High density perforating gun system producing reduced debris

• US 20070240599A1
• Filed: 04/17/2006
• Published: 10/18/2007
• Est. Priority Date: 04/17/2006
• Status: Abandoned Application

• Current Assignee: Owen Oil Tools LP (Core Laboratories NV)
• Original Assignee: Owen Oil Tools LP (Core Laboratories NV)
• Inventors: Pratt, Dan, Chawla, Manmohan
• Application Number:
  US11/405,148
• Publication Number:
  US 20070240599A1
• 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
• CPC Class Codes: F42D 3/04 for rock blasting

Abstract

A perforating system has a perforating module comprising a unitary body of explosive. The explosive is contained within a non-explosive casing, or liner, having formed indentations and a cover thereover. The indentations, which will transform into explosively formed penetrators (EFP'"'"'s) upon detonation, have a perimeter shape that allows for improved packing density, e.g., a hexagonal perimeter, which results in relatively little “dead space” wherein no perforating penetrators are generated. In operation, the module provides a relatively dense shot pattern and substantially reduced amount of post-detonation debris that could clog the perforations and/or require remedial clean-up or repeat perforation.

Claims

1. An apparatus for perforating a subterranean formation comprising:

a perforation module conveyable into a wellbore drilled into the subterranean formation, the module including at least;

(a) a body of explosive material;

(b) a detonator for detonating the body of explosive material; and

(c) a liner surrounding at least a portion of the explosive material, the liner forming a plurality of perforating elements when the body of explosive material is detonated.

3. The apparatus of claim 1, wherein the liner circumferentially surrounds the body of explosive material.

4. The apparatus of claim 1, wherein the detonator comprises a layer of primasheet.

5. The apparatus of claim 1 further comprising a support member within the body of explosive material that connects with a conveyance string.

6. The apparatus of claim 1, wherein the liner is formed of tantalum.

2. The apparatus of claim 2, wherein the liner forms perforating elements that travel in a direction substantially perpendicular to a longitudinal axis of a wellbore.

7. An apparatus for use in perforating a subterranean formation, comprising:

a perforation module comprising

a body of high explosive material; and

a liner surrounding the body of high explosive material, the liner presenting a radially outer surface having a plurality of indentations formed therein to be transformed into directional penetrators upon detonation of the body of high explosive material.

8. The apparatus of claim 7, wherein the perforation module further comprises a substantially cylindrical cover member that radially surrounds the non-explosive liner to provide a standoff for the directional penetrators transformed from the indentations.

9. The apparatus of claim 7, wherein the indentations have perimeters whose shape enables closer packing of the indentations than would be possible if the indentations had circular perimeters.

10. The apparatus of claim 9, wherein each indentation has a perimeter that is one of:

(i) triangular;

(ii) square;

(iii) pentagonal;

(iv) hexagonal; and

(v) octagonal.

11. The apparatus of claim 9, wherein the indentations are arranged in a pattern over the outer radial surface such that each indentation is linearly contiguous with at least one other indentation.

12. A method of perforating a subterranean formation comprising:

perforating a formation intersected by a wellbore with a plurality of penetrators formed from one liner.

13. The method of claim 12 further comprising detonating a body of high explosive in a wellbore to form the penetrators.

14. The method of claim 13 further comprising at least partially surrounding the body of high explosive with the one liner.

15. The method of claim 12 further comprising forming a plurality of indentations on the one liner.

16. The method of claim 12 further comprising directing the penetrators into the formation along a direction substantially normal to a longitudinal axis of the wellbore.

17. The method of claim 12 further comprising forming the penetrators to penetrate at least a casing positioned in the wellbore.