After drilling various sections of a subterranean wellbore that traverse a formation, individual lengths of relatively large diameter metal tubulars are typically secured together to form a casing string that is positioned (e.g., cemented) within the wellbore. This casing string increases the integrity of the wellbore and provides a path for producing fluids to travel from the producing intervals to the surface. To produce fluids into the casing string, openings or perforations are made through the casing string, the cement and a short distance into the formation.
These perforations are created by detonating a series of charges that are disposed within the casing string adjacent to the formation of interest. For example, one or more perforating guns may be loaded with charges that are connected with a detonator via a detonation cord. The perforating guns are then connected within a tool string that is lowered into the wellbore at the end of a tubing string, wireline, slick line, coil tubing or another conveyance. Once the perforating guns are properly positioned in the wellbore (e.g., such that the charges are adjacent to the formation of interest), the charges are detonated, thereby creating the desired openings or perforations.
Reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
Specific examples are described in detail and are shown in the drawings, with the understanding that the present disclosure is to be considered an exemplification of the principles of the disclosure, and is not intended to limit the disclosure to that illustrated and described herein. It is to be fully recognized that the different teachings of the examples discussed herein may be employed separately or in any suitable combination to produce desired results.
A detonation alignment apparatus and method are disclosed for beneficially securing a detonation cord used in a perforating gun assembly. In various example configurations detailed below, the apparatus may allow the detonation cord to be received within the opening of a housing, and to secure the detonation cord within the housing by resisting movement of the detonation cord relative to the opening once received. One or more example configurations of such a housing may allow the detonation cord to be slidingly inserted into the opening of the housing, while resisting movement of the cord in an opposite direction relative to the housing. More particularly, disclosed configurations of the housing may include one or more inwardly directed protrusions oriented and relatively positioned to automatically increase resistance in response to urging the detonation cord in an opposite direction thereby resisting removal. In one or more configurations, the detonation cord may be inserted into the housing in an insertion direction, and urging the detonation cord in the opposite direction automatically increases resistance thereby resisting removal. Preferably, the resistance is increased sufficiently to prevent removal of the detonation cord from the housing under foreseeable handling conditions of the perforating gun system.
The use of a detonation cord alignment apparatus as described herein, alone or in combination with other alignment features, may beneficially allow for a consistent and reliable coupling of a detonation cord with other explosive features, thereby improving the reliability of the chain of explosives used in the detonation process. For instance, the use of the detonation cord alignment apparatus as described herein may allow for a consistent and reliable coupling of the detonation cord and the detonator, for example by linearly securing the detonation cord relative to the detonator. Additionally, the use of the detonation cord alignment apparatus as described herein may allow for a consistent and reliable coupling of the detonation cord with the plurality of shaped charges that the detonator cord is configured to ignite, for example by linearly securing the detonation cord relative to the plurality of shaped charges. This may help avoid an improper, incomplete, and/or unreliable coupling to avoid the failure of a shaped charge to detonate, and thus avoiding the failure of subsequent shaped charges in the chain to detonate as well. This may help avoid a need to withdraw the perforating gun assembly from the wellbore, which can be a costly process that takes several days while presenting the possibility of a misfire while being withdrawn from the wellbore. The various characteristics mentioned above, as well as other features and characteristics described in more detail below, will be readily apparent to those skilled in the art with the aid of this disclosure upon reading the following detailed description of the embodiments, and by referring to the accompanying drawings.
The wellbore 130 may be drilled into the subterranean formation 125 using any suitable drilling technique. In the example illustrated in
A wellbore conveyance 140 may be lowered into the wellbore 130 for a variety of drilling, completion, workover, treatment, and/or production processes, amongst others, throughout the life of the wellbore 130. The example shown in
Coupled to the wellbore conveyance 140, in the example illustrated in
The first gun set 210a includes a first carrier gun body 220a, which in one example may comprise a cylindrical sleeve, which may further have a plurality of recesses 225a. Radially aligned with each of the recesses 225a is a respective one of a first plurality of shaped charges 230a, only six of which are visible within the first gun set 210a of
The first plurality of shaped charges 230a, in the example shown, are retained within the first carrier gun body 220a by a charge tube 240a. In certain examples, the charge tube 240a supports a discharge end of the first plurality of shaped charges 230a, wherein an additional inner charge tube (not shown) supports an initiation end of the first plurality of shaped charges 230a.
