Bridge plugs

A bridge plug for a well includes an actuator member that moves from a first position such that the bridge plug is in a retracted position and a second position such that the bridge plug is in a deployed position. The bridge plug includes a slip section comprising one or more slips that grip a surface radially outward of the bridge plug in the deployed position and a petal section positioned downward of and adjacent to the slip section, the petal section comprising a plurality of petals that fan radially outward from the bridge plug in the deployed position to catch a slurry. The bridge plug also includes a centralizer section positioned downward of and adjacent to the pedal section, the centralizer section having a plurality of centralizers that ramp outwardly in an upward direction in the deployed position for centralizing the bridge plug.

BACKGROUND

The present disclosure relates to bridge plugs and similar downhole tools and more specifically to through-tubing bridge plugs having low cost and high expansion that can be run and set using non-explosive, battery powered electromechanical setting tools.

2. Description of Related Art

Oil and gas wells are sometimes closed off, for example, when a lower zone of a well becomes non-productive, but one or more upper zones continue to be productive. A bridge plug provides a convenient way to seal off the zones from one another. The bridge plug may be set at a desired location within the well casing to isolate the zones of the well. Bridge plugs may be permanent or they may be retrievable. A retrievable bridge plug is typically used for certain drilling and workover operations to provide a temporary separation of zones. Permanent bridge plugs may be used when it is preferable to permanently close off a portion of the well.

One common type of permanent bridge plug is a “through tubing” bridge plug, or “thru tubing” bridge plug. The through-tubing bridge plug, as the name suggests, is lowered through a tubing string via a slickline, wireline, coiled tubing, or similar conveyance. The through-tubing bridge plug may then be set by axially compressing one or more packing elements on the bridge plug. The axial compression of the packing elements forces them to expand radially outward to contact the inner surface of the casing and thereby seal off a portion of the well.

Because through-tubing bridge plugs are passed through a tubing string, conventional through-tubing bridge plugs have a small outer diameter, which limits the extent to which the bridge plugs can radially expand. A larger expansion generally requires the through-tubing bridge plug to have a longer length, which in turn necessitates a setting tool with longer stroke (i.e., axial displacement), as long as 75 inches or more in some cases. Additionally, conventional through-tubing bridge plugs often employ an explosive charge to provide a sufficiently powerful force to actuate the bridge plugs, which requires special precaution and handling. Thus, in short, conventional through-tubing bridge plugs are large, expensive, and require powerful setting tools to operate.

Accordingly, a need exists for a through-tubing bridge plug that is low-cost, has high expansion, and can be operated using non-explosive, battery-powered setting tools.

DETAILED DESCRIPTION

As alluded to above, the embodiments disclosed herein provide a low-cost, high-expansion through-tubing bridge plug that can be run (i.e., in the retracted position) on a slickline, wireline, coiled tubing, and the like, and set (i.e., in the deployed position) using a conventional downhole power unit and an electro-mechanical setting tool instead of an explosive charge because a less powerful stroke is required to create a high-expansion seal. The downhole power unit may be a battery power unit in some embodiments and the setting tool may be a battery-powered electro-mechanical setting tool. Among other advantages, the through-tubing bridge plug may be used as a low-cost cement bridge that allows cement to be added and cured above the bridge plug to form a permanent plug.

Unlike traditional bridge plugs, the through-tubing bridge plug disclosed herein does not need a long stack of elastomeric seals that “climb” over each other to create a seal. As a result, a pull length of the actuator member is much shorter than conventional through-tubing bridge plugs which require setting tools with strokes longer than 75 inches, in some cases. As appreciated by those having ordinary skill in the art, the bridge plug100as described herein can be utilized in a system for well operations on a slickline, wireline, or any other suitable line. For example, a method includes setting a bridge plug on a slickline in a well. In certain embodiments, setting the bridge plug can include actuating an actuator member of the bridge plug over a pull length of less than 15 percent of the length of the bridge plug or any other suitable pull length.

Reference will now be made to the drawings wherein like reference numerals identify similar structural features or aspects of the subject disclosure.

