Patent Application
20230349258
Swellable packers are often utilized in oil and gas operations, particularly those with non-cemented lower completions, to seal annular regions against hydrocarbon, sand, and water migration. Swellable packers are formed of elastomers which expand due to a reaction of the packer with wellbore fluids. Elastomers used to form swellable packers may be oil-activated elastomers, which work on the principle of absorption and dissolution, or water-activated elastomers, which work on the principle of osmosis. The amount of swelling may depend, for example, on the chemistry of the elastomer and fluids and the temperature at which the exposure occurs.
Swellable packers may be installed around tubulars by wrapping the packer material around a tubular or by sliding a slip-on packer around a tubular, for example.
In some cases, there may be fluids in the wellbore which may cause a premature reaction, leading to expansion of the packer before it reaches setting depth. In such cases, a prematurely swelled packer may need to be removed, which may increase costs and delay subsequent operations.
This 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 one aspect, embodiments disclosed herein relate to a packer protection system. The packer protection system may include a swellable packer disposed along a tubular and a packer protection apparatus disposed around the swellable packer. The packer protection apparatus may include a shell body, a first connection mechanism provided on the shell body, and a second connection mechanism provided on the shell body, where the first connection mechanism and the second connection mechanism interlock. The packer protection apparatus may also include a shear pin removably fitted through the first connection mechanism and the second connection mechanism and at least one fluid port provided in the shell body. The shell body may extend entirely around the swellable packer to create a sealed chamber between an inner surface of the shell body and an outer surface of the swellable packer.
In another aspect, embodiments disclosed herein relate to a packer protection apparatus. The packer protection apparatus may include a shell body, which comprises a plurality of shell sections, a first connection mechanism provided on a first section of the plurality of shell sections, and a second connection mechanism provided on a second section of the plurality of shell sections. The first connection mechanism and the second connection mechanism may interlock, and the plurality of shell sections may be circumferentially arranged and connected together to define an interior chamber. The packer protection apparatus may also include a fluid port formed through the shell body. The fluid port may include an opening communicating the interior space to an exterior of the shell body and a pressure relief device sealing the opening.
In yet another aspect, embodiments disclosed herein relate to a method for protecting a swellable packer, which may include surrounding a swellable packer with a packer protection apparatus, where the swellable packer is disposed along a tubular and where the packer protection apparatus comprises a shell body and a fluid port formed through the shell body. The method may further include running the tubular to a setting depth within a wellbore, circulating a fluid within the wellbore, transitioning the fluid port from a closed configuration to an open configuration, flowing the fluid through the fluid port to contact the swellable packer, expanding the swellable packer with the fluid to an expanded configuration, and using the expanding swellable packer to break apart the shell body.
Other aspects and advantages of the claimed subject matter will be apparent from the following description and the appended claims.
Specific embodiments of the disclosed technology will now be described in detail with reference to the accompanying figures. Like elements in the various figures are denoted by like reference numerals for consistency. The size and relative positions of elements in the drawings are not necessarily drawn to scale. For example, the shapes of various elements and angles are not necessarily drawn to scale, and some of these elements may be arbitrarily enlarged and positioned to improve drawing legibility. Further, the particular shapes of the elements as drawn are not necessarily intended to convey any information regarding the actual shape of the particular elements and have been solely selected for ease of recognition in the drawing.
In the following detailed description of embodiments of the disclosure, numerous specific details are set forth in order to provide a more thorough understanding of the disclosure. However, it will be apparent to one of ordinary skill in the art that the disclosure 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.
Throughout the application, ordinal numbers (e.g., first, second, third, etc.) may be used as an adjective for an element (i.e., any noun in the application). The use of ordinal numbers is not to imply or create any particular ordering of the elements nor to limit any element to being only a single element unless expressly disclosed, such as using the terms “before”, “after”, “single”, and other such terminology. Rather, the use of ordinal numbers is to distinguish between the elements. By way of an example, a first element is distinct from a second element, and the first element may encompass more than one element and succeed (or precede) the second element in an ordering of elements.
