Wellbore Genius

Phase-field DEM — laminated shale

v6 Tier-2 primer

AT-1 / AT-2 damage + cohesive Mode I/II traction-separation coupled to a He-Hutchinson kink-vs-pierce classifier. Surfaces fracture-tip behaviour at the next bedding interface and the steady-state σ_h degradation that feeds back into the Geertsma poroelastic engine.

Crack-tip state & next interface

Tip depth [ft]

Propagation direction

K_I [psi·√in]

K_II [psi·√in]

Poisson ν [-]

Active lamina E [psi]

In laminaL1

G_tip [J/m²]33.42

Gc_matrix / Gc_bed4.44

Verdict

Kink into bed

MTS kink angle [°]-23.5

Bedding interface (cohesive)

Depth [ft]

Gc_interface [J/m²]

Peak normal [psi]

Peak shear [psi]

δ_c [ft]

Opening δ_n [ft]

Sliding δ_s [ft]

T_N(δ_n) [psi]720.0

T_S(δ_s) [psi]720.0

W_coh [psi·ft]5.460

Phase-field damage & σ_h feedback

Variant

ℓ regularization [ft]

History H [J/m³]

Residual stiffness k

d (damage)

0.998

g(d) stiffness

0.000

Base σ_h [psi]

7200

σ_h reduction [psi]

7200

Lamina stack

ID	Top [ft]	Bottom [ft]	Gc [J/m²]	E [Mpsi]	σ_h [psi]	Active
L1						tip here
L2						—
L3						—