US20240052721A1

US20240052721A1 - Method and Apparatus for providing a plug with a 2-steps expansion activated by cup and untethered object

Info

Publication number: US20240052721A1
Application number: US18/270,859
Authority: US
Inventors: Gregoire Max Jacob
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-01-25
Filing date: 2021-01-25
Publication date: 2024-02-15
Also published as: WO2022159065A1

Abstract

A plug assembly includes an expandable assembly, a locking ring and a cup. The expandable assembly is adapted to be deformed radially over the locking ring and the cup. The locking ring has a stopping inner surface. The plug assembly is used with one or more untethered objects, the untethered objects having an outer surface adapted to couple with the cup, and the cup having an outer surface adapted to couple with the stopping inner surface of the locking ring. The combination of cup and untethered objects is also adapted to contact an inner surface of the plug assembly and, using well fluid pressure, to apply forces to the plug assembly. The forces cause the longitudinal movement of the cup and untethered objects while contacting the inner surface of the plug assembly until the cup contacts the stopping inner surface of the locking ring.

Description

BACKGROUND

This disclosure relates generally to methods and apparatus for providing a sensing device on a plug inside a tubing string containing well fluid. This disclosure relates more particularly to methods and apparatus for providing a plug with a 2-steps expansion activated by cup and untethered object.
The first nine figures (FIGS. 1 to 9 ) refer to one environment example in which the methods and apparatus for providing a plug with an untethered object inside a tubing string containing well fluid described herein may be implemented and used.
FIG. 1 illustrates a typical cross section of an underground section dedicated to a cased-hole operation. The type of operation is often designated as Multi-Stage-Stimulation, as similar operations are repeatedly performed inside a tubing string in order to stimulate the wellbore area.
The wellbore may have a cased section, represented with tubing string 1. The tubing string contains typically several sections from the surface 12 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, like water and hydrocarbons.
The tubing string 1 can be partially or fully cemented, referred to as cemented stimulation, or partially or fully free within the borehole, referred to as open-hole stimulation. Typically, an open-hole stimulation will include temporary or permanent section isolation between the formation and the inside of the tubing string.
The bottom section of FIG. 1 illustrates several stimulation stages starting from well end. In this particular well embodiment, at least stages 14 a, 14 b, 14 c have been stimulated and isolated from each other. The stimulation is represented with fluid penetration inside the formation through fracturing channels 13, which are initiated from a fluid entry point inside the tubing string. This fluid entry point can typically come from perforations or sliding sleeves openings.
Each isolation includes a plugging element 3 with its untethered object 5, represented as a spherical ball as one example.
The stimulation and isolation are typically sequential from the well end. At the end of stage 14 c, after its stimulation 13, another isolation and stimulation may be performed in the tubing string 1.
FIG. 2 depicts a sequential step of FIG. 1 with the preparation of subsequent stage 14 d. In this representation, a toolstring 10 is conveyed via a cable or wireline 15, which is controlled by a surface unit 16. Other conveyance methods may include tubing conveyed toolstring, 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. In FIG. 2 , the toolstring 10 conveys an unset plug 17, dedicated to isolating stage 14 c from stage 14 d.
FIG. 3 depicts a close-up view of FIG. 2 , focused on toolstring 10 and unset plug 17.
FIG. 4 depicts a sequential view of FIG. 3 , whereby the toolstring 10 is actuated to set the plugging element 3 inside the tubing string 1, typically uphole of the last entry points for fracturing channels 13.
FIG. 5 depicts a sequential view of FIG. 4 , whereby the toolstring 10 is pulled away of the set plugging element 3. The toolstring 10 would typically perform perforations uphole of the set plugging element 3.
FIG. 6 depicts a sequential view of FIG. 2 or of FIG. 5 , whereby further perforating inside the tubing string 8 has been performed uphole of the set plugging element 3. Typically, the set plugging element 3 creates a restriction in the tubing string 8 able to receive, at a later time, an untethered object 5 such as a ball. Note that the untethered object 5 may also be included inside the toolstring 10 and released after the actuation of the plugging element 3 inside the well fluid 2, uphole of the set plugging element 3. Operations with carried untethered object 5 by the toolstring 10 typically refer to ball-in-place operations. In a ball-in-place operation, additional launching of the untethered object 5 from surface, as further described in FIG. 7 is therefore no more necessary to obtain a well fluid 2 isolation within the tubing string 1. The toolstring 10 and cable 15 of FIG. 2 or of FIG. 5 have then been removed from the tubing string.
FIG. 7 depicts a sequential view of FIG. 6 , where an untethered object 5 is pumped from surface 12 with the well fluid 2 inside the tubing string 1.
FIG. 8 depicts a sequential view of FIG. 7 , where the untethered object 5 lands on the set plugging element 3 and creates a well fluid isolation between the uphole and downhole sides of the plug position. Depending on the configuration of the plugging element 3, multiple, typically identical, untethered objects 5 may be necessary to create a well fluid isolation on the set plugging element 3.
FIG. 9 depicts a sequential view of FIG. 8 , where further pumping fluid 18 may increase pressure uphole of the position of the set plugging element 3, including on the untethered object 5, of stage 14 d. Additional pumping rate and pressure may create a fluid stimulation 13 inside the formation located on or near stage 14 d. When the stimulation is completed, another plug may be set and the overall sequence of stages 1 to 5 may start again. Typically, the number of stages may be between 10 and 100, depending on the technique used, the length of well and spacing of each stage.
There is a continuing need in the art for methods and apparatus for a plug providing a fluid isolation inside a tubing string containing well fluid. Preferably, the plug includes a 2 two-steps expansion process including an activation of cup associated with one or more untethered objects.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more detailed description of the embodiments of the disclosure, reference will now be made to the accompanying drawings.

FIG. 1 is a wellbore cross-section view of typical Multi-Stage-Stimulation operation ongoing, with three stages completed.

FIG. 2 is a wellbore cross-section view of toolstring conveyance to install the third isolation device for the fourth stage.

FIG. 3 is a Close-up cross-section view of FIG. 2 .

FIG. 4 is a Close-up cross-section view of toolstring installing 3rd isolation device.

FIG. 5 is a Close-up cross-section view of 3rd isolation device installed and toolstring moved up.

FIG. 6 is a wellbore cross-section view of the third stage isolation device being set and the fourth stage being perforated.

FIG. 7 is a wellbore cross-section view of an untethered object being dropped inside the well and moving towards the third isolation device through the perforated area.

FIG. 8 is a wellbore cross-section view of 3rd stage with untethered object being landed on isolation device.

FIG. 9 is a wellbore cross-section view of the fourth stage isolated from the third stage by a plug and untethered object, and completed with pressure pumping operation.

FIG. 10A is an isometric view of a plug assembly in a set stage.

FIG. 10B is an isometric view of a plug assembly in a set stage with an untethered object.

FIG. 10C is another isometric view of same embodiment as FIG. 10B

FIG. 11A is an isomeric view of an expandable gripping ring and an isometric view of a back-pushing ring, in the same viewing direction, according to an example embodiment.

