Patent ID: 6588502
Filing Date: 2003-07-08
Classification: E21B

Abstract:
A well pressure activated pack off head for use in conjunction with a wellhead situated on a hydrocarbon producing wellbore comprising:a hollow body formed for coaxial connection to the wellhead and for providing unobstructed passage of a data transmitting wireline therethrough; a pack off rubber having an axial passage therein formed for passage of a data transmitting wireline therethrough, said pack off rubber is coaxially situated within said hollow body; a pack off bushing having an axial passage therein formed for passage of a data transmitting wireline therethrough, said pack off bushing is coaxially situated within said hollow body; a piston coaxially situated within said hollow body and having an axial passage therein formed for passage of a data transmitting wireline therethrough, said piston having a wellbore pressure side and an ambient pressure side, said wellbore pressure side in pressure communication with said wellbore, said ambient pressure side is in pressure communication with the ambient space surrounding said pressure pack off head; wherein said pack off rubber is located between said pack off bushing and said piston; and a dampening system that controls the rate of force applied to said pack off rubber by said piston, said dampening system comprising a restriction orifice for regulating the fluid flow from the ambient side of said piston to the ambient area surrounding said pressure pack off head.