Field of Invention. The present invention relates to the field of isolation in a well. More specifically, the invention relates to a device and method for isolating annular portions of a well as well as related systems, methods, and devices.
One aspect of the present invention is an isolation device or packer that has a metal bladder that is deformed downhole to create a seal. Other aspects are discussed in detail below.
The manner in which these objectives and other desirable characteristics can be obtained is explained in the following description and attached drawings in which:
a-c illustrate a valve implemented in the present invention.
It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
In the following description, numerous details are set forth to provide an understanding of the present invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible.
The present invention relates to various apparatuses, systems and methods for establishing isolation in a well. One aspect of the present invention relates to an isolation device or packer that has a metal bladder that is plastically deformed downhole, such as by hydroforming. A metal sleeve is inflated and plastically deformed to create the isolation seal. Other aspects of the present invention, which are further explained below, relate to methods for implementing and using the isolation device, manufacturing techniques for making the device, sleeve properties and other device components.
As an example,
The sleeve 16 is formed of a metal material capable of withstanding downhole conditions. Materials suitable for the deformation needed (e.g., by hydroforming the sleeve 16) are materials with significant plastic strain prior to reaching the tubes ultimate strength (i.e., a plastic strain greater than 10% and more preferably at least 20%). Additionally, the selected material may have a relatively low yield stress between 10 and 60 ksi. Using a material with a yield stress that is sufficiently low is useful so that excessive pressures are not needed to deform the material. The low yield stress may be particularly important in downhole applications where high pressure may damage other well equipment or the well. Examples of materials that may be used include low carbon steels, normalized low alloy steels, austenitic stainless steel alloys in the annealed condition (304, 316, etc.), and austenitic nickel alloys such as INCOLOY 825. In addition, the sleeve 16 preferable has a low elastic relaxation so that is maintains its shape after inflation.
The thickness, material, and other design properties of the sleeve 16 are selected to allow inflation of the sleeve 16. In the embodiment shown, the sleeve 16 is free of voids or radial passageways therethrough so that the sleeve can hold pressure without relying on additional sealing materials (e.g. without requiring an elastomer or other coating to assist in holding the inflation pressure). The base pipe 12 however is generally designed and selected to withstand the inflation pressures without experiencing significant deformation.
Stiffening rings 22 surround each of the end portions 18 of the sleeve 16. The stiffening rings 22 restrict outward radial movement of the end portions 18 (i.e., during inflation of the sleeve). The stiffening rings 22 thereby protect the connections of the sleeve 16 to the connecting rings 20, and the base pipe 12, by preventing bending at the connection. An optional jacket 24 is placed on the sleeve 16, such as by bonding. The jacket 24 may be formed of an elastomer, resin, or other material. The jacket 24 may be used to improve the seal between the sleeve 16 and the well 25 (see
A fluid passageway 26, or inlet, extends between an interior of the base pipe and a cavity 28 formed between the base pipe 12, sleeve 16, and connecting rings 20. The fluid passageway 26 in the figure ports to the base pipe interior and thereby communicates the tubing pressure to the cavity 28. In alternate designs the fluid passageway 26 may communicate with the well annulus or with a control line that extends to the surface or to some other region in the well (e.g., an annulus above a packer).
In one method of manufacturing the isolation device 10, a metal plate is formed into a tubular sleeve 16 (e.g., by rolling and then welding the abutting ends). Note that the sleeve 16 could also be machined or cold drawn. The sleeve 16 is placed on the base pipe 12 by sliding the sleeve 16 onto the base pipe 12. Finally, the sleeve 16 is connected and sealed to the base pipe 12.
In operation, pressure applied to the cavity 28 through the fluid inlet 28 deforms the sleeve 16 causing it to expand outward against the surrounding well conduit 25.