FIG. 11B is a cross-sectional isometric view of the same parts represented in FIG. 11A, from a different viewing angle, according to an example embodiment.

FIG. 12 is an isomeric view of an expandable continuous seal ring, according to an example embodiment.

FIG. 13 is a cross-sectional isometric view of the expandable continuous seal ring positioned next to a cross-sectional isometric view of the expandable gripping ring, as two parts would be positioned in an unset or run-in-hole position, according to an example embodiment.

FIG. 14 is a cross-sectional isomeric view of a locking ring, according to an example embodiment.

FIG. 15A is a cross-sectional view of a plug assembly in a set stage inside a tubing string with the landing position of an untethered object.

FIG. 15B is a cross-sectional view of a plug assembly in a set stage inside a tubing string with the untethered object pressing on the plug assembly using well fluid pressure.

FIG. 16A is a detailed view of a cross-sectional view of a plug assembly in a set stage inside a tubing string with the landing position of an untethered object.

FIG. 16B is a detailed view of a cross-sectional view of a plug assembly in a set stage inside a tubing string with the untethered object pressing on the plug assembly using well fluid pressure.

FIG. 17 is a flow diagram representing a technique sequence of deployment of a plug and action of an untethered object on an expandable continuous ring.

FIG. 18 is a flow diagram representing a technique sequence of deployment of a plug, with the action of an untethered object for further expanding the expandable assembly and contacting a stopping surface on the locking ring.

FIG. 19A is a cross-section view of another embodiment of a plug assembly, in a run-in hole position inside a tubing string, over a setting tool including a carried untethered object or ball-in-place.

FIG. 19B is an isometric view of FIG. 19A without showing the tubing string.

FIG. 20A is an isometric view of a hemispherical cup, according to an example embodiment.

FIG. 20B is an isometric view of FIG. 20A from another orientation.

FIG. 21 is a cross-section view of a plug assembly, in a set position inside a tubing string, over a setting tool including a carried untethered object or ball-in-place.

FIG. 22 is a cross-section view of a plug assembly, in a set position inside a tubing string, after longitudinal movement of a rod, over a setting tool including a carried untethered object or ball-in-place.

FIG. 23A is a cross-section view of a set plug assembly, with the decoupling of the retrievable setting tool, releasing a carried untethered object.

FIG. 23B is an isometric view of FIG. 23A without showing the tubing string.

FIG. 23C is an isometric view of FIG. 23B from another orientation.

FIG. 24A is a cross-section view of a plug assembly, in a set position inside a tubing string, with the carried untethered object landing on the hemispherical cup.

FIG. 24B is an isometric view of FIG. 24A without showing the tubing string.

FIG. 25 is cross-section view of a plug assembly, in a set position inside a tubing string, with the carried untethered object pressing on the plug assembly using well fluid pressure.

FIG. 26A is a detailed view of the cross-section view of FIG. 24A, with the carried untethered object landing on the hemispherical cup.

FIG. 26B is a detailed view of the cross-section view of FIG. 25A, with the carried untethered object pressing on the plug assembly using well fluid pressure.

FIG. 27 is a flow diagram representing a technique sequence of deploying a plug assembly with a caged untethered object and hemispherical cup having the action of further expanding the expandable assembly and contacting a stopping surface on the locking ring.

FIG. 28 is a cross-section view of another embodiment of a plug assembly, in a run-in hole position inside a tubing string, over a setting tool.

FIG. 29 is a cross-section view of the plug assembly, in a set position inside a tubing string, over the setting tool.

FIG. 30 is a cross-section view of the plug assembly, in a set position inside a tubing string, after longitudinal movement of a rod, over the setting tool.

FIG. 31 is a cross-section view of the set plug assembly, with the decoupling of the retrievable setting tool.

FIG. 32 is a cross-section view of the set plug assembly, with the travelling of an untethered object towards the set plug assembly.

FIG. 33A is a cross-section view of the set plug assembly, with the untethered object landed on the set plug assembly.

FIG. 33B is cross-section view of the plug assembly, in a set position inside a tubing string, with the untethered object pressing on the plug assembly using well fluid pressure.

FIG. 34A is a detailed cross-section view of FIG. 33A.

FIG. 34B is a detailed cross-section view of FIG. 33B.

FIG. 35 is an isometric view of the plug assembly shown in FIG. 28 , in a run-in hole position inside a tubing string, over a setting tool.

FIG. 36 is an isometric view of the set plug assembly with the untethered object as shown in FIG. 33A.

FIG. 37A is an isometric view of a hemispherical cup, according to an example embodiment.

FIG. 37B is an isometric view of FIG. 37A from another orientation.

FIG. 38 is an isometric view of a locking ring, according to an example embodiment.

FIG. 39 is a flow diagram representing a technique sequence of deploying a plug assembly with a hemispherical cup having the action of further expanding the expandable assembly and contacting a stopping surface on the locking ring.

FIG. 40 is an isometric view of another plug assembly, including two carried untethered objects, in a run-in hole position, over a setting tool.

FIG. 41A is a cross-section view of the plug assembly, including two carried untethered objects, in a run-in hole position inside a tubing string, over a setting tool.

FIG. 41B is a cross-section view of the same plug assembly as FIG. 41A shown in a different cut view orientation at a 90 deg plane compared to FIG. 41A along center axis.

FIG. 42 is an isometric view of an external mandrel with two carried untethered objects and showing two shaft extensions.

FIG. 43 is a cross-section view of the plug assembly, in a set position, with two carried untethered objects landed on the hemispherical cup.

FIG. 44 is an isometric view of the set plug assembly.

FIG. 45 is an isometric view of the set plug assembly with two untethered objects landed on the hemispherical cup, as shown on FIG. 43 .

FIG. 46 is a schematical isometric and cross-section view of a hemispherical cup holding three untethered objects.

FIG. 47 is a flow diagram representing a technique sequence of deploying a plug assembly having multiple carried untethered objects, with a hemispherical cup having the action of further expanding the expandable assembly and contacting a stopping surface on the locking ring.

DETAILED DESCRIPTION OF THE INVENTION

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.
The description of the apparatus and methods from FIG. 10A to FIG. 18 are included in the detailed description as reference. Multiple components described in this sequence from FIG. 10A to FIG. 18 are further used similarly in additional sequence descriptions done in FIG. 19A to FIG. 27 , FIG. 28 to FIG. 40 and FIG. 41 to FIG. 47 .
FIGS. 10A, 10B, 10C represent different isometric views of a possible embodiment of a plug on a retrievable setting tool.
As represented in FIGS. 10A, 10B and 10C, the plug includes four main parts:

- a continuous expandable seal ring 170,
- an expandable gripping ring 161 which includes one or more anchoring devices, represented as buttons 74,
- a locking ring 180,
- a back-pushing ring 160,
- plus an untethered object 5.

