Pseudosteady-State Dimensionless Pressure Drop for Horizontal Well Calculator
Enter the required inputs, confirm the units, and run the calculator to solve P_D. Review the formula source and assumptions before using the result in engineering work.
Calculation context and source notes
Pseudosteady-State Dimensionless Pressure Drop for Horizontal Well calculates wellbore dimensionless pressure drop for pressure transient analysis workflows in reservoir engineering. The page keeps the declared variables, units, source relationship, and output definition visible for technical review.
Use this formula when the listed inputs (t_DA, C_Ah, L, A) are known and the assumptions behind the cited pressure transient analysis relationship match the engineering case being checked.
Solves for
P_D (dimensionless)
Best next page
Formula, variables, and sourceFormula, variables, and default calculation
Reproducible default result
With the default values shown below, the calculation returns P_D = 1.68803 dimensionless. Defaults demonstrate the implementation; they are not recommended field values.
0.1
30
2000
27878400
Input definitions
t_DA
dimensionlessDimensionless Time Based on Drainage Area
C_Ah
dimensionlessHorizontal Well Shape Factor
L
ftHorizontal Well Length
A
ft^2Drainage Area
Output definitions
P_D
Wellbore Dimensionless Pressure Drop
t_DA
Dimensionless Time Based on Drainage Area
C_Ah
Horizontal Well Shape Factor
A
Drainage Area
Engineering use, assumptions, and limits
Use this formula when the listed inputs (t_DA, C_Ah, L, 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.
Frequently asked questions
What inputs does the Pseudosteady-State Dimensionless Pressure Drop for Horizontal Well calculator need?
The calculation uses Dimensionless Time Based on Drainage Area (t_DA), Horizontal Well Shape Factor (C_Ah), Horizontal Well Length (L), Drainage Area (A). Enter values on the units shown beside each field.
What result does this calculator return?
The primary result is wellbore dimensionless pressure drop in dimensionless. 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. The calculation does not replace a full engineering model or operating procedure. Mixing unit systems without converting the inputs.
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.
Joshi, S. D. Horizontal Well Technology, PennWell Publishing Company, Chapter 7, Page 216.
Open source reference