A pervasive necessity in industries focused on recovery of materials from below the earth's surface, for example the hydrocarbon recovery art, is to seal componentry downhole in a number of different configurations, at different pressures, temperatures, environments, and other factors. Many types of sealing devices have been developed to address particular applications and to improve overall sealing in different applications and such development has been occurring since the very beginnings of hydrocarbon exploration of recovery.
As wells continue to become more complex, further development of sealing technology is required due to such factors as instrumented completions, instrumented drilling apparatus, etc. that cause inside dimensions along a string to vary, for example.
An element includes a tube, at least in part including a shape memory material; and a swellable material disposed adjacent the tube.
A method for making a seal includes configuring a shape memory material to a shape; heating the material to above a transition temperature for the material; reconfiguring the material; cooling the material to a temperature below the transition temperature of the material; and disposing a swellable material adjacent the shape memory material.
Referring now to the drawings wherein like elements are numbered alike in the several Figures:
Referring to
In each illustrated case, after the tube 12 is deformed in the desired shape or dimensions, the temperature of the tube is brought back to below the transition temperature of the shape memory material such that the shape is maintained (“frozen”). In this condition, the swellable material 14 is added thereto in a generally tubular configuration therearound. It is also contemplated to add the swellable material before the deformation of the tube 12 providing that the swellable material is tolerant of the heat required to exceed the transition temperature of the shape memory material. In this condition, the seal 10 is ready for deployment in a wellbore or other target structure. Upon installing the seal 10 in the downhole environment, and assuming that the temperature of the environment is as anticipated, or higher, or in an accessory heat source embodiment, the accessory heat source succeeds in bringing the temperature of the material back above its transition temperature, the shape memory material will reform to its original shape. In each of the illustrated embodiments, the “remembered” shape is of larger outside dimensions thereby facilitating the creation of a force against on outer tubular which may be employed as a seal force or an actuation force. The swellable material 14, being disposed radially outwardly of the tube 12, in this embodiment, will be urged into contact with an outer tubular when the shape memory material regains its original shape. Further, because the swellable material element 14 is indeed swellable, exposure thereof to an appropriate swelling fluid (water, oil, etc.) will swell the element 14 and thereby create a greater force, which may be a tighter seal or a greater actuation force, for example, between the tube 12 and the outer tubular in which the element 10 is set.
In one embodiment, the swellable material is a composite material including portions thereof swellably responsive to a number of different swelling fluids. Such a composite swellable material increases the chances that a seal or actuation force will be effected by ensuring that the material will react to at least one of the fluids in the wellbore at any given time. In one embodiment, the swellable material element comprises portions responsive to contact with water, portions responsive to oil and portions responsive to methane. The swellable material will thus have a very high likelihood of swelling in a downhole environment as seldom will all of the three noted swelling fluids be absent.
Although the discussion above is directed to a seal 10 or actuator that operates with radially outward expansion, the concept hereof is reversible such that the shape memory material is configured to regain a smaller diametrical dimension to urge a swellable material disposed on the inside dimension thereof to be forced against a more radially inwardly located component, whereafter, swelling of the swellable material will create more radially inwardly directed force. Additionally, it is to be appreciated that although the foregoing discussion relates to radial expansion, the concept of combining a shape memory material and a swellable material for the purpose of for example sealing or actuation is not limited to radial expansion. Rather, the expansion can be in any direction. For example, the shape memory material may change in length and the swellable material may be configured to swell in the same direction for a lengthwise actuation. Further, the shape may be any geometric shape obtainable with shape memory material and the swellable material may be positioned and configured to enhance the motion provided by the shape material or may be positioned and configured to swell in a different direction or shape.
While preferred embodiments have been shown and described, modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustrations and not limitation.
This application claims the benefit of an earlier filing date from U.S. Provisional Application Ser. No. 60/940,713 filed May 30, 2007, the entire disclosure of which is incorporated herein by reference.
Number | Date | Country | |
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60940713 | May 2007 | US |