Patent Application
20250237119
The present invention generally relates to an improved retrievable bridge plug.
Retrievable bridge plugs are used in thermal well operations to isolate the reservoir or wellbore. Plugs can be installed together with a circulating valve that can hold pressure from below and allow flow from above, and may be used to plug formation pressure in the tubing string while providing flow area for pumping into the formation. Plugs with equalizing standing valves allow flow through the plug from below while holding pressure from above.
In some thermal well operations, where reservoir pressure exceeds hydrostatic pressure in the wellbore, dual retrievable plugs may be placed one above the other, with an intermediate space in between. However, in some circumstances, fluid trapped in the intermediate space between two retrievable plugs could experience thermal expansion, creating a pressure high enough to rupture a liner or casing, leading to a loss of well integrity.
In some cases, nitrogen is used to blow down the well and remove the hydrostatic head before a second plug is installed. Alternatively, it is known to swab the well to remove the hydrostatic head. Although both methods are effective to create a dry space between the two plugs, both methods are costly and time-consuming.
In one aspect, disclosed is a retrievable bridge plug having both an expandable packer element to seal to a casing and a slip mechanism to anchor to the casing, and defining a flow path including at least one check valve for restricting fluid flow through the bridge plug.
In one embodiment, the retrievable bridge plug comprises:
In another aspect, disclosed is a method of controlling pressure in a wellbore, comprising the steps of:
The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate some, but not the only or exclusive, examples of embodiments and/or features.
Embodiments of the present invention are described below with reference to the accompanying drawings, in which some, but not all embodiments of the invention are exemplified. Indeed, this invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout. It is to be understood that this invention is not limited to the particular methodology and protocols described, as such may vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present invention.
Many modifications and other embodiments of the invention set forth herein will come to mind to one skilled in the art to which the invention pertains having the benefit of the teachings presented in the foregoing description and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.
In this description, the directional prepositions of up, upwardly, down, downwardly, front, back, top, upper, bottom, lower, left, right and other such terms refer to the device as it is oriented and appears in the drawings and are used for convenience only; they are not intended to be limiting or to imply that the device has to be used or positioned in any particular orientation. Conventional components of the invention are elements that are well-known in the prior art and will not be discussed in detail for this disclosure. The retrievable bridge plug 10 of the present invention is shown in the drawings with the uphole side on the left hand side.
In one embodiment, a retrievable bridge plug 10 has an inner mandrel 11, a coupling 12, an upper mandrel 20, a lock ring housing 21, a lower mandrel 22, a slip setting sleeve 24, slips 26, and packing elements 28. For deployment, an operator may use wireline, slickline, coiled tubing or drill pipe (not shown) connected by a wireline or hydraulic setting tool (not shown) to the coupling 12 and deploy the bridge plug 10 to a desired point in the borehole casing C. At the desired point, the plug 10 is set using the wireline or hydraulic setting tool (not shown). As the plug 10 is set, its slips 26 move outwards to engage the casing C, and the packing elements 28 move outwards to seal to the casing C. As a result, the wellbore is isolated above and below the plug 10.
In general, the slip setting sleeve 24 is manipulated relative to the lower mandrel 22 to push the slips 26 outward between wedge members 30, 31. The packing elements 28 are actuated by the lock ring housing 21, which slides between the slip setting sleeve 24 and the lower mandrel 22 in order to compress the packing elements 28 between gage rings 50 and 51 and spacer elements 52.
The bridge plug 10 is configured to allow fluid flow downward through the plug under set conditions. A fluid flow path is defined in the annular space between the upper mandrel 20 and the lock ring housing 24. A coupler 23 connects the upper mandrel 20 and the lower mandrel 22, and defines at least one opening through which fluid can pass from the annular space between the upper mandrel and the lock ring housing 24 to the annular space between the inner mandrel 11 and the lower mandrel 22. At least one, and preferably two, check valves 34 are positioned within the flow path to block fluid from flowing upwards while allowing fluid to pass downwards through the plug 10. The two check valves 34 are preferably positioned in series, but may be positioned in parallel (not shown). The flow path is closed by a burst disc 48 positioned at the top of the flow path, which burst disc has a design pressure at which it yields to open the flow path. The bottom sub 70 also defines a plurality of openings which allow fluid to flow through the plug.
As used herein, a “check valve” is a valve which permits fluid to flow through in one direction only. Preferably, the check valve is a two-port valve, consisting only of an entry opening and an exit opening. The check valves 34 may have a desired crack pressure, which may as low or as high as desired, such as about 1-5 psi, or as high as about 1000 psi.
For retrieval, a pulling tool (not shown) is run on a tubing string downhole to the setting depth. Fluid is circulated to clear the plug 10 of debris. Once clear, the pulling tool is set down to the coupling 12 with a predetermined amount of load to shift the upper and lower mandrels 20, 22 upwards to release the slips 26 and the packing elements 28.
One exemplary embodiment is shown in
An upper setting ring 46 secures the upper end of the lock ring housing 21 to the upper mandrel 20 with shear bolts 47. The upper setting ring 46 includes the burst disc 48 which closes off the annular space 20a between the lock ring housing 21 and the upper mandrel 20. The burst disc 48 has a design pressure at which it yields to open the annular space 20a to the fluids above the plug 10.
