Devices and Methods for Perforating A Wellbore

• US 20090255433A1
• Filed: 03/18/2009
• Published: 10/15/2009
• Est. Priority Date: 03/19/2008
• Status: Active Grant

• Current Assignee: Owen Oil Tools LP (Core Laboratories NV)
• Original Assignee: Owen Oil Tools LP (Core Laboratories NV)
• Inventors: Noe, Paul, Wang, Zeping, Pratt, Dan
• Granted Patent: US 8,459,186 B2
• Time in Patent Office: Days
• US Class Current: 102/307
• CPC Class Codes: E21B 43/117 Shaped-charge perforators E21B43/118 takes precedence
• CPC Class Codes: F42B 1/028 characterised by the form of the liner

Abstract

An apparatus and method for perforating a subterranean formation is disclosed. The apparatus includes a tubular carrier; a charge tube disposed in the tubular carrier; and at least one shaped charge mounted in the charge tube which includes a casing, an explosive material and a liner enclosing the explosive material within the casing. An apex portion of the liner has a cross-sectional thickness greater than a cross-sectional thickness of any other portion of the liner. The cross-sectional thickness of the apex portion may be at least fifty percent thicker than a cross-section of a portion adjacent the apex portion. A density of the apex portion may be greater than the density of any other portions of the liner.

Claims

1. An apparatus for perforating a subterranean formation, comprising:

a tubular carrier;

a charge tube disposed within the tubular carrier;

at least one shaped charge mounted in the charge tube, the shaped charge comprising;

a casing;

an explosive material within the casing; and

a liner enclosing the explosive material within the casing, the liner including an apex portion having a cross-sectional thickness greater than a cross-sectional thickness of any other portion of the liner.

2. The apparatus according to claim 1 wherein the cross-sectional thickness of the apex portion is at least fifty percent thicker than a cross-section of a liner portion adjacent the apex portion.

3. The apparatus according to claim 1 wherein a material density of the apex portion is greater than the material density of any other portion of the liner.

4. The apparatus according to claim 2 wherein the liner has an axial length L, and wherein the liner includes a first region having the apex portion and a second region having a skirt portion, wherein the first region and the second region each make up substantially one-half of the axial length of the liner, and wherein the first region has more mass than the second region.

5. The apparatus according to claim 1, wherein the explosive material adjacent the liner is distributed to reduce a pressure generated in a region proximate the apex.

6. A method of perforating a subterranean formation, comprising:

conveying a shaped charge into a wellbore penetrating the formation, the shaped charged including a casing, an explosive material in the casing, and a liner enclosing the explosive material within the casing, the liner including an apex portion having a cross-sectional thickness greater than a cross-sectional thickness of any other portion of the liner; and

detonating the shaped charge.

7. The method according to claim 6 wherein the cross-sectional thickness of the apex portion is at least fifty percent thicker than a cross-section of a liner portion adjacent the apex portion.

8. The method according to claim 6 wherein a material density of the apex portion is greater than the material density of any other portion of the liner.

9. The method according to claim 7 wherein the liner has an axial length L, and wherein the liner includes a first region having the apex portion and a second region having a skirt portion, wherein the first region and the second region each make up substantially one-half of the axial length of the liner;

and wherein the first region has more mass than the second region.

10. The method according to claim 6, wherein the explosive material adjacent the liner is distributed to reduce a pressure generated in a region proximate the apex.

11. The method according to claim 6 further comprising conveying the shaped charge in the wellbore using one of:

(i) a coiled tubing, (ii) a drill pipe, (iii) a wireline, and (iv) a slick line.