| 摘要 |
Mounting arrangement for a bimetallic pipe base well screen which must operate at elevated temperatures includes a pair of expandable end boss rings at the ends of a cylindrical screen member. The end boss rings overlie unperforated portions of the outer surface end portions of an internal pipe member which has perforations along a portion of its length which underlie the well screen. The screen member and the end boss rings have a greater temperature coefficient of expansion than the pipe base. At room temperature, the end boss rings have a smaller inner diameter than the outer diameter of the pipe base. The boss ring portions are heated and shrunk-fit onto the pipe base to a degree that at operational temperatures they will either expand slightly out of contact with the pipe base, or at least become substantially unstressed, thus preventing damage to the screen member while also blocking out the entry of particles. The arrangement is particularly useful where many screen sections are used in a string since the screen members can remain fixed in position in a gravel packed well while the pipe base sections can move up and down inside them in response to temperature variations. |