An upper gage ring 50, a lower gage ring 51 and element spacers 52 frame and engage the packing elements 28. The lower gage ring 51 is locked to the slip setting sleeve 24, which is connected to the lock ring housing 21 with shear bolts 53. A crosslink 54 stabilizes a lower end of the lock ring housing 21. The lower end of the lock ring housing 21 defines ratchet teeth 55 which engage pawls on an outer surface of the lower mandrel 22.
The slip setting sleeve 24 has a wedge element cone 30 which also ratchets on ratchet tee on the outer surface of the lower mandrel 22. A lower cone 31 is affixed to the bottom sub and a slip cage 60 retains the slip mechanism against the lower mandrel 22.
From the RIH configuration shown in
Continued application of force will then shear bolts 53, which then allows relative movement between the lock ring housing 21 and the slip setting sleeve 24, thereby activating the packing elements outwards 28, as they are squeezed between the upper and lower gage rings 50, 51. The plug 10 is now in the configuration shown in
Upon release with a release tool, the inner mandrel 11, the upper and lower mandrels are pulled upwards relative to the lock ring housing and the slip setting sleeve. As a result, the slips 26 and the packing elements 28 retract and disengage the casing. The bleeder sleeve 42 is shifted downwards such that the equalization ports 44 of the upper collet 43 are open to the wellbore through the bleeder sleeve 42 openings. This opens up the fluid flow path B shown in
Check valves 34 may be commercially available with different crack pressures and readily installed in embodiments of a bridge plug. In an alternative embodiment, where a high crack pressure is desired, the check valve may be integrally formed with annular members configured as shown in
A flow sleeve 60 is disposed concentrically around the mandrel 11 and defines at least one passageway 61 for fluid flow downwards through the flow sleeve. The flow sleeve 60 includes at least one piston 62 which is biased to close the valve, such as with spring 65, by bearing upwards on a moveable valve member 64. The valve member 64 includes a pin 66 is sealed within a passageway formed in valve block 68, as is shown in
After the burst disc 48 has yielded, fluid pressure bears on the upper end of the pin 66, which transmits force through the valve member 64 and piston 62. When the force exceeds a threshold value and compresses the biasing means or spring 65, valve member moves downwards, opening a chamber between the valve block 68 and valve member 64. Fluid may then move downwards around the valve member 64 and through the flow sleeve 60.
In an embodiment, a bridge plug 10 having a fluid flow passage is installed and second bridge plug is installed above the lower bridge plug, as shown in
The upper bridge plug may be a conventional bridge plug, or a bridge plug having a check valve as described herein. In one embodiment, the upper bridge plug comprises a check valve having a crack pressure greater than the lower bridge plug check valve. The integrity of the bridge plugs can then be tested by pressuring the wellbore to a pressure intermediate the upper and lower crack pressures. If the intermediate pressure holds, then the upper bridge plug is intact and securely installed. If the intermediate pressure cannot be held, then the upper bridge plug is compromised. In the latter case, a pressure lower than the crack pressure of the lower bridge plug can then be imposed. If this lower pressure can be maintained, the lower bridge plug is securely installed. However, if it cannot, then the lower bridge plug is compromised.
The forgoing description supplies specific details in order to provide a thorough understanding. Nevertheless, the skilled artisan would understand that the apparatuses, systems, and associated methods of using the apparatuses and systems can be implemented and used without employing these specific details. Indeed, the apparatuses, systems, and associated methods can be placed into practice by modifying the illustrated apparatus and associated methods and can be used in conjunction with any other apparatus and techniques conventionally used in the industry.
The corresponding structures, materials, acts, and equivalents of all means or steps plus function elements in the claims appended to this specification are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed.
References in the specification to “one embodiment”, “an embodiment”, etc., indicate that the embodiment described may include a particular aspect, feature, structure, or characteristic, but not every embodiment necessarily includes that aspect, feature, structure, or characteristic. Moreover, such phrases may, but do not necessarily, refer to the same embodiment referred to in other portions of the specification. Further, when a particular aspect, feature, structure, or characteristic is described in connection with an embodiment, it is within the knowledge of one skilled in the art to affect or connect such module, aspect, feature, structure, or characteristic with other embodiments, whether or not explicitly described. In other words, any module, element or feature may be combined with any other element or feature in different embodiments, unless there is an obvious or inherent incompatibility, or it is specifically excluded.
It is further noted that the claims may be drafted to exclude any optional element. As such, this statement is intended to serve as antecedent basis for the use of exclusive terminology, such as “solely,” “only,” and the like, in connection with the recitation of claim elements or use of a “negative” limitation. The terms “preferably,” “preferred,” “prefer,” “optionally,” “may,” and similar terms are used to indicate that an item, condition or step being referred to is an optional (not required) feature of the invention.
The singular forms “a,” “an,” and “the” include the plural reference unless the context clearly dictates otherwise. The term “and/or” means any one of the items, any combination of the items, or all of the items with which this term is associated. The phrase “one or more” is readily understood by one of skill in the art, particularly when read in context of its usage.
As will also be understood by one skilled in the art, all language such as “up to”, “at least”, “greater than”, “less than”, “more than”, “or more”, and the like, include the number recited and such terms refer to ranges that can be subsequently broken down into sub-ranges as discussed above. In the same manner, all ratios recited herein also include all sub-ratios falling within the broader ratio.
| Number | Date | Country | |
|---|---|---|---|
| 63624602 | Jan 2024 | US |
