Well stimulation operations may be conducted downhole in a well that extends through a hydrocarbon bearing formation for purposes of enhancing hydraulic communication between the formation and the well. As an example, a jetting operation may be performed to remove debris that was introduced during the drilling of the well or during downhole perforating operations. In this manner, a jetting tool may be run, or deployed, downhole on a coiled tubing string, and an acidic jetting fluid may be communicated via the coiled tubing string through nozzles of the tool to remove the debris from the near wellbore to increase the well's permeability.
Hydraulic fracturing is another example of a well stimulation operation. In hydraulic fracturing, fluid in the well is pressurized to fracture the surrounding formation rock and introduce a fracture pack (proppant, for example) into the resulting fractures for purposes of holding the fractures open when the pressure is released. Well stimulation operations may be performed sequentially in multiple isolated segments, or stages, of the well and may involve the deployment and use of various downhole tools, such as fracturing plugs, sleeve valves, and so forth.
The summary is provided to introduce a selection of concepts that are further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.
In accordance with an example implementation, a technique includes deploying an isolation assembly into a tubing string that was previously installed in a well; deforming the isolation assembly at a downhole location in the well to secure the assembly to the tubing string; receiving an object in a restriction of the isolation assembly; and using the received object in the isolation assembly to perform a downhole operation in the well.
In accordance with another example implementation, an apparatus that is usable with a well includes a tubular assembly and an expansion tool. The tubular assembly has a radially contracted state and includes a restriction. The restriction is adapted to catch an object that is deployed into the well to form a fluid barrier when caught by the restriction. The expansion tool is deployed downhole with the tubular assembly inside a tubing string. The expansion tool is adapted to deform the tubular assembly to anchor the tubular assembly to the tubing string.
In accordance with yet another example implementation, a system that is usable with a well includes a tubing string and an isolation assembly. The tubing string supports a wellbore, and the wellbore has multiple stages. The isolation assembly is deployed in the central passageway of the tubing string to form an isolation barrier for a given stage of the multiple stages. The isolation assembly includes a tubular assembly and an expansion tool. The tubular assembly has a radially contracted state and includes a seat. The seat is adapted to catch an untethered object that is deployed into the central passageway of the tubing string to form a fluid barrier due to the untethered object being caught by the seat. The expansion tool is deployed downhole with the tubular member as a unit inside the tubing string. The expansion tool is adapted to deform the tubular assembly to anchor the tubular assembly to the tubing string.
Advantages and other features will become apparent from the following drawings, description and claims.
In general, systems and techniques are disclosed herein to deploy and use a deformable isolation assembly in a well for purposes of performing a downhole operation. In this regard, the isolation assembly that is disclosed herein has a radially contracted state, which allows the assembly to be run downhole in the well inside the central passageway of a tubing string (a casing string, for example) that was previously installed in the well. When at the appropriate downhole location, the isolation assembly may be radially expanded and secured, or anchored, to the tubing string to form a downhole obstruction, or fluid barrier, inside the central passageway of the tubing string; and this fluid barrier may then be used in connection with a downhole operation. The downhole operation may be any of a number of operations (a stimulation operation, perforating operation, a jetting operation and so forth) that rely on a fluid barrier inside a tubing string.
In accordance with example implementations that are disclosed herein, the isolation assembly has a central passageway and a restriction that is formed in its central passageway for purposes of allowing an object to be landed in the restriction to form the fluid barrier after the assembly had been anchored in place and radially expanded. As a more specific example, the isolation assembly may be a fracturing plug assembly, and the restriction may be an inner, object catching seat. In this context, “object catching seat” refers to the seat being constructed to catch an object that is deployed through the tubing string, such as a ball, a dart, a barrel, a rod, or any other object that is constructed to land in the seat to form the fluid barrier.
In general, the isolation assembly is run downhole in a collapsed, or unexpanded state (also referred to as the “radially contracted state” herein), which allows the isolation assembly to have a smaller overall cross-section. This smaller cross-section allows the isolation assembly to be freely run downhole inside the central passageway of a tubing string without being impeded by features of the string. As further described herein, after being placed in the appropriate downhole location, the isolation assembly may be transitioned to its expanded state (also called the “radially expanded state” herein) in which the isolation assembly is secured, or anchored, to the tubing string wall. In this radially expanded stage, the isolation assembly may be used to catch an object that is deployed in the central passageway of the string for purposes of forming a fluid barrier.
