US20220290517A1

US20220290517A1 - Pressure enhanced frac plug

Info

Publication number: US20220290517A1
Application number: US17/692,481
Authority: US
Inventors: Henry Joe Jordan, Jr.; Wesley PRITCHETT; Rockni Van Clief
Original assignee: DOWNHOLE INNOVATIONS LLC; GR Energy Services Management LP
Current assignee: DOWNHOLE INNOVATIONS LLC; GR Energy Services Management LP
Priority date: 2021-03-15
Filing date: 2022-03-11
Publication date: 2022-09-15

Abstract

The disclosure relates to a frac plug having an uphole side and a downhole side and having a first cone, wherein the first cone defines one or more chambers within the first cone; one or more pistons each partially inserted into the one or more chambers at a first end of the one or more pistons; a second cone connected to a second end of each of the one or more pistons; a slip barrel surrounding the first cone and the second cone.

Description

STATEMENTS REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable.

NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT

Not Applicable.

BACKGROUND

Unconventional Well Completions involve many different operations. Stimulation or fracturing of the well formation to provide increased production of hydrocarbon is typically required and is a time consuming and costly operation. One of the most popular means of isolating the individual zones or stages of the well during the stimulation process is the utilization of either a composite frac plug or a self-dissolving (dissolvable) frac plug. The composite or dissolvable frac plug is generally pumped down the well as part of a bottom hole assembly (hereinafter, also referred to as “BHA”) that includes the plug, a setting adapter with setting tool, and a series of one or more perforating guns. This BHA is attached to an electric line (also referred to as “E-line”) which is spooled off as the BHA is pumped down the well and out into the well's horizontal section. Once the BHA is located at the correct position within the well, an electric current is sent down the wireline to actuate the setting tool and causes the frac plug to be actuated or set in the well casing to create an isolation seal. The plug further releases itself from the BHA. In the process of setting the composite or dissolvable frac plug, an anchoring means typically called a slip is imbedded into the casing to hold the plug in its position within the well casing. Once the plug has been set in place, the further operation of perforating the casing above the plug is continued until all of the perforating guns on the BHA are spent, then the BHA is removed from the well. Typically, a ball is located on top of the frac plug to completely isolate the upper zone above the plug from the lower zone below the plug when the stimulation or frac pressure is applied down the well bore. Other techniques are also used to create this same isolation effect, including flappers, poppets, etc. Once these operations have been complete, the frac pressure is applied to the well bore to create a high-pressure and high-flow rate at the perforations and cause the well formation to break-down or fracture, thus creating many fractured paths that will eventually allow for the movement of hydrocarbon to escape the formation and travel up the well bore.
Normally this process is repeated numerous times at progressive locations within the well with all of the plugs remaining in the well following the full stimulation job. Once the stimulation job (or frac job) has been completed on the full well, the composite plugs or dissolvable plugs need to be removed from the well so that the zones below it can be produced. The removal process is different for a composite frac plug than for a dissolvable frac plug.
For composite frac plugs, the plugs are typically removed with a mill assembly run in the well on threaded pipe or coiled tubing. The tubing is installed in the well from the surface to the depth of the first bridge plug. The mill drills or grinds up the plug leaving small debris in the well to be removed by fluid circulation. This process continues until all the plugs are removed.
For dissolvable frac plugs, the plugs will degrade, and the material of the plugs will dissolve over a given time to cause the plugs to disappear or go away from the well on their own. When using these plugs, typically the operator does not have to mill them up and will only run into the well to perform a clean-out or fluid circulation run to verify the plugs are all gone.
The traditional composite or dissolvable plug is set in the well casing with a setting tool that applies a high setting force to cause the plug to anchor in the casing and to create a seal against the casing. However, this is a ‘one-time’ applied setting force through the use of the setting tool and integrity of this force retainment in the plug is typically maintained by a ratchet type mechanical locking mechanism designed as part of the plug itself. These mechanisms are designed only to retain the initial setting force applied to the plug. A first known problem with currently available frac plugs is that the plugs can become loose due to rubber extrusion or back-lash in the locking mechanism, and the plug can lose its initial setting force allowing the plug to release its grip on the casing and potentially move in the well bore when frac pressure is applied to it. This is a major problem for the operator if the plug moves when they are applying the stimulation or frac pressure to the top of the plug. This can create an incomplete or bad stimulation/frac job.
In a similar fashion, and relating to a second known problem with currently available frac plugs, sometimes the perforating guns do not perform correctly, and the operator is required to back-flow the well to remove the ball that is sitting on top of the frac plug so that they can perform a new BHA pump-down operation. This process causes a high-pressure differential across the frac plug due to flow and pressure drops across the plug from below and can cause the plug to move up the well bore. Most frac plugs are not designed to take these high loads from below, but only from above where the frac pressure is applied. In the event a plug moves upwards under this condition, this will create an expensive problem for the operator to have to remove the plug before continuing normal operations.
Another issue related to only the currently available dissolvable frac plugs is the rate of degradation that the frac plug may experience based on the conditions within the well bore. Dissolvable plugs are designed to start degrading the moment they come into contact with the activating fluid which is typically water. This means that even before the plug is set in the casing, the plug begins the process of degrading. Once a plug is set and anchored in the casing, the plug is still continually degrading before the perforating operations are complete and before the frac pressure is applied. This degradation process may cause the frac plug to lose some of its anchoring or sealing integrity before the plug sees the full load from the high differential frac pressure that is applied to it.
Under this situation, the plug could move within the wellbore due to significant material loss once the frac pressure is applied, again resulting in a poor frac job. This can be a major problem for the operator if the plug moves when they are applying the stimulation or frac pressure to the top of the plug. This can create an incomplete or bad stimulation/frac job.
The present disclosure is intended to capture several novel concepts and solve at least the several known problems as described above.

