Patent ID: 12234698

DETAILED DESCRIPTION

Embodiments of the present disclosure will now be described in detail with reference to the accompanying Figures. Like elements in the various figures may be denoted by like reference numerals for consistency. Further, in the following detailed description of embodiments of the present disclosure, numerous specific details are set forth in order to provide a more thorough understanding of the claimed subject matter. However, it will be apparent to one of ordinary skill in the art that the embodiments disclosed herein may be practiced without these specific details. In other instances, well-known features have not been described in detail to avoid unnecessarily complicating the description. Additionally, it will be apparent to one of ordinary skill in the art that the scale of the elements presented in the accompanying Figures may vary without departing from the scope of the present disclosure.

Embodiments in accordance with the present disclosure generally relate to the downhole isolation of wellbores and, more particularly, to retrievable plugs for use in wellbores exhibiting a range of sizes (diameters). The plugs or “bridge plugs” described herein may be deployed in a wellbore, casing, or tubing and are fully retrievable and reusable. Further, the methods of installation, utilization, and retrieval of the plugs are also disclosed herein to illustrate the advantages presented by the disclosed embodiments, such as a reduced energy requirement and elimination of specialized tooling required for installation.

FIG.1Ais a cross-sectional side view of a prior art plug100. The plug100is shown inFIG.1Aa first or “unactuated” state. The plug100is depicted as being lowered into a wellbore102drilled into a subterranean formation104. In some cases, the wellbore102may be lined with a string of casing106, but the casing106could alternatively be omitted and the plug100may be deployed in an “open-hole” wellbore. The plug100can be lowered into the wellbore102on a conveyance108, which can include wireline, slickline, coiled tubing, drill pipe, production tubing, or any combination thereof. Those skilled in the art will readily recognize that the type of conveyance108utilized may depend upon the actuation mechanism required by the plug100. The conveyance108may be operatively coupled to the plug100via a top connector110, which in some cases may comprise a setting fish neck. The plug100is conveyed into the wellbore102to a predetermined location and actuated to isolate downhole portions of the wellbore102from uphole portions.

The plug100may include a generally cylindrical body112sized to be received within and lowered into the wellbore102. One or more seal elements114are arranged or provided on the body112and are actuatable to create a seal within the wellbore102as the plug100actuates. Actuating the plug100to expand the seal elements114may be facilitated via a variety of expansion devices or mechanisms116, shown generally inFIG.1Ain dashed lines. In the illustrated example, the expansion mechanism116comprises an inflatable device operable to hydraulically or pneumatically expand the seal elements114into sealing contact with the inner wall of the wellbore102or the casing106. In alternative examples, the expansion mechanism116may comprise interacting mechanical components configured to axially compress the seal elements114, which causes the seal elements114to expand radially outward and into sealing contact with the inner wall of the wellbore102or the casing106.

FIG.1Bis a cross-sectional side view of the prior art plug100in a second or “actuated” state. InFIG.1B, the expansion mechanism116has been activated or actuated to expand or force the seal elements114into sealing contact with the inner wall of the wellbore102or the casing106. The seal elements114are thereby capable of fluidly isolating portions of the wellbore102above and below the actuated plug100. The actuated plug100may then facilitate hydrocarbon extraction operations within either isolated portion of the wellbore102, and may be retained in place permanently or later retrieved.

Prior art plugs, such as the plug100, are conventionally designed and sized to operate in wellbores of a predetermined size (diameter). Accordingly, larger diameter wellbores will require plugs sized to seal the larger diameter, and smaller diameter wellbores will require plugs sized to seal the smaller diameter. Further, removing the plug100oftentimes requires a drilling or milling operation to physically destroy the plug100downhole, or may alternatively require additional downhole tooling and mechanisms designed to reverse or deactivate the expansion mechanism116. In either removal scenario, the plug100may be damaged or unusable in further downhole sealing operations.

