�?�?t ρ l k + �?�?x i ρ l k v l = �?�?x j μ + μ t σ k �?k �?x j + G k �?ρ l ε �?Y M The pure fractures encountered in the particular drilling procedure are certainly not parallel fractures with a uniform width along the length in the fracture. Through the loss system, in the event the fluid stress while in the frac