Perforating guns are used to access the formation behind a wellbore casing. In wellbore operations it is common to run into and out of a well a number of times to create isolated sections of the wellbore, perforate and treat the well. However, the increasing costs of well bore operations, including the rental rates for a rig and lost time, are urging operators to speed all wellbore service operations including those relating to wellbore perforating.
In accordance with a broad aspect of the present invention there is provided a perforating gun assembly including an upper end, a perforating gun connected to the upper end, a hydraulically actuated tool connected to the perforating gun on an end opposite the upper end and a fluid conduit extending through the upper end and to the hydraulically actuated tool, the fluid conduit allowing fluid communication past the perforating gun to the hydraulically actuated tool such that fluid can be communicated through the upper end to actuate the hydraulically actuated tool.
In accordance with another broad aspect of the present invention, there is provided a method for perforating a well including: (a) providing a perforating gun assembly including an upper end, a perforating gun, a hydraulically actuated tool connected to the perforating gun on an end opposite the upper end and a fluid conduit extending through the upper end and to the hydraulically actuated tool, the fluid conduit providing a fluid path past the perforating gun to the hydraulically actuated tool; (b) running the perforating gun assembly to a position in a well; and (c) in any order (i) communicating fluid to he fluid conduit to actuate the hydraulically actuated tool; and (ii) actuating the perforating gun to perforate the well.
It is to be understood that other aspects of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein various embodiments of the invention are shown and described by way of illustration. As will be realized, the invention is capable for other and different embodiments and its several details are capable of modification in various other respects, all without departing from the spirit and scope of the present invention. Accordingly the drawings and detailed description are to be regarded as illustrative in nature and not as restrictive.
Referring to the drawings wherein like reference numerals indicate similar parts throughout the several views, several aspects of the present invention are illustrated by way of example, and not by way of limitation, in detail in the figures, wherein:
a and 4b are axial sectional views through a check valve assembly useful in a perforating gun assembly.
The detailed description set forth below in connection with the appended drawings is intended as a description of various embodiments of the present invention and is not intended to represent the only embodiments contemplated by the inventor. The detailed description includes specific details for the purpose of providing a comprehensive understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without these specific details.
A perforating gun assembly is proposed that includes a number of tools thereon including a perforating gun and enables an operator to both hydraulically actuate a tool below the perforating gun and fire the perforating gun to perforate the wellbore casing wall. In particular, the perforating gun assembly includes a bypass line that communicates hydraulic fluid from surface past the perforating gun to a tool located therebelow. The tool below the perforating gun can be one or more of a plug (drill out, retrievable, etc.), a packer, another perforating gun, a time delay assembly, a shear assembly, etc.
Connector 10 and tubing arrangement 14 include at least partly therethrough a longitudinal bore 20 creating an inner diameter through which fluid can be received from the inner diameter of tubing string 12, as communicated from surface. Bore 20 may include a plug 22 permanently or releasably installed therein. Plug 22, if it is in place, blocks fluid communication to the perforating gun through the bore.
The assembly further includes a bypass line 24 extending from bore 20 to tool 18, acting as a conduit through which fluid can be communicated from the tubing arrangement to the tool to allow hydraulic actuation thereof. Bypass line 24 allows fluid to get past the perforating gun to be communicated to tool 18. In one embodiment, fluid conveyed through bore 20 can pass through bypass line 24 to reach the tool below the perforating gun. In some embodiments, when plug 22 is present, fluid may be communicated to tool 18, without also being communicated to perforating gun 16. In such an embodiment, bypass line 24 and plug 22 may isolate fluid from the perforating gun.
Connector 10 may take various forms depending on the form of tubing string intended to be used with the assembly and the downhole manipulation of the assembly which is sought to be achieved. For example, the assembly may conveniently be used with coiled tubing and, therefore in such an embodiment, a crossover connector suitable for connecting to coiled tubing may be employed.
Perforating gun 16 may take various forms depending on the wellbore conditions, the type of perforating job that is sought to be accomplished, operator preferences, etc. For example, perforating gun may be hydraulically, mechanically or electrically actuated to immediately detonate or after a time delay. For example, the gun may be actuated by a mechanical device, such as a ball, bar or dart dropped or otherwise conveyed from surface, an electrical device such as a wireline connected or downhole programmable logic controller, or hydraulically by various fluids and mechanisms.
