Patent Grant
11976532
The following description generally relates to slip assemblies incorporated into downhole tools, such as packers and the like, for use in hydrocarbon wells. In one particular aspect, the present description relates to a retrievable packer with slips that are, in one aspect, actuated bi-directionally.
In the field of hydrocarbon production, a wellbore is drilled into a hydrocarbon-containing subterranean formation, and a tubing string, or production tubing, is then provided within the wellbore for providing fluid communication from the formation to the surface. In many applications, a casing may also be provided to line the wellbore. In other cases, the wellbore may be left uncased, in which case, the wellbore surface would function as the casing. Tubing strings comprise a plurality of generally axially (i.e., end to end) connected tubular elements, along with any number of tools, or “tool subs”, which are also provided coaxially as part of the tubing string. Such tools may include valves, packers, etc., which aid in either the production of fluids (in particular hydrocarbon materials) entering the wellbore, or in stimulating a subterranean region proximal to the wellbore. Many such tools would be known in the art.
Packers are well known in the art and serve to isolate one or more zones of a wellbore. An isolated zone may then be selected for production of hydrocarbon materials from the adjacent region of the well. Alternatively, the isolated zone may be subjected to a stimulation procedure for causing or enhancing production. For achieving the zonal isolation, packers comprise one or more radially expandable sealing elements, which are formed of a resilient material, such as rubber. The expansion of the sealing elements can be achieved by mechanically compressing the elements, or by causing such elements to swell. In the case of mechanically compressed packing elements, the actuation, or setting, of packers can be accomplished either mechanically, by running an actuation tool downhole on wireline, or hydraulically, by pressurizing the bore of the tubing string. In both cases, actuation, or setting of the packer causes an axial compressive force to be applied on the resilient packing elements, which results in the radial expansion of such elements. In this way, when the packer is set, the sealing element(s) expand radially outward against the casing of a wellbore to form a seal between the casing and the packer. By providing a pair of packers spaced apart on a tubing string, an isolated annular region is thereby formed in the well, bounded by the tubing string, the casing, and the actuated packing elements of the respective packers.
In some cases, the packers may also be unset and removed from the well or moved and reset at a different location. In such case, the axial force applied on the packing elements may be released, causing radial contraction of such elements. In such state, the tubing string comprising the packers may be removed or moved to a new location along the wellbore and reset as mentioned above.
It is also known to provide packers with slips, which generally comprise a number of rigid bodies having a plurality of teeth or the like on their outer surfaces. Upon actuation (setting) of the packer, the slips are moved radially outward and are thereby forced against the surface of the casing. In this way, the slips grip the interior surface of the casing and ensure that the packer is secured in position along the length of the casing. In particular, the slips serve to prevent axial displacement of the packer by supplementing the frictional forces created between the packing elements and the casing.
Slips generally comprise a wedge-shaped inner portion (opposite the gripping surface), which are designed to cooperate with an oppositely wedge-shaped member provided on the packer. The wedge-shaped member is typically in the form of a cone, which is slidably provided on the packer. During the setting process of the packer, the cone and slip are axially advanced against each other whereby the opposite wedge portions result in the slips being cammed or urged radially outward. Examples of packers having slips are provided in U.S. Pat. Nos. 7,198,110; 7,654,334; 9,291,029; 9,291,044; 10,633,942; and US/2004/0244966. In many of the known retrievable packers, springs or similar biasing means are also provided to urge the slips into the set or unset positions. In this way, the actuation of the packer serves to act against the action of such springs.
Although the slips are provided to supplement the frictional forces resulting from the expanded packing elements, they too are susceptible to being dislodged, such as in situations where pressure fluctuation, namely pressure reversals, occur in the well. There exists therefore a need for an improved slip mechanism that aids in counteracting the effects of pressure variations in a well.
In a broad aspect, the present description provides a unique slip assembly, wherein the slips, once set, are maintained in an energized state by means of one or more biasing members that act upon cones that drive the slips.