Further description of the separate parts and their features can be found in the description from FIG. 11A to FIG. 14 .
All parts of the plug, such as the expandable seal ring 170, the expandable gripping ring 161, the locking ring 180, the back-pushing ring 160, the untethered object 5, may be built out of a combination of dissolvable materials, whether plastics or metals. Dissolvable materials have the capacity to react with surrounding well fluid 2 and degrades in smaller particles over time. After a period of preferably a few hours to a few months, most or all the dissolvable components have degraded to particles remaining in the well fluid 2.
FIGS. 11A and 11B show detailed views of two parts of the plug, namely the expandable gripping ring 161 and the back-pushing ring 160. FIG. 11A represents an isometric view of both parts within the same orientation along axis 12. FIG. 11B represents another isometric view of both parts seen as a cut view, along axis 12.
The expandable gripping ring 161 can be built with a preferably cylindrical outer shape separated by slit cuts 162. The slit cuts 162 separate the expandable gripping ring in the same numbers of ring sections 179. The ring sections 179 are kept together as a single part, in the unexpanded state, through a thin section 163, each positioned at the opposite end of the slit cuts 162. Preferably, the number of slit cuts 162, as well as ring sections 179 and thin sections 163, is between 4 and 16. The preferably cylindrical outer shape may contain one diametrical dimension around axis 12, or several sub-cylindrical faces with potentially larger outer curvatures for each ring section 179. The adaptation of the curvatures may be needed to cope with the expanded shape which might be closer to the inside diameter of the tubing string. Other possible features on each or on some of the ring sections 179 are anchoring devices such as buttons 74. Alternatively, slip teeth or rough surfaces, can be used as anchoring devices and be present on the outer surface of the ring sections 179. The purpose of the anchoring devices 74 is to penetrate the inner surface of the tubing string 1 to provide a local anchoring. Alternatively, the anchoring devices may increase the surface friction between the expanding gripping ring 161 and the inner face of the tubing string to an adherence point. The number of buttons 74 may preferably be between 1 and 10 for each ring section 179.
The bottom surface 178 of the expandable gripping ring 161 may include radial directing rails 164. Those rails 164 may preferably be positioned in the center of each ring sections 179.
The back-pushing ring 160 may have the counter shapes of the rails 164, protruding out as radial bars 166.
The two parts 161 and 160 may have therefore a matching feature between each other's, symbolized by the alignment 168.
The inner surface of the back-pushing ring may be cylindrical with openings 167 allowing to position shear screw, shear pins or shear rings.
FIG. 11B allows seeing the possible inner surface of the expandable gripping ring 161, with a principal conical shape 165, containing circular teeth or other anti-backing feature, such as slips or buttons. The front part of the conical shape 165 may include a groove 169.
FIG. 12 represents an isometric view of the continuous expandable seal ring 170. As main features represented, the outer surface 173 may be cylindrical, along axis 12. Potential crenelated groove features 172 may be added on this cylindrical surface 173. The inner surface of continuous expandable seal ring 170 may be conical 171.
FIG. 13 represents an isometric cut view of both the continuous expandable seal ring 170 and the expandable gripping ring 161. The position represented is the assembly in the unset, run-in-hole position, as shown in FIG. 15A. The two parts 170 may share a common contact surface 174, which may be a cylindrical, annular, or conical contact. The two surfaces 171 and 165 may have the same conical angle, as referred to axis 12. A preferred angle may be between 2 and 30 degrees. As an additional alignment or positioning feature, the groove 169 of the expandable gripping ring 161 may match the counter form 168 on the continuous expandable seal ring 170.
FIG. 14 represent the isometric cut view of the locking ring 180.
The locking ring 180 may include on its external surface conical surfaces 181 and 182. The angle of the conical surfaces 181 and 182 may be similar to the angle of the surface 171 of the continuous expandable seal ring 170 and of the surface 165 of the expandable gripping ring 161. The conical surfaces may include a slick conical surface 181 and rough conical surface 182, which may include teeth or corrugated features with a matching pattern compared to surface 165 of the expandable gripping ring 161
The inner surface of the locking ring 180 may include a conical surface 184. With the front section of the locking ring 180 having both an external 181 and internal 184 conical surfaces, it results in a funnel feature. The thickness 186 between both conical surfaces may be thin, in the order of 0.02 in to 0.4 in [0.5 mm to 10 mm]. Further inside the inner surface of the locking ring 180, the conical surface 184 may transition to a hemispherical surface 185 (i.e, a stopping inner surface). The back inner surface may then transition to a cylindrical surface 183.
FIG. 15A represents a cut view of the plug described in FIGS. 10A to 10C, set inside the tubing string 1. It represents the same plug as in FIG. 10C, set inside the tubing string 1. The position of the untethered object 5, as landed on the plug, is contacting the surface 184 of the locking ring 180, while not necessary contacting the inner conical surface 171 of the expandable continuous seal ring 170.
The untethered object 5 may have the shape of a sphere, or for the purpose of this embodiment only contain a spherical surface which will contact the inner surface 185 of the locking ring 180. As other possible shapes for the untethered object containing a spherical front surface, it may include pill shape or dart shape.
As represented in FIG. 15A, the diameter of the spherical portion of the untethered object 5 may be adapted to contact the conical surface 184 of the locking ring 180, while not contacting the hemispherical surface 185.
FIG. 15B is a sequence of FIG. 15A. It represents the action of the untethered object 5. Through pumping well fluid 2 inside the tubing string 1, such as from surface, the flow restriction constituted by the set plug component 170, 161 and 180, along with the untethered object 5, creates a flow restriction and in turn a pressure 250 on the untethered object, which created a force. This force is transmitted through the contact surface 184 and induces a conical expansion force 251. This force 251 expands the thin section of the locking ring 180 and in turn the inner surface 171 of the expandable continuous seal ring 170. This further expansion of the continuous expandable seal ring may provide enhanced contact surface with the tubing string 1, and consequently enhance the sealing of the plug. The expansion movement of the continuous expandable seal ring may continue as long as the untethered object moves longitudinally inwards through the conical surface 184, and may be stopped at the point where the untethered object 5 contacts the hemispherical surface 185 of the locking ring 180. The other plug components 161 and 160 may not move during this further expansion process of the continuous expandable seal ring 170.
FIGS. 16A and 16B represent close-up views of already depicted views in FIGS. 15A and 15B.
FIG. 16A shows in detail the untethered object 5 contacting the inner surface 184 of the locking ring 180. The resulting force 251, induced from pressure force 250 on the untethered object 5, is transmitted through the thin section between the surfaces 184 and 181 of the locking ring 180. Assuming a material with sufficient ductility, preferably above 5%, the force 251 is then transferred to the continuous expandable seal ring 170, on its inner conical surface 171. As depicted in FIG. 16A, the continuous expandable seal ring 170 may not contact the inner surface of the tubing string 1. A possible radial gap may be present between the external cylindrical surface 173 of the continuous expandable seal ring 170 and the inner surface of the tubing string 1.
The expandable gripping ring 161 may be locked longitudinally with the anchoring devices 74 penetrating inside the tubing string 1. The expandable gripping ring 161 may be also locked radially with locking ring 180. Therefore, the force 251 acting on the expandable continuous seal ring 170 may be guided along the surface 174 contacting the expandable gripping ring 161. The expandable continuous seal ring 170 may expand further radially following the surface 174, represented as a conical surface. A possible groove 169 on the expandable gripping ring 161 may have a similar radial gap to allow this relative radial movement between both parts 161 and 170.
FIG. 16B shows the possible final position of the untethered object 5. Force 251 has expanded both the thin section of the locking ring 180 and further the expandable continuous seal ring 170 up to contacting the outer surface 173 with the inner surface of the tubing string 1. The expandable continuous seal ring 170 is therefore radially further expanded, following the guiding surface 174. The groove gap 169 may be closed after this expansion. The untethered object 5 may move longitudinally during the expansion process of both the locking-ring 180 and expandable continuous seal ring 170. This longitudinal movement of the untethered object 5 may stop as the untethered object 5 is contacting the hemispherical surface 185 of the locking ring 180. At the point of contact, the expansion process of the locking ring and expandable continuous ring may stop as well, and the force 250 from the untethered object may then be shared between further force 251 and a force 260. The force 260 may be directed from the untethered object 5, towards the locking ring 180 and transmitted to the expandable gripping ring 161, allowing to possibly reinforce the anchoring penetration of the anchoring devices 74 inside the tubing string 1.
FIG. 17 represents a technique sequence 270, which includes major steps depicted in FIG. 10A to FIG. 16A.
Step 271 corresponds to the deployment of the plug assembly (170, 180, 161, 160) into the tubing string (1) containing well fluid (2). During step 272, the plug assembly with its expandable continuous seal ring (170) is deformed radially, and the expandable gripping ring 161 is expanded radially, both due to the action of a retrievable setting tool (150), over a locking ring (180). During the same step 272, the expandable gripping ring contacts at least one point of the inner surface of the tubing string (1). Then, during step 273, the retrievable setting tool (150), is retrieved. Further during step 274, an untethered object (5), is launched, such as from surface, inside the tubing string (1). Then, during step 275, the untethered object (5) reaches the position of the set plug in step 272 and contacts radially the inner surface of the locking ring (180). Finally, during step 276, the well fluid (2) pressure and flow restriction up-hole of the untethered object (5) is used to act as a force on both the locking ring (180) and the expandable continuous seal ring (170) to enhance the surface contact with the tubing string (1). This isolation state allows performing a downhole operation inside the well.
FIG. 18 represents a technique sequence 280, which includes major steps depicted in FIG. 10A to FIG. 16B.
Step 281 corresponds to the deployment of the plug assembly (170, 180, 161, 160) into the tubing string (1) containing well fluid (2). During step 282, the plug assembly with its expandable continuous seal ring (170) is deformed radially, and the expandable gripping ring (161) is expanded radially, both due to the action of a retrievable setting tool (150), over a locking ring (180). During the same step 272, the expandable gripping ring 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 is less than the tubing string (1) inner diameter. Then, during step 283, the retrievable setting tool (150), is retrieved. Further during step 284, an untethered object (5), is launched, such as from surface, inside the tubing string (1). Then, during step 275, the untethered object (5) reaches the position of the set plug in step 282 and contacts radially the inner surface of the locking ring (180). Finally, during step 286, the well fluid (2) pressure and flow restriction up-hole of the untethered object (5) is used to act as a force to deform further both the locking ring (180) and the expandable continuous seal ring (170), up to surface contact with the tubing string, allowing further enhanced contact between all plug components from the untethered object (5) to the tubing string (1) passing through the locking ring (180) and expandable continuous seal ring (170). The force also provides enhanced anchoring action on the expandable gripping ring (161). This isolation state allows performing a downhole operation inside the well.
FIGS. 19A to 27 represent another embodiment of a plug and retrievable setting tool. FIGS. 19A to 27 relates in particular of a plug with a cup and a carried untethered object.
FIG. 19A represents a cut view of the embodiment inside the tubing string 1, along tool axis 12.
The embodiment is an unset or run-in-hole position. This represents the unactuated or undeformed position for the plug and the retrievable setting tool, which allows traveling inside the tubing string 1.
The plug includes the following components:

