This disclosure relates generally to methods and apparatus for providing a plug inside a tubing string containing well fluid. This disclosure relates more particularly to methods and apparatus for providing a plug including a continuous expandable sealing ring having an embedded radial gap feature.
The first figure (
The wellbore may have a cased section, represented with tubing string 1. The tubing string contains typically several sections from the surface 3 until the well end. The tubing string represented schematically includes a vertical and horizontal section. The entire tubing string contains a well fluid 2, which can be pumped from surface, such as water, gel, brine, acid, and also coming from downhole formation such as produced fluids or condensates, like water and hydrocarbons in liquid or gas form.
The tubing string 1 can be partially or fully cemented, referred as cemented stimulation, or partially or fully free within the borehole, referred as open-hole stimulation. Typically, a stimulation will include temporary or permanent section isolation between the formation and the internal volume of the tubing string.
The bottom section of
Each isolation includes a set plug 6 with its untethered object 5, represented as a spherical ball as one example.
The stimulation and isolation are typically sequential from the well end, from downhole to uphole. At the end of stage 4c, after its stimulation 7, another isolation and stimulation, represented as subsequent stage 4d, may be performed in the tubing string 1.
In this representation, a toolstring 10 is conveyed via a cable or wireline 9, which is controlled by a surface unit 8. Other conveyance methods may include tubing conveyed toolstring or coiled tubing. Along with a cable, a combination of gravity, tractoring and pump-down may be used to bring the toolstring 10 to the desired position inside the tubing string 1. The toolstring 10 may convey an unset plug 11, dedicated to isolating stage 4c from stage 4d.
Additional pumping rate and pressure may create a fluid stimulation 7 inside the formation located on or near stage 4d. When the stimulation is completed, another plug may be set and the overall sequence of stages 4a to 4d may start again. Typically, the number of stages within a wellbore may be between 10 and 100, depending on the technique used, the length of the well and spacing of each stage.
There is a continuing need in the art for methods and apparatus for methods and apparatus for providing a plug inside a tubing string containing well fluid. Preferably, the plug is provided using a 2-step ball contact, first with one or more deformable plug components, second with one or more rigid plug components.
For a more detailed description of the embodiments of the disclosure, reference will now be made to the accompanying drawings.
It is to be understood that the following disclosure describes several exemplary embodiments for implementing different features, structures, or functions of the invention. Exemplary embodiments of components, arrangements, and configurations are described below to simplify the disclosure; however, these exemplary embodiments are provided merely as examples and are not intended to limit the scope of the invention.
A reference to U.S. application Ser. No. 17/275,509 filed Mar. 11, 2021, titled “Methods and Apparatus for providing a plug with a two-step expansion” can provide a detailed description of the
The plug may include the following components:
an expandable continuous seal ring 170,
an expandable gripping ring 161, which preferably includes anchoring devices 74,
a back-pushing ring 160, including shear devices 65 which may be positioned on the inner diameter of the back-pushing ring 160,
a locking ring 410, which includes a conical external shape matching the inner surface of the expandable gripping ring 161 and the inner surface of the expandable continuous seal ring 170. The locking ring 410 may include a hemispherical inner surface 419 and a conical inner surface 416, and,
a hemispherical cup 411.
The retrievable setting tool may include the following components:
an external mandrel 414, which may include a cylindrical pocket 418. The pocket 418 may have a channel 415 linking the pocket 418 with the well fluid 2 present inside the tubing string 1. In this representation, the external mandrel 414 may contact the locking ring 410 along the conical surface 416. In addition, the external mandrel 414 may contact the hemispherical cup 411 along a conical surface 417,
a rod 412 which can move longitudinally relative to the external mandrel 414. The rod 412 may provide a link to the shear devices 65, securing the longitudinal position of the back-pushing ring 160.
In addition, an untethered object 413 may be included inside the pocket 418 of the external mandrel 414.
This embodiment may be referred to as ‘ball in place’, where the untethered object 413 may be a ball which is included in the retrievable setting tool. Other embodiments for the untethered object 413 may be a pill, a dart, a plunger, preferably with at least a hemispherical or a conical shape.