In one aspect, the present description provides a slip assembly for a downhole tool, the slip assembly comprising:
In another aspect, the description provides a slip system for a downhole tool, the slip system comprising:
In another aspect, the description provides a method of operating a slip assembly provided on a downhole tool, the slip assembly comprising a plurality of slips adapted to be radially outwardly extended, the method comprising:
The features of certain embodiments will become more apparent in the following detailed description in which reference is made to the appended figures wherein:
As used herein, the term “sub” will be understood to mean a tubing string component, such as a tubular member, a coupling, a tool etc. as known in the art. As also known, a sub has a generally cylindrical structure and is adapted to be connected to adjacent tubular members, or other subs, to form the tubing string. As with typical tubular members, a sub may have a female or “box” end and a male or “pin” end. The box end includes an internal threaded portion that is adapted to receive and threadingly engage an external thread provided on a pin end of an adjacent component (e.g., a tubular member, a sub, or a tool etc.). In this way, all components of the tubular string are connected together in an end-to-end manner. Alternatively, the ends of the sub may be the same (i.e., both may be a box, or both may be a pin), in which case the sub can be connected to adjacent components by means of a coupling.
The term “tool” as used herein will be understood to refer commonly known tubing string components that are used for performing various tasks. Examples of tools include valves, such as sliding sleeve valves, packers, liner hangers, etc.
The terms “comprise”, “comprises”, “comprised” or “comprising” may be used in the present description. As used herein (including the specification and/or the claims), these terms are to be interpreted as specifying the presence of the stated features, integers, steps, or components, but not as precluding the presence of one or more other feature, integer, step, component, or a group thereof as would be apparent to persons having ordinary skill in the relevant art. Thus, the term “comprising” as used in this specification means “consisting at least in part of”. When interpreting statements in this specification that include that term, the features, prefaced by that term in each statement, all need to be present but other features can also be present. Related terms such as “comprise” and “comprised” are to be interpreted in the same manner.
The term “and/or” if used herein can mean “and” or “or”.
Unless stated otherwise herein, the article “a” when used to identify any element is not intended to constitute a limitation of just one and will, instead, be understood to mean “at least one” or “one or more” unless indicated otherwise.
The terms “top”, “bottom”, “up”, or “down” may be used herein. It will be understood that these terms will be used purely for facilitating the description and, unless stated otherwise, are not intended in any way to limit the description to any spatial or positional orientation. In one example, the terms “top” or “uphole” may be used herein to refer to a direction along the tubing string or component towards the surface. Similarly, the terms “bottom” or “downhole” may be used herein to refer to a direction along the tubing string or component towards the bottom of the well, i.e., away from the surface.
The present description relates generally to a downhole tool for incorporation into a tubing string, where the tool comprises a number of slips arranged in a circumferentially spaced apart manner. The slips are urged radially outwardly by an urging means, such as a cone or other such ramped surface that is axially slidable along the longitudinal axis of the tool. The slips include cooperatively arranged ramped surfaces arranged opposite to the ramped surfaces of the urging means. In such arrangement, as the urging means is axially moved towards the slips, the slips are forced in a radially outward direction. Uniquely, the tool is provided with one or more biasing member associated with the urging means, whereby the urging means is/are maintained in an “energized” state, wherein the urging means constantly applies a degree of axial tension against the slips. These features are discussed in more detail below.
In one aspect, the tool described herein comprises a packer, in particular a retrievable packer that is preferably adapted to be set and re-set as needed. The packer comprises a number of slips along with the urging means and biasing member as described above.
One example of the presently described packer is illustrated in
As shown, the packer 10 comprises a top sub 12 and a bottom sub 16. In general, the top sub 12 is connected to the top, or uphole portion of the tubing string, and the bottom sub 16 is connected to the bottom, or downhole portion of the tubing string. In one aspect, the top sub 12 comprises a box end 14, for receiving a pin end of an adjacent tubular. Similarly, the bottom sub 16 comprises a pin end 18, for being received within a box end of an adjacent tubular member. A packer body 20 is provided between the top sub 12 and bottom sub 16. The packer body 20 is, in turn, comprised of several components as will be described below. As will be understood, the top sub 12 and bottom sub 16 are provided to facilitate the connection of the packer 10 to a tubing string. Such subs are generally provided on packers as separate units that are connected to the packer body 20. However, it will be understood that such subs may also be integrally formed with one or more components of the body 20.
