Economical, tough, debris-free shaped charge device and perforating gun assembly employing same

Claim 2

In a gun assembly for perforating a conduit in a well penetrating subterranean formations and adapted to fire shaped charge devices in response to a firing means, the improvement comprising: a. a plurality of lineal, rodlike members in spaced relationship and adapted to be lowered into said conduit, b. a plurality of shaped charge devices disposed in spaced apart relationship along said plurality of rodlike members; each comprising a case containing a shaped charge, said cases being formed of a frangible plastic containing about 20-40 percent by weight of a macerated filler material, being sealed to resist invasion of well fluids, and being shaped to resist deformation under temperature and pressure of well environment and fluids to depths in excess of 6,000 feet, and c. flexible lineal detonation means connected with said cases at the rear thereof for firing said shaped charges therewithin and connected with said firing means for initiating detonation of said detonation means.

Claim 3

The gun assembly of claim 1 wherein said case has a thickness adjacent said detonation means in the range of 0.060 - 0.095 inch.

Claim 4

The gun assembly of claim 1 wherein said case has a generally spherical external configuration to better resist deformation under said temperature and pressure.

Claim 5

The gun assembly of claim 1 wherein each case comprises two parts, one part having a shaped charge emplaced therein and each part having a recess for receiving each of said plurality of rodlike members, and said parts are sealingly bonded together about said shaped charge and said rodlike members.

Claim 6

The gun assembly of claim 1 wherein said frangible plastic is selected from the group consisting of phenol-hexamethylenetetramine copolymer and phenol-formaldehyde copolymer.

Claim 7

The gun assembly of claim 1 wherein said macerated filler material in said frangible plastic is selected from the group consisting of finely particulated cellulose fiber and wood flour.

Claim 8

The gun assembly of claim 6 wherein about 30 percent by weight of the macerated cellulose material is employed in a frangible thermosetting plastic.

Claim 9

The gun assembly of claim 1 wherein said frangible plastic is phenol-hexamethylenetetramine copolymer and it contains about 30 percent by weight of wood flour.

Claim 10

A shaped charge device comprising: a. a case comprised of a frangible plastic material containing about 24-40 percent by weight of a macerated filler material, being sealable to resist invasion of well fluids and being of sufficient thickness and shape to resist deformation under temperature and pressure of well environment and fluids to depths in excess of 6,000 feet and having an internal cavity adapted to receive an explosive shaped charge, said case having a rear end wall with an outer surface portion thereof adapted for securing detonation means thereon and an inner surface portion adjacent thereto and defining a thickness of said rear end wall between said surface portions in the range of 0.060 -0.095 inch; b. booster explosive material loosely disposed in said case contiguous said inner surface portion for boosting the force of said detonation means; c. explosive shaped charge disposed in said case and extending toward the rearward end of said internal cavity with the rearward end being disposed adjacent said booster explosive material in said case, and having a frustoconical metal liner secured at its forward end, said shaped charge having been compressed sufficiently to obtain the desired density and to retain the shape of said shaped charge; and d. sealing means sealing said shaped charge and said booster explosive powder within said case.

Claim 11

A shaped charge device comprising: a. a case comprised of a frangible plastic material containing about 24-40 percent by weight of a macerated filler material, being sealable to resist invasion of well fluids and being of sufficient thickness and shape to resist deformation under temperature and pressure of well environment and fluids to depths in excess of 6,000 feet and having an internal cavity adapted to receive an explosive shaped charge, said case having a rear end wall with an outer surface portion thereof adapted for securing detonation means thereon and an inner surface portion adjacent thereto and defining a thickness of said rear end wall between said surface portions in the range of 0.060 -0.095 inch; b. booster explosive material loosely disposed in said case contiguous said inner surface portion for boosting the force of said detonation means; c. explosive shaped charge disposed in said case and extending toward the rearward end of said internal cavity with the rearward end being disposed adjacent said booster explosive material in said case, and having a frustoconical metal liner secured at its forward end, said shaped charge having been compressed sufficiently to obtain the desired density and to retain the shape of said shaped charge; and d. sealing means sealing said shaped charge and said booster explosive powder within said case.

Claim 12

The shaped charge device of claim 9 wherein said case has a generally spherical external configuration to better resist deformation under said temperature and pressure.

Claim 13

The shaped charge device of claim 9 wherein said frangible plastic containing said macerated filler material has a flexural strength of at least 10,000 pounds per square inch (p.s.i.), a compressive strength of at least 28,000 p.s.i. and a minimum impact strength of 1.1 foot pounds per inch notch, side, on Izod impact test apparatus in accordance with ASTM test D256.

Claim 14

The shaped charge device of claim 9 wherein said frangible plastic is selected from the group consisting of phenol-hexamethylenetetramine copolymer and phenol-formaldehyde copolymer and acrylonitrile-butadiene-styrene copolymer.

Claim 15

The shaped charge device of claim 9 wherein said macerated filler material in said frangible plastic is selected from the group consisting of finely particulated cellulose fiber and wood flour.

Claim 16

The shaped charge device of claim 13 wherein about 30 percent by weight of the macerated cellulose material is employed in a frangible thermosetting plastic.

Claim 17

The shaped charge device of claim 9 wherein said frangible plastic is phenol-hexamethylene-tetramine copolymer and it contains about 30 percent by weight of wood flour.

Claim 18

The shaped charge device of claim 9 wherein said frangible plastic is selected from the group consisting of thermosetting plastic and thermoplastic plastic and said macerated filler material is selected from the group consisting of wood flour, cotton flock, fine mica flakes, and finely particulated nylon.

Claim 19

The shaped charge device of claim 16 wherein about 30 percent by weight of said macerated filler material is employed in said frangible plastic.