Granted Patent B2

US 12,723,480 · App. 19/053,174 · Granted Sep 1, 2026

Inventor: James G. Rairigh (Houston, TX)

E21B29/02E21B23/0414

Abstract

Claims (37)

1 . A downhole tool string configured for conveyance within a wellbore, wherein the downhole tool string comprises:

upper tools;

a lower tool comprising an explosive charge; and

a sub between the upper tools and the lower tool, wherein the sub is configured to attenuate a shock wave caused by the explosive charge when detonated to thereby reduce damage to the upper tools caused by the shock wave, and wherein the sub comprises an axial bore and a plurality of radial bores extending between the axial bore and a space external to the sub.

2 . The downhole tool string according to claim 1 , wherein the sub further comprises an upper connector connecting the sub to the upper tools and a lower connector connecting the sub to the lower tool.

3 . The downhole tool string according to claim 1 , wherein the radial bores are distributed axially and circumferentially along the sub.

4 . The downhole tool string according to claim 1 , wherein the radial bores are distributed in a helical pattern along the sub.

5 . The downhole tool string according to claim 1 , wherein the sub comprises a retrievable tubing gun carrier.

6 . The downhole tool string according to claim 1 , wherein the sub comprises a spent perforating gun tube of a previously used perforating gun, and wherein the plurality of radial bores comprise perforations formed by shaped charges of the previously used perforating gun.

7 . The downhole tool string according to claim 1 , wherein the upper tools comprise at least one of a centralizer and an electronic downhole tool.

8 . The downhole tool string according to claim 1 , wherein the lower tool comprises at least one of:

a downhole cutting tool for cutting a wall of a downhole tubular installed within the wellbore when the explosive charge is detonated;

a downhole perforating tool for perforating the wall of the downhole tubular installed within the wellbore when the explosive charge is detonated; and

a downhole expansion tool for expanding, without puncturing, the wall of the downhole tubular installed within the wellbore when the explosive charge is detonated.

9 . A downhole system comprising:

a tubular string configured for conveyance within a wellbore;

an upper downhole tool connected to the tubular string;

a lower downhole tool connected to the tubular string below the upper downhole tool, wherein the lower downhole tool comprises an explosive charge, and wherein the lower downhole tool comprises a downhole expansion tool for expanding, without puncturing, a wall of a downhole tubular installed within the wellbore when the explosive charge is detonated; and

a sub between the upper downhole tool and the lower downhole tool, wherein the sub is configured to attenuate a shock wave caused by the explosive charge when detonated to thereby reduce damage to the upper downhole tool caused by the shock wave, and wherein the sub comprises an axial bore and a plurality of radial bores extending between the axial bore and a space external to the sub.

10 . The downhole system according to claim 9 , wherein the tubular string comprises one of a coiled tubing and a plurality of tubular joints connected together.

11 . The downhole system according to claim 9 , further comprising a downhole centralizer connected to the tubular string, wherein the downhole centralizer is operable to centralize at least one of the upper downhole tool and the lower downhole tool within the wellbore.

12 . The downhole system according to claim 9 , wherein the upper downhole tool comprises at least one of a centralizer and an electronic downhole tool.

13 . The downhole system according to claim 9 , wherein the radial bores are distributed axially and circumferentially along the sub.

14 . A method of expanding a wall of a downhole tubular installed within a wellbore, wherein the method comprises:

connecting an upper downhole tool as part of a tool string;

connecting a sub as part of the tool string below the upper downhole tool, wherein the sub comprises an axial bore and a plurality of radial bores extending between the axial bore and a space external to the sub;

connecting a lower downhole tool as part of the tool string below the sub, wherein the lower downhole tool comprises an explosive charge, and wherein the lower downhole tool comprises a downhole expansion tool for expanding, without puncturing, the wall of the downhole tubular installed within the wellbore when the explosive charge is detonated;

conveying the tool string within the wellbore until the lower downhole tool is at a predetermined position within the downhole tubular; and

operating the lower downhole tool to detonate the explosive charge to expand the wall of the downhole tubular, wherein the sub attenuates a shock wave caused by the explosive charge when detonated to thereby reduce damage to the upper downhole tool caused by the shock wave.

15 . The method according to claim 14 , further comprising connecting a downhole centralizer above the sub.

16 . The method according to claim 14 , wherein conveying the tool string within the wellbore comprises unwinding coiled tubing from a reel.

17 . The method according to claim 14 , wherein:

conveying the tool string within the wellbore comprises connecting a plurality of tubular joints end-to-end, one tubular joint at a time; and

the plurality of tubular joints comprises at least one of a plurality of pipe joints, a plurality of drill pipe joints, and a plurality of casing joints.

18 . The method according to claim 14 , wherein the radial bores are distributed axially and circumferentially along the sub.

19 . The method according to claim 18 , wherein the radial bores are distributed in a helical pattern along the sub.

20 . The method according to claim 14 , wherein the sub comprises a retrievable tubing gun carrier.

Continuity (8)

References Cited (80)