In the following description of
In one aspect, embodiments disclosed herein relate to a packer protection apparatus which may be installed around a swellable packer. A packer protection apparatus according to embodiments disclosed herein may prevent premature expansion of swellable packers before the packers reach a desired setting depth. In another aspect, embodiments disclosed herein relate to an installation method for a packer protection system within a wellbore.
In one or more embodiments, the packer protection apparatus 1 may have a shell body 5. The shell body 5 may be designed to break away from the tubular 3 when a predetermined condition is met, and a swellable packer 11 within the packer protection apparatus 1 swells, as described in more detail below. The shell body 5 may break apart using different design features incorporated along the shell body 5.
For example, in some embodiments, the shell body 5 may be composed of a continuously formed shell section having break lines formed around the shell. Break lines are areas or lines of reduced shell thickness, where the shell thickness is measured between the inner surface and exterior surface of the shell. By providing break lines of reduced shell body thickness along the shell body 5, the break lines may act as fracture initiation sites upon application of a force. For example, similar to the theory behind notching a well wall to reduce hydraulic fracture initiation pressure, break lines may act as lines of notches formed along the shell body 5, which may require relatively less force to break than the remaining areas of the shell body 5. A shell body may be formed with a single continuously formed shell section having break lines, or with multiple continuously formed shell sections having break lines. In some embodiments, a single continuously formed shell section with break lines may form the shell body, where the single continuously formed shell section may have a generally tubular shape. In such embodiments, the single continuously formed shell section may be slid around a tubular section, and packer material may be injected into the interior chamber formed between the inner surface of the shell body and the outer surface of the tubular section. In some embodiments, when multiple continuously formed shell sections with break lines forms the shell body, the sections may be assembled and sealed around an already installed packer on a tubular section.
In other embodiments, the shell body 5 may be composed of a plurality of shell sections 7 that are releasably joined together, e.g., via releasable fasteners such as shear pins. When the swellable packer 11 within the packer protection apparatus 1 swells, the swellable packer 11 may apply a force capable of breaking apart the shell sections 7.
In one or more embodiments, the shell body 5 may be composed of fiber glass. However, there may be other embodiments in which other materials are utilized to create the shell body.
In one or more embodiments, the shell body 5 may have a maximum outer diameter 4 measured at the widest part of the shell body exterior profile, a first axial end 12, and a second axial end 6 opposite the first axial end 12. According to embodiments of the present disclosure, the overall shape of the shell body 5 (e.g., including the size and location of a maximum outer diameter) may correspond with and fit around a swellable packer 11. For example, in some embodiments, the inner surface of the shell body 5 may correspond in shape and size with an exterior profile of the swellable packer 11 assembled to a tubular 3, such that the interior profile of the shell body 5 matches the exterior profile of the packer assembly and the shell body 5 closely fits around the swellable packer 11. The exterior profile of the shell body 5 may match the interior profile of the shell body 5, where the shell body 5 may generally have a uniform thickness, or the exterior profile of the shell body 5 may be different from its interior profile, where the shell body 5 may vary in thickness.
In some embodiments, the maximum outer diameter 4 may be located in the axial center of the shell body 5. In one or more embodiments, the second axial end may have an outer diameter less than the maximum outer diameter 4. The shell body 5 may also have one or more fluid ports 9 provided circumferentially around the shell body 5 along an upstream interfacing surface 2 of the shell body 5. In one or more embodiments, the upstream interfacing surface 2 may be located within a region between the maximum outer diameter 5 and the second axial end 6 and may slope inwardly in a direction from the maximum outer diameter toward the tubular 3. When disposed in a well, fluid may flow through the well to the upstream interfacing surface 2 of the packer protection apparatus 1, where the fluid may enter the fluid port(s) 9 to flow inside the packer protection apparatus 1 and contact the swellable packer 11.
