Down hole well tool with rolling means

摘要

A down hole well tool for installing a casing or liner in a well bore includes a tool unit and an expansion module for expansion of the casing or liner. The expansion module has at least two sets of rolling means arranged along an axial direction of the expansion module, and each set of rolling means is provided at an outer circumference of the expansion module. The diameter of the rolling means decreases at least between the two sets along the expansion module, providing the expansion module with a decreasing diameter in an axial down hole direction of the well bore.

主权项

1. A down hole well tool for installing a casing or liner in a well bore, wherein the down hole well tool comprises:
a tool unit; and an expansion module for expansion of the casing or liner having a plurality of rolling units arranged along an axial direction of the expansion module and at an outer circumference of the expansion module, the diameter of the rolling units decreasing along the axial direction of the expansion module to provide the expansion module with a decreasing diameter, each of the rolling units comprising a pair of roller sets, each roller set comprising a plurality of wheels supported on bearings, wherein the roller sets of each pair of roller sets are displaced in a circumferential direction relative to each other and the wheels are supported to rotate on axes that are substantially perpendicular to an axial axis of the tool.