BRIEF SUMMARY

The disclosure relates to a frac plug having an uphole side and a downhole side and having a first cone, wherein the first cone defines one or more chambers within the first cone; one or more pistons each partially inserted into the one or more chambers at a first end of the one or more pistons; a second cone connected to a second end of each of the one or more pistons; a slip barrel surrounding the first cone and the second cone.
As used herein, the terms “frac” or “frack” also includes encompasses the terms “fracture”, “fracturing”, “fracking”, “fracing”, or “fraccing” or “hydraulic fracturing” as commonly understood in the petrochemical field.

BRIEF DESCRIPTION OF THE DRAWINGS

The exemplary embodiments may be better understood, and numerous objects, features, and advantages made apparent to those skilled in the art by referencing the accompanying drawings. These drawings are used to illustrate only exemplary embodiments and are not to be considered limiting of its scope, for the disclosure may admit to other equally effective exemplary embodiments. The figures are not necessarily to scale and certain features and certain views of the figures may be shown exaggerated in scale or in schematic in the interest of clarity and conciseness.

FIG. 1 depicts a cross-section view of an exemplary embodiment of a bottom hole assembly including a setting tool and a frac plug.

FIG. 2 depicts a front view of an exemplary embodiment of a frac plug.

FIG. 3 depicts a cross-section view of an exemplary embodiment of a frac plug in its run-in position.

FIG. 4 depicts a cross-section view of an exemplary embodiment of a frac plug within and set into a casing.

FIG. 5 depicts a partially cut-away perspective view of an exemplary embodiment a frac plug.

FIG. 6A depicts a front view of an exemplary embodiment of an upper cone of a frac plug.

FIG. 6B depicts a top view of the exemplary embodiment of the upper cone of the frac plug in FIG. 6A.

FIG. 7A depicts a top view of an exemplary embodiment of a lower cone of a frac plug.

FIG. 7B depicts a front view of the exemplary embodiment of the lower cone of the frac plug in FIG. 7A.

FIG. 8A depicts a front view of an exemplary embodiment of a slip barrel of a frac plug.

FIG. 8B depicts a top view of the exemplary embodiment of the slip barrel of the frac plug in FIG. 8A.