- the expandable continuous seal ring 170, which may have similar features and shapes as described in FIG. 12 ,
- the expandable gripping ring 161 including anchoring devices 74, which may have similar features and shapes as described in FIG. 11A,
- the back-pushing ring 160, which may have similar features and shapes as described in FIG. 11A. The shear devices 65 may be positioned on the inner diameter of the back-pushing ring 160,
- a locking ring 410. The locking ring 410 includes additional features compared to the locking ring 180 previously described in FIG. 14 . The locking ring 410 may include a flared external surface 426, represented conical, matching the inner surface 165 of the expandable gripping ring 161 and the inner surface 171 of the expandable continuous seal ring 170. The locking ring 410 may include a flared internal surface 427, represented conical, on a first portion of its inner surface. The locking ring 410 may include another flared internal surface 419, represented hemispherical, as second portion of its inner surface. This surface 419 is referred as a stopping surface for the locking ring 410. The locking ring 410 may include finally another inner surface 416, represented conical or cylindrical, as third portion of its inner surface.
- a hemispherical cup 411, which will be further described in FIGS. 42A and 42B.

The retrievable setting tool includes the following components:

- an external mandrel 414, which may include a cylindrical hollow pocket 418. The hollow 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 surface 417, represented conical.
- a rod 412 which can move longitudinally within 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.
FIG. 19B represents the same embodiment as FIG. 19A, without the tubing string 1, and as an isometric view, along axis 12.
External plug components visible in FIG. 19B include the back-pushing ring 160, the expandable gripping ring 161 with its anchoring devices 74, the expandable continuous seal ring 170, the locking ring 410 and the hemispherical cup 411.
Regarding external retrievable setting tool components visible in FIG. 19B, it includes the external mandrel 414 and the rod 412
FIG. 20A and FIG. 20B depict detailed views of the hemispherical cup 411.
FIG. 20A represents an isometric view of the hemispherical cup 411. The first portion of the external outer surface 420 may be conical. Surface 420 may be matching the inner conical surface 427 of the locking ring 410. The two surfaces 420 and 427 may be designed as conical with similar angle, typically from 2 deg to 30 deg. The two surfaces 420 and 427 may be designed to allow that the longitudinal movement along axis 12 of the hemispherical cup 411 would keep both surfaces 420 and 427 in contact, provide an axial expansion of surface 427 of the locking ring 410 if the locking ring 410 is not moving longitudinally compared to the hemispherical cup 411. The external surface 420 may transition to second portion external surface 421, represented as a hemispherical surface. The hemispherical diameter of the surface 421 may be similar to the hemispherical diameter of the stopping surface 419 of the locking ring 410. Note that in the run-in-hole and unset position, as shown in FIG. 19A, the two surfaces 422 and 419 may not be in contact with each other. The internal surface 422 may be cylindrical with a diameter allowing a portion of the external mandrel 414 to pass through.
FIG. 20B represents another isometric view of the hemispherical cup 411. The external surfaces 420, as conical and 421 as hemispherical are visible. The inner surface 423 may be conical and match the outer surface 417 of the external mandrel 414. The cylindrical surface 422 is also visible. A chamfer or conical surface 424 may be present between surface 423 and 422.
FIG. 21 represents a sequence step of FIG. 19A. In FIG. 21 , the retrievable setting tool has been actuated which induce the longitudinal movement indicated by arrow 430 of the rod 412 compared to the external mandrel 414.
Through the link of the shear devices 65, the rod 412 movement indicated by arrow 430 induced the same longitudinal movement to the back-pushing ring 160. The back-pushing ring induces 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 is held longitudinally in position thanks to the contact 416 with the external mandrel 414, as well as 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. 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.
The expansion process of the expandable gripping ring may end when the anchoring devices 74 penetrates the inner surface of the tubing string 1, and a force equilibrium is established between the anchoring force or friction force created by the anchoring devices 74 with the shear devices 65.
The untethered object 413 may still remain inside the cylindrical pocket 418 of the external mandrel 414.
FIG. 22 represents a sequence step of FIG. 21 . In FIG. 22 , the force equilibrium between the anchoring devices 74 and shear devices 65 is stopped when the pulling force 440 on the rod 412 exceeds the rating of the shearing devices 65. Therefore, the rod 412 can continue its course longitudinally inside the external mandrel. At this point, all other parts described in FIG. 21 may remain in the same position.
FIG. 23A, FIG. 23B and FIG. 23C represents a sequence step of FIG. 22 . FIG. 23A is a cut view of the embodiment, while FIGS. 23B and 23C are the same embodiment represented in two different orientations isometric view without the tubing string 1.
In FIG. 23A, FIG. 23B and FIG. 23C, the retrievable setting tool with the rod 412 and external mandrel 414 is pulled along a longitudinal movement 450, inside the tubing string 1, as part of the toolstring 10 retrieval as described in FIG. 5 .
The retrieval of the setting tool lets the set plug component unchanged as described in FIG. 21 and FIG. 22 in their set position. The movement of the external mandrel 414 is possible through separation or sliding of several surface contacts. This include the separation of surface 417 of the external mandrel 414 from surface 423 of the hemispherical cup 411, the separation of surface 428 of the external mandrel 414 from surface 416 of the locking ring 410. The external mandrel 414 can slide through the cylindrical surface 422 of the hemispherical cup 411.
The hemispherical cup 411 may stay in position thanks to the friction contact along its conical surface 420 in common with the inner conical surface 427 of the locking ring 410. A lip feature at the edge of the inner surface 427 of the locking ring 410 may be added to avoid separation of the hemispherical cup 411 from the locking ring 410. Such lip feature is further described in another embodiment in FIG. 39 as feature 529.
With a sufficient distance of pulling movement indicated by arrow 450, preferably from several inches to several feet [0.1 to 100 m], the release of the untethered object 413 can occur. This release can be initiated preferably from a pumping force indicated by arrow 451 which introduces well fluid 2 through the channel 415, allowing the untethered object to travel towards the set plug. The movement of the untethered object 413 is symbolized with the trajectory 452. Preferably, the well fluid 2 pumping 451 would be initiated from surface. Another possibility to release the untethered object 413 would be addition of a spring inside the hollow pocket 418, which may be compressed with the presence of the untethered object 413 inside the hollow pocket 418 and may exercise an expulsion force to the untethered object toward the opening of the hollow pocket 418. The release of the untethered object 413 through the spring force would occur once the obstruction realized by the hemispherical cup 411 is removed by the separation of the set plug from the external mandrel 414.
FIG. 24A and FIG. 24B represent a sequence step of FIGS. 23A, 23B and 23C.
FIG. 24A depicts a cut view inside the tubing string 1, while FIG. 24B depicts the same embodiment with an isometric view, without the tubing string 1.
In FIG. 24A and FIG. 24B, the untethered object 413 has landed on the hemispherical cup 411 and may contact the chamfer 424.
In this position where no particular force is applied on the untethered object, the hemispherical cup 411 may remain in the same position as described from FIG. 21 to FIG. 23C.
The other plug parts remain also in their original set position as described from FIG. 21 to FIG. 23C.
FIG. 25 represent a sequence step of FIG. 24A and FIG. 24B.
FIG. 25 depicts a cut view inside the tubing string 1.
In FIG. 25 , a well fluid pressure restriction is created through well fluid 2 pumping across the set plug. This flow restriction creates in turn a force 470 on the exposed components, mainly on the untethered object 413 and the hemispherical cup 411.
In this representation, the force 470 has induced a further longitudinal movement of the hemispherical cup 411 and the untethered object 413 contacting the chamfer 424. The longitudinal movement of the hemispherical cup may create a radial deformation of the locking ring through the contact between the outer surface 420 of the hemispherical cup 411 with the inner surface 427 of the locking ring 410. This radial deformation may in turn create a further radial deformation of the expandable continuous seal ring 170.
The further longitudinal movement of the combination of hemispherical cup 411 with untethered object 413 may continue up to stopping surface contact of the hemispherical surface 421 of the hemispherical cup 411 with the corresponding surface 419 on the locking ring 410.
FIG. 26A and FIG. 26B depict close-up views of previously described FIGS. 25A and 25B.
The close-up views allow seeing in more details the further expandable continuous seal ring 170 expansion and forces involved.
In FIG. 26A, which represents the same stage as FIG. 24A, the detailed force chain is represented.
At this point, the expandable continuous seal ring 170 might not be in contact with the inner surface of the tubing string 1, creating a radial gap 482. This can be due to geometrical variation of the different parts, possible stop of the expansion process of the expandable continuous seal ring 170 before reaching the inner surface contact with the tubing string, and possible elastic restraint effect of the different parts after the setting process as described in FIG. 21 .
Force 470 is acting on the untethered object 413 and on the hemispherical cup 411, with the two parts being in contact through the 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. This resultant force indicated by arrow 481 may in turn be transmitted towards the expandable continuous seal ring 170, allowing its further deformation and closing of the gap 482.
The expandable gripping ring 161 secured with the anchoring devices 74 inside the tubing string 1 and locked internally by the locking ring 410, might not deform during the further expansion process of the expandable continuous ring 170, and provide a radial sliding guide.
In FIG. 26B, the gap 482 depicted in FIG. 48A may be now closed through the action of the further expansion of the expandable continuous ring 170.
The hemispherical cup 411 may now be in contact with the locking ring 410, as described in FIG. 25 , in a stopping position through the corresponding stopping surfaces 419 and 421. To allow a change in mechanical behavior from the radial expansion to a stopping position, the hemispherical cup 411, described in FIG. 20A and FIG. 20B, may include two surfaces 420 and 421 suitable for these two mechanical phases. The angle of the first section 420 of external surface may be shallower than final angle of the second section 421. Typically, the angle of the first section 420 may be between 2 deg and 30 deg relative to axis 12, and the angle of the furthest portion of the second section 421 may be greater than 45 deg. To be noted that the second section 421 is represented as hemispherical, it could also be represented as conical or combination of flared surface, as long as the stopping surface feature is ensured, meaning that at least a portion of this second section 421 may include a surface with an angle above 45 deg relative to the axis 12.
The resultant of the force 470 on the untethered object 413 and on the hemispherical cup 411, may now directed towards 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.
FIG. 27 represents a technique sequence 490, which includes major steps depicted in FIG. 19A to FIG. 26B.
Step 491 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 492, the plug assembly with its expandable continuous seal ring (170) is deformed radially, and the expandable gripping ring (161) is expanded radially, both due to the action of a retrievable setting tool, over a locking ring (410) and hemispherical cup (411). During the same step 492, the expandable gripping ring 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 493, the retrievable setting tool, is retrieved. Further during step 494, the carried untethered object (413), is released from the setting tool. Then, during step 495, the untethered object (413) contacts radially the inner surface of the hemispherical cup (411). Then, during step 496, the well fluid (2) pressure and flow restriction up-hole 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.
FIG. 28 to FIG. 39 relate to another embodiment of the invention. The plug is similar to the one described from FIG. 19A to FIG. 27 , with the difference that the untethered object 5 is not included in the setting toolstring, previously described as 413.
FIG. 28 represents a cut view of the embodiment inside the tubing string 1, along tool axis 12.
The embodiment is an unset or run-in-hole position. This represents the unactuated or undeformed position for the plug and the retrievable setting tool, which allows traveling inside the tubing string 1.
The plug includes the following components:

- the expandable continuous seal ring 170, which may have similar features and shapes as described in FIG. 12 ,
- the expandable gripping ring 161 including anchoring devices 74, which may have similar features and shapes as described in FIG. 11A,
- the back-pushing ring 160, which may have similar features and shapes as described in FIG. 11A. The shear device 565, as a shear ring, may be positioned on the inner diameter of the back-pushing ring 160,
- a locking ring 510. The locking ring 510 includes similar features and function compared to the locking ring 410 previously described in FIG. 19A. Additional features or details will be described in FIG. 39 .
- a hemispherical cup 511. The hemispherical cup 511 includes similar features and function compared to the locking ring 410 previously described in FIGS. 20A and 20B. Additional features or details will be described in FIGS. 38A and 38B.

The retrievable setting tool includes the following components:

- an external mandrel 514. The external mandrel 514 include includes similar features and function compared to the external mandrel 414 previously described in FIG. 19A, without hollow pocket 418. In this representation, the external mandrel 514 may contact the locking ring 510 along the conical surface 516. In addition, the external mandrel 514 may contact the hemispherical cup 511 along a surface 517, represented cylindrical.
- a rod 512 which can move longitudinally within the external mandrel 514. The rod 512 is represented as a hollow cylinder. The rod 512 may provide a link to the shear ring 565, securing the longitudinal position of the back-pushing ring 160.
- an end cylinder 513, securing the position of the shear ring 565 on the rod 512.

