Drilling EngineeringDirectional Drilling
Borehole Torsion by Cylindrical Helical Method Formula
Borehole Torsion by Cylindrical Helical Method calculates borehole torsion for directional drilling workflows in drilling engineering.
How engineers use this formula
Use this formula when the listed inputs (k_h, k_v, k, a) are known and the assumptions behind the cited directional drilling 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, t equals 1.32 degree/100 ft.
k_hdegree/100 ft
2
k_vdegree/100 ft
1.2
kdegree/100 ft
3
adeg
45
Inputs
k_h
degree/100 ftHorizontal curvature
k_v
degree/100 ftVertical curvature
k
degree/100 ftWellbore trajectory curvature
a
degInclination angle
Outputs
t
degree/100 ft
Borehole torsion
k_h
degree/100 ft
Horizontal curvature
k_v
degree/100 ft
Vertical curvature
k
degree/100 ft
Wellbore trajectory curvature
Source and review
reviewed501 Solved Problems and Calculations for Drilling Operations, Robello, S.E. (2015)
Robello, S.E. 2015. 501 Solved Problems and Calculations for Drilling Operations, Sigma Quadrant, Houston, Texas, Page 84.
Source