Drilling EngineeringDirectional Drilling
Three-Dimensional Wellbore Center-to-Center Separation Formula
Three-Dimensional Wellbore Center-to-Center Separation calculates three-dimensional center-to-center separation for directional drilling workflows in drilling engineering.
How engineers use this formula
Use this formula when the listed inputs (dN, dE, dTVD) 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, S_3D equals 72.801099 ft.
dNft
60
dEft
40
dTVDft
10
Inputs
dN
ftNorth-South Offset Between Well Centers
dE
ftEast-West Offset Between Well Centers
dTVD
ftTrue Vertical Depth Difference Between Well Centers
Outputs
S_3D
ft
Three-Dimensional Center-to-Center Separation
Source and review
reviewedMansouri, Khosravanian, Wood, and Aadnøy 2020. Anti-well-collision proximity analysis using 3-D least distance.
Source