US20140305627A1

US20140305627A1 - Anti-wear device for composite packers and plugs

Info

Publication number: US20140305627A1
Application number: US13/862,600
Authority: US
Inventors: Kevin Ray Manke
Original assignee: Halliburton Energy Services Inc
Current assignee: Halliburton Energy Services Inc
Priority date: 2013-04-15
Filing date: 2013-04-15
Publication date: 2014-10-16
Also published as: WO2014172048A1

Abstract

A downhole packer tool having components made essentially of non-metallic engineering grade plastic materials. The tool having an apparatus for anchoring the tool in an annular structure. The tool has a mandrel; a slip assembly positioned on the mandrel, the slip assembly having at least one spacer ring and a plurality of slip elements; and at least one wear resistant insert installed in an outer surface of the tool and extending outwardly therefrom whereby the at least insert button is abrasion resistant upon setting yet has favorable drillability characteristics upon drilling the tool from the wellbore.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

None.

BACKGROUND

1. Technical Field
This application relates generally to downhole tools for use in oil and gas wellbores, and more particularly, to such tools having one or more drillable components made from non-metallic materials, such as engineering grade plastics and composite materials. This application relates particularly to downhole packers and plugs.
2. Background Art
In the drilling or reworking of oil wells, a great variety of downhole tools are used to block or channel flow in the wellbore. For example, but not by way of limitation, it is often desirable to close off the well or to seal the annulus around tubing or other pipe in the wellbore casing. Downhole tools referred to as packers tools are designed for these general purposes and are well known in the art of producing oil and gas. As used herein the term, “packer tool” refers to a tool that has an expandable seal or packing element that radially expands to contact and seal against the wellbore tubing. Packer tools include, for example: tools know as packers, bridge plugs and frac plugs.
Halliburton Energy Services, Inc. introduced to the industry a line of drillable packer tools currently marketed by Halliburton under the trademarks FAS DRILL® and Obsidian®. These tools comprise components made of non-metallic materials, such as, engineering grade plastics to improve the drillability of such downhole tools. The FAS DRILL® and Obsidian® line of tools has been very successful and a number of U.S. patents have been issued to Halliburton Energy Services, Inc., including U.S. Pat. No. 5,271,468 to Streich et al., U.S. Pat. No. 5,224,540 to Streich et al., U.S. Pat. No. 5,390,737 to Jacobi et al., U.S. Pat. No. 5,540,279 to Branch et al., U.S. Pat. No. 5,701,959 to Hushbeck et al., U.S. Pat. No. 5,839,515 to Yuan et al., U.S. Pat. No. 5,984,007 to Yuan et al. and U.S. Pat. No. 6,394,180 to Berscheidt et al. The preceding patents are specifically incorporated herein by reference.
The FAS DRILL® and Obsidian® type packer tools comprise a mandrel with elements mounted thereon for sealing against the wellbore wall and for contacting the wellbore wall to anchor the tool in position in the well. The term “mandrel” is a term of art and comprises the structural backbone of the tool and is typically in the shape of a rod or tube which may or may not have a cylindrical exterior surface. In a process called setting, the sealing and anchoring element of these packer tools change shape, in that, these elements radially expand into contact with the wellbore wall. When these packer tools are lowered or run into the well the packing and anchoring elements are in a run state (radially contracted to clear the wellbore wall) and the tools have been set in position in the well these elements are in a set state (radially expanded into contact with the wellbore).
Packing assemblies provide the sealing function and slip assemblies provide the anchoring function. As used herein the term “packing assembly” means an assembly comprising one or more annular rings of compressible material which when axially compressed expands radially from the run state into contact with the wellbore wall. Packing assemblies may or may not include one or more back up and anti-extrusion rings. As used herein the term “slip assembly” means an assembly comprising one or more wedges and slips which when axially compressed interact to radially expand from the run state where the slips are in contact with the wellbore wall.
These packer tools also comprise elements for axially retaining the packing and anchoring assemblies on the mandrel. These retaining elements comprise shoulders connected to the mandrel and located on the mandrel adjacent the ends of the mandrel with the packing and anchoring assemblies confined there between. Typically, the shoulders are formed on annular shaped elements connected to or integrally formed on the mandrel. The lower retaining element on the mandrel is sometimes referred to as a “bullnose or muleshoe.” In the FAS DRILL® and Obsidian® type packer tools the muleshoe comprises an annular member of easily drillable non-metallic material and has a larger outer diameter than the packing and anchoring elements when in the run state. The upper retaining element in the In the FAS DRILL® and Obsidian® type packer tools comprise a setting ring made of easily drillable non-metallic material and has a larger outer diameter greater than the packing and anchoring elements when in the run state. This tool configuration with the radially recessed packing and anchoring elements holds these elements away from the wellbore wall and protects the packing and anchoring elements from damage and prevents the wellbore wall contact from causing premature element setting.
In some prior art packer tools ceramic teeth have been included in the slip elements to penetrate the wellbore wall for the purpose of improving the anchoring function. Ceramic teeth in slip segments are described in detail in U.S. Pat. Nos. 5,984,007 and 6,394,180, which are incorporated herein by reference for all purposes. In other prior art packer tools the slips are made of drillable cast iron with integrally formed teeth. However, teeth on the slips cannot and do not contact the wellbore wall during run in of the tool and if they did they would function to penetrate the wellbore wall and interfere with the movement of the tool in the well.
It should be appreciated that while the tool is being run into the well that the non-metallic retaining elements contact the wellbore wall and hold the packing and anchoring elements out of contact with the wellbore. In today's hydrocarbon well environment, a large portion of these engineering grade plastics packer tools are run long distances into horizontally extending wells. As these tools travel in these horizontal sections, they are typically forced to one side and ride against the wellbore casing wall. This contact causes increased wear on the engineering grade plastics parts of this tool. This wear or abrasion can compromise the design and functionality of the tool.
Accordingly there is a need to provide protection of the tool against wear or erosion damage caused by contact with the wellbore wall.