FIG. 9 depicts a front view of an exemplary embodiment of a piston of a frac plug.

FIG. 10A depicts a front view of an exemplary embodiment of a seal ring of a bottom hole assembly.

FIG. 10B depicts a top view of the exemplary embodiment of the seal ring of the bottom hole assembly in FIG. 10A.

DESCRIPTION OF EMBODIMENT(s)

The description that follows includes exemplary apparatus, methods, techniques, and instruction sequences that embody techniques of the inventive subject matter. However, it is understood that the described embodiments may be practiced without these specific details.
FIG. 1 depicts a cross-section view of an exemplary embodiment of a bottom hole assembly 10 including a setting tool 20 and a frac plug 30, as being maneuvered or pumped into a wellbore and connected to the surface via an electric line 14. A first end, in relation to the wellbore, is defined as being the uphole end 11 or closer towards the surface, and a second opposite end, in relation to the wellbore, is defined as being the downhole end 12, as being farther away from the surface. These ends 11, 12 are also present in a horizontal wellbore, wherein the downhole end 12 is further within the wellbore in contrast to the uphole end 11.
The setting tool 20 includes a setting tool adapter tool kit 21, outer setting sleeves 22, a retention device 23, a shear ring 24 on the retention device 23, a solid stem 25 inserted through the frac plug 30, and a ball 26 as the BHA 10 is being run into the casing 13 or wellbore. The setting tool adapter kit 21, outer setting sleeves 22, retention device 23, shear ring 24, and solid stem 25 may all be connected during the run-in phase of the wellbore operation.
A front view and a cross-section view of the plug or frac plug 30 in an unset or run-in position 70 is provided for in FIGS. 2 and 3, respectively. FIG. 5 depicts a partially cut-away perspective view of an exemplary embodiment the frac plug 30 in the unset or run-in position 70. The frac plug 30 includes a top, or upper frustoconical cone 31 a; a bottom, or lower frustoconical cone 31 b; and a slip barrel or collar 50. The upper cone 31 a may define an inclined or angled exterior surface 33 a which connects a top surface 34 a of the upper cone 31 a to the bottom surface 38 a of the upper cone 31 a; and the lower cone 31 b may define an inclined or angled exterior surface 33 b which connects a top surface 34 b of the lower cone 31 b to the bottom surface 38 b of the lower cone 31 b (see e.g. FIG. 4). The bottom surface 38 a of the upper cone 31 a may also define a ball seat 27 against which the ball 26 is engaged when the frac plug 30 is in a set position 72 in the casing 13. In the exemplary embodiments as depicted in FIGS. 1-5, the top surface 34 a of the upper cone 31 a may be oriented towards the downhole direction 12, and the bottom surface 38 a of the upper cone 31 a may be oriented towards the uphole direction 11. Further in the exemplary embodiments as shown, the top surface 34 b of the lower cone 31 b may be oriented towards the uphole direction 11, and the bottom surface 38 b of the lower cone 31 b may be oriented towards the downhole direction 12. The top surfaces 34 a, 34 b may have or define a smaller diameter than the corresponding bottom surfaces 38 a, 38 b (see e.g. FIGS. 6A-7B). This disclosure will apply to plugs 30 made of both composite and dissolvable materials.
The upper cone 31 a includes one or more holes 32 a used in conjunction with pistons 40 to create chambers 32 defined within the interior of the upper cone 31 a through the top surface 34 a and not through the bottom surface 38 a. The chambers 32 may be optionally evenly distributed in a circular pattern about the top surface 34 a, although other patterns are considered within the scope of the disclosure. By way of example only, referring at least to FIGS. 6A-6B, there may be six chambers 32 defined within the upper cone 31 a, although any number of chambers 32 is considered within the scope of this disclosure. The chambers 32 may be set at atmospheric pressure during the run-in process. The chambers 32 may take the form of a tube-like cavity, duct or hole and have a substantially complimentary shape and length to engage the pins or pistons 40. The lower cone 31 b is connected to one or more pins, rods, or pistons 40 via threading 35 on the cone 31 b and threading 42 on the pistons 40 at one end 43 of the pistons 40. FIGS. 7A-7B depict an enlarged view of the lower cone 31 b prior to the assembly, attachment or connection of the pistons 40. The pistons 40 extend from the top surface 34 b of the lower cone 31 b, and arranged in a similar pattern to the chambers 32 so as to be able to engage or insert into the chambers 32 at the other end 44 of the piston 40. The pistons 40 for each particular embodiment are equal in number to the number of chambers 32 in cone 31 a and are partially inserted into the chambers 32 up to a shoulder 41 when the frac plug 30 is assembled and run-in. Each piston 40 includes an extended shoulder or