Isolation Tool and Method

Abstract

An isolation tool and method including a mandrel, a load ring, a first seal, a second seal, a third seal, at least one composite slip, and a nose cone. The tool may include a slip backup, a bevel, a groove, slip segments, a drilled hole, a nut such as a bridge plug nut, an interior flat section, an interior beveled section, and/or gripping material. The isolation tool is preferably a frac plug and the slip is preferably a coated composite slip.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application for patent is a continuation-in-part application that claims priority to U.S. patent application Ser. No. 14/992,317, entitled “Isolation Tool and Method,” filed Jan. 11, 2016.

BACKGROUND OF THE INVENTION

Technical Field of Invention

The invention disclosed and taught herein relates generally to isolation tools for use in completion of an oil or gas well.

Background of the Invention

In the completions process of an oil or gas well, there are multiple zones in the well that should be treated or f racked in order to improve production. These zones are at multiple depths in the wellbore and are designed to be treated individually or separate from one another. This separation of zones is accomplished by using some type of isolation tool that is lowered into the wellbore using various methods such as e-line or coiled tubing.

As the isolation tool is being lowered to the desired depth, it is subjected to opposing forces in the well bore that can sometimes cause the tool to pre-set if the opposing forces are not distributed evenly around the tool. When successful depth is achieved, the tool is activated. Once activated, this isolation tool should be able to stay anchored in the desired position. A seal is then completed using various options of isolation tools and the zones are effectively isolated from each other and can then be treated. Once all zones are treated, these isolation tools are drilled back out and debris from the drill out flows to the surface.

A need exists for an isolation tool that has the design capabilities to allow pressure and fluid to be dispersed evenly around the tool as it is run down hole. Also, there is a need to perform multiple functions by making minimal changes to the same tool while on location when a different design and function is needed to prevent a shutdown from having to switch to a different tool.

SUMMARY OF THE INVENTION

The present invention is an isolation tool known as a frac plug. This frac plug 100 has the capability to eliminate the risk of pre-sets by allowing opposing fluid and pressures to be dispersed evenly around the tool as it is running downhole due to the design of the nose cone end 1b, which is screwed onto the outer diameter threads 14 of end 1b of mandrel 1. This invention has the capability to have positive lockup engagement with the nose cone threads 12 screwing onto threads 9 of end 1a on mandrel 1, which saves time and money during drillout process. The present invention has the capability of becoming a ball in place tool by placing a frac ball 11b in the seating area 11a of mandrel 1, end 1a, and then securing setting adapter onto end 1a with shear screws in shear pin holes 10 of mandrel 1. By doing this, the operator can pressure up on the invention to ensure positive set before perforating or fracing. This invention can perform multiple functions by making minimal changes to the same tool on location when a different design and function is needed. The present invention reduces the risk of coil or e-line getting stuck in the well due to the buildup of heavy debris from the drillout. By having coated slips this invention minimizes metal build up.

The present invention relates to a multifunctional frac plug for use in isolating zones in a well bore. There is a need in the industry for a frac plug designed for multiple functions on location. It is desired that this frac plug be designed in a manner that eliminates the need to purchase multiple types of frac plugs to complete necessary operations in the field. It is also a desire in the industry to create a frac plug designed to lessen the necessity of presets by designing a nose cone capable of displacing fluids and pressure evenly while pumping down. The current invention may be converted into various designs such as Ball In Place, Top Set Caged Ball, Bridge Plug or Ball Drop or Bottom Set Caged Ball, Bridge Plug, or Ball Drop simply by making changes to the invention using various inserts and setting adapters right on location.

In the preferred embodiment, the isolation tool and the method of forming it includes a mandrel 1, with threads 9, and shear pin holes 10 on the outer diameter of end 1a, and threads 14 on end 1b of the outer diameter of the mandrel 1. The mandrel 1 also has: frac ball seating area 11a in the inner diameter of end 1a; threads 13a in end 1a of the mandrel 1; threads 13b in the inner diameter of the end 1b of mandrel 1; a nut 7 screwed into the inner diameter of the end 1b; a load ring 2; a slip 3a; a slip backup 4a; a first seal 5a; a second seal 6; a third seal 5b; a second slip backup 4b; a second slip 3b; and a nose cone 8 screwed onto the outer diameter of the threads 14 of end 1b of the mandrel 1. The tool may include a slip backup, a bevel, a groove, slip segments, a drilled hole, a nut such as a bridge plug nut, an interior flat section, an interior beveled section, and/or gripping material.