Through the connection of the shear devices 65 with the rod 412, the movement of the rod 412, indicated by arrow 430, may induce the same longitudinal movement as the back-pushing ring 160. The back-pushing ring may induce in turn an expansion movement to the expandable gripping ring 161, which in turn induces an expansion movement through the deformation of the continuous expandable seal ring 170. The expansion of the expandable gripping ring 161 and of the continuous expandable seal ring 170 occurs both longitudinally and radially over the conical external shape of the locking ring 410. The locking ring may be held longitudinally in position thanks to the contact 416 with the external mandrel 414, and may be held radially in position through the conical contact with the hemispherical cup 411, itself held in position through the conical contact 417 with the external mandrel or centered around the internal rod 142. To be noted during this expansion process, the hemispherical surface 419 of the locking ring 410 may not come in contact with the hemispherical surface 421 of the hemispherical cup 411, in-between keeping a longitudinal gap 112.
The expansion process of the expandable gripping ring may end when one of the anchoring devices 74 start penetrating inside the inner surface of the tubing string 1, and a force equilibrium is established between the anchoring force or friction force created by penetrating the anchoring devices 74 inside the tubing string 1, relative to the holding resistance of the shear devices 65.
At this point, the expandable continuous seal ring 170 might not be in continuous contact with the inner surface of the tubing string 1. This can be due to the geometry of the parts or possible elastic restraint effect of the expanded parts including the expandable continuous sealing ring 170.
As depicted in
The hemispherical cup 411 may stay in its longitudinal position thanks to the friction contact along its conical surface 420 in common with the inner conical surface of the locking ring 410, or thanks to a clipping mechanism with the locking ring 410.
As depicted in
The well fluid 2 may be pumped downhole across the set plug, creating a flow restriction and in turn a local pressure uphole of the set plug. The local pressure, uphole of the set plug, may create a force on the uphole surfaces exposed to the well fluid pressure, and symbolized with arrows 470. As representing the largest surface area exposed to the uphole local fluid pressure, the force 470 may act mainly on the untethered object 413 and on the hemispherical cup 411.
As depicted in
The further longitudinal movement may continue up to surface contact of the hemispherical surface 421 of the hemispherical cup 411 together with the corresponding surface 419 on the locking ring 410, therefore closing the longitudinal gap 112, depicted in
The force 470 is acting on the untethered object 413 and on the hemispherical cup 411, with the two parts being in contact through a chamfer 424 and providing a force indicated by arrow 480 at this contact surface. The resultant force indicated by arrow 481 of these two parts may be directed perpendicular to the conical contact surface 420 with the locking ring 410.
The expandable gripping ring 161 secured with the anchoring devices 74 inside the tubing string 1 and locked internally by the locking ring 410, may not deform during the further expansion process of the expandable continuous ring 170, and provide a radial sliding guide.
Having the hemispherical cup 411 in contact with the locking ring 410, therefore closing the longitudinal gap 112, the resultant of the force 470 on the untethered object 413 and on the hemispherical cup 411, may now directed towards forces 483 and 484. Force 483 may compress the expandable continuous seal ring 170 further towards the tubing string, possibly enhancing the sealing feature of the plug. Force 484 may compress the expandable gripping ring 161 further towards the tubing string via the anchoring devices 74, possibly enhancing the anchoring feature of the plug.
