WELLBORE TRACTOR

摘要

A wellbore tractor system (100, 600, 300) comprising at least one slip unit (123, 634, 311, 413) for alternately and releasably anchoring the system within a wellbore or within a tubular member, the system having a component (101, 651, 327, 418) intended to be moved continuously or stepwise along the axis of the wellbore. When the system has two slip units, they may be powered alternately and in relation to each other so that the system provides continuous motion. Each slip unit is alternately clamped to the wellbore wall and released for longitudinal movement with the axially-movable system component. The units are spaced apart from each other, and the component being moved, to which a payload (158, 651, 324) may be connected, is driven axially relatively to the clamped unit.