Patent Application
20130105175
In the drilling and completion industry, the formation of boreholes for the purpose of production or injection of fluid is common. The boreholes are used for exploration or extraction of natural resources such as hydrocarbons, oil, gas, water, and CO2 sequestration. Various downhole tools function therein by actuating specific components while being operated in the borehole. One method of activating a downhole tool is the application of fluid pressure to hydraulic components included in the tool.
One such downhole tool is a pressure actuated sleeve used in a cementing assembly that is responsive to tubing pressure to open a port. When the pressure is built up in the tubing to a certain point, access is provided to a piston on the sleeve that is referenced to a low pressure or atmospheric chamber by breaking a rupture disc. The sleeve can then move to open the port or ports for annulus access. Other types of downhole tools also use pressure operated sleeves that respond to tubing pressure with an associated piston that is open on one side to tubing pressure and on the other side to annulus pressure.
In addition to using a burst disk, downhole tools are held in a deactivated state through the use of either a shear pin, shear screw, shear ring, or seal friction. These methods have limited repeatability, most within +/−5-10 of applied pressure, and therefore do not afford the operation of a well with more accurate pressure actuation windows, posing a problem in wells that have limited casing pressure ratings. Additionally, these prior devices for actuating tools are not changeable by the end user, but will only operate at an “as delivered” pressure, which is not always within acceptable ranges.
Therefore, the art would be receptive to a device and method for actuating tools downhole that provides for more actuation accuracy, while allowing for tuneability to ensure that the device will operate within an acceptable pressure range.
A frangible pressure control plug includes a first portion of a body adjacent a first end of the plug; a second portion of the body adjacent a second end of the plug, the second portion attached to the first portion in a first condition; a groove in the body interposed between the first portion and the second portion; and a bore within the body passing through the first end and the first portion and inaccessible from the second end; and wherein, fluid communication between the bore and the groove is prevented in the first condition and allowed in a second condition.
A pressure actuatable tool includes a sleeve having a wall, the sleeve having an aperture through the wall; a frangible pressure control plug plugging the aperture and preventing fluid communication between an interior and an exterior of the sleeve in a first condition, and providing fluid communication between the interior and the exterior of the sleeve in a second condition, the plug including: a first portion of a body adjacent a first end of the plug; a second portion of the body adjacent a second end of the plug, the second portion attached to the first portion in the first condition; a groove in the body interposed between the first portion and the second portion; a bore passing through the first end and the first portion and inaccessible from the second end; and wherein fluid communication between the longitudinal bore and the groove is prevented in the first condition and allowed in a second condition.
A method of actuating a tool using a pressure control plug, the plug including a first portion of a body adjacent a first end of the plug, a second portion of the body adjacent a second end of the plug, the second portion attached to the first portion in a first condition, a groove in the body interposed between the first portion and the second portion, and a bore passing through the first end and the first portion and inaccessible from the second end, the method including inserting the plug in an aperture of a sleeve of the tool, with the second end of the plug facing an interior of the sleeve; increasing pressure within the sleeve and directing the pressure to the groove towards the first portion; and, actuating the tool by applying a critical pressure that fractures the first portion from the second portion in the second condition of the plug to provide fluid access from the sleeve to the groove and bore.
The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:
A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures.
The pressure control plug 10 includes a body 26 having a first end 28 and a second end 30. The second end 30 faces an area receiving hydraulic pressure, such as the interior 22 of the sleeve 12. The first end 28 faces away from the area receiving hydraulic pressure. In the exemplary embodiment shown, the first end 28 faces the exterior 24 of the sleeve 12 and the atmospheric pressure chamber 20. A first portion 32 of the body 26 is adjacent the first end 28 and a second portion 34 of the body 26 is adjacent the second end 30. Both the first portion 32 and the second portion 34 may be substantially cylindrically shaped, although other shapes are also usable. The first and second portions 32, 34 may have substantially the same outer diameter, or the first portion 32 may have a larger outer diameter than the second portion 34. The second portion 34 may include threads 36 that mate with threads 38 in the aperture 16 in the sleeve 12. Alternatively, other securement features may be employed on the second portion 34 and the sleeve 12 or other cooperating body for the second portion 34 to be retained therein. If the actuatable tool 100 is a one-time use type tool, the second portion 34 of the plug 10 may even be integrally formed with the tool 100. The first portion 32 is preferably not threaded or at least not threaded into the aperture 16, and the first portion 32 is retained in the aperture 16 via its connection to the second portion 34. The first portion 32 may be integrally formed with the second portion 34, however, in some embodiments, may be otherwise attached to the second portion 34.
A notched groove 40, or other weakened area in the body 26, is interposed between the first and second portions 32, 34. The notched groove 40 preferably circumscribes the plug 10, however it may instead be formed at one or more discrete locations on an outer circumference of the plug 10. In one exemplary embodiment, the groove 40 includes a first face 42 on the first portion 32 and a second face 44 on the second portion 34 intersecting to form a non-zero angle therebetween.