In accordance with example implementations, in its expanded state, the isolation assembly is constructed to receive, or catch, an object, which is deployed in the passageway of the tubing string. In accordance with example implementations, the object may be a solid object that is constructed to be caught by the isolation assembly's restriction so that the landed object in conjunction with the assembly substantially closes off fluid communication through the assembly to form a downhole fluid barrier. “Substantially closes off” fluid communication refers to fluid communication through the isolation assembly being inhibited to the extent that a fluid column above the assembly may be pressurized to perform a downhole operation (pressurized to conduct a hydraulic fracturing operation, for example). Fluid leakage between the landed object and the restriction may or may not occur, depending on the particular implementation.
The object that lands in the restriction may be an “untethered object,” in accordance with example implementations. In this context, an “untethered object” refers to an object that is communicated downhole through the passageway of the string along at least part of its path without the use of a conveyance line (a slickline, a wireline, a coiled tubing string and so forth). As an example, the untethered object may be deployed from the Earth surface of the well. In accordance with further example implementations, the untethered object may be run downhole into the well by a conveyance mechanism, such as a wireline, slickline, coiled tubing string or jointed tubing string and then released to travel into the tubing string containing the isolation assembly to land in the assembly's restriction. In accordance with further example implementations, the object may be tethered to the end of a conveyance mechanism or tool, which is run downhole to position the object in the isolation assembly's restriction. Thus many implementations are contemplated, which are within the scope of the appended claims.
In accordance with example implementations described herein, the isolation assembly includes a sleeve that is constructed to be deformably expanded downhole in the well to anchor the isolation assembly to the tubing string. For example, in accordance with some implementations, the isolation assembly may be run downhole with a setting tool on a conveyance mechanism, such as a tubular string, coiled tubing, a wireline, and so forth. After being placed in the proper position, the setting tool may be actuated using actions initiated from the Earth surface of the well for purposes of exerting a force to deform the sleeve to cause the sleeve to radially expand and become anchored to the surrounding wall of the tubing string.
In accordance with example implementations, the sleeve of the isolation assembly may be radially expanded to anchor the sleeve to the tubing string, and the sleeve may contain a restriction to form a seat to catch an untethered object to form a fluid barrier in the tubing string. More specifically, in accordance with example implementations that are described herein, the setting tool may have an expansion member that, for the assembly's radially contracted state, has an overall outer dimension that is greater than the overall inner dimension of the isolation assembly; and when the isolation assembly has been run downhole and placed at the appropriate target downhole location, the conveyance mechanism may be pulled uphole to draw the expansion tool member through the interior of the isolation assembly to deform and radially expand isolation assembly. After the isolation assembly has been radially expanded and anchored in place, the setting tool and conveyance mechanism may then be pulled out of the well; and then an object may be deployed to land in the restriction of the isolation assembly to form a fluid barrier.
In accordance with further example implementations, the seat of the isolation assembly may be separate from the sleeve of the isolation assembly. In this manner, the isolation assembly may include a seat member (containing the seat) and a deformable sleeve. A setting tool on which the isolation assembly is mounted may be run downhole in the central passageway of the tubing string to a target downhole location. The setting tool may then be actuated to radially expand the sleeve member and force the sleeve member between the seat member and the tubing string wall for purposes of forming a wedge, or friction, fit between the seat member and the tubing string.
As described herein, in accordance with some implementations, the sleeve member may be run into the well mounted uphole of the seat member on the setting tool. A tension mandrel of the setting tool may be secured to the seat member so that the setting tool may be actuated to engage a sleeve member of the isolation assembly to exert a force on the sleeve member and axially translate the sleeve member to force the sleeve member into a seat member of the isolation assembly. In this manner, the force that is applied by the setting tool and the axial translation of the sleeve member caused by this force causes the sleeve member to radially expand to form a wedge between the seat member and the tubing string wall.
In accordance with further example implementations that are described herein, the isolation assembly may include a sleeve member and a seat member, with the seat member being mounted on the setting tool uphole of the sleeve member. A tension mandrel of the setting tool may be secured to the sleeve member so that the setting tool may be actuated to apply a force to the seat member to axially translate the seat member into the sleeve member to cause the sleeve member to deform and radially expand to form a wedge between the seat and the tubing string wall.