shear tab 41 abutting the top surface 34 a of the cone 31 a to prevent inadvertent setting of the frac plug 30 during the run-in operation, via preventing the piston 40 from further insertion into the corresponding atmospheric chambers 32 (see e.g., FIG. 9 for an enlarged view of the piston 40 including the shoulder or shear tab 41). The top of each of the upper cone 31 a and the lower cone 31 b are facing each other in the run-in position, held at a distance 37 between each respective top surface 34 a, 34 b of each cone 31 a, 31 b. After setting of the frac plug 30, as depicted in FIG. 4, in an anchored or set position 72 of the plug 30, a greater or increased length of the pistons 40 may be further inserted into the chambers 32 past the shear tabs 41, as compared with the length of the pistons 40 inserted into the chambers 32 in the run-in or unset position 70.
In alternative exemplary embodiments, the chambers 32 (or holes 32 a) may instead all be defined on the lower cone 31 b, and the pistons 40 may instead all be attached to the upper cone 31 a. In further alternative exemplary embodiments, the upper cone 31 a may contain a combination of chambers 32 (or holes 32 a) and pistons 40; in this particular further alternative exemplary embodiment, the lower cone 31 b would contain a complementary or mating pattern of chambers 32 (or holes 32 a) and pistons 40 so that the upper cone 31 a can complementarily engage with or insert into the lower cone 31 b. By way of example only, in an exemplary embodiment, the upper cone 31 a may contain two chambers 32 and two pistons 40, and the lower cone may contain two pistons 40 that correspondingly engage with the upper cone 31 a's chambers 32 or holes 32 a; and the lower cone may further define two chambers 32 or holes 32 a that correspondingly engage with the upper cone 31 a's pistons 40.
The slip or slip barrel, or anchoring mechanism 50 has a substantially cylindrical ring-like or collar-like shape having an outer surface 51 and an inner surface 52. The inner surface 52 of the slip 50 further defines a first inclined surface 53 a, and a second inclined surface 53 b. The inclined surfaces 53 a and 53 b slidably engage with the angled exterior surface 33 a of the upper cone 31 a, and the angled exterior surface 33 b of the lower cone 31 b, respectively. As can be best seen in the enlarged FIGS. 8A-8B, the slip 50 also includes a pattern of slots, cavities, slits, reliefs, or gaps 57 defined through the slip 50 which allows the slip 50 to be adjustable, such as to extend/expand or retract, in size, as the slip 50 moves over exterior angled surfaces 33 a,33 b of the cones 31 a, 31 b.
The outer surface 51 of the slip 50 also defines a number of depressions 58 for the attachment or mounting of slip buttons 55. These slip buttons 55 in certain exemplary embodiments may be made of a ceramic material that is harder than the material of the casing 13; the slip buttons 55 may in alternative exemplary embodiments be made of other materials such as carbide or cast iron or any other material as known to one of ordinary skill in the art. The surface of each slip button 55 are positioned at an angle 56 within the slip 50, which may be an askew or non-perpendicular angle. These slip buttons 55 a and 55 b may also be described to be “back-facing” (e.g. the exterior surface of top slip buttons 55 a are tilted or angled towards the top 30 a of the plug 30, and the exterior surface of bottom slip buttons 55 b are tilted or angled towards the bottom 30 b of the plug 30). By way of example only, slip buttons 55 a situated nearer or proximate to upper cone 31 a may engage the casing 13 via a gripping corner, sharp edge, square edge, or right angle 59 at the downhole side 12 of the same button 55; and slip buttons 55 b situated nearer or proximate to the lower cone 31 b may engage the casing 13 via a gripping corner, sharp edge, square edge, or right angle 59 at the uphole side 11 of said button 55. The angle 56 of the slip buttons 55 a may be opposite or opposing angles to angle 56 of slip buttons 55 b. Slip buttons 55 may be one example of an anchoring mechanism 16 for ‘biting’, anchoring, or engaging the casing 13. Other techniques or mechanisms 16 beyond slip buttons 55 that provide for ability of the slip 50 to anchor, bite, engage, or grip into the casing 13, as known to one of ordinary skill in the art, are considered within the scope of the present disclosure. By way of example only, one such anchoring mechanism 16 in place of the buttons 55 may be to machine or manufacture the profile of ‘teeth’, peaks, or sharp points on the exterior of the slip 50 body itself so that the anchoring mechanism 16 will bite, anchor, grip, or otherwise engage with the case 13 when the slip 50 body is expanded.