Since the assembly is intended to facilitate hydraulic operations for tools to be actuated before or after the firing of the gun, it may be useful to also select a hydraulically actuated perforating gun. Such a gun may be actuated by hydraulic pressure in the annulus 27 about the gun or by through tubing pressures. In the illustrated embodiment of
Perforating gun 16, in the illustrated embodiment, further includes a charge tube in a housing sleeve 38, which is the outer perforated sleeve shown in the drawing. The charges installed along the charge tube are detonated by hydraulic operation of firing head 30.
As noted, perforating gun 16 can take various forms and configurations. As shown in
Tubing arrangement 14 may include an unmodified tubular sub or may include one or more subs with straight tubing or any of various mechanisms, as desired, considering the operation of the assembly including the operation of the perforating gun and selected downhole operations to be conducted. For example, the tubing arrangement may include any or all of a swivel, a shear release, a fluid outlet sub, or other mechanisms. For example, a fluid outlet sub may be incorporated in the tubing arrangement where it is desired to direct fluid from the assembly into the annulus. A fluid outlet sub including, for example, a valve, an openable port, etc. may allow fluid to be contained in the tubing arrangement until it is desired to open the outlet to the exterior of the assembly. Such an outlet sub may be for example, a sleeve-closed port such as the tubing drain 40, as shown, or otherwise. Tubing drain 40, in the illustrated embodiment, includes a pressure release connection with a shear pin arrangement 42 that can be overcome by fluid pressure to create an opening through the wall of the drain. The shear pin arrangement can, for example, release the connection between a telescoping outer sleeve and an inner tube into which bore 20 extends and ports 44 are formed. It may be desired to open fluid communication to the outer surface, and thereby annulus 27 about the perforating gun assembly, for annular hydraulic actuation of a perforating gun, such as is shown in
In another embodiment, where it is not desirable to open fluid access to the outer surface of the tool and annulus about the tool until nearer the time or after the perforating gun is detonated, a port can be provided in association with the firing head. For example, a port can be provided that is positioned to be covered by the firing head body or an extension thereof and which is opened by movement of the firing head, after the firing head has been sufficiently hydraulically actuated to initiate detonation of the perforating gun.
As a further example, it may be useful to employ a swivel in the tubing arrangement to allow the assembly to be rotated relative to the tubing string long axis. In the illustrated embodiment, a swivel 46 is incorporated in the tubing arrangement. Swivel 46 allows, for example, the assembly to be rotated to allow a side of the assembly, for example that side carrying bypass line 24, to be out of contact with the wellbore wall.
Although the illustrated components of the tubing arrangement, swivel 46 and tubing drain 40, are shown positioned in a particular orientation and formed in a particular way. Of course, other positional orientations and forms can be employed, if these components are used at all.
As noted, bore 20 of tubing arrangement 14 may include a plug, such as plug 22, that can be a valve, a frangible member, or a permanent member such as a wall. Plug 22, when it is in place, isolates perforating gun 16, from through tubing conveyed hydraulic pressure, for example, when using bypass line 24 and hydraulically manipulating tool 18. In particular, plug 22 blocks fluid passage along bore 20 such that pressure applied to the tubing string inner bore passes through bypass line 24 rather than acting on the perforating gun's firing head. Plug 22 may be positioned anywhere between the intersection of bypass line 24 and bore 20 and firing head 30. Of course, a plug can be omitted where the firing head is connected, as by selection of shear or biased connections, to only be moved by pressures in selected ranges that are different than those pressure ranges selected to actuate tool.
If perforating gun is hydraulically actuated using any source of tubing conveyed hydraulic pressure, such pressure must eventually be communicated from bore 20 to the firing head. Where an embodiment as shown in
Bypass line 24, as noted above, conveys a flow of fluid from bore 20 to a tool 18 positioned on the other side of the perforating gun from bore 20, which in wellbore operations would be considered downhole from the perforating gun. Hydraulic actuation can be by various fluids including liquid or gas, such as including but not limited to drilling mud, water, nitrogen, etc. Line 24 is selected to withstand the rigors of downhole use and to convey fluid and hold pressure at the differentials selected for operation. In some embodiments, it may be possible to position and form line 24 to withstand and retain its fluid conveying function even after perforating gun has been detonated. This may be achieved by forming the line of durable materials and positioning line 24 out of alignment with the explosive path of the perforating gun charges.
