Wellbore Genius

Downhole Simulator

Performance modeling

v1.0Solver: OK

Depletion stress

Poroelastic + thermoelastic horizontal-stress change. Negative ΔP (depletion) and negative ΔT (cooling) reduce σ_h, biasing child-well fractures into the depleted region (frac hits).

Sign convention

Sign convention: negative ΔP (pore-pressure depletion) and negative ΔT (rock cooling) BOTH reduce σ_h. Positive values raise σ_h. Predicted direction from current ΔP / ΔT: stress drop (frac-hit risk ↑).

Inputs

Scenario presets(sets ΔP and ΔT with the correct sign convention)

Biot–Willis coefficient α (–)

0.7–1.0 typical (auto-derived from K, K_s if you edit those)

Poisson's ratio ν (–)

0.20–0.30 typical

Young's modulus E (psi)

2–6 × 10⁶ psi typical

Thermal expansion α_T (1/°F)

4–6 × 10⁻⁶ /°F typical

Reference temperature T_ref (°F)

Virgin rock temperature

ΔP (pore pressure change) (psi)

Negative = depletion

ΔT (temperature change) (°F)

Negative = cooling

Initial σ_h (psi)

For σ_h_new computation

Bubble radius R (ft)

Depleted core radius

Drained bulk modulus K (psi)

Skeleton stiffness; K = E/(3(1−2ν))

Grain bulk modulus K_s (psi)

Quartz ≈ 5.5e6, calcite ≈ 1.0e7

Fluid bulk modulus K_f (psi)

Water ≈ 3.2e5; gas much lower

Porosity φ (–)

0.03–0.20 typical

Derived poroelastic properties

α (derived) = 1 − K/K_s

0.564

Biot modulus M

2959159 psi

Undrained K_u

3340083 psi

Skempton's B

0.499

Storage S_ε (uniaxial strain)

4.70e-7 1/psi

Storage S_σ (unconstrained)

3.38e-7 1/psi

α mismatch

Manual α = 0.80 differs from derived α = 0.56.

Stress change at bubble centre

Δσ poroelastic

-1149 psi

Δσ thermoelastic

-1282 psi

Δσ total

-2431 psi

σ_h new

6569 psi

T_ref

250 °F

ΔT

-50 °F

T absolute = T_ref + ΔT

200 °F

Net stress drop — depleted region biases child-well fractures inward (frac-hit risk).

Radial Δσ_h decay

Depletion field plots

ΔP, ΔT and the resulting Δσ_h versus measured depth and radial distance — driven directly by the current Phase 11 run inputs above.

Plot window

ΔP, ΔT, σ_h, α, ν, E, α_T and bubble radius R come from the current Phase 11 run above. The fields below only set the rendering window.

Peak MD (ft)

Axial half-extent (MD) (ft)

Plot start MD (ft)

Plot end MD (ft)

Plot max radius (ft)

Compare runs

Snapshot the current Phase 11 run to overlay its Δσ_h curves on the axial & radial charts below. Toggle visibility per run; curves are recomputed against the active plot window.

Snapshot label

No saved runs yet.

ΔP, ΔT & Δσ_h vs measured depth

Click anywhere on the chart to inspect ΔP, ΔT and the predicted Δσ_h at that depth.

Mark first Δσ_h = 0 (axial)

ΔP, ΔT & Δσ_h vs radial distance from wellbore

Mark first Δσ_h = 0Show all Δσ_h = 0Bracket detailsMono ε (ft)

Tooltip units

Unit check:length 1 ft = 1.0000e+0 ft100 ft → 100.000 ft100 ft → 100.000 ft✓ length round-trippressure 1 psi = 1.0000e+0 psi100 psi → 100.000 psi100 psi → 100.000 psi✓ pressure round-trip

Radial grid:61 samplesspan 1000.0 ftΔr min 16.00 ftavg 16.67 ftmax 17.00 ft⚠ non-uniform

Radial heatmap

σ_h_new and Δσ_h on a square map around the parent well, using the current run's bubble radius R and Phase 11 influence model.

Radial heatmap — σ_h_new & Δσ_h around depleted parent-well bubble

Plot half-extent (ft)

Grid resolution (cells/side)

Mask outside radius

Off

Mask radius (ft)

σ_h_new (psi)

6.6k9.0k psi

mid 7.8k psi

Δσ_h (psi, signed)

-2.4k2.4k psi

mid 0 psi

Child-well position picker

Click anywhere on either heatmap to drop a child-well marker. Frac-hit metrics below update for the picked location.

Child x (ft)

Child y (ft)

Distance from parent

— pick a point —

Radial line profile through bubble centre

Sampled along the highlighted ray on each heatmap, from r = 0 outwards.

Profile angle (0–360°, 0 = +x / east, CCW)0°E (+x)

+x · 0°+y · 90°−x · 180°−y · 270°+x · 360°

Follow heatmap hover

Second ray B (0–360°)90°N (+y)

Samples

Centre marker is the parent well; dashed circle shows the bubble radius R from the current run. Cool blue = lower σ_h (depletion); warm red on Δσ_h = stress drop. A child well drilled into the cool zone is biased toward fracturing back into the depleted region (frac-hit risk).

Multi-parent depletion at child-tip

Add multiple depleted parent wells (x, y, R, ΔP, ΔT) and inspect the linearly superposed Δσ_h at the current child-fracture tip.

Parent wells & combined depletion at child-tip

Each parent contributes a Δσ_h bubble using the shared run's rock / thermal context (α = 0.8, ν = 0.22, E = 4.0×10⁶ psi, α_T = 5.0e-6 /°F). Per-well ΔP and ΔT drive the local poro + thermo stress drop; influence decays radially beyond R. Linear superposition assumes elastic medium.

Sign convention

Sign convention: negative ΔP (pore-pressure depletion) and negative ΔT (rock cooling) BOTH reduce σ_h. Positive values raise σ_h.

Child-fracture tip

x_tip (ft)

y_tip (ft)

Parent wells (2)

x (ft)

y (ft)

R (ft)

ΔP (psi)

ΔT (°F)

x (ft)

y (ft)

R (ft)

ΔP (psi)

ΔT (°F)

Plan-view map

Combined radial Δσ_h from all sources

Linear superposition along a ray from the child tip.

Direction (° from +x)

Max distance (ft)

Combined Δσ_h at tip = -2915 psi

Poro: -1350 psi · Thermo: -1565 psi

σ_h_new at tip = 6085 psi (~32.4% of σ_h_initial)

Per-well contribution at tip

Well	r (ft)	w(r/R)	Δσ poro	Δσ thermo	Δσ total
Parent A	300	0.500	-574	-641	-1215
Parent B	292	0.901	-776	-924	-1699