In addition, one of the connecting rings 20a shown in
In
Another inflation material 34 that may be used in the present invention is a two-part foam (e.g., silicone foam, elastomer foam, urethane foam). The foam components are combined as they are injected and swell the element until it touches the formation. The foam would cure into a solid mass, keeping the element engaged to the formation. A service or running tool or a control line may be used to inject the materials into the cavity. Alternatively, the materials may be stored in the cavity and kept separate until a predetermined time and then combined (e.g., as by opening a valve or rupturing a container). The isolation device 10 may employ other types of inflation materials 34 as well.
For example, the valve 38 may restrict or prevent fluid from exiting the cavity 28 through the fluid passageway 26. The valve 38 may take many forms, including a check valve or an inflation valve. Inflation valves, such as those used in inflation packers, use pistons controlled by springs and shear pins with the intent of permanently trapping a pressurized fluid inside the bladder. The design of these valves generally allows control of the pressure at which inflation begins, pressure at which inflation ends, and permanently closing of the bladder communication at inflation end. Examples of some ECP-type valves are shown in U.S. Pat. Nos. 4,776,396, 4,711,301, and 4,260,164 and in U.S. patent application No. 2003/0183398. Other types of valves 38 may also be used in the present invention. The sleeve 16 may be designed to inflate at reasonable pressures within the wellbore. Maintaining the pressure within the bladder 16 will support the bladder 16 and improve its resistance to collapse and its ability to hold pressure and better perform the isolation function of the isolation device 10. Thus, the valve 38 performs an important step of maintaining a pressure within the bladder 16 to support the bladder 16 and improve its collapse resistance.
Note also that in the embodiments of
a-c illustrate a portion of an isolation device 10 of the present invention in which the base pipe 12 defines a plurality of fluid passageways 42 therein. A valve 44 controls the flow through the passageways 42. The valve 44 and passageways 42 provide a similar function to the relief ports 36 discussed in connection with
Each of the passageways 42a-c communicates with the well annulus. A lateral passageway 55 provides communication between passageway 42b and passageway 42a at the backside of the piston 48 (distal the tubing port 46). The piston 48 uses the annulus or well pressure as a reference pressure and the communication between passageways 42a and 42b as shown helps to ensure that the reference pressure is supplied to the back side of the piston 48.
Passageway 42c is in fluid communication with passageway 42a. Check valve 56 allows fluid to enter the bladder cavity 28 via the passageways 42c and 42a, but prevents fluid from exiting the cavity 28.
A rupture disk 58 in passageway 42b restricts the flow of fluid from the annulus to the bladder cavity 28 until after the disk 58 is ruptured (e.g., as by supplying a sufficient rupture pressure).
Thus, the valve 44 has (1) a piston 48 that closes communication between the tubing and inflated bladder 16, (2) a rupture disk 58 that opens bladder 16 to unidirectional annulus pressure, (3) a check valve 56 that protects the rupture disk 58 from hydrostatic pressure during RIH (“run in hole”) and prevents an atmospheric chamber in the bladder cavity 28, and a spring 54 and J-slot 50 that change the piston 44 position from open to closed. In operation, the valve 44 shown follows a specific series of events relating to the pressure applied to the inflating bladder 16. Initially, the J-slot 50 holds the piston 48 in the open position during RIH and as shown in
Although only a few exemplary embodiments of this invention have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the following claims. For example, although the above description discusses hydraulic and mechanical systems for maintaining the pressure in the bladder 16 and for establishing fluid communication between the bladder cavity 28 and the high pressure side of the annulus, the isolation device 10 could employ electrical systems such as electric valves and solenoid valves or chemical or explosive systems (which could also be used for inflating the bladder 16). In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents, but also equivalent structures. Thus, although a nail and a screw may not be structural equivalents in that a nail employs a cylindrical surface to secure wooden parts together, whereas a screw employs a helical surface, in the environment of fastening wooden parts, a nail and a screw may be equivalent structures. It is the express intention of the applicant not to invoke 35 U.S.C. § 112, paragraph 6 for any limitations of any of the claims herein, except for those in which the claim expressly uses the words ‘means for’ together with an associated function.