Step 101 corresponds to the deployment of a plug assembly (170, 410, 411, 161, 160) including a carried untethered object (413) into the tubing string (1) containing well fluid (2). During step 102, the plug assembly is expanded radially, including the radial deformation of the continuous seal ring (170), and the radial expansion of the expandable gripping ring (161), with the action of a retrievable setting tool, over a locking ring (410) and hemispherical cup (411). During the same step 102, the expandable gripping ring (161) contacts at least one point of the inner surface of the tubing string (1), while the expandable continuous seal ring (170) is deformed to an outer diameter which may be less than the tubing string (1) inner diameter. Then, during step 103, the retrievable setting tool, is retrieved. Further during step 104, the carried untethered object (413), is released from the setting tool. Then, during step 105, the untethered object (413) contacts radially the inner surface of the hemispherical cup (411). Then, during step 106, the well fluid (2) pressure and flow restriction uphole of the untethered object (413) and hemispherical cup (411) is used to act as a force to deform further the expandable continuous seal ring (170), up to its outer surface contact with the tubing string (1) inner surface, allowing further enhanced contact between all plug components from the untethered object (413) to the tubing string (1) passing through the hemispherical cup (411), the locking ring (410) and the expandable continuous seal ring (170). The same force may also enhance the anchoring action on the expandable gripping ring (161). This isolation state allows performing a downhole operation inside the well.
In some embodiments, the method may comprise the step of diverting a portion of the well fluid outside the tubing string, or the step of sealing a portion of the well fluid inside the tubing string with the plug assembly. The method may comprise the step of dissolving at least one component of the plug assembly, the cup, or the untethered object.
an expandable continuous sealing ring 130,
an expandable gripping ring 161, which may include one or more anchoring devices, represented as buttons 74,
an integral locking ring 180,
a back-pushing ring 160.
The continuous expandable sealing ring 130 may include additional features compared to prior disclosures in related US patent applications as cross-references, as item 170. Details regarding the continuous expandable sealing ring 130 will be depicted in future figures, in particular in
The descriptions made in U.S. application Ser. No. 17/275,509 filed Mar. 11, 2021 for the expandable gripping ring 161, the anchoring devices 74, the back-pushing ring 160, can be taken as reference for this current CIP application.
The integral locking ring 180 can be considered as the combination of the locking ring 111 and hemispherical cup 110 into an integral part. The integral locking ring 180 may therefore not include the function of the longitudinal gap 112 which may be present when considering the combination of two parts 110 and 111.
All the plug components, 130, 161, 74, 160, 180, including the untethered object 22 may be built out of dissolvable material. The dissolvable material may be a metallic alloy, a plastic alloy or a composite material which may dissolve or decompose within the well fluid 2 over time. The dissolving or decomposition may include an oxidation-reduction or corrosion reaction with some components of the well fluid 2. Some environmental conditions may influence the dissolving of some of the plug dissolving components, such as the well fluid 2 temperature, pressure, salinity, pH, density, movement, gas/fluid/solid content proportions, and chemical composition. The plug components may include different types of dissolving materials, which may have different dissolving rate and different mechanical properties, such as yield strength, ductility, hardness, based on the function within the plug. Coatings and heat treatment may also influence dissolving rate and mechanical properties of the different type of dissolving materials. Within the same part, multiple materials with different properties, such as mechanical or dissolving, may be used.
The plug with the above listed components may typically be conveyed on a toolstring 10, including a setting tool and a setting adapter. The setting adapter, also known as adapter kit, may include two components, similar to the ones seen in
A detailed section 200 is marked in
In the set position, the expandable continuous sealing ring 130, depicted as 130b, may be bridging between the flared outer surface 181 of the integral locking ring 180 and inner surface 15 of the tubing string 1. At the end of the deformation occurring during the setting process, the expandable continuous sealing ring 130b may have different surfaces in contact with other plug or tubing components. An external prominent surface 131 may come in contact with the inner surface 15 of the tubing string. The inner flared surface 134 may keep its contact with the external flared surface 181 of the integral locking ring 180. A cavity 133, as radial gap, may be positioned within the expandable continuous sealing ring 130, radially positioned under the external prominent surface 131. The remaining external surface 132 of the expandable continuous sealing ring 130 may not be in contact with the inner surface 15 of the tubing string 1, at this stage of the expansion process, namely at the end of the plug setting process. One reason for the positioning of the cavity 133 under the external prominent surface 131, may be to keep deformation possibility once the external prominent surface 131 comes in contact with the inner surface 15. Therefore, the contact force between the expandable continuous sealing ring 130 and inner surface 15, as depicted with arrow 140, may be limited during the plug setting process. The contact force between the anchoring devices 74 and the inner surface 15 of the tubing string 1, as depicted with arrows 141, may be important relative to the contact force 140. A potential reason for this force relationship, 140 over 141, may be the focus during the plug setting process to transmit the maximum of the setting force, coming from the setting tool and toolstring 10, towards the anchoring devices 74. It could be an operation goal to focus the majority of the available setting force towards the anchoring of the anchoring devices 74, and therefore enhance the stability of the expandable gripping ring 161 relative to the tubing string 1. The cavity 133 may act as a radial gap for the expansion of the expandable continuous sealing ring 130 giving the ability to adjust the contact surfaces 131 and 15, independently of typical well conditions, such as dimensional variations of the inner diameter or shape of the tubing string, irregularities in surface 15 conditions, presence of debris within the tubing string 1 and inside the well fluid 2. The cavity 133 may compensate for operation variations while possibly ensuring a contact between surface 131 with surface 15, and while transmitting as much force 141 as possible to the anchoring devices 74 to ensure an enhanced gripping and stability of the set plug.