The slip 50 may further include a sealing system, element or mechanism 62 having a seal ring 60 and a seal 61 at an uphole end 11 of the slip 50. Please refer to FIGS. 10A and 10 b for an enlarged depiction of the seal ring 60. The deformable elastomeric seal 61 is seated within the seal ring 60 (which may be made of metal). The elastomeric seal 61 engages and seals against the casing 13 when the frac plug 30 is set. The seal ring 60 and the seal 61 may be the primary seal for the frac plug 30 for creating an isolation zone and may assist with preventing the ball 26 and/or plug 30 from leaking. The sealing ring 60 and elastomeric seal 61 may be one example of a sealing system, element, or mechanism 62 for the plug 30. In further alternative exemplary embodiments, a rubber seal may be utilized in place of the expansion ring 60 and an elastomeric seal 61 for the purposes of providing a primary seal for the frac plug 30; in a further alternative exemplary embodiment, the sealing system 62 may be a single or unitary piece elastomeric packing element. Other traditional elastomeric sealing systems 62 as known to one of ordinary skill in the art is considered within the scope of the disclosure.
When the frac plug 30 is at the desired location within the casing 13 in the wellbore (see e.g. FIG. 4 depicting one anchored or ‘set’ position 72 of the frac plug 30), setting tool 20 is fired or stroked via the electric line 14 to set the frac plug 30, creating by way of example only, 30,000 lbs of pressure applied to the shear ring 24 and overcoming the shear tabs 41 on the pistons 40. The outer setting sleeves 22 and shear ring 24 are pulled which releases the setting tool 20 and allows the setting tool 20, including the setting tool adapter kit 21, outer sleeves 22, retention device 23 and solid stem 25 to be retrieved from the wellbore. The stroking of the setting tool 20 also pushes down on the top 30 a of the frac plug 30 and pushes against the bottom 30 b of the frac plug 30, thus driving the slip barrel 50 to engage with the casing 13 via slip buttons 55 gripping into the casing 13. The ball 26 is also released during this process and the deformable elastomeric seal 61, or sealing system 62, seals against casing 13 as the plug 30 is set by the wireline 14. Media pumped into the casing 13 will seat the ball 26 into the ball seat 27. In the event that the ball 26 needs to be retrieved, the back-facing slip buttons 55 will prevent the plug 30 from releasing from the casing 13. After setting, in a second or additional set or anchored position 72 after the initial set or anchored position 72, the wellbore hydrostatic pressure 15 surrounding the frac plug 30 also continuously drives or forces the upper cone 31 a and the lower cone 31 b together, decreasing or maintaining the shortened distance 37 between the cones 31 a, 31 b, and also drives the pistons 40 into the chambers 32, which may be, by way of example only, at atmospheric pressure. The chambers 32 may be at other pressures when the plug 30 is at the desired location in the casing 13, but the chambers 32 are generally at a different and lower pressure as compared to the hydrostatic pressure 15 in the wellbore. There may be multiple set or anchored positions 72 of the frac plug 30 ranging from the initial actuation or stroking of the setting tool 20 setting the frac plug 30 in a first set position 72 and as the hydrostatic pressure 15 increases or boosts the anchoring, retention, or hold of the frac plug 30 into the casing 13 in further set positions 72 of the frac plug 30.
As depicted in at least FIG. 4, the frac plug 30 allows for pressure 15 from the surrounding well to boost or enhance the initial setting force on the sealing and gripping mechanisms (including at least the sealing system 62, the seal ring 60, deformable elastomeric seal 61, the slip 50 and the slip buttons 55 in an exemplary embodiment) of the frac plug 30. Because of the setting depth of the frac plug 30 within a well bore, there is a natural high hydrostatic pressure 15 surrounding the plug 30. This disclosure utilizes this natural high hydrostatic pressure 15 to act against one or more atmospheric piston chambers 32 to continually boost or enhance the forces 36 acting on the plug 30 to cause continued cinching or tightening of the plug 30 beyond the initial setting force applied through the wireline 14.
As described above, the frac plug 30 allows the continued use of the well's surrounding hydrostatic pressure 15 to apply a continued tightening force 36 on the seal, (by way of example, and not to be limited to, the sealing system 62 having the sealing ring 60, and deformable elastomeric seal 61 in one exemplary embodiment) and on the gripping mechanism (by way of example, and not to be limited to, the slip 50 and the slip buttons 55). This prevents the plug 30 from loosening its grip from the casing 13 as it maintains a strong and positive anchoring force until the plug 30 is removed.
Because this frac plug 30 responds to pressure, once the surface frac pressure is applied to create a higher pressure down in the well to perform the stimulation job or frac job, this higher applied pressure will combine with the existing hydrostatic pressure 15 around the plug 30 to cause even a greater tightening force 36 on the plug 30.
