WIRELINE DOWN JAR

摘要

A jar assembly for use downhole includes a housing, a piston assembly slidable within and selectively coupled to the housing, a mandrel assembly coupled on a lower end of the piston assembly, and an anvil coupled to an end of the mandrel assembly opposite the piston assembly. The jar assembly is deployed in a wellbore by a conveyance means that couples with the housing. A hydraulic circuit in the piston assembly activates a latch for decoupling the piston assembly from the housing; when decoupled, the housing slides downward and impacts the anvil to generate a jarring force. The jar assembly is re-cocked by raising it with the conveyance means.

主权项

1. A jar assembly comprising:
an annular housing; an elongated mandrel in selective telescoping relationship with the housing; an anvil coupled with an end of the mandrel; a piston assembly coupled with the mandrel and comprising a latch assembly that is selectively reconfigured from a latching position coupled to the housing to an unlatched position, and that is slidable in the housing when decoupled from the housing, so that when substantially all the weight of the jar assembly is supported by the mandrel, the latch assembly moves into the unlatched position, and the housing slides axially with respect to the mandrel into impacting contact with the anvil.