Engineering Verification

ISCWSA Reference Comparison Results

DirectionalPlan calculations compared with published ISCWSA survey uncertainty and R4 clearance examples. These comparisons were performed by DirectionalPlan and do not constitute ISCWSA certification or endorsement.

Download Numerical Comparisons ↓ Back to Anti-Collision →

Survey Uncertainty

Covariance Matrix Comparisons

Three ISCWSA error-model example wellpaths and six NEV covariance components (NN, EE, VV, NE, NV, EV). Of 6,396 total and source comparisons, 6,395 satisfy the applied acceptance rule. One Well 1 NE total differs by −0.000002527 m² at MD 1,620 m.

The charts below show full covariance overlays for each ISCWSA reference well. Published ISCWSA values are shown as dotted black lines and DirectionalPlan values are shown as solid blue lines so the overlay can be visually inspected.

ISCWSA Example 3 covariance overlay with dotted black ISCWSA lines and solid blue DirectionalPlan lines — Well 03 — full covariance overlay (NN, EE, VV, NE, NV, EV)

ISCWSA Example 2 covariance overlay with dotted black ISCWSA lines and solid blue DirectionalPlan lines — Well 02 — full covariance overlay (NN, EE, VV, NE, NV, EV)

ISCWSA Example 1 covariance overlay with dotted black ISCWSA lines and solid blue DirectionalPlan lines — Well 01 — full covariance overlay (NN, EE, VV, NE, NV, EV)

Well 2 EE covariance reference comparison — Well 2 EE covariance — 131 paired depth stations

Covariance parity for all three reference wells — All three wells — covariance parity

R4 Clearance

Anti-Collision Ratio Comparisons

The supplied dataset contains 1,000 paired values: 100 measured-depth pairs for each of offsets 1–9 and 11. Offset 10 is not included in this export. These charts compare ISCWSA ACR, which differs from DirectionalPlan's displayed Separation Factor.

Offset 11 published and calculated ACR — Offset 11 — ACR comparison with logarithmic axis

ACR parity for ten offsets — All ten offsets — ACR parity

Numerical Differences

Residuals and Documented Exceptions

Among 444 comparisons with published ACR below 10, the largest absolute ACR difference is 0.0098925. The single covariance check outside tolerance is shown separately.

Differences for 444 low-ACR reference comparisons — Reference ACR below 10 — 444 comparison residuals

Well 1 NE covariance residual at 1620 meters — Well 1 — NE covariance residual at MD 1,620 m

Scope and Sources

Interpreting the Comparisons

Results were calculated by DirectionalPlan and compared with published ISCWSA reference examples, rather than independently certified by an external organization.
The R4 dataset includes reference C-C distances, but not corresponding calculated C-C distances, so these files do not independently establish C-C agreement.
Sidetrack reference checks are a separate test series, not represented in the R4 comparison CSV.
The covariance comparison retains the original acceptance tolerance and one documented exception.

ISCWSA R4 Reference Workbook → ISCWSA Error Model Resources → Download Data and Figures ↓