FIG. 29 represents a sequence step of FIG. 28 . In FIG. 29 , the retrievable setting tool has been actuated which induce the longitudinal movement indicated by arrow 530 of the rod 512 compared to the external mandrel 514.
Through the link of the shear ring 565, the rod 512 movement indicated by arrow 530 induced the same longitudinal movement to the back-pushing ring 160. The back-pushing ring induces 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 510. The locking ring is held longitudinally in position thanks to the contact 516 with the external mandrel 514, as well as radially in position through the conical contact with the hemispherical cup 511, itself held in position through the surface contact 517 with the external mandrel. To be noted during this expansion process, the hemispherical surface 519 of the locking ring 510 may not come in contact with the hemispherical surface 521 of the hemispherical cup 511.
The expansion process of the expandable gripping ring 161 may end when the anchoring devices 74 penetrates the inner surface of the tubing string 1, and a force equilibrium is established between the anchoring force or friction force created by the anchoring devices 74 with the shear ring 565.
FIG. 30 represents a sequence step of FIG. 29 . In FIG. 30 , the force equilibrium between the anchoring devices 74 and shear ring 565 is stopped when the pulling force 540 on the rod 512 exceeds the rating of the shearing ring 565. Therefore, the rod 512 can continue its course longitudinally inside the external mandrel. The shear ring 565 may be sheared in two sections, a first section 567 remaining with the back-pushing ring 160, and a second section 566 remaining on the rod 512 next to the end cylinder 513. At this point, all other parts described in FIG. 29 may remain in the same position.
FIG. 31 represents a sequence step of FIG. 30 . In FIG. 31 , the retrievable setting tool with the rod 512 and external mandrel 514 is pulled along a longitudinal movement 550, inside the tubing string 1, as part of the toolstring 10 retrieval as described in FIG. 5 .
The retrieval of the setting tool lets the set plug component unchanged as described in FIG. 30 in their set position. The movement of the external mandrel 514 is possible through separation or sliding of several surface contacts. This include the separation of surface 517 of the external mandrel 514 from surface 523 of the hemispherical cup 511, the separation of surface 516 of the external mandrel 514 from surface 525 of the locking ring 510. The external mandrel 514 can slide through the cylindrical surface 522 of the hemispherical cup 511.
The hemispherical cup 511 may stay in position thanks to the friction contact along its conical surface 520 in common with the inner conical surface 527 of the locking ring 510. A lip feature at the edge of the inner surface 527 of the locking ring 510 may be added to avoid separation of the hemispherical cup 511 from the locking ring 510. Such lip feature is further described in FIG. 39 as feature 529.
FIG. 32 represent a sequence step of FIG. 31 . In FIG. 32 , the untethered object 5 has been launched, typically from surface and is travelling down with the well fluid 2 inside the tubing string 1. The movement of the untethered object 5 is represented with the arrow 560.
FIG. 33A represents a sequence step of FIG. 32 . In FIG. 33A, the untethered object 5 has landed on the hemispherical cup 411 and creating a contact line on the chamfer 424 of the hemispherical cup. The movement of the untethered object 5 is represented with the arrow 570.
In this position, if no well fluid 2 flow is applied, no particular force is applied on the untethered object 5, the hemispherical cup 511 may remain in the same position as described from FIG. 30 to FIG. 32 . The other plug parts remain also in their original set position as described in FIG. 32 .
FIG. 33B represent a sequence step of FIG. 33A.
In FIG. 33B, a well fluid pressure restriction is created through well fluid 2 pumping. This flow restriction creates in turn a force 571 on the uphole exposed components, mainly on the untethered object 5 and the hemispherical cup 511.
In this representation, the force 571 has induced a further longitudinal movement of the hemispherical cup 511 and the untethered object 5 contacting the chamfer 524. The longitudinal movement of the hemispherical cup may create a radial deformation of the locking ring through the contact between the outer surface 520 of the hemispherical cup 511 with the inner surface 527 of the locking ring 510. This radial deformation may in turn create a further radial deformation of the expandable continuous seal ring 170.
The further longitudinal movement of the combination of hemispherical cup 511 with untethered object 513 may continue up to stopping surface contact of the hemispherical surface 521 of the hemispherical cup 511 with the corresponding surface 519 on the locking ring 510.
FIG. 34A and FIG. 34B depict close-up views of previously described FIGS. 33A and 33B.
The close-up views allow seeing in more details the further expandable continuous seal ring 170 expansion and forces involved.
In FIG. 34A, which represents the same stage as FIG. 33A, the detailed force chain is represented.
At this point, the expandable continuous seal ring 170 might not be in contact with the inner surface of the tubing string 1, creating a radial gap 582. This can be due to geometrical variation of the different parts, possible stop of the expansion process of the expandable continuous seal ring 170 before reaching the inner surface contact with the tubing string, and possible elastic restraint effect of the different parts after the setting process as described in FIG. 29 .
Force 571 is acting on the untethered object 5 and on the hemispherical cup 511, with the two parts being in contact through the chamfer 424 and providing a force indicated by arrow 580 at this contact surface. The resultant force indicated by arrow 581 of these two parts may be directed perpendicular to the conical contact surface 520 with the locking ring 510. This resultant force indicated by arrow 581 may in turn be transmitted towards the expandable continuous seal ring 170, allowing its further deformation and closing of the gap 482.
The expandable gripping ring 161 secured with the anchoring devices 74 inside the tubing string 1 and locked internally by the locking ring 510, might not deform during the further expansion process of the expandable continuous ring 170, and provide a radial sliding guide.
In FIG. 34B, the gap 482 depicted in FIG. 34A may be now closed through the action of the further expansion of the expandable continuous ring 170.
The hemispherical cup 511 may now be in contact with the locking ring 510, as described in FIG. 34A, in a stopping position through the corresponding stopping surfaces 519 and 521.
The resultant of the force 571 on the untethered object 5 and on the hemispherical cup 511, may now directed towards 581 and 584. Force 581 may compress the expandable continuous seal ring 170 further towards the tubing string, possibly enhancing the sealing feature of the plug. Force 584 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.
FIG. 35 represents an isometric view of the plug described in FIG. 28 , in an unset or run-in-hole position.
FIG. 36 represents an isometric view of the plug described in FIG. 33A, in a set position with the untethered object 5 landed on the hemispherical cup 511.
FIG. 37A and FIG. 37B show two isometric views of the hemispherical cup 511. The description is similar to the hemispherical cup 411 described in FIG. 20A and FIG. 20B. In particular, the two external surfaces 520 and 521 may relate to surfaces 420 and 421 of the hemispherical cup 411. The angle of the first section 520 of external surface may be shallower than final angle of the second section 521. Typically, the angle of the first section 520 may be between 2 deg and 30 deg relative to axis 12, and the angle of the furthest portion of the second section 521 may be greater than 45 deg. To be noted that the second section 521 is represented as hemispherical, it could also be represented as conical or combination of flared surface, as long as the stopping surface feature is ensured, meaning that at least a portion of this second section 521 may include a surface with an angle above 45 deg relative to the axis 12
FIG. 38 represents an isometric view of the locking ring 510.
