Cementing Stage Collar with Dissolvable elements

Abstract

A cementing stage collar and a method. The cementing stage collar may include dissolvable parts.

Description

This application claims priority from U.S. provisional patent Ser. No. 62/502961 filing date May 8, 2017.

BACKGROUND

A hydraulic, ball or cement plug-actuated cementing stage collars provide effective isolation for specifically targeted, annular sections of a wellbore when the standard method of placing cement from the bottom of the well depth to the surface exerts greater hydrostatic pressure than what the targeted formation can tolerate. Typically, a well design where the formation to be stimulated requires to be open hole, a cementing stage collar can facilitate cementing of a production casing string while leaving the open hole section undisturbed. FIG. 1 illustrates a cement stage collar 100 that is used to provide cement 14 to a certain segments of a wellbore. The cement 14 is delimited by liner hangers 12. A debris sub 110 is positioned downstream to the liner hangers 12 and prevents the progress of debris downstream towards a frac sleeve 22. Open hole packers are used to segment an open hole 24.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, both as to organization and method of operation, together with objects, features, and advantages thereof, may best be understood by reference to the following detailed description when read with the accompanying drawings in which:

FIG. 1 illustrates an example of a well;

FIG. 2 is an example of a cementing stage tool before drill out;

FIG. 3 is an example of cementing stage tool after drill out;

FIG. 4 illustrates various examples of various parameters of dissolvable materials;

FIG. 5 is an example of a protective coating;

FIG. 6 is an example of a cementing stage tool;

FIG. 7 is an example of a cementing stage tool;

FIG. 8 is an example of a cementing stage tool;

FIG. 9 is an example of a cementing stage tool;

FIG. 10 is an example of a cementing stage tool;

FIG. 11 is an example of a cementing stage tool; and

FIG. 12 is an example of a cementing stage tool.

DETAILED DESCRIPTION OF THE DRAWINGS

In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the present invention.

It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements.

Any reference in the specification to a system should be applied mutatis mutandis to a method that can be executed by the system.

Because the illustrated embodiments of the present invention may for the most part, be implemented using mechanical components known to those skilled in the art, details will not be explained in any greater extent than that considered necessary as illustrated above, for the understanding and appreciation of the underlying concepts of the present invention and in order not to obfuscate or distract from the teachings of the present invention.

Most Cementing Stage Collars functions similarly in that Opening Sleeve is actuated by applied casing pressure acting on a differential piston area of the Opening Sleeve. In FIG. 2, a cementing stage collar 100 is illustrates as including a body 110 an opening sleeve 106, a closing sleeve 102 and a closing seat 104 that is configured to receive a ball 120 thereby forming a seal for preventing the progress of cement.

The applied internal casing pressure shifts the Opening Sleeve down to expose flow ports. Cement can then be pumped through these ports and into the casing annulus. Upon the completion of the cement pumping cycle, A Ball is pumped down to land on the Closing Seat. By applying specific casing pressure to the landed Ball, the Closing Seat and physically coupled Closing Sleeve are shifted down. Ultimately, the Closing Sleeve seals off the flow ports to shutoff the pressure communication and flow to the annulus and locks into position such that no inadvertent movement would occur that could reopen the Closing Sleeve.

After the cement has been injected into the annulus through the Cementing Stage Collar, the Ball, Closing Seat and Opening Seat must be removed from the well bore so that fluids can pass freely from the surface to the entirety of the well bore.

The Closing Seat, Ball and Opening Sleeve are manufactured from drillable material, commonly cast iron or aluminum.

To remove the Ball, Closing Seat and Opening Seat, a milling tool, sized according to the casing drift diameter or smaller, is lowered to the top of cement that remains above the Cementing Stage Collar. Using the rotary capabilities of the Rig or a downhole motor, the milling tool is pressed against the remaining cement above the Cementing Stage Collar and is rotated such that the milling tool drills through the cement, Ball, Closing Seat, and Opening Sleeve of the Cementing Stage Collar. Once the ID of the Cement Stage Collar is fully open, subsequent work can commence without having mechanical obstructions at the Cementing Stage Collar.

A common consequence of “drilling out” these components is that thin, cylindrical remnants (112 and 124 of FIG. 3) which are mechanically attached to the Closing Sleeve remain as the drill milling tool passes through.

Often due to the wobbling of the milling tool, these remaining remnants can be irregularly shaped, even broken. In all cases these remnants can be dislodged such that they can fall down through the wellbore during post-drill out operations. These remnants form debris that can and will interfere with many precision equipment located below the Cementing Stage Collar. A typical solution to deal with the issue is to mount an additional component in the casing string such as a Debris Sub below the Cement Stage Collar to capture this debris. However, these Debris Subs ultimately are drilled out as well leaving debris in the well bore.