According to the present disclosure, embodiments of an expandable and retrievable plug are described. The expandable and retrievable plug includes an inflatable element operable to be inflated and thereby transition a plurality of arm bars and expandable blades radially outward. As the arm bars and expandable blades expand radially outward, an expandable seal correspondingly expands radially outward to sealingly engage an inner diameter of the wellbore where the plug is deployed. The radially outward movement of the arms and blades allows the expandable seal to seal against a wide range of wellbore diameters. Moreover, actuation of the plug is reversible, which allows the plug to be deactivated and retrieved back to surface.

FIG.2is a bottom end view of an example expandable retrievable plug200, according to at least one embodiment of the present disclosure. As described herein, the expandable retrievable plug200(hereinafter, “the plug200”) may be conveyable into a wellbore (e.g., the wellbore102ofFIG.1) and actuated between a first or “unactuated” state and a second or “actuated” state. The plug200is shown inFIG.2in the actuated state, or in the process of transitioning to the actuated state. The plug200is conveyed into the wellbore in the un-actuated state and, upon reaching a predetermined location within the wellbore, the plug200may be actuated to the actuated state, thereby sealing the wellbore and isolating uphole and downhole portions of the wellbore at the plug200.

In some embodiments, as illustrated, the plug200may include a central component or “base”201(shown in dashed lines), an inflatable element202, and a plurality of arm bars204. The base201forms the central component part or element of the plug200, and the inflatable element202and the arm bars204may be operatively coupled thereto. More specifically, the inflatable element202may be attached to the base201, and the arm bars204may be pivotably attached to the base201at corresponding hinges (not shown) and engageable with the inflatable element202. As described herein, the inflatable element202may be inflated (expanded in size), and as the inflatable element202inflates, the arm bars204may be urged to pivot radially outward based upon the level of inflation of the inflatable element202.

The plug200may further include a pressure vessel206in fluid communication with the inflatable element202. The pressure vessel206may be operable and otherwise selectively actuatable to provide (inject) a fluid to the inflatable element202to inflate the inflatable element202. In some embodiments, the pressure vessel206may comprise a pneumatic pressure vessel, and the fluid may comprise a compressed gas (e.g., air) that is selectively released into the inflatable element202. In other embodiments, however, the pressure vessel206may comprise a hydraulic pressure vessel, and the fluid may comprise a hydraulic fluid that is selectively pumped into the inflatable element202under pressure. As the fluid is injected into the inflatable element202, the inflatable element202inflates and its enlarged size correspondingly engages the arm bars204, which are urged to pivot radially outward, as described in more detail below. Accordingly, the pressure vessel206may be selectively activated downhole to actuate (expand) the inflatable element202and thereby expand the arm bars204.

In some embodiments, the pressure vessel206may be time-activated. In such embodiments, the pressure vessel206may include (or be in communication with) an internal timer that may be set or programmed prior to deploying the plug200. Moreover, in such embodiments, the internal timer may be programmed with a predetermined time or duration, which will enable proper positioning of the plug200prior to activating the pressure vessel206and releasing the gas into the inflatable element202. In other embodiments, however, the pressure vessel206may be in communication with surface equipment (either wired or wirelessly) such that the pressure vessel206may be selectively actuated remotely by a well operator when the plug200is positioned in the desired location within the wellbore.

The arm bars204may be made of a variety of rigid materials. In some embodiments, for example, the arm bars204may be formed of a metal, such as cast iron, stainless steel, a steel alloy, or aluminum, which help maintain high yield strengths for high force applications. In other embodiments, however, the arm bars204may be made of other rigid materials, such as a high-strength polymer or a composite material, without departing from the scope of the disclosure. While four arm bars204are depicted inFIG.2, more or less than four may be employed in the plug200, without departing from the scope of the disclosure. Moreover, while the arm bars204are depicted as being equidistantly spaced from each other, the arm bars204could alternatively be non-equidistantly spaced.