Also because the piston rods 40 and the atmospheric chambers 32 are defined on opposingly situated and separate cones 31 a, 31 b at the top 30 a and bottom 30 b, respectively, of the plug 30, the forces (which may include hydrostatic pressure 15 of the wellbore, as well as applied surface frac pressure to the plug 30) that are generated across these pistons 40 and chambers 32 act to drive the upper cone 31 a and lower cone 31 b together, thus driving the seal 60 or sealing system 62 and the slip 50 to create a greater or tighter engagement with the casing 13. This load creates the same high engagement forces at the top 30 a of the plug 30 and the bottom 30 b of the plug 30. This creates a situation where the plug 30 will have the same resistance to any load coming from above/uphole 11 or below/downhole 12 the plug 30, so in the case of flow-back the frac plug 30 will be more resistant than conventional plugs.
Further this hydraulically boosting frac plug 30 can be made composed of either composite material or dissolvable material (e.g. , but not limited to, magnesium). It is a notable feature that as the dissolvable plug 30 begins to degrade and lose material from the plug 30, the hydraulic boosting effect will cause the plug 30 to tighten and maintain its pressure and anchoring integrity for a longer period of time than a traditional or conventional dissolvable plug that will become loose more quickly when it has structural material loss. Conventional or traditional plugs do not allow further tightening of the plug into to casing once the plug is set by the wireline. In the instant plug 30, even as the material from the dissolvable plug 30 is degrading, the pistons 40 will continue to further insert into the chambers 32 after disconnection with the setting tool 20 and the electric line 14, thus maintaining the anchoring or engagement integrity with the casing 13.
An additional feature of this improved frac plug 30 is that the atmospheric piston chambers 32 are only initially protected from contact with the dissolving media in the well. Once a dissolvable plug 30 has performed its primary function of allowing the frac job to be complete, the plug 30 then will begin to dissolve over time and go away. With this design, once the atmospheric chambers 32 are breached by the dissolution process, the amount of surface area exposed to the dissolution media within the upper cone 31 a mass increases dramatically and thereby the dissolution or dissolving process for the entire dissolvable frac plug 30 accelerates, making this a desirable feature to cause the plug 30 to go away faster once it has completed its job downhole.
According to the methodology described herein after the frac plug 30 is set, relative motion between the cones 31 a and 32 b may continue to occur. The radial travel of the slip(s) 50 may vary according to the surrounding inner diameter of the hole of the casing and the diameter of the frac plug 30.
The present disclosure encompasses at least: a plug 30 of any material (dissolvable or non-dissolvable) that uses one or more atmospheric chambers 32 and pistons 40 to boost or continually enhance the forces required to seal or grip the casing 13; the combined use of applied surface frac pressure and existing downhole hydrostatic pressure 15 that will continually act to increase the forces of sealing and gripping of the plug 30 against the casing 13 after actuating a setting tool and setting the frac plug 30; increased gripping forces which are bi-directional (from above/uphole 11 and below/downhole 12 the plug 30) causing the resistance to movement of the plug 30 to be increased from both directions in the event of frac pressure loading or back-flow loading; the use of atmospheric pistons 40 and chambers 32 allows for continual tightening of a dissolvable frac plug 30 as the material begins to degrade and there is substantial material loss; and the rate of normal material degradation of a dissolvable plug 30 is proportional to the exposed material surface area, and the dissolution rate of the plug 30 will increase as the atmospheric chambers 32 are breached during the material degradation process, thus making the dissolvable plug 30 go away faster.
While the embodiments are described with reference to various implementations and exploitations, it will be understood that these embodiments are illustrative and that the scope of the inventive subject matter is not limited to them. Many variations, modifications, additions, and improvements are possible.
Plural instances may be provided for components, operations or structures described herein as a single instance. In general, structures and functionality presented as separate components in the exemplary configurations may be implemented as a combined structure or component. Similarly, structures and functionality presented as a single component may be implemented as separate components. These and other variations, modifications, additions, and improvements may fall within the scope of the inventive subject matter.