The isolation tool is preferably a frac plug and the slip is preferably a coated composite slip.

DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a perspective view of a preferred embodiment of an isolation tool in the form of a frac plug.

FIG. 2 shows a cross-sectional, side view of a frac plug.

FIG. 3 is a cross-sectional, side view of a mandrel.

FIG. 4 is a cross-sectional, side view of a load ring.

FIG. 5 is a cross-sectional, side view of a slip.

FIG. 6 is a cross-sectional, side view of a slip backup.

FIG. 7 is a cross-sectional, side view of a first and third seal.

FIG. 8 is a cross-sectional, side view of a second seal.

FIG. 9 is a cross-sectional, side view of a nose cone.

FIG. 10 is a cross-sectional, side view of an embodiment of a nut 7a.

FIG. 11 is a cross-sectional, side view of an embodiment of a nut 7b.

FIG. 12 is a cross-sectional, side view of an embodiment of a nut 7c.

FIG. 13 is a partial, perspective view of the gripping member in the form of a preferred embodiment of a composite slip.

FIG. 14 is a side view of a composite slip segment.

FIG. 15 is a front view of a composite slip segment.

FIG. 16 shows a cross sectional view of the composite slip coated with gripping material.

FIG. 17 shows a top view of the composite slip coated with gripping material.

FIG. 18 shows a side view of a preferred embodiment of an isolation tool.

FIG. 19 shows a cross-sectional, side view of the isolation tool.

FIG. 20 shows a cross-sectional, side view of a slip backup.

FIG. 21 shows a cross-sectional, side view of a slip ring.

FIG. 22 shows a side view of a slip backup engaging a slip ring.

FIG. 23 shows a perspective view of a slip backup engaged to a slip ring.

DESCRIPTION OF THE DISCLOSED EMBODIMENTS

The drawings described above and the written description of specific structures and functions below are presented for illustrative purposes and not to limit the scope of what has been invented or the scope of the appended claims. Nor are the drawings drawn to any particular scale or fabrication standards, or intended to serve as blueprints, manufacturing parts list, or the like. Rather, the drawings and written description are provided to teach any person skilled in the art to make and use the inventions for which patent protection is sought. Those skilled in the art will appreciate that not all features of a commercial embodiment of the inventions are described or shown for the sake of clarity and understanding.

Persons of skill in this art will also appreciate that the development of an actual, real world commercial embodiment incorporating aspects of the inventions will require numerous implementation specific decisions to achieve the developer's ultimate goal for the commercial embodiment. Such implementation specific decisions may include, and likely are not limited to, compliance with system related, business related, government related and other constraints, which may vary by specific implementation, location from time to time. While a developer's efforts might be complex and time consuming in an absolute sense, such efforts would nevertheless be a routine undertaking for those of skill in this art having the benefit of this disclosure.

It should also be understood that the embodiments disclosed and taught herein are susceptible to numerous and various modifications and alternative forms. Thus, the use of a singular term, such as, but not limited to, “a” and the like, is not intended as limiting of the number of items. Similarly, any relational terms, such as, but not limited to, “top,” “bottom,” “left,” “right,” “upper,” “lower,” “down,” “up,” “side,” and the like, used in the written description are for clarity in specific reference to the drawings and are not intended to limit the scope of the invention or the appended claims.

FIG. 1 shows a perspective view of a preferred embodiment of an isolation tool in the form of a frac plug 100 with components fully assembled. A frac plug 100 may include a variety of fiber and resin, metal alloys, epoxy, plastic or a combination of the listed materials. As shown, a mandrel 1 of the frac plug includes threads 9 on the outside diameter at end 1a of the mandrel 1, with holes 10 bored in that end 1a to accommodate shear screws.

As shown in FIG. 2, the mandrel 1 is preferably designed to receive a frac ball 11b, in ball seat area 11a of end 1a and has threads 13a in end 1a, to receive a caged ball or bridge plug nut 7c (shown in FIG. 12), and threads 13b in the inner diameter of the end 1b to receive a nut 7a or 7b (shown in FIGS. 10 and 11, respectively) in the end 1b.

