MX2012011101A

MX2012011101A - Convertible downhole isolation plug.

Info

Publication number: MX2012011101A
Application number: MX2012011101A
Authority: MX
Inventors: Jesse C Porter; Kevin Ray Manke
Original assignee: Halliburton Energy Serv Inc
Priority date: 2010-03-31
Filing date: 2011-03-24
Publication date: 2012-11-29
Also published as: US20110240295A1; WO2011121277A2; EP2553213A2; CA2792013A1; AU2011234240A1; WO2011121277A3; CN102918227A

Abstract

A downhole tool that is capable of isolating communication pressure from below the set downhole tool, and is capable of being converted to a frac plug is provided. The downhole tool includes a packer with a ball seat defined therein. A plug is disposed at a lower end of the downhole tool to isolate the upper well from the lower well. A sealing ball is carried with the packer into the well by a setting tool. The movement of the sealing ball away from the ball seat is limited by isolation of the sealing ball from the lower well. A rod is disposed through the downhole tool contacting the plug. The rod is partially disposed in the ball seat, preventing the sealing ball from sealing. When the packer is set, flow within the well is isolated, thereby allowing treatment of the well above the packer. With the application of sufficient pressure, the sealing ball applies force to the rod which shears the plug from within the tool. The tool is converted to a standard frac plug.

Description

CONVERTIBLE INSULATION PLUG FOR INSIDE WELLS FIELD OF THE INVENTION This disclosure refers to tools for the interior of wells for use in oil and gas wells and for methods for the treatment of wells. This disclosure pertains particularly to in-hole plugs that are convertible from a bridge plug to a fracture plug without removing the plug from the well.

BACKGROUND OF THE INVENTION In the drilling or revocation of oil wells, numerous varieties of tools are used for the interior of the well. For example, but not by way of limitation, it is often desirable to seal another pipe in a well casing when it is desired to pump cement or other slurry into the pipe and force the slurry into the formation. Therefore, it becomes necessary to seal the pipe with respect to the well casing, and prevent the fluid pressure in the slurry from lifting the pipe out of the well. Well interior tools, referred to as bridge plug plugs, are designed to provide the ability to seal other pipes in the well casing, and are well known in the art for producing oil and gas.

Bridge plug plugs typically make use of metallic or non-metallic sliding elements, or sliders. The sliders are initially retained near the mandrel, but are often forced out away from the mandrel to engage a pre-installed liner inside the well. Therefore, when the tool is positioned at the desired depth, the sliders are forced out against the well to secure the plug, or bridge plug, so that the tool will not move relative to the backing during operations. . Some exemplary non-limiting operations include testing, production well emulation, or all or a portion of the well.

A problem encountered by well operators using plug and bridge plugs is that the plug and / or plug must be removed before installing other types of plugs. A fracture plug is a good example. A fracture plug is essentially plugged into the well with a ball seat to receive a sealing ball. When the obturator is placed the sealing ball engages with the ball seat, the liner, or another tube in which the fracture plug is placed, is sealed. Once the sealing ball is placed, the operator is able to pump fluid into the well, and the pumped fluid can be forced into a formation above the fracture plug. Often, it is necessary to completely block the flow from a lower zone to facilitate the treatment of an upper zone, or to conduct some other process in the upper zone after the initial treatment or other processes are completed, it may be desirable to allow the flow to flow from the lower area, and be able to restrict that flow. There is a need for tools that can be placed in the well to act as a bridge plug, and can be converted into a fracture ratio while in the well.

BRIEF DESCRIPTION OF THE INVENTION One modality that is disclosed is a tool for the interior of wells for use in a well. The well interior tool comprises a mandrel defining a central flow passage therethrough and an integrated ball seat. The sealing element is placed above the mandrel. The tool for the interior of wells is movable from a position not placed to a position placed in the well in which the sealing element is coupled to the well. A solid plug to block the flow through the tool into the well is removably connected to the mandrel. A sealing ball positioned in the well is longitudinally separated from the ball seat. Applying a predetermined pressure in the well will simultaneously remove the solid plug and move the sealing ball into engagement with the ball seat.

