| 摘要 |
<p>The present invention comprises a retrievable gravel packer for circulation and squeeze type gravel packing. The gravel packer includes a compression-set packer element, a J-slot assembly to releasably maintain the gravel packer in an unset mode, a ratchet assembly to releasably lock the gravel packer in a set mode, an intake passage to receive fluid from a tubing string, a return passage to receive fluid from a gravel screen below the gravel packer, a circulation passage extending from the exterior of the gravel packer to intake passage, a closeable crossover assembly to receive fluid from the return passage, relief ports between the intake passage and the return passage, a first valve for closing said intake passage from said circulation passage, a second valve for opening communication through said relief ports, a check ball at the lower end of the gravel packer, and a check ball release assemblyfor selectively releasing the check ball from the gravel packer.</p> |