Referring first toFIG. 1, an offshore oil or gas well10is shown in which a through-tubing bridge plug in accordance with the embodiments disclosed herein may be used. In a typical arrangement, the well10has a semi-submersible platform12centered over subterranean oil and gas formations14,16located below the sea floor18. A subsea conductor20extends from a deck22of the platform12to the sea floor18and through a wellbore24formed in the subterranean formations14,16. The wellbore24includes a casing26that is typically supported by a cement sheath28. The casing26has two sets of perforations30,32in the intervals proximate the oil and gas formations14,16.

A tubing string34extends from a wellhead36to a location below the gas formation16but above the oil formation14and provides a conduit for oil and/or gas to travel to the surface. Packers38,40provide a seal between the tubing string34and the casing26to direct the flow of oil and/or gas from the formation16to the interior of the tubing string34. Within the tubing string34is a slickline42used to convey a downhole power unit44and a through-tubing bridge plug46. Even though the downhole power unit44and through-tubing bridge plug46are depicted as being deployed on a slickline, it is to be understood by those skilled in the art that the downhole power unit44and the bridge plug46may be deployed on other types of conveyances, including, but not limited to a wireline, coiled tubing, and the like, without departing from the scope of the disclosed embodiments.

In general operation, the through-tubing bridge plug46is run in a retracted configuration through the tubing string34until the bridge plug46reaches its target location in the wellbore24. Once there, the through-tubing bridge plug46is set into its sealing configuration against the casing26using the downhole power unit44to seal off a portion of the wellbore24(e.g., the portion containing oil formation14). The design of the bridge plug46, as discussed further below, is such that no explosive charge is needed to actuate the bridge plug46. Rather, a conventional electromechanical setting tool (not expressly shown) and the downhole power unit44may be used to actuate the bridge player46. Any suitable downhole power unit44may be used, including a battery power unit, with the electromechanical setting tool. And by virtue of its innovative design, as discussed further below, the bridge plug46can achieve higher expansion then existing tools without requiring the setting tool to have a long stroke.

Note that althoughFIG. 1depicts a vertical well, it should be understood by those skilled in the art that the through-tubing bridge plug disclosed herein is equally well-suited for use in deviated wells, inclined wells, horizontal wells, multilateral wells and the like. Likewise, althoughFIG. 1depicts an offshore operation, it should be understood by those skilled in the art that the through-tubing bridge plug disclosed herein is equally well-suited for use in onshore operations. Following now are exemplary implementations of the through-tubing bridge plug46according to various aspects of this disclosure.

In accordance with at least one aspect of this disclosure, referring next toFIG. 2A, a through-tubing bridge plug100capable of being run within a tubing string includes a shaft like actuator member101operable to set or otherwise deploy the bridge plug100. The actuator member101is designed to move between a first position as shown inFIG. 2Asuch that the bridge plug100is put in a retracted position, and a second position as shown inFIG. 2Bsuch that the bridge plug100is put in a deployed position. For added clarity,FIG. 2Cshows a perspective view of the bridge plug100in the deployed position andFIG. 2Dshows a front plan view of the bridge plug100in the deployed position.

Referring still toFIG. 2A, the through-tubing bridge plug100includes a slip section103comprising a number of equally spaced slips103a(e.g., five). Each slip103ais designed to move between a retracted position as shown inFIG. 2Aand a deployed position as shown inFIG. 2B. When in the deployed position, the slips103aextend radially outwardly to grip the casing or wellbore, thereby anchoring or locking the bridge plug100in place. The slips103acan be of any suitable shape and design and can be actuated in any suitable manner to extend outwardly, as appreciated by those having ordinary skill in the art. For example, as seen inFIG. 2B, the slips103amay have a hinged design that may be actuated via an axial compression force on the hinged slips103ain some embodiments.

The bridge plug100can also include a petal section105downward (to the right) of and adjacent to the slip section103. The petal section105can include a plurality of individual petals105athat, when deployed (e.g., by actuator member101), fan radially outward from the bridge plug100to catch and hold slurry, concrete, and other operating material delivered down the casing and/or wellbore (e.g., to create a seal). The petal section105can allow for high expansion relative to the diameter of the plug100in a running configuration by virtue of having the folding pedals105a. The pedals105acan expand outwardly further than a traditional bridge plug elastomeric seal of the same length.

