The dual stripper device of the invention has a hollow body formed for coaxial connection to the wellhead which provides for unobstructed passage of a slick cable, such as a data transmitting cable which transmits data in real time to the well surface. Disposed coaxially within the hollow body is a resilient wiper element with an internal bore formed along its longitudinal axis for passage of the slick cable. A hydraulically actuated piston applies a compressive force to the wiper element so that a pressure seal is formed between the wiper element and the cable when the wiper element is sufficiently compressed by the piston. The seal can be maintained during dynamic movement of the slick cable through the wiper element. A mirror image backup wiper assembly can be actuated in the case of failure of the first wiper assembly.