A cross-sectional, side view of the frac plug 100, the mandrel 1 preferably has a through bore completely through an inside diameter and is threaded in the inside diameter 13a of the end 1a and threaded in inside diameter 13b of the end 1b to receive a nut 7a, 7b such as a ball drop nut or bridge plug nut. The mandrel 1 is also threaded on the outside diameter 14 of the end 1b of the mandrel 1 to receive the threaded nose cone 8. Also shown in FIG. 2 are threads 9 and shear pin holes 10 on the outer diameter of the end 1a of the mandrel 1.

As shown in FIGS. 1 and 2, a load ring 2 is engaged by sliding onto the mandrel 1 at the end 1b and is slid down to rest on a bevel of determined degree. A slip 3a is adjacent to the load ring 2. A slip backup 4a is adjacent to the slip 3a. A first seal 5a is adjacent to the slip backup 4a. A second seal 6 is adjacent to the first seal 5a and a third seal 5b is adjacent to seal 6. A slip backup 4b is adjacent to the third seal 5b. A slip 3b is adjacent to the slip backup 4b. A ball drop nut 7b is threaded into threads 13b of the end 1b, of mandrel 1. A nose cone 8 is threaded onto threads 14 of the end 1b and engaged onto the end 1b of mandrel 1 and is adjacent to the slip 3b.

FIG. 3 is a cross-sectional, side view of the mandrel 1. The mandrel 1 preferably has a trough bore completely through an inside diameter and is threaded in the inside diameter 13b of the end 1b to receive a nut 7a, 7b such as a ball drop nut or bridge plug nut shown in FIGS. 10 and 11. The mandrel 1 is also threaded on the outside diameter 14 of the end 1b to receive the threaded nose cone 8 shown in FIGS. 1 and 2.

As shown, there are also threads 9 on the outer diameter of the end 1a of the mandrel 1 that are shown as end of frac plug 100 in FIGS. 1, 2, and 3. The holes 10 that may be formed or drilled in mandrel 1, end 1a are shown in FIGS. 1, 2, and 3.

FIG. 4 is a cross-sectional, side view of the load ring 2. The load ring 2 may be round in shape and can have a flat space on the inside diameter 15 of the load ring 2 as well as having an angled surface 16 on the inside diameter of the load ring 2. The load ring 2 can engage with the mandrel 1 by sliding onto the outer diameter of the end 1b. The load ring 2 may be designed to withstand the force applied by a desired setting tool to compress the components during the setting process. The load ring 2 may also have a number of holes 17a, 17b drilled through the thickness of the load ring 2 to receive a set screw.

FIG. 5 is a cross-sectional, side view of the slip, shown as slips 3a, 3b in FIGS. 1 and 2. Each slip 3a, 3b may have an outside diameter of preferably about 2.5 inches to preferably about 7 inches. The slip 3a, 3b may also have an inside diameter of preferably about 2 inches to preferably about 6.5 inches. The slip 3a, 3b may have bevels milled into the slip 3a, 3b to allow the slip to separate into sections and expand.

The slip 3a, 3b as depicted can have beveled edges 19 on the outer surface of the outer diameter at varying angles that are designed to engage with the casing and secure the frac plug 100 inside the casing. The slip 3a, 3b may have holes 20 drilled into the slip 3a, 3b which may have a diameter of preferably about 0.125 inches to preferably about 0.5 inches with a depth completely through the center body of the slip 3a, 3b or a depth of preferably about 0.290 inches as shown herein. The slips also may have relief grooves 18a, 18b milled radially into the inside diameter of the slip 3a, 3b at determined depths and locations.

The slips 3a, 3b may have a flat surface 21 on the inside diameter of a determined length and a beveled surface 22 on the inside diameter with an angle ranging from preferably about 45 degrees to preferably about 20 degrees. The slip 3a, 3b may also have second relief grooves 18c, 18d milled into the surface of the slips, and into the milled areas 18e between the slips 3a, 3b segments to allow to break into smaller pieces during the drill out process.

FIG. 6 is a cross-sectional, side view of the slip backup shown as slip backups 4a, 4b in FIGS. 1 and 2. The slip backup 4 may have an outside diameter of preferably about 2 inches to preferably about 7 inches and an inside diameter of preferably about 1.5 inches to preferably about 6.5 inches. The slip backup 4 may have a length of preferably about 2 inches to preferably about 6 inches.

