A method for enhancing wellbore integrity and/or for sealing a wellbore by sealing formation or micro-annulus fractures in a wellbore. Such sealing can be at least partially accomplished by the use of timed expansion of an expandable sealant material that is placed a wellbore. The expansion of the expandable sealant material causes the cement surface or formation surface to be compressed, thereby creating a tight seal and/or eliminating annulus cracking, fracture, and/or gas channels in the wellbore. A degradable polymer can be used when restoration of the wellbore formation is desired.