Patent Application
20160123709
The present disclosure relates generally to a liner for a perforator to be located in a wellbore and, more particularly (although not necessarily exclusively), to a liner having a fold around an opening in an apex portion of the liner.
Hydrocarbons can be produced from wellbores drilled from the surface through a variety of producing and non-producing formations. A wellbore may be substantially vertical or may be offset. A variety of servicing operations can be performed on a wellbore after it has been initially drilled. For example, a lateral junction can be set in the wellbore at the intersection of two lateral wellbores or at the intersection of a lateral wellbore with the main wellbore. A casing string can be set and cemented in the wellbore. A liner can be hung in the casing string. The casing string can be perforated by firing a perforation gun or perforation tool.
Perforation tools can include explosive charges that are detonated to fire for perforating a casing and create perforations or tunnels into a subterranean formation that is proximate to the wellbore. Creating a large perforation in casing is desirable.
Certain aspects and features relate to a shaped-charge liner for a well perforator. The liner may be parabolic shaped and it can have a radius around an opening in the liner. The radius can be folded into the liner and can be supported by explosive material. The folded and supported liner portions can cause a reverse detonation wave that can spread liner material until a hollow or donut-shaped jet is created, which can create a larger hole through casing to provide more flow area for hydrocarbons to enter a wellbore.
Using a shaped-charge assembly with a shaped-charge liner according to certain aspects to perforate a casing may reduce the velocity by which hydrocarbons enter the wellbore and it may help control sanding problems when hydrocarbons are produced from unconsolidated formations.
These illustrative aspects and examples are given to introduce the reader to the general subject matter discussed here and are not intended to limit the scope of the disclosed concepts. The following sections describe various additional features and examples with reference to the drawings in which like numerals indicate like elements, and directional descriptions are used to describe the illustrative aspects but, like the illustrative aspects, should not be used to limit the present disclosure.
The servicing rig 16 may be a drilling rig, a completion rig, a workover rig, a servicing rig, or other mast structure, or a combination. The servicing rig 16 can support a workstring 18 in the wellbore 12, but in other examples a different structure may support the workstring 18. For example, an injector head of a coiled tubing rigup can support the workstring 18. In some aspects, the servicing rig 16 may include a derrick with a rig floor through which the workstring 18 extends downward from the servicing rig 16 into the wellbore 12. The servicing rig 16 may be supported by piers extending downwards to a seabed in some implementations. Alternatively, the servicing rig 16 may be supported by columns sitting on hulls or pontoons (or both) that are ballasted below the water surface, which may be referred to as a semi-submersible platform or rig. In an off-shore location, a casing may extend from the servicing rig 16 to exclude sea water and contain drilling fluid returns. Other mechanical mechanisms that are not shown may control the run-in and withdrawal of the workstring 18 in the wellbore 12. Examples of these other mechanical mechanisms include a draw works coupled to a hoisting apparatus, a slickline unit or a wireline unit including a winching apparatus, another servicing vehicle, and a coiled tubing unit.
The workstring 18 may include a conveyance 30, a perforation tool 32, and other tools or subassemblies (not shown) located above or below the perforation tool 32. The conveyance 30 may include any of a slickline, a coiled tubing, a string of jointed pipes, a wireline, and other conveyances for the perforation tool 32. The perforation tool 32 can include one or more explosive charges that may be triggered to explode for perforating a casing (if present), perforating a wall of the wellbore 12, and forming perforations or tunnels out into the formation 14. The perforating may promote recovering hydrocarbons from the formation 14 for production at the surface, storing hydrocarbons flowed into the formation 14, or disposing of carbon dioxide in the formation 14.
The shaped-charge assemblies 50 may be disposed in a first plane perpendicular to the axis of the tool body, and additional planes or rows of additional shaped-charge assemblies 50 may be positioned above and below the first plane. In one example, four shaped-charge assemblies 50 may be located in the same plane perpendicular to the axis of the tool body, and 90 degrees apart. In another example, three shaped-charge assemblies 50 may be located in the same plane perpendicular to the axis of the tool body, and 120 degrees apart. In other examples, however, more shaped-charge assemblies may be located in the same plane perpendicular to the axis of the tool body. The direction of the shaped-charge assemblies 50 may be offset by about 45 degrees between the first plane and a second plane, to promote more densely arranging the shaped-charge assemblies 50 within the tool body. The direction of the shaped-charge assemblies 50 may be offset by about 60 degrees between the first plane and a second plane, to promote more densely arranging the shaped-charge assemblies 50 within the tool body.
A frame structure (not shown) may be included in the tool body that retains the shaped-charge assemblies 50 in planes, oriented in a preferred direction, and with appropriate angular relationships between rows. In some aspects, a detonator cord couples to each of the shaped-charge assemblies 50 to detonate the shaped-charge assemblies 50. When the perforation tool 32 includes multiple planes or rows of shaped-charge assemblies 50, the detonator cord may be disposed on the center axis of the tool body. The detonator cord may couple to a detonator apparatus that is triggered by an electrical signal or a mechanical impulse, or by another trigger signal. When the detonator activates, a detonation can propagate through the detonation cord to each of the shaped-charge assemblies 50 to detonate each of the shaped-charge assemblies 50 substantially at the same time.
The liner 54 can include an apex portion 55 and a skirt portion 57. The skirt portion 57 may be coupled to the housing 52. The apex portion 55 can include a radius defining an opening 58 in the liner 54. The size of the opening 58 may vary, for example from 0.0001 inches to one inch. An apex portion of the liner 54 around the opening 58 defines a fold 60. For example, part of the apex portion can be constructed, such as by being turned up, to define the fold 60. In some aspects, the fold 60 is curved.
The explosive material 56 supports the liner 54, including the fold 60. The explosive material 56 supports the liner 54 by abutting one side of the liner 54. In some aspects, the explosive material 56 supports the fold 60 by being located up to the opening 58 in the liner 54. The liner 54 may be made from any suitable material. Examples of suitable materials from which the liner 54 can be made include brass, copper, steel, aluminum, zinc, lead, and uranium (or combinations of these and other suitable materials).
In other aspects, the fold 60 does not define a curve. For example, the fold 60 may define a 90 degree angle between the opening side portion 64 and the housing side portion 66, in which a middle portion is defined between the opening side portion 64 and the housing side portion 66. The middle portion can be on a different plane than the opening side portion 64 and the housing side portion 66.
The foregoing description of certain aspects, including illustrated aspects, has been presented only for the purpose of illustration and description and is not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. Numerous modifications, adaptations, and uses thereof will be apparent to those skilled in the art without departing from the scope of the disclosure.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2013/051207 | 7/19/2013 | WO | 00 |