The slip backup 4 can have a flat surface 24 on the outside diameter and a beveled surface 25 on the end with angles ranging from preferably about 20 degrees to preferably about 45 degrees. The slip backup 4 may have slots cut 26a into the body with a depth of preferably about 1 inch to preferably about 2 inches and a width of preferably about 0.05 to preferably about 0.25 inches and may have as many as preferably about 4 to preferably about 12 slots. The slip backup 4 may have a number of holes 27 with a diameter of preferably about 0.125 inches to preferably about 0.25 inches drilled through the body to receive a set screw. The beveled surface 25 of the slip backups 4a, 4b are adjacent to the slips 3a, 3b shown in FIGS. 1 and 2. The slip backups may have a counter bore 26b with a width of about 0.125 inches to about 1.00 inch and a depth of about 0.125 to about 0.500 inches.

FIG. 7 is a cross-sectional, side view of a seal shown as first and third seals 5a, 5b in FIGS. 1 and 2. The seal 5a or 5b is preferably a seal made of an elastomer, a polytetrafluoroethylene material including synthetic fluoropolymer of tetrafluoroethylene materials such as but not limited to the product sold under the trade name Teflon®, plastic, or other malleable material. The seal 5a, 5b may have an outside diameter of preferably about 2 inches to preferably about 7 inches and an inside diameter of preferably about 1.5 inches to preferably about 6.5 inches.

The first or third seals 5b, 5c may have a flat surface 28 on the surface of the seal and a beveled surface 29 with angles ranging from preferably about 20 degrees to preferably about 40 degrees on the outside diameter. The seals 5a, 5b may also have an overall length of preferably about 1.5 inches to preferably about 6 inches. The seal may have a flat surface 31 in the inside diameter adjacent to the beveled surface 30 of the inside diameter. From that flat surface 31 on the inside diameter, the seals 5a, 5b may have the beveled area 30 on the inside diameter at angles ranging from preferably about 20 degrees to preferably about 45 degrees, extending outwardly.

FIG. 8 is a cross-sectional, side view of the seal 6. Seal 6 may be made from an elastomer, a polytetrafluoroethylene material including synthetic fluoropolymer of tetrafluoroethylene materials such as but not limited to the product sold under the trade name Teflon®, plastic, or another malleable material. The large seal 6 may be preferably about 2 inches to preferably about 7 inches in length and may have an outside diameter of preferably about 2 inches to preferably about 7 inches along with an inside diameter of preferably about 1.5 inches to preferably about 6.5 inches.

The seal 6 may have a flat surface 32 on the outside diameter, extending preferably about 2 inches to preferably about 6 inches in the center of the outside diameter, adjacent to a beveled portion 33 of the seal 6. Seal 6 may have a beveled areas 33 on the outside diameter with angles ranging from preferably about 20 degrees to preferably about 45 degrees. The seal 6 illustrates a flat portion 34 on the inside diameter of seal 6, extending to the beveled portion 35 in the inside diameter. The beveled portion 35 of the inside diameter on seal 6 may have a bevel or radius of preferably about 20 degrees to preferably about 45 degrees.

FIG. 9 is a cross-sectional, side view of the nose cone 8. In a preferred embodiment, the nose cone 8 is detachable, and is threaded 39 and capable of engaging with the mandrel 1 shown in FIGS. 1, 2, and 3. The nose cone 8 is preferably conical in shape and can be preferably about 2 inches to preferably about 7 inches in diameter.

The nose cone 8 has a flat section 36 on the surface and a tapered off section 37 to a bevel of preferably about 60 degrees to preferably about 90 degrees. The outside diameter of the nose cone 8 may have a recessed area 38 to accommodate a pump down ring. The nose cone 8 depicts threads 39 in the inside diameter that can be engaged with the outside diameter threads 14 of the end 1b of the mandrel 1. The inside diameter of the nose cone 8 also has threads 40 designed to engage with the threads 9 of end 1a of the mandrel 1. The nose cone 8 may also have preferably about 2 to preferably about 4 holes 41 drilled in the nose cone. These holes 41 may have a diameter of preferably about 0.25 to preferably about 0.5 inches.

