High density perforating gun system producing reduced debris

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.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The invention relates generally to the design of perforating tools for use in creating perforations in wellbores to improve the flow of fluids from the wellbore. [0003] 2. Description of the Related Art [0004] Perforation guns are used within wellbore holes to increase the permeability of the formation surrounding the wellbore. In general, perforation guns producing greater numbers of perforations are considered to be more effective than those producing fewer perforations. It is therefore often desired to maximize the number of penetrating jets within a segment of the wellbore. This may be difficult, however, because there are limitations relating to placement of the charges used for perforation. Standard shaped charges have an outer housing formed of metal or another material that encloses the high explosive charge. The shaped charge holder has openings that have typically circular perimeters. When packing the char...

AI Technical Summary

Benefits of technology

[0010] During the detonation, the constituent components of the module, including in some embodiments the high explosive, the liner, and the outer cover, are largely destroyed. As a result, the amount of debris resulting from the detonation is reduced or eliminated, as compared with the amount of debris produced by many conventional perforation devices.

Problems solved by technology

This may be difficult, however, because there are limitations relating to placement of the charges used for perforation.

When packing the charges in an adjoining manner in the charge tube, interstitial spaces are unavoidably left between the neighboring charges as a result their shape.

This packing results in “dead spaces,” that is, areas from which no perforating product, i.e., no jets, is / are provided, between the charges, and limits the density with which the charges can be packed.

This debris is undesirable, both because it must be removed by wireline or by other means in a secondary operation, and because it may clog the perforations that are formed by the perforation operation, thereby making the perforations less effective and sometimes necessitating repeat perforation operations.

The Chawla et al. invention thus suffers from problems relating to both “dead space” and debris creation.

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