초록 ▼

An apparatus for opening perforations in a casing string. The casing string has a special casing section defining a plurality of holes therethrough. Rupturable ceramic discs or inserts are disposed in said holes and retained therein. The ceramic discs or inserts are adapted to withstand the fluid di

An apparatus for opening perforations in a casing string. The casing string has a special casing section defining a plurality of holes therethrough. Rupturable ceramic discs or inserts are disposed in said holes and retained therein. The ceramic discs or inserts are adapted to withstand the fluid differential pressures normally present in the wellbore but are rupturable in response to impact by a mild explosive charge. The explosive charge is provided by detonating a length of det-cord disposed in the casing string adjacent to the holes in the special casing section. A method of perforating using this apparatus is also disclosed.

대표청구항 ▼

[ What is claimed is:] [1.] A method of opening perforations in a 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;cementing said casing string in said wellbore without cemen

[ What is claimed is:] [1.] A method of opening perforations in a 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;cementing said casing string in said wellbore without cement being placed adjacent to said plugged holes;positioning a separate explosive charge in said casing string adjacent to said holes; anddetonating said explosive charge in said casing string adjacent to said holes for rupturing and thereby unplugging said holes. [2.] An apparatus for use in a wellbore comprising:a casing string positionable in said wellbore and adapted for being cemented therein, said casing string comprising 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 an explosive force;explosive means for generating said explosive force, said explosive means being separate from said casing string and positionable therein after said casing string is positioned in said wellbore; andretaining means for retaining said plug means in said holes prior to rupturing, said retaining means comprising a retainer ring disposed in each of said holes for preventing radially outward movement of said plug means.