Claims

1. A frac plug having an uphole side and a downhole side, comprising a first cone, wherein the first cone defines one or more chambers within the first cone;

one or more pistons each partially inserted into the one or more chambers at a first end of the one or more pistons;

a second cone connected to a second end of each of the one or more pistons;

a slip barrel surrounding the first cone and the second cone.

2. The frac plug of claim 1, wherein the one or more pistons each include a shear tab configured to resist further insertion of the one or more pistons into the one or more chambers up to a predetermined amount of force.

3. The frac plug of claim 2, wherein each of the one or more chambers are initially set at atmospheric pressure.

4. The frac plug of claim 3, wherein the frac plug comprises a dissolvable material.

5. The frac plug of claim 4, further comprising a plurality of slip buttons, wherein each of the plurality of slip buttons is embedded in the slip barrel at a first non-perpendicular angle.

6. The frac plug of claim 5, wherein the plurality of slip buttons comprise a first group of slip buttons proximate the uphole side of the frac plug, and a second group of slip buttons proximate the downhole side of the frac plug; and further wherein the first group of slip buttons are embedded at the first non-perpendicular angle, and the second group of slip buttons are embedded at a second non-perpendicular angle.

7. A method of running and setting a frac plug at a desired location in a casing within a wellbore, comprising the steps of:

providing a first cone and a second cone of the frac plug situated at a distance from each other; wherein the first cone comprises one or more chambers defined within the first cone, and wherein the second cone comprises one or more pistons partially inserted into the one or more chambers;

setting each of the one or more chambers at a predetermined pressure;

preventing the one or more pistons from further engaging with the one or more chambers via a shear tab on each of the one or more pistons;

and providing a slip barrel surrounding the first cone and the second cone.

8. The method of claim 7, further comprising the steps of:

actuating a setting tool connected to the frac plug;

shearing the shear tab of each of the one or more pistons;

decreasing the distance between the first cone and the second cone; and

driving the one or more pistons further into the one or more chambers after shearing the shear tab of each of the one or more pistons.

9. The method of claim 8 further comprising the step of:

anchoring the frac plug into the casing via the slip barrel.