SUMMARY OF THE INVENTIONS

The present invention provides an improved packer tool with plastic components which are protected to minimize damage from contact with the wellbore wall during installation in the well. The invention provides surfaces on the engineering grade plastic tool components that resist wear. According to a feature of the present invention, abrasion resistant materials are embedded in components of the downhole tool, such as, components with the largest outer diameters, to minimize the damage to the components. In a preferred embodiment, wear resistant inserts are installed in the retaining elements, such as, the setting ring and/or muleshoe of the downhole tool. In a preferred embodiment, the wear resistant inserts extend radially outward as far as or further than the other components of the packer tool.
The inserts may be formed in whole or part of materials, such as, zirconia ceramic, metallic-ceramic composites or drillable cast iron materials whereby the inserts have a relatively high abrasion resistance yet have favorable drillability characteristics upon drilling the downhole tool from a wellbore.
Additional objects and advantages of the invention will become apparent as the following detailed description of the preferred embodiment is read in conjunction with the drawings which illustrate the preferred embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings are incorporated into and form a part of the specification to illustrate at least one embodiment and example of the present inventions. Together with the written description, the drawings serve to illustrate and explain the principles of the invention. The drawing figures are only for the purpose of illustrating at least one preferred example of at least one embodiment of the invention and are not to be construed as limiting the invention to only the illustrated and described example or examples. The various inherent advantages and features of the various embodiments of the present invention are apparent from a consideration of the drawings in which:

FIG. 1 is an exemplary packer tool having anti-wear inserts embodying the present invention;

FIG. 2 is a plan view of an exemplary packer tool attached to a setting apparatus embodying the present invention,

FIG. 3 is a side elevation view of a muleshoe with and alternative embodiment of an insert installed therein and embodying the present invention, and

FIG. 4 is a side elevation view of a muleshoe with an even further embodiment of inserts installed therein and embodying the present invention.