Another mode provides a tool for the interior of wells for use in a well. The tool for the interior of wells comprises a mandrel having an upper end and a lower end of the mandrel defining central longitudinal flow passage therethrough. The mandrel also defines a ball seat at the upper end thereof. The sealing element is placed on the mandrel to be hermetically coupled to the well. A cap is detachably retained within the mandrel and placed one / within the central longitudinal flow passage the bar has a first end that contacts the cap, second end that contacts the sealing ball to separate the ball from sealing of the ball seat.

Another embodiment provides a method for converting the well interior tool positioned in a well from a bridge plug to a fracture button. The method involves lowering the tool for the interior of wells inside the well. The well interior tool defines a flow path at the central end through it. The method also includes the step of placing the tool for the interior of wells in the well, where the tool for the interior of wells is coupled to the well. The flow through the tool blocks both in the upward and downward direction through the central longitudinal flow passage with a solid plug removably connected to the tool. A sealing ball is positioned in the well above the central longitudinal flow passage. The pressure increases in the well, thus causing the solid plug to detach from the tool into the well and to move with the sealing ball in engagement with the ball seat that is positioned in the tool in the well. When the sealing ball is in engagement with the ball seat, flow down through the tool into the well is prevented but flow up through it is allowed.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows schematically two tools for the interior of wells positioned in a well.

Figure 2 is a cross-sectional view of the tool for the interior of wells in an unoccupied position.

Figure 3 is a cross-sectional view of the tool for the interior of wells in a placed position.

Figure 4 is a cross-sectional view of the tool for the interior of wells with the cap removed.

DETAILED DESCRIPTION OF THE INVENTION In the description that follows, similar parts are marked throughout the specification and drawings with the same reference numbers, respectively. The drawings are not necessarily to scale, and the proportions of certain parts have been exaggerated to better illustrate the details and features of the invention. In the following description, the terms "upper", "upward", "lower, below", "in the well", and the like as used herein mean with respect to the extent of the bottom or furthest from the well surrounding. This applies even in the well or portions thereof that may be offset or horizontal. The terms "inward" and "outward" are directions approaching and moving away, respectively, from the geometric center of a referenced object. Where relatively well-known design components are used, their structure and operation will not be described in detail.

With reference to the drawings, and in particular Figure 1, the tool for the interior of wells of the present invention is shown and designated by the number 10. The tool for the interior of wells 10 has an upper end 11 and an end lower 13. In Figure 1, two tools for the interior of wells 10 are shown, and can be referred to herein as the lower tool for the interior of wells 10a and the second or upper tool for the interior of wells 10b. The tools for the interior of wells 10a and 10b may be identical, and the subscripts a and b are used to simply designate that the tools are in different positions in the well.

Figure 1 schematically depicts tools for the interior of wells 10 in positions positioned within well 14, which comprises well 12 with a liner 16 cemented therein. The well 14 can cross one or more formations or zones, such as the first zone 18 the second zone 20. The tools for the interior of wells 10 are shown after being lowered into the well 14 with a positioning tool 22. The tool of placement 22 may be of any type known in the art. An example of positioning tool 22 is shown in Figure 2.

With reference to Figure 2, a cross-section of the tool for the interior of wells 10 is shown with the positioning tool 22 attached thereto for running the tool for the interior of wells 10 inside the well 14. The tool for the well interior 10 is in a position not placed in Figure 2. The well interior tool 10 is commonly referred to as an obturator, and is referred to herein as the obturator 24. The obturator 24 comprises the mandrel 26 with the first, or upper end 28, and second, or lower end 30. Mandrel 26 defines central longitudinal flow passage 32 to allow fluid communication therethrough. The mandrel 26 defines the ball seat 34 at the upper end 28 thereof. The ball seat 34 has a lower end 33 positioned where the ball seat 34 flows into the central longitudinal flow passage 32. The sealing ball 35 is positioned between the positioning tool 22 and the ball seat 34 and is separated from the ball seat 34. The sealing ball 35 can be referred to as a fracture ball 35.

