Unformatted text preview: the above equations, Hubbert & Willis
apparently consider only the variation in
pore pressure gradient. Matthews &
Kelly also consider the changes in rock
matrix stress coefficient, and in the
matrix stress ( Ki and σ i ).
Fracture Gradients 1.11- 28 Summary of Results
4 Ben Eaton considers
variation in pore pressure gradient,
overburden stress and
and is probably the most accurate of
the three methods. The last two
methods are actually quite similar, and
usually yield similar results.
Fracture Gradients 1.11- 29 Similarities
Ben Eaton: P S −P γ +
D 1− γ D σ Ki
Matthews and Kelly:
Fracture Gradients 1.11- 30 Fracture Gradients 1.11- 31 Experimental Determination of
The leak-off test
4 Run and cement casing
4 Drill out ~ 10 ft
below the casing seat
4 Close the BOPs
4 Pump slowly and
monitor the pressure
Fracture Gradients 1.11- 32 Fracture Gradients 1.11- 33 Fracture Gradients 1.11- 34 Fracture Gradients 1.11- 35 Fracture Gradients 1.11- 36...
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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