As the pore pressure increases so does the fracture

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

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 Poisson’s ratio, 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 + F= * D 1− γ D σ Ki P F= + D D Matthews and Kelly: Fracture Gradients 1.11- 30 Fracture Gradients 1.11- 31 Experimental Determination of Fracture Gradient 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...
View Full Document

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.

Ask a homework question - tutors are online