The plug 24 is designed to be placed in the well 14. Therefore, the mandrel 26 has the sealing element 36 positioned around it. Spacer ring 38 is secured to mandrel 26 with bolts 40. Spacer ring 38 provides a splice serving to axially retain sliding segments 42, which are positioned circumferentially around mandrel 26. Sliding segments 42 may utilize ceramic buttons 44 as described in detail in U.S. Patent No. 5,984,007, which is incorporated by reference herein. The sliding retaining bands 46 serve to radially retain the sliding segments 42 in an initial circumferential position relative to the mandrel 26. The sliding retaining bands 46 can be made of a steel wire, a plastic material, or a material compound having the requisite characteristics of sufficient strength to hold the sliding segments 42 in place before placing the tool for the interior of wells 10, and may be pierceable. Preferably, the retaining bands 46 are not expensive and are easily installed in the sliding segments 42. The sliding wedge 48 is initially positioned in a sliding relationship with, and partially below, the sliding segment 42. The sliding wedge 48 is shown bolted in place by means of the bolts 50. At least one sealing element 36 is located below the sliding wedge 48. The embodiment of Figure 2 has a sealing member assembly 52 consisting of three elements. expandable seals, or shutters 36 positioned on the mandrel 26. The seal shoes 56 are positioned on the upper and lower ends of the sealing element assembly and provide axial support thereto. The particular sealing arrangement or sealing element shown in Figure 2 is representative only, since various arrangements of sealing elements in the material are known and used.

A plurality of sliding segments 42 are located below the lower sliding wedge 48. A mounting shoe 58 is secured to the mandrel 26 by radially oriented bolts and / or epoxy glue 60. The mounting shoe 58 extends below the lower end 30 of the mandrel 26 and has a lower end 62, which comprises the lower end 13 of the tool for the interior of wells 10. The lower portion of the tool for the interior of wells 10 need not be a mounting shoe 58, but could be any type of section, which serves to determining the structure of the tool for the interior of wells 10, or serving as a connector for connecting the tool for the interior of wells 10 with other tools, a valve, pipe or other equipment for the interior of wells.

Referring again to Figure 2, the mandrel 26 has a recess 66 positioned at or near the lower end 30 thereof. The central longitudinal flow passage 32 has the first inner diameter 68 and the second inner diameter 70 defining the gap 66. The second inner diameter 70 is therefore larger than the first inner diameter 68. The gap 66 also defines a shoulder 72. A solid plug 74 is removably positioned in the mandrel 26, preferably in the recess 66. The plug 74 is releasably connected to the mandrel 26 with a cutting pin 76 other retention method. The plug 74 has a receptacle 78 at an upper end 80 thereof. The plug 74 has the O-ring 82 to be hermetically coupled to the recess 66.

A bar 84 having the upper end 86 and the lower end 88 is positioned in the central longitudinal flow passage 32. The lower end 88 engages the solid plug 74, and is received in the receptacle 78, contacting therewith. The upper end 86 extends beyond the lower end 33 of the ball seat 34 to separate the ball seat 34 from the sealing ball 35 and to prevent the sealing ball 35 from prematurely seating in the ball seat 34. In an alternative embodiment, the receptacle 78 is not used, and the rod 84 simply contacts the upper end 80 of the plug 74.

The operation of the tool for the interior of wells 10 is as follows. The tool for the interior of wells 10 is lowered into the well 12 with the positioning tool 22, which is a placement tool of a type known in the art. While the well interior tool 10 is lowered into the well 12, flow through the central longitudinal flow passage 32 is prevented due to the solid plug 74. The sealing ball 35 is positioned and separated from the ball seat 34 by the bar 84. Once the tool for the interior of wells 10 has been lowered to a desired position in the well 14, the positioning tool 22 is used to move the tool for the interior of wells 10 from its non-position. placed to the placed opposition, as represented in Figures 2 and 3, respectively. A coaxial laying pipe (not shown) will engage the spacer ring 38, so that the positioning tool 22 moves upwardly, the spacer ring 38 is held in place. Once placed, all fluid communication is prevented up and down from above and below the plug 74. The tool 10 then acts as a bridge plug to prevent flow in the well. The tool 10 can be placed in the well above a previously perforated and fractured zone, for example, the second zone 20 in Figure 1. An above, for example, the first zone 18, can be fractured, and the tool 10a, which acts as a bridge plug, prevents the fluid in zone 20 from passing upward, and also prevents the fluid pressure above tool 10a from acting in zone 20.

