Fracture initiation mode

§10.5–§10.6 — Vertical vs horizontal initiation classifier with pressure sweep, threshold visualization, and the dipping-fracture proppant-flow multiplier.

Stress state

Fluid pressure(psi)

Sh (min horizontal)(psi)

Sv (overburden)(psi)

Tstr (vertical)(psi)

Tstrv (horizontal)(psi)

Dipping fracture (§10.5)

Dip angle(°)Reduction factor

Pressure sweep

P min(psi)

P max(psi)

Steps

Result

Vertical threshold7700 psi

Horizontal threshold9800 psi

Vertical readyyes

Horizontal readyno

Margin800 psi

Preferred modevertical

Proppant flow multiplier0.875

Behind-casing crossflow (§10.7)

Auto-save

Enable derate

When limited entry is partially defeated, the surface treating pressure drives more parallel paths and the cluster sees only P_floor + effectiveness · (P − P_floor). Phase 5: neighbour weighting decays with distance, perf ΔP responds to stage rate (Bernoulli), and leakage admittance scales with fluid viscosity.

± uncertainty as:

# clustersCluster spacing(ft)Connection distance(ft)Neighbour weighting

Barrier transmissibility(md·ft)Perf conductance(md·ft)

Stage rate(bpm)

± rate(%)

Slurry density(ppg)

± density(%)

Leakage viscosity(cp)

± viscosity(%)

Hydrostatic floor(psi)

Enable the derate to see crossflow effects.

Pressure margin sweep

Margin = P − min(Sh+Tstr, Sv+Tstrv). Color encodes the preferred mode at each pressure. Crossings of zero indicate breakdown thresholds.

Hover the chart to inspect the preferred mode and margin at any pressure.

Sweep zone breakdown

Step counts and pressure spans for each initiation regime across the 25-step sweep.

Zone	Steps	% of sweep	P min (psi)	P max (psi)	Span (psi)
Vertical only	9	36.0%	7750	9750	2000
Horizontal only	0	0.0%	—	—	—
Both (transition)	9	36.0%	10000	12000	2000
Neither	7	28.0%	6000	7500	1500

Downhole Ballistics Simulator