The locking ring 510 may include a first inner surface 527, which matches in shape and angle the corresponding first outer surface 520 of the hemispherical cup 511. The first inner surface 527 is represented conical with an angle between 2 and 30 deg relative to the axis 12, and similar with the angle of surface 520 of the hemispherical cup 511.
The locking ring 510 may include a second inner surface 519, which matches in shape and angular variation the corresponding first outer surface 521 of the hemispherical cup 511. The surface 519 represents the stopping surface as possible ending contact with the surface 521 of the hemispherical cup 511, after expansion of the first surface 527 through longitudinal movement of hemispherical cup 511 towards the locking ring 510.
The locking ring 510 may include a third inner surface 525, which matches in shape and angle the corresponding surface 516 of the external mandrel 514.
The locking ring 510 may include an external flared surface 526, represented conical, which matches in angle the inner surface 171 of the expandable continuous sealing ring 170 and the inner surface 165 of the expandable gripping ring 161. A section 528 of the external flared surface 526 may include circular teeth or rough surface to improve the locking the expandable gripping ring 161 on its internal surface 165.
The two surfaces 527 and 526 may have a similar angular orientation, keeping a thickness between the two surfaces in a thin range, typically from 0.02 and 0.4 inches [0.5 to 10 mm].
The locking ring 510 may include a recess lip 529 at the highest diameter of the internal first surface 527. The recess lip 529 is designed to let the assembly of the hemispherical cup 511 by slight compression over the external surface 520, while providing an anti-return for the hemispherical cup 511, once the locking ring 510 and hemispherical cup 511 are assembled together, as part of the plug assembly prior to being deployed.
FIG. 39 represents a technique sequence 590, which includes major steps depicted in FIG. 28A to FIG. 38 .
Step 591 corresponds to the deployment of a plug assembly (170, 510, 511, 161, 160) into the tubing string (1) containing well fluid (2). During step 592, the plug assembly with its expandable continuous seal ring (170) is deformed radially, and the expandable gripping ring (161) is expanded radially, both due to the action of a retrievable setting tool, over a locking ring (510) and hemispherical cup (511). During the same step 592, 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 593, the retrievable setting tool, is retrieved. Further during step 594, untethered object (413), is launched from surface. Then, during step 595, the untethered object (5) contacts radially the inner surface of the hemispherical cup (511). Then, during step 596, the well fluid (2) pressure and flow restriction up-hole of the untethered object (5) and hemispherical cup (511) 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 (5) to the tubing string (1) passing through the hemispherical cup (511), the locking ring (510) 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.
FIGS. 40 to 47 depict another embodiment of the invention. This embodiment is a variation of the embodiment of FIGS. 19A to 27 , with the major difference that two untethered objects are carried within the retrievable setting tool.
FIG. 40 represents an isometric view of the plug with its associated setting tool, in a run-in-hole or unset position.
FIG. 40 represents similar parts and features described previously, namely an expandable gripping ring 161, an expandable continuous sealing ring 170 and anchoring device 74. The other parts, are different to allow the passing of two shafts 615 linked to the rod 612. Therefore, a back-pushing ring 660, a locking ring 610 and an external mandrel 614 may be adapted for the passing of two shafts and two untethered objects, from similar respective parts as back-pushing ring 560, locking ring 510 and external mandrel 514, previously described.
FIG. 41A represents a cut view of the embodiment shown on FIG. 40 within a tubing string 1.
In FIG. 41A, the external mandrel 614 is shown with two extensions 616 to contact the locking ring 610. A hemispherical cup 611 is depicted with two orifices 630 allowing the sliding passage of the two extensions 616. Same orifices 630 will later be used to receive the untethered objects 605, as further shown in FIG. 43 .
Further, both shafts extensions 615 are connected the back-pushing ring 660 through two shear rings 665, each secured by an end cylinder 613.
FIG. 41B represents another cut view of the same embodiment as FIG. 41A, with a cut view at 90 deg compared to FIG. 41B.
In FIG. 41B, the external mandrel 614 shows the inclusion of two carried untethered objects 605 in two respective hollow pockets 617.
FIG. 42 represents an isometric view of the external mandrel 614 and two shaft extensions 615. The view of FIG. 42 allows to depict the relative position of the two hollow pockets 617 and two extensions 616, as seen in the two cut views of FIGS. 41A and 41B. Both untethered objects 605 are represented inside theirs corresponding hollow pockets 617 of the external mandrel 614.
FIG. 43 represents a cut view of the set plug within the tubing string 1, after retrieval of the setting tool and release of both untethered objects 605. The process of plug setting an actuation may be similar to the process previously described in FIGS. 29, 30 and 31 , with the difference that the shearing load of both shearing rings 665 is necessary for the actuation. The process of the untethered objects 605 may be similar to the process previously described in FIGS. 23A to 24A, with the difference that both untethered objects 605 are landing on two orifices 630 inside the hemispherical cup 611. Both untethered objects may have a similar shape and size to allow to fit on any of the orifices 630 of the hemispherical cup 611.
FIG. 44 represents an isometric view of the set plug, similar to the one described in FIG. 43 , before the landing of the two untethered objects 605.
FIG. 45 represents an isometric view of the set plug, similar to the one described in FIG. 43 , after the landing of the two untethered objects 605.
FIG. 46 represents the schematic of another embodiment. In FIG. 46 , a hemispherical cup 711 includes three orifices 730. The rest of the set plug 3 is only partially shown inside the tubing string 1. The right view depicts the same embodiment after the landing of three untethered objects 705 on the three respective orifices 730 of the hemispherical cup 711.
FIG. 46 shows another arrangement of multiple untethered objects, as a quantity of three instead of quantity of two described in FIGS. 41 to 46 . This helps demonstrating that various number of untethered objects are possible with the proposed embodiment. Typically, the number of untethered objects may be between 1 and 10. The untethered objects may be carried inside the setting tool as shown previously in two embodiments from FIGS. 19A to 27 and from FIGS. 40 to 45 , or may be launched from surface as shown previously in the embodiment from FIGS. 28 to 39 . Any combination of number of untethered objects whether carried inside the setting tool or released from the surface would conform with embodiments of this invention. FIG. 27 represents a technique sequence 490, which includes major steps depicted in FIG. 19A to FIG. 26B.
FIG. 47 represents a technique sequence 690, which includes major steps depicted in FIG. 40 to FIG. 46 .
Step 691 corresponds to the deployment of a plug assembly (170, 410, 411, 161, 160) including multiple carried untethered objects (605) into the tubing string (1) containing well fluid (2). During step 492, the plug assembly with its expandable continuous seal ring (170) is deformed radially, and the expandable gripping ring (161) is expanded radially, both due to the action of a retrievable setting tool, over a locking ring (610) and hemispherical cup (611). During the same step 692, the expandable gripping ring 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 693, the retrievable setting tool, is retrieved. Further during step 694, multiple carried untethered objects (605), are released from the setting tool. Then, during step 695, the multiple untethered objects (605) contacts radially multiple corresponding inner surfaces of the hemispherical cup (611). Then, during step 696, the well fluid (2) pressure and flow restriction up-hole of the multiple untethered objects (605) and hemispherical cup (611) 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 multiple untethered objects (605) to the tubing string (1) passing through the hemispherical cup (611), the locking ring (610) 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.

