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Unformatted text preview: ation Pressure and Matrix Stress
3. Matrix stress gradient, S =P+σ
= (1.000 − 0.478 )
psi / ft σ / D = 0.522 Fracture Gradients psi/ft 1.11- 7 Formation Pressure and Matrix Stress
4. Matrix stress at 14,000 ft
= 0.522 psi/ft * 14,000 ft σ = 7,308 psi
Fracture Gradients 1.11- 8 Fracture Gradient Determination
In order to avoid lost circulation while
drilling it is important to know the variation
of fracture gradient with depth.
Leak-off tests represent an experimental
approach to fracture gradient
determination. Below are listed and
discussed three approaches to calculating
the fracture gradient.
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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