One embodiment provides a system for facilitating document printing from a portable device. The body is partially or entirely curved, partially or entirely covered with an anchoring material for supporting tissue ingrowth, and designed for subcutaneous tissue implantation. The wellbore system further comprises an annular body of a- resilient material arranged in said annular space and extending substantially the length of said portion of the tubular conduit surrounded by the salt layer. The cylindrical portion is set to have a distance between the center axis line and the outside surface to be loosely fitted in the coupling hole at the first rotational position and to be clamped between hole walls of the coupling hole at the second rotational position.