As indicated above, the arm bars204may be pivotably attached to the base201. This allows the arm bars204to transition between a first or “stowed” configuration, and a second or “extended” configuration. The arm bars204are shown inFIG.2in the extended configuration, but are transitionable to the stowed configuration when conveying the plug200downhole, or when retrieving the plug200. To transition the arm bars204to the extended configuration, the inflatable element202is inflated through actuation of the pressure vessel206, as generally described above. As the inflatable element202inflates, the body of the inflatable element202physically engages the arm bars204and urges the arm bars204to pivot radially outward and to the extended configuration. The arm bars204can be transitioned back to the stowed configuration by releasing the pressure within the inflatable element202and otherwise deflating the inflatable element202. In at least one embodiment, the arm bars204may be spring-loaded. In such embodiments, releasing the pressure in the inflatable element202will allow the spring-loaded arm bars204to naturally transition back to the stowed configuration.

The plug200further includes a set of expandable blades208angularly interposing each pair of angularly adjacent arm bars204. In some embodiments, each expandable blade208may be operatively coupled to and extend radially outward from the base201. In other embodiments, only some of the expandable blades208are operatively coupled to the base201. In yet other embodiments, the expandable blades208may instead be attached to the angularly adjacent arm bars204, as discussed in more detail below.

The expandable blades208in each set angularly overlap each other by at least a small amount, similar to how a Japanese-fan operates. The expandable blades208in each set may be movable between a first or “stacked” state, and a second or “fanned” state. When in the stacked state, the expandable blades208fully or almost fully overlap each other and are thus “stacked” atop one another. However, when the expandable blades208are transitioned to the fanned estate, as shown inFIG.2, the expandable blades208are able to spread out and angularly overlap each other by only a small amount (or not overlap at all).

As illustrated, a set of expandable blades208angularly interposes each angularly adjacent pair of arm bars204. Moreover, the first and last blades208in each set are operatively coupled to the angularly adjacent arm bars204. Accordingly, as the arm bars204are transitioned between the stowed and extended configurations, the expandable blades208are correspondingly moved between the stacked and fanned states, respectively. During actuation of the plug200to the expanded state, the expandable blades208may be spread out to form integral sections of the plug200between angularly-adjacent arm bars204.

At least two expandable blades208may be included in each set between angularly-adjacent arm bars204, but the number of expandable blades208in each set may vary depending on the application in depending on the size of the expandable blades208. In some embodiments, the expandable blades208may be formed of a similar material as the arm bars204, which helps to create a full circle of high-yield strength material. In the illustrated embodiment, the plug200includes four arm bars204, with a set of expandable blades208interposing each angular-adjacent pair of arm bars204, and thus creating four quadrants of the plug200when expanded. It should be noted, however, that any number of arm bars204and corresponding sets of expandable blades208to create the plug200, without departing from the scope of this disclosure.

FIG.3is a top end view of the plug200, according to one or more embodiments of the present disclosure. InFIG.3, the base201is visible, and one or more hinges302may be operatively coupled to the base201. Each hinge302may be coupled to a corresponding one of the arm bars204(shown in dashed lines), accordingly the number of hinges302may be similar to the number of arm bars204. The hinges302impart pivoting ability to the arm bars204, thereby allowing the arm bars204to pivotably transition between the stowed and expanded configurations while remaining anchored to the base201. The hinges302may further connect the arm bars204with the adjacent set of expandable blades208, such that the plug200may expand and retract as necessary. Moreover, as briefly mentioned above, one or more of the hinges302may be spring-loaded, which allows the arm bars204naturally returned to the stowed configuration

The base201may further include one or more coupling features used to couple the plug200to a downhole conveyance, such as wireline, slickline, coiled tubing, a string of drill pipe or production tubing, or any combination thereof. In the illustrated embodiment, the plug200includes first and second coupling features304aand304b, alternately referred to as a “setting fish neck” and a “retrieving fish neck,” respectively. The coupling features304a,bmay be operable to either set the plug200within a wellbore or retrieve the plug200after operation of the plug200is completed.