The influence of the untethered object 22 on the set plug may be further depicted in
The flow of well fluid 2 is represented with arrows 145. After the landing of the untethered object 22 on the integral locking ring 180, the well fluid 2 may be pressurized from surface, typically through pumping activity, which may induce a pressure differential across the set plug, whereby the set plug creates a flow restriction.
Typical pressure differential uphole compared to downhole of the set plug, as on
Step 201 corresponds to the deployment of a plug assembly (130, 180, 161, 160) into the tubing string (1) containing well fluid (2). During step 202, the plug assembly is expanded radially, including the radial expansion of the expandable gripping ring (161) to contact at least one point of the inner surface (15) of the tubing string (1). During the same step 202, the expandable continuous sealing ring (130) is expanded and deformed radially, to contact a prominent external surface (131) with the inner surface (15) of the tubing string (1), whereby a radial gap (133) is present underneath the prominent external surface (131) to provide a radial expansion dimensional adaptation, without transmitting radial forces between the expandable continuous sealing ring (130) and the tubing string (1). In step 202, the expansion and deformation occurs over an integral locking ring (180) with the action of a retrievable setting tool. Then, during step 203, the retrievable setting tool, is retrieved. Further during step 204, an untethered object (22) is released either from the setting tool or from surface. Then, during step 205, the untethered object (22) contacts radially the inner surface of the integral locking ring (180). Then, during step 206, the well fluid (2) pressure and flow restriction is used on the untethered object (22) and integral locking ring (180) to act as a force to provide a longitudinal displacement of the untethered object (22) and integral locking ring (180) relative to the expandable gripping ring (161). Further in step 206, the force and displacement are used to deform further the expandable continuous seal ring (130), up to a secondary external surface (132) contacts inner surface (15) of the tubing string (1), as well as enhance the anchoring action on the expandable gripping ring (161). This isolation state allows performing a downhole operation inside the well.
In some embodiments, the method may comprise the step of diverting a portion of the well fluid outside the tubing string, or the step of sealing a portion of the well fluid inside the tubing string with the plug assembly. The method may comprise the step of dissolving at least one component of the plug assembly, the cup, or the untethered object.
The present application is a Continuation-In-Part (CIP) application of U.S. application Ser. No. 17/275,509 filed Mar. 11, 2021, titled “Methods and Apparatus for providing a plug with a two-step expansion” naming Gregoire M Jacob as inventor, and a Continuation-In-Part (CIP) application of U.S. application Ser. No. 17/892,015 filed Aug. 19, 2022, titles “Methods and Apparatus for providing a plug activated by cup and untethered object” itself a Continuation application of U.S. application Ser. No. 17/275,509 filed Mar. 11, 2021. All the foregoing applications are hereby incorporated herein by reference in their entirety.
Number | Date | Country | |
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Parent | 17275509 | Mar 2021 | US |
Child | 17892015 | US |
Number | Date | Country | |
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Parent | 17892015 | Aug 2022 | US |
Child | 18105877 | US |