Analysis of Anisotropic Strength and Wellbore Unstable Zone in Shale Formation Relating to Water Content

Figure 8

Collapse mechanism in a thick-walled cylinder test performed with well oriented parallel to bedding.

(a) Laboratory tests of wellbore instability in shale formations conducted by Økland and Cook [31]

(b) Laboratory tests of wellbore instability in shale formations conducted by Bautmans et al. [32]