MULTI-ELEMENT HYBRID PERFORATING APPARATUS
A perforating apparatus includes a carrier, explosive devices mounted to the carrier, energetic cells arranged among the explosive devices, and a sleeve to receive at least a portion of the carrier, where the sleeve is formed of an energetic material.
To complete a well for purposes of producing fluids (such as hydrocarbons or other fluids) from a reservoir, or injecting fluids into the reservoir, one or more zones in the well are perforated to allow for fluid communication between a wellbore and the reservoir. Perforation is accomplished by lowering a perforating gun to a target interval within the well. Activation of the perforating gun creates openings in any surrounding casing or liner and extends perforation tunnels into the surrounding subterranean formation.
SUMMARYIn general, according to some implementations, a perforating apparatus includes a carrier, explosive devices mounted to the carrier, energetic cells arranged among the explosive devices, and a sleeve to receive at least a portion of the carrier, where the sleeve is formed of an energetic material.
Other or alternative features will become apparent from the following description, from the drawings, and from the claims.
Some embodiments are described with respect to the following figures:
To form perforations in a well (perforations are formed in a surrounding formation as well as in any casing or liner that lines the well), a perforating apparatus can be deployed into the well. An example of a perforating apparatus is a perforating gun that carries explosive devices that when detonated produces explosive jets that extend the perforations into a surrounding formation (in any intermediate casing or liner). Such explosive devices are referred to as perforator charges, and in some cases, are referred to as shaped charges.
The explosive nature of creating perforation tunnels in the subterranean formation can create a crushed zone in the formation. A “crushed zone” refers to a damaged zone that surrounds a perforation tunnel, where the perforating action has altered the formation structure and its permeability. Also, the perforating action can cause debris to fill perforation tunnels. The crushed zone damage can result in reduced ability to perform production or injection.
In accordance with some embodiments, a perforating apparatus, such as a perforating gun, is provided that includes various components formed of an energetic material that are able to produce a relatively high energy wave (or waves), such as in the form of a relatively high pressure pulse or pressure pulses. The high energy wave can result in creation of fractures in the subterranean formation, enlargement of a perforation tunnel, and/or removal or reduction of crushed zone damage in the formation. The components formed of the energetic material is activated in response to detonation of the explosive devices (such as perforator charges) in the perforating apparatus.
In some implementations, the deployment of multiple components of an energetic material allows for creation of multiple energy waves (such as multiple pressure pulses). In some implementations, the multiple components formed of an energetic material can include some combination of the following: a charge formed of an energetic material provided in a section of a perforating apparatus that is connected (above or below) to the section of the perforating apparatus that includes the explosive devices; energetic cells (formed of an energetic material) arranged among the explosive devices; a modular energetic sleeve formed around an outer surface of a carrier mounted above the explosive devices, where the carrier can include a loading tube or other type of carrier; a sleeve formed of an energetic material that is provided around an outer housing of the perforating apparatus; and a member formed of an energetic material formed as part of an individual explosive device, such as a perforator charge.
Examples of an energetic material can include any one or more of the following: a propellant, a high explosive, a gun powder, a combustible metallic powder, thermite, or any combination thereof.
In the ensuing discussion, reference is made to a carrier (to which explosive devices are mounted) that is in the form of a loading tube. Also, reference is made to perforator charges, which are a form of explosive devices. Additionally, reference is made to an energetic material that includes a propellant. Although reference is made to the foregoing example implementations, note that other example components can be employed in other embodiments.
The perforator charges 112 are ballistically connected to a detonating cord 114. Initiation of the detonating cord 114 causes detonation of the perforator charges 112.
The detonating cord 114 can be connected to a firing head 116, which can be activated from an earth surface 118, such as by use of equipment at the earth surface 118. The activation of the firing head 116 can be in response to electrical commands, acoustic commands, pressure commands, optical commands, and so forth, that can be sent from the equipment at the earth surface 118 to the firing head 116. In other examples, the activation of the firing head 116 can be performed mechanically.
The upper gun section 202 includes a propellant charge 212, which is formed of a propellant (or other energetic material). The propellant charge 212 is contained inside an outer housing 228 of the upper gun section 202 Similarly, the lower gun section 206 includes a propellant charge 214, which includes a propellant or other energetic material. The propellant charge 214 is contained inside an outer housing 230 of the lower gun section 206.
The upper gun section 202 has a gun head 216 to allow the perforating gun 108 to connect to another portion of the tool string 100 shown in
The intermediate gun section 204 also includes various components formed of a propellant or other energetic material. In some examples, as shown in
The loading tube 110 is positioned inside an outer housing 224 of the intermediate gun section 204. In some examples, another outer propellant sleeve 226 can be provided around the outer surface of the outer gun housing 224 of the intermediate gun section 204. The outer propellant sleeve 226 can also include a propellant or other energetic material.
