Formation evaluation tool and method for use of the same

摘要

A downhole tool for early formation evaluation is disclosed. The tool comprising a housing having a fluid passageway and a mandrel having an interior volume. The mandrel is slidably disposed within the housing and has a plurality of axial positions relative to the housing. The mandrel is slidably operated responsive to the fluid pressure within the interior volume such that the mandrel cycles through said plurality of positions. A retractor sleeve is operably associated with the housing and the mandrel for engaging the mandrel and slidably urging the mandrel relative to the housing. The retractor sleeve is slidably operated responsive to the fluid pressure within the interior volume. A seal assembly is slidably disposed around the housing. The seal assembly includes a floating piston. A chamber is formed between the housing and the floating piston that is in communication with the fluid passageway of the housing such that the fluid pressure within the interior volume enters the chamber and slidably urges the seal assembly, thereby stretching the seal assembly.