In certain embodiments, the petals105aare hinged to the petal section105, which allows them to rotate (at least partially) from a retracted or folded position (as shown inFIG. 2A) outwardly from a longitudinal axis (see dashed line) of the bridge plug100into a deployed or unfolded position (as shown inFIG. 2B). In certain embodiments, the petals105acan also be doubly hinged such that the pedals105acan rotate (at least partially) outwardly from the longitudinal axis of the bridge plug100as well as about a central axis of each petal105a(e.g., for pitch of each petal105ato change as the petals105adeploy). As shown more clearly inFIG. 2B, the slip section103can include a downward ramp face103bthat, when deployed (e.g., by actuator member101), force the petals105ato unfold radially outward as the petal section105is pulled toward the ramp face103b.

The petals105a, which may have generally planar or slightly curved surfaces, can include any suitable shape, such as a radially inwardly tapering shape (as more easily seen inFIG. 2D) and other shapes appreciated by those skilled in the art. In the embodiment shown here, there are 10 petals105a, but the specific number of petals may vary based on the particular shape and size of pedals and/or the size of the bridge plug100. As well, the shape of the petals105ashould be selected so that, when deployed, the petals105aminimize any gap between adjacent petals105a, but do not interfere with each other when being put into the retracted position or into the deployed position. Similarly, the petals105acan be made of any suitable material capable of withstanding downhole conditions and can have any radial length that allows the petals105ato conform to the wall of the wellbore and/or casing.

A centralizer section107is also present on the bridge plug100downhole (to the right) of and adjacent to the pedal section105. The centralizer section107has a plurality of individual centralizers107athat, when deployed (e.g., by actuator member101), help to center the bridge plug100within the casing and or wellbore. In the embodiment shown here, there are 10 centralizers107a, but as with the pedals105a, the specific number of centralizers may vary based on the size of the bridge plug100. Each centralizer107acan rotate from a retracted position as shown inFIG. 2A, outward from the longitudinal axis of the bridge plug100, and downward into a deployed position, as shown inFIG. 2B. When deployed, the centralizers107aare designed to ramp outwardly in an upward (left) direction such that the centralizers107aextend progressively more radially outward in that direction and progressively less radially outward in the downward direction. The centralizers107acan include any suitable shape, such as rectangular (as shown inFIGS. 2A and 2B), as appreciated by those skilled in the art. The petal section105can include a downward ramp portion105bthat, when deployed, is designed to drive under the centralizers107ato force the centralizers107aoutward into the deployed position.

In certain embodiments, referring toFIGS. 3A and 3B, the centralizer section107can include a polymer (e.g., elastomer) bag209disposed around the centralizers107ato seal and protect the centralizers107a.FIG. 3Ashows the bridge plug100, including the polymer bag209, in the retracted position andFIG. 3Bshows the bridge plug100, including the polymer bag209, in the deployed position. The polymer bag209can cover at least a portion of any gaps between individual centralizers107aand improve the ability of the bridge plug100to catch slurry, cement, and other operating material. For example, referring toFIG. 3C, the bridge plug100is shown in plan view wherein the polymer bag209can be seen covering a radial area of the petals105ain the deployed position.

Referring again toFIGS. 3A and 3B, as shown, the actuator member101can be a pull rod that can be pulled or otherwise moved (uphole) a pull distance between the first position (FIG. 3A) and the second position (FIG. 3B). In certain embodiments, the pull distance between the first position and the second position of the actuator member can be less than about 4.5 inches. The pull distance between the first position and the second position of the actuator member can be less than about 15 percent of a length of the bridge plug100in some embodiments. In certain embodiments, the pull distance between the first position and the second position of the actuator member can be less than about two times an outer diameter of the bridge plug100in the retracted position.

Referring toFIGS. 2A and 2Bagain, the actuator member101can be fixed to a tip member111at a downward end of the actuator member101. As shown, the centralizer section107can be hingedly fixed to the tip member111such that the centralizers107ahinge at the tip member111. The slip section103and the petal section105can be slidably disposed on the actuator member101such that the slip section103(e.g., the downward ramp face103b) pushes against the petal section105and the petal section105pushes against the centralizer section107to actuate the slips103a, petals105a, and the centralizers107aradially outwardly to the deployed position.

