Drilling EngineeringWell Control
Surface-to-Bit Strokes for Wait and Weight Schedule Formula
Surface-to-Bit Strokes for Wait and Weight Schedule calculates surface-to-bit strokes for well control workflows in drilling engineering.
How engineers use this formula
Use this formula when the listed inputs (C_dp, TD, PO) 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, S_bit equals 1,602 strokes.
C_dpbbl/ft
0.0178
TDft
9000
PObbl/stk
0.1
Inputs
C_dp
bbl/ftDrill Pipe Capacity
TD
ftMeasured Depth
PO
bbl/stkPump Output per Stroke
Outputs
S_bit
strokes
Surface-to-Bit Strokes
C_dp
bbl/ft
Drill Pipe Capacity
TD
ft
Measured Depth
PO
bbl/stk
Pump Output per Stroke
Source and review
reviewedDrillingFormulas.com. Drill Pipe Pressure Schedule Calculation for Wait and Weight Well Control Method.
Source