| 摘要 |
A temperature activated actuator installed on a tubular to actuate an adjacent device may include one or more shape-memory alloy elements. The elements may be coupled between a first portion and a second portion of a device, or the elements may be coupled between the tubular and a portion of the device. The elements are activated by raising the temperature to a transition temperature to cause metallurgical phase transformation, causing the elements to shrink and displace at least a portion of the device. The actuator may be used, for example, to actuate a centralizer from a run-in mode to a deployed mode or, alternately, to actuate a packing member from a run-in mode to an isolating mode. A nickel-titanium alloy, for example, may be used as the shape-memory alloy material from which the shape-memory element is made.
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