The design of the Cementing Stage Collar can be clearly improved by using dissolvable materials, instead of drillable materials, to manufacture at least one of the Ball, Closing Seat, and Opening Seat—and especially all of the Ball, Closing Seat, and Opening Seat. When dissolvable materials are used for these Components, any debris that remains in the wellbore will dissolve.

The Ball, Closing Seat, and Opening Seat can be made of the same dissolvable material (or materials) or may differ from each other by composition.

At least two out of the Ball, Closing Seat, and Opening Seat can be made of the same dissolvable material (materials). At least two out of the Ball, Closing Seat, and Opening Seat can be made of different dissolvable materials.

The Ball, Closing Seat, and Opening Seat are non-limiting example of delimiting components.

Non-limiting examples of dissolvable materials that can be used for forming at least one of the Ball, Closing Seat, and Opening Seat are provided below.

Any dissolvable material that can be compatible to oil and/or gas pumping operations can be used.

Any dissolvable material may be proprietary, or non- proprietary.

The dissolvable materials can be classified according to their major constituency.

Magnesium and aluminum-based alloys are most prominent.

Plastic based alloys may also be used.

The metallic materials are suitable for components of the Cementing Stage Collar given their machinability, hardness and strength.

The dissolvable materials me be designed to dissolve in any fluid- including but not limited to fluids commonly found in the well bore. The sample charts below in FIG. 4 depict a diameter loss vs time (hours) of dissolvable material in and temperature of fluids found in common wells. In FIG. 4 lines 181, 182, illustrates the fixed rates of 0.66 mm/hour and 0.55 mm/hour reduction—and curves 183 and 184 illustrates a rate variable reduction in two test cases. It should be noted that there may be a variety of dissolvable materials—all of which will dissolve at different rates in different environments.

The KCl Brine, often used in the drill out and completions operations can readily dissolve components made of dissolvable materials. As such, a non-dissolvable coating can be introduced to these components to stop premature dissolution until after drilling out. See FIG. 5. The coating may be thin.

These coatings include, but are not exclusive to paints, epoxies, elastomers, plastics, and ceramics.

The unprotected surfaces exposed by drilling out the coating may start the dissolving process and will predictively dissolve or degrade into sufficiently smaller pieces such that they will easily be transported out of the casing with normal fluid circulation.

With a full dissolution of these dissolvable components, no remnants will remain as debris to hinder downhole operations such as fracking with ball-actuated Frac Sleeves, et al.

Using one or more dissolvable materials for forming at least two out of the Ball, Closing Seat, and Opening Seat provides a simple design, No debris to interfere with downhole tools; e.g., ball-actuated Frac Sleeves, Greater ID than drilled diameter at the Stage Collar after dissolving to match casing ID., No need for Debris Sub and Reduced risk and cost.

There may be provided a method that may include (a) injecting cement or another filling material within a space that is delimited by at least one delimiting component out of Ball, Closing Seat, and Opening Seat, where at least one of the Ball, Closing Seat, and Opening Seat is made of dissolvable material (materials), and (b) dissolving (preferably after the completion of step (a)) the at least one delimiting component that is made of the dissolvable material (materials).

FIGS. 6-12 illustrates a cementing stage collar 200.

The cementing stage collar 200 may include

• • a. Body 210 that includes one or more flow ports 220. For simplicity of explanation it is assumed that there are multiple flow ports. Cement may flow through the one or more flow ports in order to fill an annulus. The flow ports may be arranged in any manner—for example in a symmetrical or a non-symmetrical manner, to form an annular array, and the like. The flow ports may include sealing elements.
  • b. A group of sleeves. The group may include one or more sleeves. FIGS. 7-10 illustrate a group of sleeves that includes an opening sleeve 240 and a closing sleeve 230. The group of sleeves includes an exit port. The group of sleeves is configured to move within the body thereby selectively blocking the flow ports and selectively exposing the flow port to an interior 260 of the cementing stage collar. When exposed to the flow port—cement that propagates through the interior flows propagates through flow ports 220 to the annulus—while being prevented (by stopper 250) to propagate via through port 262 downstream to the cementing stage collar.
  • c. A first closing element that is configured to receive a sealing element (such as ball 120) and to seal the cementing stage collar. The first closing element is dissolvable. The first closing element may be a closing seat.

The closing seat may include removable and non-solvable cover (that can be made of a protective coating such as protective coating 105 of FIG. 3) that covers a dissolvable portion of the closing seat.

At least a part of the group of sleeves may be dissolvable. For example—the opening sleeve may include at least one dissolvable part, may be entirely made of dissolvable material, and the like.

The stopper 250 may be configured to seal a through port 262 of the interior 260 thereby preventing fluid to exit downstream of the certain internal sleeve when the flow port is exposed to the interior of the certain sleeve. The stopper 250 can be made of dissolvable materials. It can include a removable and non-solvable cover.

The opening sleeve 240 may include a removable non-solvable cover that covers a dissolvable portion of the opening sleeve.

