| 摘要 |
A propulsion device for a pig (1) of the type used in downhole operations, typically in pipes (2) in connection with petroleum production, and where the pig (1) comprises a first main body (4) and at least one second main body (6) telescopingly supported to the main body (4), and where at least two of the main bodies (4,6) are equipped with gripping devices (18, 18') designed to releasably grip the inside of the pipe (2).
|