In one embodiment, bypass line 24 is connected between an upper sub 48 and a lower sub 50. An example of an upper sub 248 is shown in
Using upper sub 248 as an example of a form useful for the upper sub and the lower sub for retaining bypass line 224, the sub includes connections such as a threaded connections 252, 253 that permit the sub to be connected into a tubular string. As an upper sub, one end 252 is connected to the next adjacent component of the tubing arrangement, such as tubing swivel 46 in
Sub 248 also includes a bore 220a that may be connected into communication with a bore of the tubing arrangement, such as bore 20 in
While bypass line is shown as an external line in
Tool 18 can take various forms, as noted above, including, for example, a packer, a plug, a shear mechanism, a time delay assembly, a perforating gun, etc. In one embodiment, the tool may include a bridge plug. The form and operations of bridge plugs is well known in the art. For example, a bridge plug may carry an annular seal 60 that can be expanded to set in and seal against a wellbore wall 8. A bridge plug may be carried on the assembly to permit the wellbore below a selected area to be perforated to be sealed off. The seal created by the bridge plug may be useful to restrict wellbore fluid to an area above the plug, to allow the wellbore section above the plug to be pressured up, etc. Various hydraulically actuated bridge plugs are known. When hydraulic pressure is communicated to such a bridge plug, the annular seal is caused to be expanded radially outwardly to seal the well about the plug body 61 and set the plug in the well. It may be useful to provide a centralizer with, for example adjacent, the bridge plug to ensure an appropriate setting position for the plug and to protect it from abrasion. In one embodiment, for example, an offset sub 64 can be installed in the assembly to act as a centralizer. An offset sub includes a sub that has axially offset end connections. While the center long axis of perforating gun 16 may be offset to allow room for bypass line 24 to extend therealong, offset sub 64 positioned below the perforating gun, allows the bridge plug body and annular seal 60 to be returned to a more central position in the well.
Tool 18 can further include a shear release mechanism such as one also actuated by hydraulic pressure. A shear release mechanism allows the assembly thereabove, including for example, perforating gun 16 to be separated from the tool components, including for example the bridge plug, below the shear mechanism, when desired. The shear release mechanism can include, for example, a shear pin connection between parts that can be separated by pressuring up the tool beyond the holding force of the shear pins. Since in some embodiments it is necessary to continue to hold pressure within the assembly to hydraulically actuate further components thereof, a valve may be provided in relation to the shear release to continue to provide a closed system in at least bore 20 and possibly also bypass line 24.
It will be appreciated that in the embodiment of
One possible embodiment of a useful check valve sub 470 is shown in
As shown in
To facilitate installation and construction, a tubular insert 487, which is sealed as by use of o-rings 488 against the inner wall of housing 472, can be used to provide a stepped region in the inner diameter in which the lower end of sleeve 482 can initially be sealed and can ride along.
In use, a perforating gun assembly, such as one of the various embodiments with or without the optional features described hereinbefore, can be run into a position in a well. Thereafter, fluid can be communicated the fluid conduit through the assembly including the bypass line to actuate the hydraulically actuated tool below the perforating gun. Before or after the tool is actuated, the perforating gun may be actuated to perforate the well.
In an assembly such as that shown in
The wellbore can be treated by circulation of various fluids, such as acid, at some point, for example, after hydraulically actuating tool 18.
The perforating gun assembly may alternately be used to first detonate perforating gun 16 and then actuate tool 18. This can be achieved in various ways, such as, for example, by mechanically or electrically actuating the perforating gun followed by hydraulically actuating the tool or by selecting the perforating gun to be detonated hydraulically by pressures less than those required to actuate tool 18.
If a check valve such as one of
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to those embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded the full scope consistent with the claims, wherein reference to an element in the singular, such as by use of the article “a” or “an” is not intended to mean “one and only one” unless specifically so stated, but rather “one or more”. All structural and functional equivalents to the elements of the various embodiments described throughout the disclosure that are know or later come to be known to those of ordinary skill in the art are intended to be encompassed by the elements of the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 USC 112, sixth paragraph, unless the element is expressly recited using the phrase “means for” or “step for”.