Claims

1. (canceled)

2. (canceled)

3. (canceled)

4. (canceled)

5. (canceled)

6. (canceled)

7. (canceled)

8. (canceled)

9. (canceled)

10. (canceled)

11. (canceled)

12. (canceled)

13. (canceled)

14. (canceled)

15. (canceled)

16. (canceled)

17. (canceled)

18. (canceled)

19. (canceled)

20. (canceled)

21. (canceled)

22. A plugging apparatus, for use inside a tubing string containing well fluid, comprising:

a plug assembly including:

an expandable assembly, comprising a continuous sealing portion and a gripping portion,

a locking ring,

a cup

wherein the expandable assembly includes a flared inner surface,

wherein the locking ring includes a flared outer surface, a stopping inner surface, and a flared portion,

wherein the flared portion of the locking ring includes a flared inner surface positioned opposite of the flared outer surface,

wherein the cup includes a flared outer surface, a stopping outer surface and multiple identical stopping inner surfaces,

wherein the flared outer surface of the locking ring is contacting the flared inner surface of the expandable assembly,

wherein the flared outer surface of the cup is contacting the flared inner surface of the locking ring,

wherein the stopping outer surface of the cup is adapted to couple with the stopping inner surface of the locking ring;

wherein the locking ring includes a flared outer surface and a stopping inner surface,

wherein the flared inner surface of the expandable assembly is contacting the flared outer surface of the locking ring, and

wherein the expandable assembly is adapted to be deformed radially;

multiple identical untethered objects,

wherein the multiple identical untethered objects include each an outer surface adapted to couple with the multiple identical stopping inner surfaces of the cup and, using well fluid pressure, to apply forces to the plug assembly to cause:

the radial deformation of the flared portion of the locking ring,

the radial deformation of the continuous sealing portion of the expandable assembly,

the contact of an internal surface of the tubing string with the continuous sealing portion of the expandable assembly,

the longitudinal movement of the cup while contacting the inner surface of the locking ring until the stopping outer surface of the cup contacts the stopping inner surface of the locking ring, and

the penetration of the internal surface of the tubing string at least at one point with the gripping portion of the expandable assembly.

23. The apparatus of claim 22, further comprising a back-pushing ring and a retrievable setting tool, wherein the retrievable setting tool is adapted to displace the back-pushing ring causing the radial deformation of the expandable assembly over the flared outer surface of the locking ring.

24. The apparatus of claim 23, wherein the retrievable setting tool includes a mandrel and multiple rods,

wherein the mandrel has a surface including one or more of annular, conical, and spherical portions,

wherein the mandrel contacts the inner surface of the locking ring with the surface including one or more of annular, conical, and spherical portions,

wherein the number of rods relate to the number of untethered objects and corresponding number of stopping inner surfaces of the cup,

wherein the multiple rod couples to the back-pushing ring with multiple preset load-shearing devices.

25. The apparatus of claim 23, wherein the,

wherein the retrievable setting tool is configured to be retrieved, after the radial expansion of the expandable assembly

wherein the multiple untethered objects are included inside the retrievable setting tool,

wherein the multiple untethered objects are released from the retrievable setting tool after the radial expansion of the expandable assembly and before the retrieval of the retrievable setting tool.