FIG. 10 is a cross-sectional, side view of the nut 7a. As depicted, the nut 7a is a bridge plug nut. The nut 7a can be made of brass, aluminum, composite, bronze, or a mixture of the listed materials. The nut 7a may be preferably about 2 inches to preferably about 4 inches in length and have an outside diameter measuring preferably about 1 inch to preferably about 4 inches.

The nut 7a has threads on the outside diameter of end 42 of the nut 7a and is solid on end 43 of the nut 7a. The nut 7a may have threads in the inside 44. The nut 7a preferably has a first chamber 45 extending past the inside 44. The first chamber 45 typically has a larger inside diameter than that of the inside 44. The nut 7a preferably also has a second chamber 46a containing smaller inside diameter that extends past the first chamber 45, creating a stopping point for a setting rod.

FIG. 11 is a cross-sectional, side view of a different embodiment of the nut. 7b. As depicted, FIG. 11 shows a ball drop nut. The nut 7b can be made of brass, aluminum, composite, bronze, or a mixture of the listed materials. The nut 7b may be preferably about 2 inches to preferably about 4 inches in length and can have an outside diameter of preferably about 1 inch to preferably about 4 inches.

The nut 7b has threads on the outside diameter of end 47 and has a hole drilled through the body 50, to receive a threaded rod composed of composite, aluminum, brass, or a mixture of the listed materials. This rod is screwed into position after placing preferably about 0.625 inches or preferably about ⅝-inch ball into the inside diameter of the nut, creating a ball drop nut. The ball drop nut 7b has threads that can be sheared on the inside diameter of the nut, extending to a first chamber 48 that has a larger inside diameter. The first chamber 48 extends to a second chamber 49 with a smaller inside diameter, creating a stopping area for the setting rod. Adjacent to the second chamber 49, the caged ball nut 7b has a hole 50 bored completely through the inside diameter to allow fluid to flow through the nut 7b.

FIG. 12 is a cross-sectional, side view of a different embodiment of the nut. As depicted, the nut 7c is a caged ball nut that can be made of composite, brass, aluminum, or a mixture of the listed materials. The caged ball nut 7c can be preferably about 2 to preferably about 6 inches in length and preferably about 1 to preferably about 4 inches in diameter. The nut 7c has a smaller outside diameter of preferably about 1.220 inches which extends preferably about 0.790 inches in length

There are shown two grooves 51 cut into this flat area 52 to receive 0 rings. From the stopping point of the smaller inside diameter of end 53, there is a bevel 54 angled at preferably about 20 to preferably about 24 degrees that extends to the outside diameter of the nut 7c. There are threads 55 on the outside diameter of the nut that match the threads on the inside diameter of the end 1a of the mandrel 1 depicted in FIGS. 1-3. The caged ball nut 7c has a hole 56 drilled completely through the body of the nut 7c.

After inserting a ball made of composite, brass, aluminum, or a mixture of the listed materials, a rod is placed through the body to hold the ball in place. The caged ball nut 7c has a trough bore completely through the body of the nut 7c creating a flow passage for fluid. The inside diameter of the nut can be preferably about 0.531 to preferably about 1 inch in the first chamber

Adjacent to the first chamber 59, the second chamber 58 has a smaller inside diameter of preferably about 0.75 inches. This creates a stopping area for the setting rod. Adjacent to the second chamber 58, the third chamber 57 closes to an inside diameter of preferably about 0.175 inches. The caged ball nut 7c can also be converted into a bridge plug nut by leaving the third chamber 57 solid.

FIG. 13 is a partial, perspective view of the gripping member. In this preferred embodiment, the gripping member is a composite slip 3c, 3d. As shown, the composite slip 3c, 3d includes segments 61 that are connected together to form a full composite slip 3c, 3d as shown in FIGS. 16 and 17.

FIG. 14 is a side view of a composite slip segment 61. It is preferable for each composite slip 3c, 3d to be coated with a gripping material 69b. The composite slip segment 61 shown in FIG. 14 is coated with about 0.055 inches of a gripping material 69b. Suitable gripping materials include coatings, bonding agents, or encasement particles that may be formed from a nondestructive material such as abrasive powders, grains, elastomers, hard stones, or other materials.

