Composite liners for perforators

Abstract

A shaped charge having a charge case and liner with an outer layer and an inner layer. The liner is a generally hollow frustoconically shaped member with an open end and a closed end, where the closed end of the liner inserts into an opening in the charge case. An explosive is provided between the liner and the charge case. The inner layer of the liner includes a higher density material than material used for forming the outer layer.

Description

BACKGROUND[0001]1. Field of Invention[0002]The invention relates generally to a method and system for perforating a wellbore. More specifically, the present invention relates to a liner for a shaped charge having inner and outer layers.[0003]2. Description of Prior Art[0004]Perforating systems are used for the purpose, among others, of making hydraulic communication passages, called perforations, in wellbores drilled through earth formations so that predetermined zones of the earth formations can be hydraulically connected to the wellbore. Perforations are needed because wellbores are typically lined with a string of casing and cement is generally pumped into the annular space between the wellbore wall and the casing. Reasons for cementing the casing against the wellbore wall includes retaining the casing in the wellbore and hydraulically isolating various earth formations penetrated by the wellbore. Sometimes an inner casing string is included that is circumscribed by the casing. W...

AI Technical Summary

Benefits of technology

[0006]Disclosed herein is an example of a perforating gun that includes a gun body and a shaped charge in the gun body. In this example the shaped charge is made up of a charge case and a liner in the charge case, where the liner has an inner layer and an outer layer made of a material with a lower density and that is more ductile than a material in the inner layer. In one example, the inner layer includes tungsten and the outer layer includes aluminum. In one embodiment, the liner is frustoconically shaped. The inner and outer layers may be formed by cold pressing metal particles. A plurality of shaped charges may be included with the perforating gun, where a detonation cord couples with each of the shaped charges. In one example, further provided with the perforating gun is explosive in the charge case underneath the liner, wherein detonating the explosive inverts and discharges the liner from the charge case to form an elongate metal jet having a generally curved outer lateral periphery, wherein the jet perforates the gun body and deposits a slug on an inner surface of the gun body that blocks a flow of debris from inside of the gun body. In one example embodiment, the slug is formed substantially from material making up the inner layer.

[0007]Also provided herein is a perforating system, where the system includes an annular perforating gun selectively inserted within a wellbore and a shaped charge in the perforating gun. In this example the shaped charge is made up of a charge case having an opening an...

Problems solved by technology

Without the perforations oil/gas from the formation surrounding the wellbore c...

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