals 0.790569 dimensionless.
xft
250
Aft^2
100000
Inputs
x
ftLinear Flow Distance
A
ft^2Drainage Area
Outputs
x_D
dimensionless
Dimensionless Linear Flow Length
x
ft
Linear Flow Distance
A
ft^2
Drainage Area
Source and review
reviewedLee, Rollins and Spivey, Pressure Transient Testing, SPE Textbook Series Vol. 9, linear-flow constant-rate dimensionless variables.
Source