Gripping members or slips can be singular, or have a multitude on one tool. a couple of examples would be the slips on liner hangers or a packer that uses a slip or type of gripping member to hold it in a desired place. Other tools that could benefit from the gripping members might be an isolation tool capable of running through a very small inside diameter and once in place, then having the capability to expand and be secured in a much larger inside diameter. The possibility also exists that this non-destructive slip or gripping member be incorporated into a process that is used to lower coiled tubing, conventional pipe downhole so as to lessen the destruction done to the pipe in the process.

FIG. 15 is a front view of a composite slip segment 61. Holes 62 are drilled in at a desired depth on the exterior surface 63 of the composite slip segment 61. These holes 62 are drilled for the gripping material to penetrate the composite slip surface 63 to desired depth and create anchors into the composite slip segment 61.

FIG. 16 shows a cross sectional view of the composite slip 3c, 3d. The composite slip 3c, 3d shows the composite slip exterior surface 69a of the composite slip segments 61 having a flat surface and the gripping material 69b applied to the surface. The right end 64 of the composite slip 3c, 3d as displayed is shown with an interior flat surface section 65. In a preferred embodiment, this flat surface section 65 has a diameter of about 3.125 inches. The interior flat surface section 65 is adjacent to an interior beveled area 66 that flares to the left end 67 of the composite slip 3c, 3d as shown. In a preferred embodiment, this beveled area 66 can have an angle ranging from about 20 to about 45 degrees. In a preferred embodiment, the outside diameter of the composite slip 3c, 3d is about 3.627 inches but can have an outside diameter of about 2 inches to about 7 inches. The composite slip exterior surface 69a of the outside diameter of the composite slip 3c, 3d preferably has three flat surfaces spaced with relief grooves 68 between each section.

FIG. 17 shows a top view of the composite slip 3c, 3d. The composite slip 3c, 3d preferably includes drilled shear pin holes 70 drilled in each segment 61 to be desired depth that accommodate shear pins. The shear pins used in each section may be made of composite, brass, bronze, aluminum, or a mixture of the listed materials.

FIGS. 18 and 19 show the isolation tool 100 using this preferred embodiment of the gripping member as composite slips 3c and 3d and are similar to the embodiment of the isolation tool 100 depicted in FIGS. 1 and 2, respectfully

FIG. 20 is a cross-sectional, side view of another embodiment of the slip backup 4c that may be used in place of slip backups 4a, 4b as shown in FIGS. 1 and 2. The slip backup 4c may have an outside diameter of preferably about 2 inches to preferably about 7 inches and an inside diameter of preferably about 1.5 inches to preferably about 6.5 inches. The slip backup 4c may have a length of preferably about 2 inches to preferably about 6 inches.

The slip backup 4c can have a flat surface 24c on the outside diameter and a beveled surface 25c on the end with angles ranging from preferably about 20 degrees to preferably about 45 degrees. The slip backup 4c may have slots cut 26c into the body with a depth of preferably about 1 inch to preferably about 2 inches and a width of preferably about 0.05 to preferably about 0.25 inches and may have as many as preferably about 4 to preferably about 12 slots. The slip backups may have a counter bore 26d with a width of about 0.125 inches to about 1.00 inch and a depth of about 0.125 to about 0.500 inches.

Additionally, slip backup 4c comprises inserts 71 that are attached or bonded to the slip backup 4c in backup indentations 72 formed in the slip backup 4c. The area between inserts 71 are valleys 73 that allow for better interfacing when engaging slip ring 2c (shown in FIG. 21).

FIG. 21 shows a cross-sectional view of another embodiment of the slip ring 2c. The slip ring 2c may be round in shape and can have a flat space on the inside diameter 15c of the slip ring 2c as well as having an angled surface 16c on the inside diameter of the slip ring 2c. The slip ring 2c can engage with the mandrel 1 by sliding onto the outer diameter of the end 1b. The slip ring 2c may be designed to withstand the force applied by a desired setting tool to compress the components during the setting process. The slip ring 2c may also have connector tabs 74 that hold together adjacent segments of the slip ring 2c together. As shown, a number of O-ring grooves 76 can be formed in the slip ring 2c such that O-rings 75 (shown in FIG. 23) may be placed in the O-ring grooves 76, preferably in grit, to assist in maintaining the slip ring 2c when engaged to a slip backup 4c.