10. The method of claim 9, further comprising the steps of

driving the one or more pistons further into the one or more chambers via a hydrostatic pressure of the wellbore, wherein the hydrostatic pressure is greater than the predetermined pressure of the one or more chambers;

further decreasing the distance between the first cone and the second cone; and

boosting the anchoring of the frac plug into the casing;

wherein the steps of driving the one or more pistons further into the one or more chambers, further decreasing the distance between the first cone and the second cone, and boosting the anchoring of the frac plug into the casing occur after the step of actuating the setting tool.

11. The method of claim 10, further comprising the steps of

dissolving the frac plug with a dissolving media; and

accelerating the step of dissolving the frac plug via exposing an increased surface area of each of the one or more chambers to the dissolving media.

12. The method of claim 11, further comprising the steps of: creating an isolation zone via a sealing element connected to the slip barrel, wherein the sealing element seals against the casing.

13. The method of claim 9, further comprising the steps of: releasing a ball of the frac plug; and retrieving the ball from the wellbore while preventing the frac plug from releasing from the casing via the slip barrel anchored into the casing.

14. A method of running and setting a frac plug at a desired location in a casing within a wellbore, comprising the steps of:

setting a frac plug within the casing; and

after the frac plug is set, boosting a retention of the frac plug by enabling relative motion to occur between a first cone and a second cone.

15. The method of claim 14 wherein the first cone defines at least one chamber and the second cone comprises at least one piston extending from the second cone; and further comprising the step of inserting the at least one piston into the at least one chamber.

16. The method of claim 15, wherein the at least one piston comprises a shoulder and comprising the step of preventing the insertion of the at least one piston past the shoulder up to a predetermined pressure.

17. The method of claim 16, wherein the wellbore further comprises a hydrostatic pressure and wherein the at least one chamber comprises a chamber pressure;

and further comprising the step of setting the chamber pressure lower than the hydrostatic pressure.

18. The method of claim 17, wherein the step of setting the frac plug comprises the steps of: stroking a setting tool connected to the frac plug; overcoming the shoulder of the at least one piston and inserting the at least one piston past the shoulder into the at least one chamber; and anchoring the frac plug into the casing.

19. The method of claim 18, wherein the difference between the hydrostatic pressure and the chamber pressure drive the at least one piston further into the at least one chamber.

20. A frac plug having an uphole side and a downhole side, comprising

a first frustoconical cone and a second frustoconical cone of the frac plug, wherein each frustoconical cone defines a top surface, and the top surface of the first frustoconical cone is situated facing the top surface of the second frustoconical cone, and wherein the top surface of the first frustoconical cone and the top surface of the second frustoconical cone are separated at a distance during a run-in position of the frac plug;

a plurality of chambers defined in the first frustoconical cone;

a plurality of pistons extending from the top surface of the second frustoconical cone, wherein each of the plurality of pistons is partially inserted into each of the plurality of chambers of the first frustoconical cone during the run-in position of the frac plug;

a slip barrel surrounding the first frustoconical cone and the second frustoconical cone.

21. The frac plug of claim 20, wherein each of the plurality of pistons comprises a shoulder along each of the plurality of pistons, wherein each of the plurality of pistons is partially inserted into each of the plurality of chambers up to the shoulder during the run-in position of the frac plug.

22. The frac plug of claim 21, further comprising a first set position of the frac plug, wherein the first set position of the frac plug comprises each of the plurality of the pistons inserted further into each of the plurality of chambers beyond the shoulder of each of the plurality of pistons.

23. The frac plug of claim 22, further comprising a second set position of the frac plug, wherein the distance between the first frustoconical cone and the second frustoconical cone is decreased; and further wherein the second set position of the frac plug comprises the plurality of pistons inserted even further into each of the plurality of chambers as compared with the plurality of pistons in the first set position of the frac plug.

24. The frac plug of claim 20, further comprising

a second plurality of pistons extending from the top surface of the first frustoconical cone; and

a second plurality of chambers defined in the second frustoconical cone;

wherein each of the second plurality of pistons is partially inserted into each of the second plurality of chambers during the run-in position of the frac plug.