In accordance with at least one aspect of this disclosure, a bridge plug for a well includes an actuator member that moves from a first position such that the bridge plug is in a retracted position and a second position such that the bridge plug is in a deployed position. The bridge plug includes a slip section comprising one or more slips that grip a surface radially outward of the bridge plug in the deployed position and a petal section positioned downward of and adjacent to the slip section, the petal section comprising a plurality of petals that fan radially outward from the bridge plug in the deployed position to catch a slurry. The bridge plug also includes a centralizer section positioned downward of and adjacent to the pedal section, the centralizer section having a plurality of centralizers that ramp outwardly in an upward direction in the deployed position for centralizing the bridge plug.

In accordance with at least one aspect or combination of aspects, the centralizer section can include a polymer bag disposed around the centralizers to seal the centralizers.

In accordance with at least one aspect of this disclosure or any combination thereof, the actuator member can be a pull rod that moves a pull distance between the first position and the second position.

In accordance with at least one aspect of this disclosure or any combination thereof, the pull distance between the first position and the second position of the actuator member can be less than about 4.5 inches.

In accordance with at least one aspect of this disclosure or any combination thereof, the pull distance between the first position and the second position of the actuator member can be less than about 15 percent of a length of the bridge plug.

In accordance with at least one aspect of this disclosure or any combination thereof, the pull distance between the first position and the second position of the actuator member can be less than about two times of an outer diameter of the bridge plug in the retracted position.

In accordance with at least one aspect of this disclosure or any combination thereof, the actuator member can be fixed to a tip member at a downward end of the actuator member.

In accordance with at least one aspect of this disclosure or any combination thereof, the centralizer section can be hingedly fixed to the tip member.

In accordance with at least one aspect of this disclosure or any combination thereof, the slip section and the petal section can be slidably disposed on the actuator member such that the slip section pushes against the petal section and the petal section pushes against the centralizer section to actuate the slips, petals, and the centralizers radially outwardly to the deployed position.

In accordance with at least one aspect of this disclosure or any combination thereof, a system for well operations includes a slickline and a bridge plug attached to the slickline, the bridge plug including an actuator member that moves from a first position such that the bridge plug is in a retracted position and a second position such that the bridge plug is in a deployed position, a slip section comprising one or more slips that grip a surface radially outward of the bridge plug in the deployed position, a petal section positioned downward of and adjacent to the slip section, the petal section comprising a plurality of petals that fan radially outward from the bridge plug in the deployed position to catch a slurry, and a centralizer section positioned downward of and adjacent to the pedal section, the centralizer section including a plurality of centralizers that ramp outwardly in an upward direction in the deployed position for centralizing the bridge plug.

In accordance with at least one aspect of this disclosure or any combination thereof, the centralizer section can include a polymer bag disposed around the centralizers to seal the centralizers.

In accordance with at least one aspect of this disclosure or any combination thereof, the actuator member can be a pull rod that moves a pull distance between the first position and the second position.

In accordance with at least one aspect of this disclosure or any combination thereof, the pull distance between the first position and the second position of the actuator member can be less than about 4.5 inches.

In accordance with at least one aspect of this disclosure or any combination thereof, the pull distance between the first position and the second position of the actuator member can be less than about 15 percent of a length of the bridge plug.

In accordance with at least one aspect of this disclosure or any combination thereof, the pull distance between the first position and the second position of the actuator member can be less than about two times of an outer diameter of the bridge plug in the retracted position.

In accordance with at least one aspect of this disclosure or any combination thereof, the actuator member can be fixed to a tip member at a downward end of the actuator member.

In accordance with at least one aspect of this disclosure or any combination thereof, the centralizer section can be hingedly fixed to the tip member.

In accordance with at least one aspect of this disclosure or any combination thereof, the slip section and the petal section can be slidably disposed on the actuator member such that the slip section pushes against the petal section and the petal section pushes against the centralizer section to actuate the slips, petals, and the centralizers radially outwardly to the deployed position.

In accordance with at least one aspect of this disclosure or any combination thereof, a method includes setting a bridge plug on a slickline in a well.

In accordance with at least one aspect of this disclosure or any combination thereof, setting the bridge plug can include actuating an actuator member of the bridge plug over a pull length of less than 15 percent of the length of the bridge plug.