The packer body comprises a mandrel 22 extending generally between the top sub 12 and the bottom sub 16. The mandrel 22 comprises an elongate cylindrical body having a bore extending there-through. As shown in
Proximal to the top sup 12, and as more clearly shown in
A locking ring housing 30 is provided over the mandrel 22 and over a locking ring 32 that is provided between the locking ring housing 30 and the mandrel 22. As illustrated in
Opposite to the stop housing 26, the locking ring housing 30 is connected to a packing element assembly 41 comprising a gauge ring 42, which is coaxially provided over the mandrel 22 and is threadingly connected to the locking ring housing 30. As will be understood, with such connection, axial movement of the locking ring housing 30 over the mandrel 22 is translated to the gauge ring 42, resulting in axial movement of the gauge ring 42 over the mandrel. The downhole of the gauge ring 42 is provided with a number of packing elements 44, each separated by a spacer ring 46. Such packing elements and spacer rings are commonly known in the art. Following the last packing element, the packer 10 includes a retainer ring 48, which serves to complete the packing element assembly 41. In operation, when the packer 10 is actuated or set, the gauge ring 42 is advanced in the downhole direction thereby applying an axial force against the packing element assembly 41. In view of the resilient material forming the packing elements 44, the elements are forced to expand radially outward and thereby form a seal with the casing (not shown), as known in the art. In the present description, the retainer ring 48 is slidably provided over the mandrel 22, wherein the retainer ring 48 is permitted to be coaxially moved over the mandrel, the purpose of which is explained below.
The packer 10 also includes a slip assembly 50. In one aspect, the slip assembly 50 is provided downhole of the packing element assembly 41. The slip assembly comprises an upper cone 52 and a lower cone 54. As known the art, cones 52 and 54 comprise generally cylindrical ring structures having, at one end thereof, a wedge or ramped surface, such as shown at 56 and 58, respectively, in
As is common in the art, slip springs are provided for urging slips 60 to return to the retracted state on the tool. In one aspect, a slip spring may be provided in the groove 68 of each slip 60, wherein such spring abuts the groove 68 and the inner surface of the web 74 of the slip housing 62 to bias the slip and the slip housing away from each other. As discussed above, the slip housing is coaxially provided over the mandrel, and, therefore, once the slip and slip housing assembly is mounted on a mandrel 22, the slip springs, which bias the slips 60 against the inner surface of the slip housing 62, urge, or act to retract, the slips radially inwardly, towards the mandrel 22. The slip springs may have any configuration as known in the art. In one aspect, the slip springs may comprise a leaf spring or a device similar thereto. One example of the slip springs is shown at 61 in
As illustrated for example in
As also shown in
As can be seen in
The bottom end of the slip housing 62 is provided with a threaded inner surface 88 that is adapted to engage a correspondingly threaded outer surface 90 of a slip body cap 92, which serves to retain the slip housing. As illustrated in
As shown in
The bottom portion of the packer 10 is also provided with a release ring 110 and a shear cap 112. These components are designed to cooperate with a release tool (not shown) for releasing the packer 10 from the set state.
Returning again to
In a similar manner, and as illustrated in
In known packer and slip systems, the retaining ring 48 and collet housing cap 106 would typically be connected to the upper and lower cones, 52, 54, respectively. However, according to an aspect of the present description, and as illustrated in
According to one aspect of the description, and as illustrated in
In the present description, the body of the biasing members 114 and 116 are illustrated as having a labyrinth structure comprising a series of apertures and slots. As will be understood from the present description, such labyrinth structure of the biasing members, as illustrated in the accompanying figures, offers the advantage of a limit to the degree of contraction that the biasing member is subjected to. For example, once the slots 142 are narrowed to the extent that the opposed walls of the slots abut each other, it will be understood that no further contraction of the biasing member is possible. In this way, the slots provide a means of limiting axial contraction or compression of the biasing members. As will be understood, other physical structures may be provided on the walls of the slots to also serve to limit the degree of contraction. In such case, wider slots may be provided, but the degree of contraction of the biasing member still limited to a distance that is less than the overall width of the slots.
It will be understood that one or both of the biasing members may have other structures and/or geometries for achieving the desired purpose as described herein. For example, the biasing members may comprise wave springs, Belleville springs, or bellows assemblies, etc., and still provide the desired spring characteristics described above. Preferably, such other structures would be provided with a means to limit axial contraction in the same manner as achieved with the slots 142 described above.