The closing sleeve 230 may be configured to selectively block the flow port. The opening sleeve 240 may be configured to electively expose the flow port to an interior of the opening sleeve.

In the foregoing specification, the invention has been described with reference to specific examples of embodiments of the invention. It will, however, be evident that various modifications and changes may be made therein without departing from the broader spirit and scope of the invention as set forth in the appended claims.

The terms “including”, “comprising”, “having”, “consisting” and “consisting essentially of” are used in an interchangeable manner. For example- any method may include at least the steps included in the figures and/or in the specification, only the steps included in the figures and/or the specification.

Moreover, the terms “front,” “back,” “rear” “top,” “bottom,” “over,” “under” and the like in the description and in the claims, if any, are used for descriptive purposes and not necessarily for describing permanent relative positions. It is understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the invention described herein are, for example, capable of operation in other orientations than those illustrated or otherwise described herein.

Those skilled in the art will recognize that the boundaries between various components are merely illustrative and that alternative embodiments may merge various components or impose an alternate decomposition of functionality upon various components. Thus, it is to be understood that the architectures depicted herein are merely exemplary, and that in fact many other architectures can be implemented which achieve the same functionality.

Any arrangement of components to achieve the same functionality is effectively “associated” such that the desired functionality is achieved. Hence, any two components herein combined to achieve a particular functionality can be seen as “associated with” Each other such that the desired functionality is achieved, irrespective of architectures or intermedial components. Likewise, any two components so associated can also be viewed as being “operably connected,” or “operably coupled,” to Each other to achieve the desired functionality.

Furthermore, those skilled in the art will recognize that boundaries between the above described operations merely illustrative. The multiple operations may be combined into a single operation, a single operation may be distributed in additional operations and operations may be executed at least partially overlapping in time. Moreover, alternative embodiments may include multiple instances of a particular operation, and the order of operations may be altered in various other embodiments.

However, other modifications, variations and alternatives are also possible. The specifications and drawings are, accordingly, to be regarded in an illustrative rather than in a restrictive sense.

In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word ‘comprising’ does not exclude the presence of other elements or steps than those listed in a claim. Furthermore, the terms “a” or “an,” as used herein, are defined as one or more than one. Also, the use of introductory phrases such as “at least one” and “one or more” in the claims should not be construed to imply that the introduction of another claim element by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim element to inventions containing only one such element, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an.” The same holds true for the use of definite articles. Unless stated otherwise, terms such as “first” and “second” are used to distinguish between the elements such terms describe. Thus, these terms are not necessarily intended to indicate temporal or other prioritization of such elements. The mere fact that certain measures are recited in mutually different claims does not indicate that a combination of these measures cannot be used to advantage.

While certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes, and equivalents will now occur to those of ordinary skill in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.

Claims

1. A cementing stage collar, comprising:

a body that comprises a flow port;

a group of sleeves that comprises at least one sleeve; wherein the group of sleeves comprises exit ports; wherein the group of sleeves is configured to move within the body thereby selectively blocking the flow port and selectively exposing the flow port to an interior of the cementing stage collar; wherein at least one sleeve is dissolvable; and

a first closing element that is configured to receive a sealing element and to seal the cementing stage collar; wherein the first closing element is dissolvable.

2. The cementing stage collar according to claim 1 wherein the first closing element is a closing seat.

3. The cementing stage collar according to claim 2, wherein the closing seat comprises a removable and non-solvable cover that covers a dissolvable portion of the closing seat.

4. The cementing stage collar according to claim 1 wherein at least a part of the group of sleeves are dissolvable.

5. The cementing stage collar according to claim 1, comprising a stopper that is configured to seal a through port of the group of sleeves thereby preventing fluid to exit downstream of the cementing stage collar when the flow port is exposed to the interior of the cementing stage collar.

6. The cementing stage collar according to claim 5, wherein the stopper is dissolvable.

7. The cementing stage collar according to claim 1, wherein the group of sleeves comprises an opening sleeve and a closing sleeve.

8. The cementing stage collar according to claim 7, wherein the opening sleeve comprises a removable non-solvable cover that covers a dissolvable portion of the opening sleeve.

9. The cementing stage collar according to claim 7 wherein the closing sleeve is configured to selectively block the flow port; and wherein the opening sleeve is configured to electively expose the flow port to an interior of the opening sleeve.

10. A method for cementing an annulus, the method comprising:

feeding cement to an interior of a cementing stage collar;

outputting the cement from a flow port of a body of the cementing stage collar to the annulus while preventing the cement from propagating downstream to the cementing stage collar;

sending a sealing element to a first closing element of the cementing stage collar; forming a seal by receiving, by the first closing element, the sealing element; wherein the first closing element is dissolvable; and

dissolving parts of the cementing stage collar; wherein the parts comprises the first closing element, thereby opening a downstream fluid path that passes through the cementing stage collar.