One trip system for circulating, perforating and treating

1. A well completion apparatus comprising:

(a) a pipe string having a continuous fluid flow channel along a length thereof;

(b) an earth boring bit secured to a distal end of said pipe string;

(c) perforation means comprising gun means and a fluid flow mandrel secured at opposite distal ends between Y-adapter means at selected locations along said pipe string length for perforating a wellbore casing, said fluid flow mandrel for channeling fluid flow past said gun means toward said boring bit, each of said Y-adapter means having a threaded assembly with an adjacent pipe section and a threaded assembly with respective distal ends of said fluid flow mandrel, each of said Y-adapter means having collar means to encompass respective distal ends of said gun means and secure a substantially parallel axis alignment between said gun means and said flow mandrel, said gun means having a plurality of shaped charges distributed along a length thereof;

(d) a pair of locking rings threaded upon respective ends of said gun means and turned against opposite faces of said collar means to secure a predetermined longitudinal position of said gun means between said collar means; and,

(e) means for detonating said shaped charges by a predetermined detonation pressure.

2. A well completion apparatus as described by claim 1 wherein said pipe string further includes pipe bore scraping means.

3. A well completion apparatus as described by claim 1 wherein a leg of said Y-adapter comprises an internally threaded pipe connecting box and one arm of said Y-adapter comprises an internally threaded mandrel connecting box, a fluid flow channel within said Y-adapter links said pipe connecting box with said mandrel connecting box.

4. A well completion apparatus as described by claim 1 wherein pins secured to said gun means project into apertures in said collar means to prevent rotational movement of said gun means about an axis of said gun.

5. A well completion apparatus as described by claim 1 wherein said means for detonating comprises a percussion initiator and restrained piston means for explosively activating said percussion initiator.

6. A well completion apparatus as described by claim 5 wherein said piston means comprises shear pin means for restraining said piston means from activating said percussion initiator at a wellbore fluid pressure that is less than a predetermined shear pin failure pressure.

7. A method of assembling a well completion string comprising the steps of:

providing an axially elongated perforation gun having threaded distal end pins and shaped perforation charges distributed along the length thereof;

providing an axially elongated fluid flow mandrel having threaded distal end pins;

providing a pair of Y-adapters having threaded pipe boxes and threaded mandrel boxes, said Y-adapters also having collars bored to receive the distal ends of said perforating gun;

turning the pipe boxes of said pair of Y-adapters onto pin ends respective to adjacent pipe sections;

turning the threaded mandrel boxes onto said mandrel end pins;

inserting said perforating gun ends into said pair of Y-adapter collar bores to align said gun axis in parallel with said mandrel axis; and,

securing a longitudinal position of said perforating gun between said Y-adapter collars by turning threaded locking rings on said gun end threads against said Y-adapter collars.

8. A method as described by claim 7 wherein said perforating gun is secured from rotating about the axis of said gun by securing pins through said Y-adapter collars into said gun ends.

9. A method as described by claim 7 wherein said shaped perforating charges are detonated by wellbore pressure.