The present invention relates to methods and compositions for degrading
filter cakes in subterranean formations, and more specifically, to
improved methods and compositions for degrading filter cakes that
comprise acid-soluble portions and polymeric portions. In one embodiment,
the present invention provides a method of degrading a filter cake
comprising an acid-soluble portion and a polymeric portion in a
subterranean formation comprising the steps of: introducing a filter cake
degradation composition comprising a delayed-release acid component and a
delayed-release oxidizer component to a well bore penetrating the
subterranean formation; allowing the delayed-release acid component to
release an acid derivative and the delayed-release oxidizer component to
release an acid-consuming component; allowing the acid-consuming
component to interact with the acid derivative to delay a reaction
between at least a portion of the acid derivative and at least a portion
of the acid-soluble portion of the filter cake and to produce hydrogen
peroxide; allowing the acid derivative to degrade at least a portion of
the acid-soluble portion of the filter cake after a delay period; and
allowing the hydrogen peroxide to degrade at least a portion of the
polymeric portion of the filter cake.