To convert the tool for the interior of wells 10, the plug 74 is removed from the mandrel 26. Removing the plug 74 requires exerting a predetermined pressure to create sufficient force on the plug 74 to detach or remove the plug 74. In one embodiment, the plug 74 is retained with the cutting bolt 76 and predetermined pressure force will cut the bolt 76. The fluid pressure required to remove the plug 74 will be less than the pressure used to fracture an above, so that the tool 10 automatically becomes a fracture plug with the fracture of an above. The cutting of the cutting bolt 76 allows the plug 74 and the rod 84 to fall through the well 14. With the detachment of the plug 74, the tool 10 acts as a standard fracture plug where the sealing ball 35 sits. it leaves the ball seat 34 according to the fluid pressure communicated from above. Removing the solid plug 74 and contacting the sealing ball 35 with the ball seat 34 is simultaneous in the described manner.

Using Figure 1 for exemplary purposes, the first tool 10a can be lowered into the well 14 and placed above the formation 20, which would have been perforated and fractured prior to the placement of the tool 10a in the well 14. pressure can be increased in fracture zone 18 above. When initially positioned in the well 14, the tool 10 will act as a bridge plug to prevent upward flow through the tool from the formation 20. The fracture pressure will be greater than that required to move or disconnect the plug 74 of the mandrel 26 in the tool 10a in such a way that the application of the fracture pressure will automatically convert the tool 10a into a fracture plug. The conversion results simply from the increased pressure that will act on the cap 74 to remove it therefrom and simultaneously move the sealing ball 35 in engagement with the seat 34. The fracturing then continues in the normal manner. Once zone 18 has been fractured, the pressure can be released and the fluid from zones 20 and 18 can pass upwards towards the surface. Therefore, the tool 10a acts simply as a fracture plug. If desired, the process can be repeated in such a way that the second tool referred to in Figure 1 as the tool 10b can be placed in the well above the zone 18 and the process described in this document is repeated. The process can be repeated as many times as desired in a well. Therefore, as described herein, the tool 10 can be converted from a bridge plug to a fracture plug while in the well to effectively prevent communication from a lower zone to an upper zone and vice versa until the fracture is complete. Automatic conversion to the fracture plug will allow all zones to communicate to the surface once the fracture has been completed.

Therefore, it is noted that the apparatus and methods of the present invention easily achieve the ends and advantages mentioned as well as those inherent therein. While certain preferred embodiments of the invention have been illustrated and described for purposes of the present disclosure, numerous changes in the accommodation and construction of parts and steps can be made by those skilled in the art, where said changes are encompassed within the scope and scope of the invention. spirit of the present invention as defined by the appended claims.

Claims

NOVELTY OF THE INVENTION Having described the present invention as above, it is considered as a novelty and, therefore, the content of the following is claimed as property: CLAIMS

1. A tool for the interior of wells for use in a well that includes: a mandrel defining a central flow passage and a ball seat; a sealing element positioned above the mandrel and movable from a position not placed to a position placed in the well; a plug removably positioned in the mandrel to completely prevent flow through the central flow passage; Y a sealing ball longitudinally separated from the ball seat, wherein the application of a predetermined pressure in the well releases the plug of the mandrel and moves the sealing ball in engagement with the ball seat.

2. A tool for the interior of wells according to claim 1, further comprises a bar placed on the mandrel, wherein the bar engages with the sealing ball to separate the sealing ball from the ball seat until the cap is detached.

3. A tool for the interior of wells according to claim 1, characterized in that the plug has a bar extending therefrom to engage with the sealing ball and separating the sealing ball from the ball seat.

4. A tool for the interior of wells according to claim 1, characterized in that the tool comprises a bridge plug before the detachment of the mandrel plug, and a fracture plug after the detachment.

5. A tool for the interior of wells for use in a well, the tool includes: a mandrel having an upper end and a lower end, the mandrel defines a central longitudinal flow passage therethrough, wherein the mandrel defines a ball seat at the upper end thereof; a sealing element placed around the mandrel to be hermetically coupled to the well; a stopper detachably retained in the mandrel; Y a bar placed in the central longitudinal flow passage, the bar has first and second ends, the first end contacts the plug and extends therefrom in the longitudinal flow passage.