In the example of
The second gun set 210b may include many of the same features as the first gun set 210a. For example, the second gun set 210b includes a second carrier gun body 220b, as well as a second plurality of shaped charges 230b retained within a second charge tube 240b. Each of the second plurality of shaped charges 230b may comprise similar components as each of the first plurality of shaped charges 230a.
The perforating gun assembly 200 further includes a detonation cord 250, which is used to detonate ones of the first and/or second plurality of shaped charges 230a, 230b. In the illustrated example, the initiation ends of the first and second plurality of shaped charges 230a, 230b extend across the central longitudinal axis of the perforating gun assembly 200, allowing the detonation cord 250 to connect to the explosive material, for example through an aperture defined at an apex of the housings 232a. In the embodiment of
The perforating gun assembly 200, in accordance with one or more embodiments of the disclosure, includes one or more detonation cord alignment apparatuses 260. The one or more detonation cord alignment apparatuses 260 may vary in purpose and structure and remain within the scope of the disclosure. For example, in the embodiment of
In contrast, a gun connector housing 260b may be employed as another of the detonation cord alignment apparatuses 260. The gun connector housing 260b could therefore employ one or more connections (e.g., threaded connections) to connect the first and second carrier gun bodies 220a, 220b, and thus the first gun set 210a and second gun set 210b together. In certain embodiments, both the detonator end alignment housing 260a and the gun connector housing 260b are employed as detonation cord alignment apparatuses 260.
Notwithstanding the foregoing, in one or more embodiments, one of the one or more detonation cord alignment apparatuses 260 includes a detonation cord alignment housing having a detonation cord opening extending there through. Further to these embodiments, one or more protrusions may extend inwardly from the detonation cord opening. The one or more protrusions do not necessarily extend directly from the detonation cord opening, but may extend indirectly from the detonation cord opening, for example by way of a detonation cord retention insert located within the detonation cord opening. The one or more protrusions, in at least one embodiment, linearly fix the detonation cord 250 within the detonation cord opening. In the case of the detonator end alignment housing 260a, the one or more protrusions linearly fix the detonation cord 250 within the detonation cord opening of the detonator end alignment housing 260a, and thus keep the detonation cord 250 aligned with the detonator 255. In the case of the gun connector housing 260b, the one or more protrusions linearly fix the detonation cord 250 within the detonation cord opening of the gun connector housing 260b, and thus keep the detonation cord 250 aligned with the first or second plurality of shaped charges 230a, 230b.
The one or more protrusions 325 may take on many different designs and/or shapes and remain within the scope of the disclosure. For example, the one or more protrusions 325 may be one more angled barbs (e.g., as shown in
In the illustrated embodiment, the angled barbs may allow the detonation cord 250 to slide in the first direction toward the second end 314, but prevent the detonation cord 250 from sliding in the second opposite direction toward the first opposing end 312. Accordingly, when the detonator 255 is located within the detonator opening 330, the detonation cord 250 may be fixed in one direction relative to the detonator 255, but allowed to slide in the second opposing direction relative to the detonator 255. In the illustrated example, the one or more protrusions are linearly and radially staggered. In other embodiments, the one or more protrusions 325 are not angled, and thus linearly secure (e.g., to some degree) the detonation cord 250 in the first and second directions. For example, the one or more protrusions could be one or more nubs, which press upon the detonation cord 250 and make it difficult to slide within the detonation cord opening 320.
The one or more protrusions 325, especially when they are angled barbs, may be configured to penetrate an outer surface of the detonation cord 250 upon sliding the detonation cord 250 into the detonation cord opening 320 and then beginning to move the detonation cord 250 in the opposite direction out of the detonation cord opening 320. The detonation cord 250 generally includes an inner layer comprising an explosive, an optional layer of fiber, then an outer layer of insulation. The one or more protrusions 325 may be configured to penetrate one or more of these layers, thereby linearly securing the detonation cord 250 from movement in the one direction within the detonation cord opening 320. In one example, the one or more protrusions 325 may penetrate the insulation layer on the outside of the detonation cord 250. In another example, the one or more protrusions 325 may penetrate through the insulation and the fiber layer. In an alternate example, the one or more protrusions 325 may penetrate through the insulation and the fiber layer and into the explosive layer. The one or more protrusions 325 can be stamped, cold-formed, machined, created by a hand tool or other manual mechanical deformation injection molded, investment cast, or by any other known way of forming one or more protrusions within an opening.
