Drilling EngineeringDrilling Hydraulics
Depth of a Washout - Method 1 Formula
Depth of a Washout - Method 1 calculates depth of washout for drilling hydraulics workflows in drilling engineering.
How engineers use this formula
Use this formula when the listed inputs (N_s, P_o, C_p) are known and the assumptions behind the cited drilling hydraulics 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, D_w equals 2,808.988764 ft.
N_sstrokes
500
P_obbl/stroke
0.1
C_pbbl/ft
0.0178
Inputs
N_s
strokesNumber of Strokes Required
P_o
bbl/strokePump Output per Stroke
C_p
bbl/ftDrillpipe Capacity
Outputs
D_w
ft
Depth of Washout
N_s
strokes
Number of Strokes Required
P_o
bbl/stroke
Pump Output per Stroke
C_p
bbl/ft
Drillpipe Capacity
Source and review
reviewedFormulas and Calculations for Drilling, Production and Workover, Lapeyrouse, N.J. (2002)
Lapeyrouse, N.J. 2002. Formulas and Calculations for Drilling, Production and Workover, 2nd Edition, Gulf Professional Publishing, Page 70.
Source