Referring to
It is noted that although
Multiple stage operations (fracturing or other stimulation operations) may be performed along the wellbore 115, one stage 130 at a time. In this manner, a given stage 130 may be hydraulically isolated from the other stages 130, a given operation may be performed in the isolated stage, the isolation may be removed, and then these same steps may be performed for the next stage. The downhole operations may be performed in the stages 130 in a particular directional order, in accordance with example implementations. For example, in accordance with some implementations, downhole operations may be conducted in a direction from a toe end of the wellbore to a heel end of the wellbore 115. In further implementations, the multiple stage downhole operations may be connected from the heel end to the toe end of the wellbore 115. In accordance with further example implementations, the multiple stage operations may be performed in no particular order, or sequence.
Referring to
The radially contracted state, or run-in-hole state, of the isolation assembly 175, in accordance with an example implementation, is depicted in
As depicted in
The contracted segment of the sleeve 207, in accordance with example implementations, is radially expanded by the expansion member 252 of the expansion tool 250 for purposes of enlarging the inner passageway of the isolation assembly 175, radially extending the anchor members 230 to secure the assembly 175 to the tubing string wall and radially expanding the seal element 240 to form a seal (fluid seal, for example) between the sleeve 207 and the tubing string wall.
In accordance with example implementations, the anchor member 230 may have a profile or surface that is constructed to grip the inner surface of the tubing string 120 to secure the isolation assembly 175 to the tubing string 120. For example, in accordance with some implementations, the anchor member 230 may have a relatively high coefficient of friction (as compared to the inner wall of the tubing string 120, for example) to allow the member 230 to secure the isolation assembly 175 to the tubing string 120 when the member 230 is radially pushed against the wall of the string 120.
In accordance with some implementations, the anchor member 230 may contain pointed surfaces, or “teeth.” The teeth may be constructed of a metal that is relatively harder than the metal of the tubing string 120 so that the teeth “bite” into the tubing string wall to anchor the isolation assembly 175 to the tubing string 120. In accordance with further example implementations, the anchor member 230 may be a slip, similar to a slip used in a packer. In this manner, for these example implementations, the isolation assembly 175 may contain thimbles, or collars, which are moved closely axially together due to the expansion of the sleeve 207 (or due to actuation by a setting tool, as another example) to cause the anchor members 230 (disposed between the thimbles) to radially extend into and engage the tubing string wall.
In accordance with example implementations, the seal element 240 may be an elastomer ring that radially expands with the sleeve 207 to form a fluid tight or near fluid tight seal between the isolation assembly 175 and the tubing string 120. Materials other than an elastomer may be used for the seal element 240, in accordance with further example implementations. For example, in accordance with some implementations, the seal element 240 may be formed from metal to form a metal-to-metal seal between the isolation assembly 175 and the tubing string 120. In accordance with further example implementations, the isolation assembly 175 may not have a seal element.
As depicted in
In accordance with example implementations, the sleeve 207 may be formed from a metal, such as stainless steel or a metal that has less chromium content per mass than stainless steel, such as SAE grade 4140 metal. The sleeve 207 may be made from other metals or from materials other than metal, in accordance with further example implementations.
Although example implementations are described above in which an expansion tool is drawn through the isolation assembly to deform and radially expand the assembly, other tools and techniques may be used to deform and expand the assembly, in accordance with further example implementations. For example, an expansion tool may be pushed through the isolation assembly to deform and expand the assembly. The expansion tool may have an expansion member that is asymmetrical with respect to the longitudinal axis 201 of the isolation assembly. Moreover, the isolation assembly may be deformed and expanded using a tool or technique that does not involved mechanically contacting the sleeve 207 with an expansion member. For example, in accordance with further example implementations, a setting tool may be used to run the isolation assembly 175 downhole and may be constructed to form a temporary and removable seal inside the expanded section 258 (see
As another example, a setting tool may be used to run the isolation assembly 175 downhole, may be constructed to form one or multiple temporary and removable seal(s) inside the sleeve 207, and the setting tool may contain a chemical agent (a gas producing agent, for example) that is activated (via an activating agent communicated from the Earth surface of the well or released from the tool in response to the tool being actuated from the Earth surface of the well, as examples), which causes sufficient pressure to build up inside the sleeve 207 to deform and radially expand the sleeve 207. The setting tool may then be actuated to remove the temporary seal(s) so that the setting tool may be removed from the well.
In accordance with example implementations, the object (such as activation ball 150 of
In accordance with some implementations, the sleeve 207 and/or the untethered object that is ultimately seated in the sleeve 207 may be constructed from a milling material so that a milling tool may be run into the well to mill out the object and/sleeve when the fluid barrier is no longer needed, in accordance with example implementations.