The detonator opening 330, in the embodiment of
Further to the embodiment of
In the illustrated embodiment of
Aspects disclosed herein include:
A. A detonation cord alignment apparatus, the detonation cord alignment apparatus including: 1) a detonation cord alignment housing having a detonation cord opening extending there through for receiving a detonation cord; and 2) one or more protrusions extending inward from the detonation cord opening for linearly securing the detonation cord therein.
B. A perforating gun assembly for use in a wellbore, the perforating gun assembly including: 1) a carrier gun body; 2) a detonation cord alignment apparatus supported by the carrier gun body, the detonation cord alignment apparatus including a detonation cord alignment housing having a detonation cord opening extending there through, and one or more protrusions extending inward from the detonation cord opening; 3) a plurality of shaped charges supported within the carrier gun body; and 4) a detonation cord extending through the detonation cord alignment housing to the plurality of shaped charges, the one or more protrusions linearly securing the detonation cord in the detonation cord opening.
C. A well system, the well system including: 1) a wellbore; and 2) a perforating gun assembly positioned within the wellbore, the perforating gun assembly held in place by a conveyance and including, a) a carrier gun body; b) a detonation cord alignment apparatus supported by the carrier gun body, the detonation cord alignment apparatus including a detonation cord alignment housing having a detonation cord opening extending there through, and one or more protrusions extending inward from the detonation cord opening; c) a plurality of shaped charges supported within the carrier gun body; and d) a detonation cord extending through the detonation cord alignment housing to the plurality of shaped charges, the one or more protrusions linearly securing the detonation cord in the detonation cord opening.
Aspects A, B, and C may have one or more of the following additional elements in combination: Element 1: wherein the one or more protrusions are one or more angled barbs extending inward from the detonation cord opening for allowing the detonation cord to slide in a first direction and increase resistance to sliding of the detonation cord in a second opposite direction. Element 2: wherein the one or more protrusions are linearly and radially staggered. Element 3: wherein the one or more protrusions are only a single protrusion. Element 4: further including a detonation cord retention insert located within the detonation cord opening, the detonation cord retention insert including the one or more protrusions for linearly securing the detonation cord. Element 5: wherein the detonation cord retention insert comprises metal or plastic. Element 6: wherein the detonation cord alignment housing is a detonator end alignment housing. Element 7: wherein the detonator end alignment housing includes a detonator opening therein. Element 8: wherein the detonator opening is at least partially offset from and aligned with the detonation cord opening. Element 9: wherein the detonation cord opening and detonator opening at least partially overlap each other. Element 10: wherein the detonation cord alignment housing is a gun connector housing for connecting multiple carrier gun bodies together. Element 11: wherein the one or more protrusions are one or more angled barbs extending inward from the detonation cord opening for allowing the detonation cord to slide in a first direction and increase resistance to sliding of the detonation cord in a second opposite direction. Element 12: further including a detonation cord retention insert located within the detonation cord opening, the detonation cord retention insert including the one or more protrusions for linearly securing the detonation cord. Element 13: wherein the detonation cord alignment housing is a detonator end alignment housing supported within the carrier gun body, the detonator end alignment housing further including a detonator opening therein, and a detonator located within the detonator opening. Element 14: wherein the detonator opening is at least partially offset from and aligned with the detonation cord opening. Element 15: wherein the detonation cord alignment housing is a gun connector housing connecting the carrier gun body to a second carrier gun body having a second plurality of shaped charges supported therein, and further wherein the detonation cord extends from the plurality of shaped charges through the gun connector housing to the second plurality of shaped charges, the one or more protrusions linearly securing the detonation cord in the detonation cord opening in the gun connector housing. Element 16: wherein the detonation cord alignment housing is a detonator end alignment housing supported within the carrier gun housing, the detonator end alignment housing further including a detonator opening therein, and a detonator located within the detonator opening. Element 17: wherein the detonation cord alignment housing is a gun connector housing connecting the carrier gun body to a second carrier gun body having a second plurality of shaped charges supported therein, and further wherein the detonation cord extends from the plurality of shaped charges through the gun connector housing to the second plurality of shaped charges, the one or more protrusions linearly securing the detonation cord in the detonation cord opening in the gun connector housing.
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Number | Date | Country | |
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20210355798 A1 | Nov 2021 | US |