The shell body 5 may have a first and second connection mechanism, which interlock. In one or more embodiments, the first and second connection mechanisms may be integrally formed with the shell body 5. A shear pin 8 may be fitted through the first and second connection mechanisms to secure the shell body 5 around the tubular 3. When fluid enters the fluid port(s) 9 to contact and swell the swellable packer 11, the force from the expanding swellable packer 11 may push on the shell body 5 until the shell body 5 breaks apart (e.g., by breakage of the shear pin 8).
In one or more embodiments,
The packer protection apparatus 1 may be installed around the swellable packer 11, and any other packer installation components (e.g., end caps) that might be used to install the swellable packer 11 to the tubular 3. When the packer protection apparatus 1 is assembled around the swellable packer 11, the swellable packer 11 is sandwiched between the tubular 3 and the packer protection apparatus 1. In such configuration, the swellable packer 11 may have an interior surface that interfaces with the tubular component on which it is installed and an outer surface that interfaces directly with the inner surface of the packer protection apparatus 1 or that interfaces with a sealed chamber defined by the inner surface of the packer protection apparatus 1.
The packer protection apparatus 1 may entirely surround the outer surface of the swellable packer 11 and seal the swellable packer 11 from a well environment. In some embodiments, the axial ends 12, 6 of the packer protection apparatus 1 may be sealed against the tubular 3 (or an intermediate component between the tubular 3 and the packer protection apparatus 1) around the axial ends of the swellable packer 11 in order to enclose and seal the swellable packer 11 from the well environment. For example, in some embodiments, the axial ends 12, 6 of the packer protection apparatus 1 may have sealing surfaces that interface with the tubular 3 around opposite axial ends of the swellable packer 11. In some embodiments, sealing elements may be positioned between the tubular 3 and the axial ends 12, 6 of the packer protection apparatus 1.
The swellable packer 11 may be intended for use within the wellbore to provide zonal isolation between different wellbore regions. The swellable packer 11, when at an appropriate depth within the wellbore, may be expanded to create a seal within an annular region of the well. In one or more embodiments, expansion of the swellable packer 11 may be caused by contact of the packer with wellbore fluids. As a result, the swellable packer 11 should be prevented from contacting wellbore fluids until it is positioned at a desired setting depth within the wellbore. The shell body 5 may be fitted around the swellable packer 11 in order to provide a protective covering that prevents contact of the swellable packer 11 with wellbore fluids until reaching the desired setting depth.
Turning now to
A first connection mechanism 21 may be provided along the first edge 17 and a second connection mechanism 23 may be provided along the second edge 19. In one or more embodiments, the first and second connection mechanisms 21, 23 may be provided centrally along each of the first and second edges 17, 19. The first and second connection mechanisms 21, 23 may interlock such that a shear pin 8 may be removably fitted through the first and second connection mechanisms 21, 23 to secure the shell body 5 together around the swellable packer 11. When secured around the swellable packer 11, the shell body 5 may create a sealed chamber between the outer surface of the swellable packer 11 and the inner surface of the shell body 5. In one or more embodiments, the sealed chamber may comprise a gap of 5 mm or less between the inner surface of the shell body 5 and the outer surface of the swellable packer 11.
In one or more embodiments, one or more fluid ports 9 may be arranged circumferentially around the shell body 5. Each fluid port 9 may include an opening which may allow fluid communication of the sealed chamber with the exterior of the shell body 5. Each fluid port 9 may also include a pressure relief device which seals the openings until a device threshold pressure is reached around the pressure relief device. In one or more embodiments, the pressure relief devices may operate in a similar manner to a check valve, where once the pressure relief device is open, fluid is allowed to flow in a direction from the exterior of the shell body to an inner of the shell body but prevented from flowing in an opposite direction from the inner of the shell body to the exterior of the shell body.
Moving now to
The swellable packer 11 and the wellbore fluid 27 may be designed or selected prior to running in the swellable packer 11 such that contact between the swellable packer 11 and the wellbore fluid 27 swells the swellable packer 11. For example, in one or more embodiments, the swellable packer 11 may be formed of an elastomer designed to swell upon contact with wellbore fluids 27 having a high viscosity and a high oil concentration. In one or more embodiments, a high viscosity may refer to viscosities in a range between 25 and 35 sec, and a high oil concentration may refer to a fluid which has a minimum oil concentration of 90%.