The first coupling feature304a, for example, may provide a location to attach the plug200to a downhole conveyance, thereby enabling the plug200to be deployed within a wellbore. Moreover the first coupling feature304amay additionally provide a point of actuation for the plug200. In some embodiments, for example, the plug200may be run downhole on wireline operatively coupled to the first coupling feature304a. After locating the plug200within the wellbore at the proper or predetermined location, the first coupling feature304amay be manipulated using the wireline (conveyance) to trigger actuation of the plug200and thereby transition the plug200to the actuated state. The conveyance may further include slickline, coiled tubing, or drilling pipe, which may be connected with the first coupling feature304aat a surface location. Following the setting of the plug200, the conveyance may be jarred to free the conveyance from the first coupling feature304aand then run out of the hole.

In contrast, the second coupling feature304bmay enable retrieval of the plug200after the desired downhole operation has been performed within the wellbore. The second coupling feature304bmay provide or otherwise define a coupling structure capable of being located and grasped onto by a conveyance conveyed downhole. The coupling structure may be referred to as a “fish neck,” thus characterizing the second coupling feature304bas a “retrieving fish neck”. In at least one embodiment, the second coupling feature304bmay be operatively coupled to or otherwise include a deflating system designed to deflate the inflatable element202(FIG.2) when latching and pulling of the plug200is achieved.

As shown inFIG.3, the plug200may further include an expandable seal306. The expandable seal306may be configured to substantially cover the top end of the plug200, including covering the arm bars204and the sets of expandable blades208(FIG.2). The expandable seal306may comprise a pliable or stretchable rubber or elastomeric material capable of generating a sealed interface within a wellbore (or casing lining the wellbore) when the plug200transitions to the actuated state.

In some embodiments, the expandable seal306may comprise a type of balloon or bladder fitted about the outer circumference of the plug200and thereby substantially covering the top end of the plug200. In such embodiments, as the plug200transitions to the actuated state, the expandable seal306will correspondingly expand radially outward as the arm bars204and the expandable blades208(FIG.2) are transitioned radially outward. In other embodiments, however, the expandable seal306may comprise an elastomeric material or substance applied directly to each of the arm bars204and the expandable blades208, such as a coating, an overlay, an overmold, or the like. In such embodiments, as the plug200transitions to the actuated state, the elastomeric material coated on the arm bars204and the expandable blades208may be able to sealingly engage the inner radial wall of the wellbore casing where the plug200is deployed. In either scenario, the expandable seal306may be able to fold and contract as the plug200transitions back to the unactuated state.

Upon actuation, the expandable seal306may stretch with the expansion of the expandable blades208(FIG.2) and fill the desired diameter with the expandable seal306to form the seal. To reinforce the expandable seal306when the plug200is in the actuated state, the plug200may further include one or more reinforcing arms308(shown in dashed lines) extending radially outward from the base201. The reinforcing arms308may be coupled to the base201, the expandable blades208, or both, and may be arranged between the expandable blades208and the expandable seal306. The reinforcing arms308may be configured to support the expandable blades208when transitioned to the fanned state. In some embodiments, the reinforcing arms308may be made of a similar material as the arm bars204to increase the overall strength of the plug200and retain the shape of the expandable seal306when the plug200transitions to the actuated state. With proper sizing of the arm bars204, and the additional strength of the reinforcing arms308, the plug200may be sized to any diameter wellbore.

FIG.4is a cross-sectional side view of the plug200deployed within a wellbore102, according to one or more embodiments of the present disclosure. More specifically,FIG.4depicts the plug200in unactuated (dashed lines) and actuated states (solid lines). As depicted, when the plug200is in the unactuated state, the inflatable element202is deflated and otherwise exhibits a smaller diameter, and the arm bars204are allowed to remain in the stowed configuration. With the smaller diameter inflatable element202, the arm bars204and attached expandable seal306create a smaller profile of the overall plug200such that the plug200may be lowered into the wellbore102and the casing106.