In accordance with further example implementations, the object and/or one or more components of the isolation seat assembly 175 may be constructed from dissolvable or degradable materials. As an example, dissolvable, or degradable, alloys may be used similar to the alloys that are disclosed in the following patents, which have an assignee in common with the present application and are hereby incorporated by reference: U.S. Pat. No. 7,775,279, entitled, “DEBRIS-FREE PERFORATING APPARATUS AND TECHNIQUE,” which issued on Aug. 17, 2010; and U.S. Pat. No. 8,211,247, entitled, “DEGRADABLE COMPOSITIONS, APPARATUS COMPOSITIONS COMPRISING SAME, AND METHOD OF USE,” which issued on Jul. 3, 2012.
In accordance with an example implementation, the object may be constructed from a dissolvable or degradable material that is constructed to sufficiently dissolve/degrade after a certain time (a week, several weeks, a month, several months, and so forth) to purposefully compromise the structural integrity of the object so that the object collapses or otherwise loses its ability to be retained in the restriction 205 so that the object falls out of the restriction 205. In accordance with an example implementation, one or more of the anchor members 230 may be constructed from a dissolvable or degradable material that is constructed to sufficiently dissolve/degrade after a certain time to compromise the ability of the anchor members 230 to secure the isolation assembly 175 to the wall of the tubing string 120 so that the assembly 175 releases from the string 120.
Although implementations are discussed herein in which the isolation assembly 175 may be used as a fracturing plug assembly to form a fluid barrier for a well stimulation operation, the isolation assembly 175 may be used to form a fluid barrier for downhole operations, other than well stimulation operations. For example, the isolation assembly 175 may be used to form a fluid barrier to pressurize a fluid column for such purposes as firing a tubing conveyed pressure (TCP) perforating gun; actuating a downhole tool; shifting a sleeve valve; and so forth.
Therefore, in general, the isolation assembly 175 may be used for a wide variety of downhole operations, such as shifting a downhole operator; diverting fluid; forming a downhole obstruction; operating a tool; and so forth. Although implementations are discussed herein in which the expansion tool and isolation assembly 175 are run, or deployed, downhole as a unit, in accordance with further example implementations, the setting tool and isolation assembly may be run downhole separately.
Referring to
In this context of this application, “deforming the isolation assembly” refers to distorting at least one component of the isolation assembly. Depending on the particular implementation, this distortion may involve radially expanding the component(s), radially contracting the component(s), and as well as other distortions of the component(s).
As described above, in accordance with some implementations, a sleeve of the isolation assembly is deformed, and a restriction of the sleeve is used to catch an object to form a fluid barrier. More specifically, referring to
In accordance with further example implementations, the sleeve of the isolation assembly may contain features that enhance the anchoring of the assembly to the tubing string wall. These anchoring features may be used in lieu of a separate anchoring member of the isolation assembly (i.e., an anchoring member separate from the sleeve) or in conjunction with a separate anchoring member, depending on the particular implementation. Referring to
Referring to
Referring to
Referring to
Referring to
In accordance with further example implementations, instead of forming an object catching restriction in the sleeve, the isolation assembly may include a seat and a sleeve; and a setting tool assembly may be constructed to wedge the sleeve between the seat and the tubing string for purposes of anchoring the seat in place inside the tubing string. In this manner, the seat and sleeve may be mounted to the setting tool and run into the well as a unit with the setting tool. When at the target downhole location, the setting tool may be constructed to hold one of the seat and sleeve components in place while the setting tool applies a force to axially translate the other component to push the seat and sleeve together to wedge the sleeve between the seat and tubing string wall for purposes of anchoring the isolation assembly in place.
As a more specific example,
As depicted in
More specifically, referring to
In accordance with further example implementations, an isolation assembly may include a seat and a sleeve, which are run downhole on a setting tool, with the seat being mounted to the setting tool uphole of the sleeve. As a more specific example,
Similar to the isolation assemblies described above, one or multiple components of the isolation assemblies 600 and 700 depicted in
Thus, referring to
Referring to
While the present invention has been described with respect to a limited number of embodiments, those skilled in the art, having the benefit of this disclosure, will appreciate numerous modifications and variations therefrom. It is intended that the appended claims cover all such modifications and variations as fall within the true spirit and scope of this present invention.
Filing Document | Filing Date | Country | Kind |
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PCT/US2016/034972 | 5/31/2016 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
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WO2017/209727 | 12/7/2017 | WO | A |
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Number | Date | Country | |
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20200325748 A1 | Oct 2020 | US |