Fracture growth calculator

Not calibrated

Enter an injection and see how big the fracture grows and when it reaches each sensor — once with no water lost into the rock, once with leak-off.

Injection rate (gal/min)

Constant rate

Injection time (min)

Rock stiffness E (Mpsi)

Granite ≈ 5.8–8.7

Poisson's ratio

0–0.49

Fluid viscosity (cP)

Water = 1

Leak-off C_L (ft/√min)

0 = no water lost

Sensor distances (ft)

Comma-separated

Rock stiffness is limited to 200 GPa (≈29 Mpsi) — above that this radial model is outside any rock it was built for.

What this model assumes

Penny-shaped fracture growing from one point, viscosity-dominated (Savitski & Detournay 2002); rock toughness ignored.
Constant injection rate, Newtonian fluid, uniform rock — no layers, stress barriers or natural fractures.
Leak-off uses Carter's 1-D law on both faces: loss rate = 2·C_L·area/√(time since that area opened).
Defaults are textbook values for granite and water, not fitted to any job.

In blind checks against real field data this model has predicted fractures larger than measured, so treat results as an upper-end estimate. More free tools