FIG. 22 shows a side view of a slip backup 4c engaging a slip ring 2c in operation. The slip backup 4c has inserts 71 that will approach and shear the connector tabs 74 in engagement. The slip ring 2c segments will move up the valleys 73 in engagement.

FIG. 23 shows a perspective view of the slip backup 4c engaged to a slip ring 2c. The slip backup 4c has inserts 71 that have sheared the connector tabs 74 of the slip ring 2c and the slip backup 4c and the slip ring 2c are fully engaged. The slip ring 2c segments are fully engaged in the valleys 73 of the slip backup 4c. The O-rings 75 are preferably set down in grit to provide a more gripping connection.

While the invention has been described with reference to one or more particular embodiments, those skilled in the art will recognize that many changes may be made thereto without departing from the spirit and scope of the description. Each of these embodiments and obvious variations thereof is contemplated as falling within the spirit and scope of the claimed invention.

Claims

1. An isolation tool comprising:

a mandrel having a mandrel first end and a mandrel second end;

a load ring on the mandrel;

a first composite slip adjacent to the load ring;

a slip backup adjacent to the slip;

a first seal adjacent to the slip backup;

a second seal adjacent to the first seal;

a third seal adjacent to the second seal;

a second slip backup adjacent to the third seal;

a second composite slip adjacent to the second slip backup;

a nut secured onto the mandrel second end; and

a nose cone adjacent to the second composite slip.

2. The isolation tool of claim 1 wherein the isolation tool is a frac plug.

3. The isolation tool of claim 1 wherein the first composite slip is a coated composite slip.

4. The isolation tool of claim 1 wherein the second composite slip is a coated composite slip.

5. The isolation tool of claim 1 wherein the first composite slip further comprises at least one bevel milled into the slip.

6. The isolation tool of claim 1 wherein the first composite slip further comprises at least one second relief groove milled into a surface of the first composite slip.

7. The isolation tool of claim 1, wherein the nut is selected from the group consisting of a bridge plug nut, a ball drop nut, and a caged ball nut.

8. The isolation tool of claim 1 further comprising gripping material on the first composite slip.

9. The isolation tool of claim 1, wherein the first composite slip further comprises at least two segments;

wherein each segment comprises an interior segment surface; and

wherein each interior segment surface further comprises at least one groove.

10. The isolation tool of claim 1, wherein the first composite slip further comprises at least two segments;

wherein each segment comprises an exterior segment surface; and

wherein each exterior segment surface further comprises at least one groove.

11. The isolation tool of claim 1, wherein the first composite slip further comprises: an interior flat surface; and

at least one interior beveled surface.

12. The isolation tool of claim 1, wherein the first composite slip further comprises drilled shear pin holes.

13. The isolation tool of claim 1, wherein the slip backup comprises a plurality of inserts attached or bonded to the slip backup, wherein the isolation tool further comprises a slip ring formed of a plurality of slip ring segments connected by a plurality of connector tabs.

14. A method of forming an isolation tool comprising the steps of:

(a) connecting a load ring on a mandrel, wherein the mandrel has a first mandrel end and a second mandrel end;

(b) connecting a first composite slip adjacent to the load ring;

(c) connecting a slip backup adjacent to the first composite slip;

(d) connecting a first seal adjacent to the slip backup;

(e) connecting a second seal adjacent to the first seal;

connecting a third seal adjacent to the second seal;

(g) connecting a second slip backup adjacent to the third seal;

(h) connecting a second composite slip adjacent to second slip backup;

(i) connecting a nut to the second mandrel end; and

(j) connecting a nose cone adjacent to the second composite slip.

15. The method of claim 14 further comprising the step of connecting the cone by threading the nose cone onto the second mandrel end.

16. The method of claim 14 wherein the nut is selected from the group consisting of a bridge plug nut, a ball drop nut, and a caged ball nut.

17. The method of claim 14 wherein the first composite slip is a coated composite slip.

18. The method of claim 14 wherein the second composite slip is a coated composite slip.

19. The method of claim 14 further comprising applying gripping material to the first composite slip before the step of connecting a first composite slip adjacent to the load ring.

20. The method of claim 14, wherein the slip backup comprises a plurality of inserts attached or bonded to the slip backup, further comprising the steps of:

moving the slip backup into a slip ring, wherein the slip ring is formed of a plurality slip ring segments connected by a plurality of connector tabs, and

shearing the connector tabs.