Assessment of Chemical Effects on Wellbore Stability in Transition Shale Formation

Figure 20

Damage zone around the wellbore (a) 0.01 h, (b) 1 h, and (c) 100 h after drilling for strength degradation of 0%; (d–f) for strength degradation of 25%; and (g–i) strength degradation of 35%.

(a)

(b)

(c)

(d)

(e)

(f)

(g)

(h)

(i)