DETAILED DESCRIPTION

In the description that follows, like parts are marked throughout the specification and drawings with the same reference numerals, respectively. The drawings are not necessarily to scale and the proportions of certain parts have been exaggerated to better illustrate details and features of the invention. In the following description, the terms “upper,” “upward,” “lower,” “below,” “downhole” and the like as used herein shall mean in relation to the bottom or furthest extent of the surrounding wellbore even though the well or portions of it may be deviated or horizontal. The terms “inwardly” and “outwardly” are directions toward and away from, respectively, the geometric center of a referenced object. Where components of relatively well known designs are employed, their structure and operation will not be described in detail.
Referring now to FIGS. 1 and 2, representative downhole packer tool illustrated in the run state. The tool 2 has a hollow mandrel 4 extending through the tool. The particular packer tool 2 configuration illustrated FIG. 1 is referred to as a bridge plug and is characterized by a plug 6 permanently mounted within mandrel 4 by radially oriented pins 8. Plug 6 has a seal means 10 located between plug 6 and the internal diameter of mandrel 4 to prevent fluid flow therebetween. Without plug 6, the packer tool would be in the form of a packer.
Packer tool 2 includes a non-metallic spacer or setting ring 12 which is preferably initially held in place on the mandrel 4 in the run state by shear pins. Ring 12 provides an abutment which serves to axially retain the upper anchoring assembly comprising slip segments 18 and slip wedge 20. Slip segments 18 and wedge 20 are positioned circumferentially about mandrel 4. Slip wedge 20 has a ring shape and axially slides on the mandrel. Wedge 20 is initially positioned partially underneath slip segments 18. In the FIG. 1 embodiment spacer ring 12 includes a plurality of wear resistant inserts 19 spaced around the periphery. According to the preset insertion, the wear inserts 19 extend radially outward at least as far as or a further distance than the other components of the tool 2.
Located below slip wedge 20 is at least one packing assembly, and as illustrated, the packing assembly comprises at least one packing element 28. In some packer tools a packer shoe 29, also called an extension limiter, is included to provide axial support to respective ends of packing assembly 28. The particular packing assembly arrangement shown in FIG. 1 is merely representative as there are several packer assembly arrangements known and used within the art.
Located below the packing assembly 28 is a lower anchoring assembly comprising a slip wedge 20 and a plurality of slip segments 18. It should be noted that in some packer tools only one of the anchoring assemblies are present.
At the lowermost terminating portion of tool 2 is an angled portion referred to as a muleshoe 30 mounted on the mandrel 4. In the FIGS. 1 and 2 embodiments, a plurality of wear resistant inserts 19 in the shape of buttons are mounted in the exterior of the muleshoe. These wear inserts are spaced around the periphery and extend radially outward a distance equal to or greater than the other components of the tool 2. The presence of inserts is especially important when the tool 2 is to be installed in a long lateral well.
The ring 12 and the muleshoe 30 (sometimes referred to as a bullnose) are made from material with improved drill out characteristics, for example non-metallic engineering grade plastics. These two components comprise the retaining elements of the packer tool. The retaining elements bracket the packing and anchoring assemblies. In this embodiment ring 12 and muleshoe 30 have a larger outer diameter than the packing and anchoring assemblies.
In embodiments were wear inserts 19 in the form of buttons are installed to extend radially outward from the exterior surface of the ring 12 and muleshoe 30. These inserts are positioned to contact the interior of casing 40 to prevent wear or degrading of the ring and muleshoe components of the tool 2.
Wear inserts 19 may be mounted in cavities (not shown) in the packer tool by being molded into, or otherwise secured therein. The use of adhesives to secure inserts 19 is recommended but other methods to secure the inserts may be used.
Suitable materials for making inserts 19 may include abrasion resistant materials such as Zirconia ceramic, the materials described U.S. Pat. No. 5,984,007, drillable cast iron or other abrasion resistant materials. Inserts 19 may range from 0.250 (6.3 mm) to 0.375 inches (9.5 mm) in diameter and from 0.250 inches (6.3 mm) to 0.500 inches (12.5 mm) in length depending on the nominal diameter and working pressures and temperatures of the tool in which the insert inserts are to be used.
The subject inserts have a relatively high abrasion resistance while still maintaining the favorable characteristic of being drillable or millable in a short period of time upon destructively removing the subject tool from a wellbore. Further, due to the lesser density of the inserts taught herein, the present inserts are more easily circulated away from the drilling or milling bit by the fluid in the wellbore, thereby greatly improving drilling or milling speeds. This button density if especially important when drilling or when lighter density fluids are present in the wellbore, or annular structure, including but not limited to, weighted or unweighted water and nitrogen/water mixture.
In the packer tool 3 embodiment of FIG. 2, the tool is illustrated attached to a setting tool S. In this embodiment wear inserts 19 are installed in the lower retaining element muleshoe 30 but are absent from the ring 12. In embodiments where, as illustrated, the outer sleeve S of the setting tool has an outer diameter of about equal to or greater than the ring 12. In this regard the sleeve S acts as the wear protection for the upper end of the packer tool by suspending the upper end away from the wellbore wall. Indeed on some packer tools the ring 12 is eliminated from the assembly by using the setting tool sleeve S to contact and expand the anchoring and packing assemblies on the upper end of the mandrel.
In the illustrated embodiments the wear resistant inserts 19 are illustrated as having cylinder shapes. However, other shapes and configurations of the inserts 19 are contemplated. It is anticipated that the inserts could be formed in other shapes, with quadrilateral, polygonal, and curved sided cross-sectional shapes.
In another embodiment, a ring shaped wear resistant insert is installed in at least one of the retaining elements. The ring shaped insert could be one or more continuous rings 19 a of wear resistant material molded into the outer surface of the retaining element as illustrated in FIG. 3. The ring 19 a could be flush with or extend outward from the outer surface of the retaining element 30.
In an alternative embodiment, the inserts could comprise ring segments installed in one or more annular grooves formed in the outer surface of the retaining elements. These inserts could be mounted to extend radially outward at least a distance flush with the largest component of the tool.
In a further embodiment, the inserts could comprise plates attached to or imbedded in the outer surface of the retaining member. These inserts in the form of plates. The inserts 19 b could be narrow in width and extend axially along the outer surface of the retaining member to act as a skid as illustrated in FIG. 4. The outer surface of the insert 19 b extends radially outward at least as far as the muleshoe 30 and the largest component of the tool.
The operation of packer tools is as follows. Tool 2 and 3 are lowered into the wellbore 40 attached to a wireline setting tool of a type known in the art. As the tool 2 is lowered into the wellbore 40, inserts 19 act as a guides (especially in long horizontal wellbores) to protect fragile parts of the tool, such as parts made from engineering grade plastics materials, from undesirable excessive contact with the wellbore 40 or degrading due to excessive abrasion/erosion of the components. In the illustrated embodiments shown, the plurality of inserts 19 are installed in a preselected pattern in muleshoe 30 and spacer ring 12 of tools 2 and 3 to extend outwardly therefrom.
Once in position the packer tool is set in the wellbore and well treatment operations are conducted. When it is desirable to remove the tool from the wellbore drilling or milling operations are used to break the packer tool up into pieces that are circulated out of the well. As previously pointed out wear inserts made of ceramic material are advantageous for this application.
Although the invention has been described with reference to a specific embodiment, the foregoing description is not intended to be construed in a limiting sense. Various modifications as well as alternative applications will be suggested to persons skilled in the art by the foregoing specification and illustrations. It is therefore contemplated that the appended claims will cover any such modifications, applications or embodiments as followed in the true scope of this invention.

