Apparatus and method for sampling an earth formation through a cased borehole

摘要

An apparatus (12) is disclosed for perforating, testing and resealing casing (11) in an earth formation borehole (10). The apparatus is moveable through the casing. The apparatus can also be mounted on a wireline, on tubing (13) or on both. A perforating device is mounted in the apparatus for producing a perforation in the casing. The perforating device contains a flexible drilling means (18,19) that enables the drilling of perforations in the casing of lengths greater than the diameter of the borehole. The apparatus will usually contain components for hydraulic testing and sampling from the formation behind the casing. Also mounted in the apparatus is a device for plugging and resealing (25,26) the perforation with a solid plug. <IMAGE>