Once the plug200is located within the wellbore102at a predetermined location, the pressure vessel206may be activated to transition the plug200from the un-actuated state to the actuated state. As briefly mentioned above, the pressure vessel206may be actuated and otherwise activated using either a timer or via remote actuation. Once the pressure vessel206is activated, the pressurized fluid (e.g., gas or compressible liquid) within the pressure vessel206may flow into the inflatable element202and thereby transition the inflatable element202from a deflated state to an inflated state. In at least one embodiment, as illustrated, the pressure vessel206may be fluidly coupled to the inflatable element202via a gas tube402. The gas tube402provides a conduit to convey the fluid from the pressure vessel206to the inflatable element202. In other embodiments, however, the gas tube402may be omitted and the pressure vessel206may instead be directly coupled to (or contained within) the inflatable element202.

Upon inflating the inflatable element202, the arm bars204may pivot radially outward to the extended state. In the process, the expandable blades208(FIG.2) may transition from the stacked state to the fanned state, while simultaneously stretching the expandable seal306to reach the desired diameter of the wellbore102or the casing106.

The illustrated embodiment, the second coupling feature304bmounted to the base201may include an eye or “eyelet”404that may help a well operator locate and connect to the plug200during a fishing operation to locate the plug200. As illustrated, the conveyance108(shown in dashed lines) may be operatively coupled to the second coupling feature304bat the eyelet404.

In at least one embodiment, the eyelet404may be operatively coupled to a valve406, and the valve406may be in fluid communication with the inflatable element202. Upon connection to the eyelet404, the conveyance108attached to the plug200may apply an upward force on the second coupling feature304b, which simultaneously actuates the valve406and thereby releases fluid pressure within the inflatable element202and otherwise commences its deflation process back to the deflated state. In a further embodiment, a shearable member may hold the valve406closed, such that as a jarring force is provided by the conveyance108, the shearable member may be destroyed and the inflatable element202may deflate.

In some embodiments, the pressurized gas discharged from the inflatable element202may be released to the wellbore102. During this process, the inflatable element202deflates and otherwise reduces in size. The reduction in size of the inflatable element202may allow (cause) the arm bars204to unseat from the walls of the wellbore102(or the casing106that lines the wellbore102), and 1 transition back toward the stowed configuration, as represented by the dashed lines. Thus, releasing the gas and unseating of the arm bars204eliminates the seal within the wellbore102, and places the plug200back to the un-actuated state {e.g., a smaller radial profile) and otherwise in a condition to be removed from the wellbore102. The conveyance108may then be retracted back towards the well surface, and simultaneously drawing the plug200uphole as coupled to the second coupling feature304b. Once returned to the well surface, the plug200may be prepared to be reused in a subsequent downhole operation. For example, the pressure vessel206may be replenished with fluid and the plug200may be subsequently redeployed for further use.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, for example, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “contains”, “containing”, “includes”, “including,” “comprises”, and/or “comprising,” and variations thereof, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

Terms of orientation used herein are merely for purposes of convention and referencing and are not to be construed as limiting. However, it is recognized these terms could be used with reference to an operator or user. Accordingly, no limitations are implied or to be inferred. In addition, the use of ordinal numbers (e.g., first, second, third, etc.) is for distinction and not counting. For example, the use of “third” does not imply there must be a corresponding “first” or “second.” Also, if used herein, the terms “coupled” or “coupled to” or “connected” or “connected to” or “attached” or “attached to” may indicate establishing either a direct or indirect connection, and is not limited to either unless expressly referenced as such.

While the disclosure has described several exemplary embodiments, it will be understood by those skilled in the art that various changes can be made, and equivalents can be substituted for elements thereof, without departing from the spirit and scope of the invention. In addition, many modifications will be appreciated by those skilled in the art to adapt a particular instrument, situation, or material to embodiments of the disclosure without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed, or to the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. Moreover, reference in the appended claims to an apparatus or system or a component of an apparatus or system being adapted to, arranged to, capable of, configured to, enabled to, operable to, or operative to perform a particular function encompasses that apparatus, system, or component, whether or not it or that particular function is activated, turned on, or unlocked, as long as that apparatus, system, or component is so adapted, arranged, capable, configured, enabled, operable, or operative.