Apparatus and method for removing a frangible rupture disc or other frangible device from a wellbore casing

A method of opening perforations in a well casing without damaging areas outside the well casing comprising the steps of:

• providing a casing string in a wellbore wherein said casing string has a section defining a plurality of rupturably plugged holes therein;
• positioning a wave generating device in said casing string adjacent to said holes;
• and
• generating a pressure wave with said wave generating device wherein said pressure wave impinges on said plugged holes and ruptures and unplugs said holes without damaging areas outside said casing string.

An apparatus for use in a wellbore comprising:

• a casing string positionable in the wellbore and having a casing section defining a plurality of holes through a wall thereof;
• rupturable plug means disposed in each of said holes in said casing section for rupturing in response to impingement by an acoustic wave;
• and
• an acoustical horn for generating said acoustic wave, said acoustical horn being separate from said casing string and positionable therein after said casing string is positioned in the wellbore.

A method of opening perforations in a well casing without damaging areas outside the well casing comprising the steps of:

• providing a casing string in a wellbore wherein said casing string has a section defining a plurality of rupturably plugged holes therein;
• positioning an acoustical horn in said casing string adjacent to said holes;
• and
• generating an acoustic wave with said acoustical horn such that said acoustic wave impinges on said holes and ruptures and unplugs said holes.