Well pressure activated pack-off head

摘要

A well pressure activated pack off head comprising a hollow body formed for coaxial connection to the wellhead which provides for unobstructed passage of a data transmitting wireline therethrough. Disposed coaxially within the hollow body is a pack off rubber with a passage formed along its longitudinal axis for passage of a data transmitting wireline. Located below the pack off rubber is a piston in pressure communication with the wellbore. High pressure inside of the wellbore squeezes the piston against the pack off rubber and compresses it tightly around the wireline. A pressure seal is formed between the pack off rubber and the wireline when the pack off rubber is sufficiently compressed by the piston.