As further shown in
The detonating cord 114 further extends from the intermediate gun section 204 to the lower gun section 206. The lower gun section 206 includes a central passageway 236 that extends through the perforator charge 214. The detonating cord 114 extends inside the central passageway 236.
In operation, an activation signal (e.g. electrical signal, acoustic signal, optical signal, hydraulic signal, mechanical stimulus, etc.) can be provided to the gun head 216. In some examples, the gun head 216 can include a firing mechanism that can initiate the detonating cord 114. Initiation of the detonating cord 114 causes an initiation wave to travel down the detonating cord 114.
Initiation of the portion of the detonating cord 114 in the central passageway 234 in the upper gun section 202 causes activation of the propellant charge 212. A pressure wave caused by the activation of the propellant charge 212 travels through openings 238 in the outer housing 228 of the upper gun section 202.
The initiation wave continues to travel along the detonating cord 114 until it reaches the intermediate gun section 204. Initiation of the portion of the detonating cord 114 in the intermediate gun section 204 causes detonation of the perforator charges 112, which in turn causes activation of the propellant cells 220, the modular propellant sleeve 222, and the outer propellant sleeve 226. Activation of the propellant cells 220, the modular propellant sleeve 222, and the outer propellant sleeve 226 causes resultant pressure waves to be generated, which can be propagated through openings in the outer housing 224 of the intermediate gun section 204. Such openings in the outer housing 224 are produced by perforating jets generated by the detonated perforator charges 112.
The initiation wave continues to travel down the detonating cord 114 to the lower gun section 206. Initiation of the detonating cord 114 in the central passageway 236 of the lower gun section 206 causes activation of the propellant charge 214, which causes the resultant pressure wave to travel through openings 240 in the outer housing 230 of the lower gun section 206.
Although a specific example of the perforating gun 108 is shown in
More generally, different configurations of the perforating gun 108 can include different combinations of the following propellant elements: propellant charge 212, propellant charge 214, propellant cells 220, modular propellant sleeve 222, and outer propellant sleeve 226.
As discussed further below, in other implementations, the perforator charges 112 can be incorporated with a propellant or other energetic material. Such propellant or other energetic material incorporated into a perforator charge 112 can be used in addition to or in place of any or some combination of the foregoing propellant elements.
In addition to the openings 302, the tubular structure 300 of the propellant sleeve 222 also includes grooves 304 that interconnect adjacent openings 302. These grooves 304 are arranged to receive the detonating cord 114. In some examples, the grooves 304 are arranged along a spiral path to allow the detonating cord 114 to be arranged in a spiral pattern around the perforator charges 112.
The perforator charge 112 includes an outer case 502 that acts as a containment vessel designed to hold the detonation force of the explosion of the perforator charge 112 for a length of time to allow for a perforating jet to form. The outer case 502 can be formed of a metal, such as steel, or some other material. A main explosive 504 is contained inside the outer case 502. The main explosive 504 is sandwiched between the inner wall of the outer case 502 and a surface of a liner 506.
In some examples, the liner 506 is generally conically shaped. As a result of the general conical shape of the liner 506, the main explosive 504 is also generally conically shaped between an inner wall of the outer case 502 and the liner 506. In other examples, the liner 506 can be generally bowl-shaped or have a parabolic shape.
In examples according to
In some examples, a retaining element 512 is attached (e.g. glued, welded, or otherwise attached) to the outer case 502. The retaining element 512 can be a retaining wire, for example, which is bendable for holding the detonating cord 114 against the rear portion 510 of the main explosive 504. In other examples, the retaining element 512 can be another type of retaining element, or alternatively, the retaining element 512 can be omitted.
According to some embodiments, the perforator charge 112 further has an energetic material 514, which is placed at a front portion of the perforator charge 112. The “front portion” of the perforator charge 112 is the portion of the perforator charge 112 through which the perforating jet extends upon detonation of the perforator charge 112. Stated differently, the “front portion” of the perforator charge 112 is at the front opening of the outer case 502, through which the perforating jet passes.
The energetic material 514 is generally a discrete segment formed of the energetic material that is placed at the front portion of the perforator charge 112. A “discrete segment” of energetic material can refer to any layer, piece, or other amount of the energetic material that has a predefined extent such that the energetic material does not surround an outer surface 503 of the outer cover 502. In some examples, the discrete segment of energetic material 514 does not contact any part of the outer surface 503 of the outer cover 502.
The energetic material 514 is retained to the outer case 502 of the perforator charge 112 using a retaining structure that is attached to the outer case 502. In some implementations, the retaining structure can be a retaining shell (or retaining cap) 516 that covers the discrete segment of energetic material 514. The retaining shell 516 has a receiving chamber 518 in which the energetic material 514 is positioned. The retaining shell 516 has a protruding portion 520 that extends into an inner opening of the energetic material 514 The retaining shell 516 is attached to the outer case 502 (at 517). The attachment can be a threaded connection between the retaining shell 516 and the outer case 502. Alternatively, the retaining shell 516 can be attached to the outer case 502 using another type of attachment mechanism, such as by use of a screw, a rivet, glue, and so forth.