A longitudinal bore 46 passes through the first end 28 and extends through the first portion 26. In an exemplary embodiment, the longitudinal bore 46 is centrally located within the plug 10 by extending along a longitudinal axis of the plug 10. While a single bore 46 is disclosed, in an alternative exemplary embodiment, a plurality of bores may be spaced within the first portion 32. The longitudinal bore 46 passes partially into the second portion 34 of the plug 10, longitudinally past the notched groove 40, however the longitudinal bore 46 does not pass through the second end 30 of the plug 10, and is not accessible from either the second end 30 of the plug 10 or the notched groove 40 in the first condition of the plug 10 shown in
As further shown in
The plug 10 can be used to accurately actuate downhole tools 100 in oil and gas wells. The design of the plug 10 allows for more actuation accuracy than other pressure control devices. The notched groove 40 on the frangible pressure control plug 10 can be adjusted during the manufacturing process to give tighter pressure tolerances on the critical fracture pressure. The plug 10 can be either pressure or load tested to determine the correct diameter, depth, and shape of the groove 40 for its intended application, which is a significant benefit to the user. For example, increasing a depth of the notched groove 40 will lower the critical pressure needed to fracture the plug 10 and actuate a tool 100, while decreasing a depth of the notched groove 40 will increase a critical pressure needed to fracture the plug 10 and actuate a tool 100. Decreasing the depth of the groove 40 may be accomplished by adding a filler material therein, or by simply manufacturing a plug 10 having decreased depth. It should be noted that a change in the size of the notched groove 40 need not change the size of the aperture 16 in the sleeve 12, and therefore the pressure rating for actuating the tool 100 may be changed without significant changes to the sleeve 12 or tool 100 itself Alternatively, while one flow passageway 48 through the sleeve 12 is shown, it should be understood that multiple flow passageways pointing toward the notched groove 40 may be formed in the sleeve 12, or flow passageways having varying diameters and angles may be formed in the sleeve 12, which will also selectively serve to increase or decrease the pressure required to fracture the plug 10.
The body 26 of the plug 10 is made in such a way that the first portion 32 of the plug 10 acts as a hydraulic piston 52 that tries to pull the first portion 32 away from the secured second portion 34. As previously noted, the pressure at which the plug 10 fractures is controlled by the depth or size of the notched groove 40 below the hydraulic piston 52. The bore 46 in the first portion 32 of the body 26 is exposed to the pressure and flow from the passageway 48 via the fracture 50 once the plug 10 is fractured at the notched groove 40. The hydraulic piston 52 is interposed between the fracture 50 and the first end 28 to assist in maintaining the communication between the bore 46 and the passageway 48 established by the fracture 50. An O-ring 54 and a solid (non-cut) backup ring 56 act within a port 58 (in the sleeve 12 for example) to create a net longitudinal force on the first portion 32 of the plug 10 with the application of pressure exteriorly of the second end 30 of the second portion 34. The O-ring 54 and backup ring 56 surround a periphery of the first portion 32 of the body 26 and abut and press on a lip 60 of the first portion 32 of the body 26 that protrudes from the first portion 32 of the body 26 adjacent the first end 28 of the body 26. The backup ring 56 is interposed between the O-ring and the lip 60. The O-ring may be an elastomeric sealing ring. The plug 10 has been designed such that only a small longitudinal displacement of the first portion 32 from the second portion 34 will allow full flow through the plug 10, such that the O-ring 54 and backup ring 56 do not need to be completely expelled from the port 58 for full communication flow to be established through the fracture 50 as shown in
In an exemplary embodiment, the first end 28 of the body 26 includes a seal preventer designed to prevent the plug 10 from making any type of seal against anything that it hits when the plug 10 fractures and the first portion 32 is moved longitudinally. The seal preventer ensures that even if a surface of the first end 28 of the body 26 hits the housing 14, it will not form a seal with the housing 14 and will not prevent fluid communication from the bore 46 to the exterior 24. As shown in
In the embodiment shown in
In
In
In
Thus, the frangible pressure control plug 10, in any of its various embodiments or combinations thereof, provides an improved alternative to other conventional methods of actuating tools downhole including shear pins, shear screws, shear rings, and burst disks. All of these other methods have limited repeatability, most within +/−5 to 10 of applied pressure and are not tuneable or changeable. The frangible pressure control plug 10 described herein is infinitely tuneable via dimension changes to its notched groove 40, and thus provides an accurate actuation of downhole tools.
Turning now to
A first atmospheric chamber 118 contains air that can be independently tested through a first pressure test port 120, while a second atmospheric chamber 122 also contains air that can be independently tested through a second pressure testing port 124. The pressure control plug 10 is held into place within an aperture 16 located in a wall 18 of the inner shifting sleeve 110.
The valve 102 is run on casing and cemented into place within the well. After cementation the valve 102 is scraped with wiper dart prior to actuation. Once the cement has set on the outside of the valve 102, it is ready to be opened with a combination of high hydrostatic and applied pressure. Once the critical pressure is reached, the pressure control plug 10 is fractured and opens the first atmospheric chamber 118 to the applied pressure. This pressure acts on the piston area created by internal bore piston seals 126 and larger internal bore piston seals 112 and drives the inner shifting sleeve 110 to compress the air within the atmospheric chamber 122 and open the fluid communication ports 106 on the ported housing 104. Chamber 122 has an initial pressure of atmospheric or a predetermined value less than the anticipated hydrostatic pressure within sleeve 110. The volume of chamber 122 decreases and its internal pressure rises as sleeve 110 moves to open ports 106. The valve 102 includes a plurality of the pressure control plugs 10.
While one exemplary tool has been shown and described, it should be understood that the pressure control plug 10 is usable in any of a number of actuatable tools.
While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited. Moreover, the use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another. Furthermore, the use of the terms a, an, etc. do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.