6. A tool for the interior of wells according to claim 5, further comprises a sealing ball separated from the ball seat.

7. A tool for the interior of wells according to claim 6, characterized in that a second end of the bar engages the sealing ball to separate the sealing ball from the ball seat and to prevent the sealing ball from engaging the ball. ball seat until a pressure of a predetermined amount is applied in the well.

8. A tool for the interior of wells according to claim 7, characterized in that the predetermined pressure is sufficient to detach the plug from the mandrel.

9. A tool for the interior of wells according to claim 7, characterized in that the plug is detached and removed from the mandrel and the ball moves in engagement with the ball seat with the application of the predetermined pressure in the well.

10. A tool for the interior of wells according to claim 7, characterized in that the tool is converted from a bridge plug to a fracture plug in the well with the detachment of the plug from the mandrel.

11. A tool for the interior of wells according to claim 5, characterized in that the tool for the interior of wells is movable from a position not placed to one placed in the well.

12. A method for converting a tool for the interior of wells of a bridge plug to a fracture plug comprising: To lower the tool for the interior of wells towards the interior of the well, the tool for the interior of wells defines a central longitudinal flow passage through it; blocking the flow both in an upward direction and in a downward direction through the central longitudinal flow passage with a solid plug placed therein; place the tool for the interior of wells in the well in such a way that the tool for the interior of wells is hermetically coupled to the well; positioning a sealing ball in the well above the central longitudinal flow passage; increase a pressure in the well to a predetermined pressure to remove the solid plug; Y contacting a ball seat in the tool for the interior of wells with the sealing ball, the sealing ball prevents flow in the downward direction through the central longitudinal flow passage.

13. A method according to claim 12 further comprises the step of drilling the well above the tool before the step of increasing the pressure in the well up to the predetermined pressure.

14. A method according to claim 12 further comprises the step of fracturing an area above the tool after the step of contacting the ball seat with the sealing ball.

15. A method according to claim 12, further comprises separating the ball from the ball seat with a rod that engages the solid plug.

16. A method for fracturing a plurality of zones in a well comprising: (a) fracture a first zone in the well; (b) lowering a bridge plug into the well, the bridge plug comprises a mandrel with a sealing element placed around it and a solid plug placed therein, the mandrel defining a longitudinal flow passage through the same; (c) placing a sealing ball in the well before placing the bridge plug in the well; (d) separating the sealing ball from the longitudinal flow passage; (e) place the bridge plug in the well above the first fractured zone; (f) simultaneously releasing the solid plug and moving the sealing ball in engagement with the ball seat to convert the bridge plug to a fracture plug; Y (g) fracture a second zone above the tool.

17. A method according to claim 16, characterized in that the simultaneous step of detaching and moving comprises increasing the pressure in the well above the bridge plug.

18. A method according to claim 16, further comprising decreasing the pressure in the well to allow the fluid of the first zone to pass upwards through the longitudinal flow passage.

19. A method according to claim 16, further comprising: repeat steps (a) - (e) above the second fractured zone with a second bridge plug; simultaneously removing the solid plug and moving the sealing ball of the second bridge plug in engagement with the ball seat of the second bridge plug to convert the second bridge plug into a second fracture plug; Y fracture a third zone above the second fracture plug.

20. A method according to claim 19 further comprises reducing the pressure in the well after fracturing the third zone such that fluid from the first, second and third fractured zones can pass upward in the well.

21. A method for converting a tool for the interior of wells of a bridge plug to a fracture plug in the well comprising: lowering a mandrel having an upper end and a lower end towards the interior of the well, the mandrel defines a central longitudinal flow passage therethrough and a ball seat at the upper end thereof, the mandrel has a solid plug connected to it. the same to block the flow through it; positioning a fracture ball in the well separated from the ball seat; simultaneously releasing the solid plug from the mandrel and moving the sealing ball in engagement with the seat, so that flow down through the central longitudinal passage is prevented and flow up through it is allowed.

22. A method according to claim 21, further comprising: position a bar in the longitudinal flow path; and separating the sealing ball from the seat with the bar before detaching the plug from the mandrel.

23. A method according to claim 22, characterized in that the bar is coupled to the solid plug and to the sealing ball.