| 摘要 |
<p>A well jar (11) having an elongated body (14) with an axial passageway (15) and threaded connections (12, 13) for assembly into a string of well pipe. The body has a tubular mandrel (16) slideably mounted within a tubular barrel (17) with the annulus (18) therebetween exposed to well fluid. Fluid seals in the annulus provide an isolated chamber (22) containing a latch whereby the mandrel and barrel are selectively released for delivering an impact to the well pipe. The improvement to the jar comprises a plurality of elongated, resilient vibration snubbers (77) integrally carried by the mandrel and aligned longitudinally in the annulus (18) between the mandrel and the barrel. The snubbers slideably engage the barrel throughout its telescopic movement along the mandrel. The snubbers are circumferentially spaced apart about the mandrel with the intervening spaces forming flow channels in the annulus to accomodate well fluid flows when the jar is mounted in the string of well pipe being rotated in the well bore.</p> |
