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Unformatted text preview: ture Gradients 1.11- 9 Fracture Gradient Determination where Fracture Gradients Fmin Fmax 1. Hubbert & Willis: 1 2P = 1 + 3
D 1 P
= 1 + 2 D F = fracture gradient, psi/ft
= pore pressure gradient, psi/ft
1.11- 10 Fracture Gradient Determination
2. Matthews & Kelly: K iσ
where Ki = matrix stress coefficient σ = vertical matrix stress, psi
Fracture Gradients 1.11- 11 Fracture Gradient Determination
3. Ben Eaton: P S −P γ +
D 1− γ D where S = overburden stress, psi γ = Poisson’s ratio
Fracture Gradients 1.11- 12 Example
A Texas Gulf Coast well has a pore pressure
gradient of 0.735 psi/ft. Well depth = 11,000 ft.
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This note was uploaded on 09/18/2012 for the course ENGINEERIN 102 taught by Professor Clyde during the Spring '12 term at A.T. Still University.
- Spring '12