Sealed jar

摘要

A device has a first, lower sub housing, a second, upper sub housing, and an extensible joint connecting the lower sub housing to the upper sub housing. A pressure equalization chamber is attached to the upper sub housing and demarcates an inner zone including an internal mechanism of the extensible joint, and an outer zone open to well bore fluids and pressure. A fluid barrier moves within the pressure equalization chamber in response to changes in well bore pressure to alter a volume of the inner zone to equalize a pressure of the inner zone.

主权项

1. A device, comprising:
first and second sub ends having an extensible joint therebetween containing a latching mechanism that allows the joint to expand from a contracted position to an expanded position in response to a predetermined tensile force on the upper and lower sub ends; and a sealing chamber isolating the latching mechanism from well bore fluids, the sealing chamber defining a first volume that is exposed to well bore fluids and a second volume that is isolated from well bore fluids by a flexible barrier and is in fluid communication with an internal volume of the extensible joint; wherein the flexible barrier moves in response to well bore fluid pressure to alter the second volume to equalize pressure inside the internal volume of the extensible joint to the pressure of the well bore fluid; and wherein the flexible barrier moves in response to extension and contraction of the joint to alter the second volume to equalize pressure inside the internal volume of the extensible joint to the pressure of the well bore fluid.