Claims

1. A packer tool comprising:

a mandrel;

a packing assembly mounted on the mandrel;

an anchoring assembly mounted on the mandrel;

a retaining element mounted on the mandrel, and

a wear resistant insert mounted on the outer surface of one of the retaining elements.

2. The packer tool of claim 1 wherein the retaining element comprise a spacer ring and a muleshoe.

3. The packer tool of claim 2 wherein a wear resistant insert is mounted on the outer surface of the muleshoe.

4. The packer tool of claim 2 wherein a wear resistant insert is mounted on the outer surface of the spacer ring.

5. The packer tool of claim 2 wherein a wear resistant insert is mounted on both the outer surface of the muleshoe and the spacer ring.

6. The packer tool of claim 1 wherein the wear resistant insert comprises metallic-ceramic composite material.

7. The packer tool of claim 1 wherein the wear resistant insert comprises a zirconia ceramic compound.

8. The packer tool of claim 1 wherein the wear resistant insert comprises a drillable cast iron material.

9. The packer tool of claim 1 wherein the wear resistant insert comprises a titanium compound having a density ranging between about 5 to 7 grams per cubic centimeter.

10. The packer tool of claim 1 wherein the retaining element containing a wear resistant insert comprises engineering grade plastic material.

11. The packer tool of claim 1 wherein the wear resistant insert extends radially outward at least as far as the remaining portions of the tool.

12. An improved packer tool for installation in the wellbore at a subterranean location, the plug having an upper end for being positioned in the wellbore closest to the wellhead and a lower end for being positioned furthest away from the wellhead, the plug comprising a tubular mandrel, a packing assembly comprising an annular member comprising deformable material, the annular member being of a size and shape such that when it is axially compressed it extends radially into contact with the wellbore, upper and lower opposed slip assemblies positioned on the mandrel, wherein the upper and lower slip assemblies each comprise an annular member with a wedge surface, an annular spacer ring and a plurality of slips located around the mandrel between an annular wedge surface and the annular shoulder of the slip support, the slips being of a size and shape that when the slip assemblies are axially compressed, the slips extend radially into contact with the wellbore, the packing assembly being positioned on the mandrel between the upper and lower opposed slip assemblies, components of the plug forming the outer surfaces comprise engineering grade plastic and, wherein the improvement comprises a plurality of wear resistant inserts installed on an outer surface of the plug so as to minimize abrasion damage to the plug from contact with the wellbore.

13. The packer tool of claim 12, wherein the wear resistant inserts are made of a metallic-ceramic composite material.

14. The packer tool of claim 12, comprising a muleshoe mounted on the mandrel and wherein wear resistant inserts are disposed in the muleshoe.

15. The packer tool of claim 12, wherein wear resistant inserts are disposed in the outer surface of the spacer ring.

16. The packer plug of claim 12, wherein at least one of plurality of wear resistant inserts is disposed in a surface of the plug with the largest outside diameter.

17. The packer tool of claim 12, wherein the wear resistant inserts comprise metallic-ceramic composite material.

18. The packer tool of claim 12, wherein the wear resistant insert comprises a zirconia ceramic compound.

19. The packer tool of claim 12, wherein the wear resistant insert comprises a drillable cast iron material.

20. The packer tool of claim 12 wherein the wear resistant inserts comprise a titanium compound having a density ranging between about 5 to 7 grams per cubic centimeter.

21. The packer tool of claim 1 wherein the wear resistant inserts extend radially outward at least as far as the remaining portions of the tool.