In the set state, as shown in
In a preferred aspect, the amount of radially outward travel, or radial expansion, of the slips 60 would be pre-determined based upon the internal diameter of the well (e.g., casing) and the external diameter of the packer 10. Further, in the set orientation, the slips 60 would preferably not be at the limit of their radial expansion. This arrangement results in the biasing members 114 and 116 applying a generally constant energizing force on the slips 60 while the packer is in the set state. This results in an improved packer, wherein the cones, and therefore the slips, remain in the set and energized state while in use, even in situations where the well pressure fluctuates or reverses. As a result, movement of actuated slips is avoided or minimized.
As mentioned earlier, the presently described packer is retrievable and, for this purpose, the packer is capable of being released from its set state and moved to another location in the well or extracted from the well.
As with the setting operation, the release of the packer 10 is accomplished by means of a release tool as would be known in the art. Such release tool is generally run-in and manipulated by wireline. The present description is not limited to any particular release tool.
In addition to the structure of the packer as discussed above, the present description also provides an improved method of operating a packer. In particular, as will be understood from the above description, the operation of a packer is improved by providing a constant axial force on cones that serve to actuate slips. As discussed above, while springs and the like are known for use directly on slips, mainly to force retraction of the slips when the expansion force is removed, the present description offers a unique advantage by applying axial forces on the cones that drive the outward expansion of the slips.
The present description has focused on a mechanically set packer, wherein wireline driven setting and release tools are used. However, the packer described herein can also be hydraulically actuated. In such case, coaxial components surrounding the mandrel would include valves and ports are known in the art, whereby an increase in pressure within the lumen of the mandrel serves to drive one or more pistons to result in relative axial movement between the mandrel and the coaxial components. However, it will be appreciated that the biasing members 114 and 116 would still function in the same manner as indicated above. In particular, whether the packer is designed for mechanical or hydraulic actuation, the biasing members would energize the slips once the packer is set.
In the above description, the packer 10 has been defined as having a bi-directional application of axial forces on the slips, using upper and lower cones. It will be understood that the biasing members described herein, and the aforementioned method, may also be incorporated into a packer having a unidirectional application of force on slips.
The slip assembly or apparatus has been described herein as being associated with a packer, such as packer 10. However, it will be appreciated that the slip assembly may be used with any downhole tool, such as bridge plugs, liner hangers or the like, where slips are commonly incorporated. The present description is not limited to any particular downhole tool.
In the present description, various components have been described as being slidable or slidably provided over the mandrel defined herein. It will be understood that the intent of such term is to indicate that the components in question need only be slidable over the relevant section of the mandrel where the components act and not necessarily along the entire length of the mandrel.
Although the above description includes reference to certain specific embodiments, various modifications thereof will be apparent to those skilled in the art. Any examples provided herein are included solely for the purpose of illustration and are not intended to be limiting in any way. Any drawings provided herein are solely for the purpose of illustrating various aspects of the description and are not intended to be drawn to scale or to be limiting in any way. The scope of the claims appended hereto should not be limited by the preferred embodiments set forth in the above description but should be given the broadest interpretation consistent with the present specification as a whole. The disclosures of all prior art recited herein are incorporated herein by reference in their entirety.
The present application claims priority under 35 U.S.C. 119 to U.S. Application No. 62/706,989, filed Sep. 22, 2020, the entire contents of which are incorporated herein by reference.
| Number | Name | Date | Kind |
|---|---|---|---|
| 2715441 | Bouvier | Aug 1955 | A |
| 4018274 | Cochran | Apr 1977 | A |
| 5904207 | Rubbo | May 1999 | A |
| 20050034894 | Beach | Feb 2005 | A1 |
| 20200308921 | Hrupp | Oct 2020 | A1 |
| Entry |
|---|
| Schlumberger. (2014). Versalok: Conventional wireline-set packer [brochure]. |
| Number | Date | Country | |
|---|---|---|---|
| 20220090464 A1 | Mar 2022 | US |
| Number | Date | Country | |
|---|---|---|---|
| 62706989 | Sep 2020 | US |