As a result of the wellbore fluid 27 contacting the swellable packer 11, the swellable packer 11 may begin to expand within the sealed chamber formed by the packer protection apparatus 1. Expansion of the swellable packer 11 may exert pressure upon the shell body 5, such that one or more releasable fasteners (e.g., the shear pin 8) may be broken, as shown in
Initially, a swellable packer 11 may be installed along a tubular 3. The installed swellable packer 11 may then be surrounded with a packer protection apparatus 1, S402. In one or more embodiments, step S502 may be completed at the surface, prior to running the tubular 3 downhole. In one or more embodiments, the tubular 3 is one of a plurality of tubulars threadably connected together to form a toolstring. For example, the swellable packer 11 may be installed around a tubular 3 forming a production toolstring (where production tubing may be installed in a well for collection of fluids being produced from the well). Once the packer protection apparatus 1 is installed, the tubular and corresponding toolstring may be run downhole to a setting depth within a wellbore 25, S504. In one or more embodiments, the desired setting depth may be determined in order to provide appropriate zonal isolation within the wellbore, particularly in circumstances where the wellbore 25 includes non-cemented lower completions.
Once the tubular 3 has reached the desired setting depth, a fluid may be circulated within the wellbore 25, S506. In one or more embodiments, this step may also include increasing a circulation pump rate of wellbore fluids 27. An increase in circulation pump rate may increase pressure exerted upon the packer protection apparatus 1, particularly on the fluid ports 9 disposed on an upstream interfacing surface of the shell body 5. Once the pressure exceeds a given value, the fluid ports may transition from a closed configuration to an open configuration, S508. In one or more embodiments, a pressure relief device may be installed within the fluid port, such that once the pressure exceeds a device threshold value, the pressure relief device may activate, allowing for the transition from a closed configuration to an open configuration. The device threshold value may vary depending on the respective wellbore conditions. For example, an operator may select a pressure relief device with an appropriate activation threshold pressure depending on wellbore conditions.
Once the fluid ports 9 have transitioned to an open configuration, wellbore fluids 27 may flow through the fluid ports into the packer protection apparatus 1, where the wellbore fluids 27 may contact the swellable packer 11, S510. Contact between the wellbore fluids 27 and the swellable packer 11 may cause a reaction. For example, the swellable packer 11 may be formed of an elastomer designed to react with wellbore fluids 27 composed of fluids with a high viscosity and oil concentration. In one or more embodiments, for example, the elastomer may be silicon rubber or nitrile rubber. Such a reaction will induce expansion of the swellable packer 11 from an original configuration to an expanded configuration, S512.
As the swellable packer 11 expands, pressure may build up against the inner surface of the shell body 5, causing the shell body 5 of the packer protection apparatus 1 to break apart. For example, in embodiments having shell sections releasably joined together via releasable fasteners, such as shear pin 8, force from an expanding swellable packer 11 may break the releasable fasteners. As a result, the expanding swellable packer 11 may break apart the shell body 5 of the packer protection apparatus 1, S514. In one or more embodiments, the broken fragments of the shell body 5 may float through the annular region in the well to the surface. The swellable packer 11 may then freely expand without obstruction to fill the wellbore 25 annulus, creating a zonal isolation.
Embodiments of the present disclosure may provide at least one of the following advantages. In present deployment methods, swellable packers are often exposed to a variety of wellbore fluids, including oil-based mud or water-based mud, which may cause premature expansion of the swellable packers prior to reaching a desired setting depth. Embodiments of the present disclosure provide an easily installed protection mechanism designed to prevent such premature expansion, improving efficiency of operations. Such a protection mechanism offers a more efficient and cost-effective solution than other proposed solutions, such as coating the packer or altering the manufacturing process of the rubber of the swellable packer.
Although only a few example embodiments have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the example embodiments without materially departing from this invention. Accordingly, all such modifications are intended to be included within the scope of this disclosure as defined in the following claims.