In examples according to
In different implementations, rather than providing the generally ring-shaped energetic material 514 that has the inner opening 515, a generally disk-shaped energetic material can be provided, which does not include the inner opening 515 in an inner portion (e.g. center) of the energetic material. In other examples, instead of providing an energetic material that is generally circular in cross section, energetic materials having other shapes can be employed.
As further shown in
In other implementations, the shock attenuator 522 can be omitted.
In operation, the detonating cord 114 of
The collapse of the liner 506 under the detonation force starts near an apex portion 524 of the liner 506, and proceeds to near the base portion 526 of the liner 506. The tip of the perforating jet produced from collapse of the liner 506 is formed by the apex portion 524 of the liner 506, while the tail of the perforating jet is formed by the base portion 526 of the liner 506.
In implementations where the energetic material 514 is generally ring-shaped, the perforating jet extends through the opening 515 (
In the foregoing description, numerous details are set forth to provide an understanding of the subject disclosed herein. However, implementations may be practiced without some or all of these details. Other implementations may include modifications and variations from the details discussed above. It is intended that the appended claims cover such modifications and variations.
Claims
1. A perforating apparatus comprising:
- a carrier;
- explosive devices mounted to the carrier;
- energetic cells arranged among the explosive devices; and
- a sleeve defining an inner chamber that receives at least a portion of the carrier, the sleeve being formed of an energetic material, the energetic cells and the sleeve for activation in response to detonation of the explosive devices.
2. The perforating apparatus of claim 1, wherein the carrier is a loading tube containing the explosive devices and the energetic cells.
3. The perforating apparatus of claim 1, wherein the explosive devices include perforator charges.
4. The perforating apparatus of claim 3, wherein at least one of the perforator charges includes:
- a case;
- an explosive inside the case;
- a liner to be collapsed by detonation of the explosive to form a perforating jet; and
- a member formed of an energetic material for activation in response to detonation of the explosive, wherein the member is retained to the case.
5. The perforating apparatus of claim 1, further comprising:
- an outer housing in which the carrier is contained; and
- a second sleeve formed of an energetic material around an outer surface of the outer housing.
6. The perforating apparatus of claim 1, wherein the energetic material is selected from the group consisting of a propellant, a high explosive, a gun powder, a combustible metallic powder, thermite, or any combination thereof.
7. The perforating apparatus of claim 1, comprising a plurality of sections, wherein a first of the sections includes the carrier, explosive devices, and sleeve, and wherein a second of the sections connected to the first section includes a charge formed of an energetic material.
8. The perforating apparatus of claim 1, wherein the sleeve includes openings corresponding to positions of the explosive devices mounted to the carrier.
9. The perforating apparatus of claim 8, wherein the sleeve further includes grooves interconnecting the openings, and the perforating apparatus further comprises a detonating cord arranged along the grooves, wherein the detonating cord is ballistically connected to the explosive devices.
10. A modular sleeve comprising:
- a tubular structure defining an inner chamber to receive a carrier mounted with explosive devices, the tubular structure formed of an energetic material for activation by detonation of the explosive devices,
- the tubular structure including openings corresponding to positions of the explosive devices mounted to the carrier.
11. The modular sleeve of claim 10, wherein the tubular structure further includes grooves interconnecting the openings, the grooves to receive a detonating cord for ballistic coupling to the explosive devices.
12. The modular sleeve of claim 11, wherein the grooves extend generally along a spiral path along the tubular structure.
13. The modular sleeve of claim 10, wherein the energetic material is selected from the group consisting of a propellant, a high explosive, a gun powder, a combustible metallic powder, thermite, or any combination thereof.
14. A method of assembling a perforating apparatus, comprising:
- providing a carrier;
- mounting explosive devices to the carrier;
- arranging energetic cells among the explosive devices; and
- providing a sleeve around the carrier, the sleeve being formed of an energetic material, and the sleeve and energetic cells for activation in response to detonation of the explosive devices.
15. The method of claim 14, wherein providing the carrier comprises providing a loading tube containing the explosive devices and energetic cells.
16. The method of claim 14, further comprising providing the carrier inside an outer housing of the perforating apparatus.
17. The method of claim 16, further comprising providing a second sleeve around the outer housing, the second sleeve formed of an energetic material for activation in response to detonation of the explosive devices.
18. The method of claim 14, wherein mounting the explosive devices comprises mounting perforator charges.
Type: Application
Filed: Feb 15, 2012
Publication Date: Aug 15, 2013
Inventors: Guofu Feng (Shanxi), Changshuan Wang (Shanxi), Oliver Han (Beijing), Yuanwen Yao (Shanxi), Senyuan Li (Shanxi), Baoxing Wang (Shanxi), Feng Wang (Beijing)
Application Number: 13/397,077
International Classification: E21B 43/11 (20060101); E21B 43/119 (20060101);