Patent ID: 7584786
Filing Date: 2009-09-08
Classification: E21B

Abstract:
1. A probe assembly for employment by a downhole tool disposed in a wellbore surrounded by a layer of contaminated fluid, the wellbore penetrating a subsurface formation having a virgin fluid therein beyond the layer of contaminated fluid, the probe assembly comprising: a probe body extendable from the downhole tool; an outer packer disposed in the probe body for sealingly engaging a first portion of the wellbore, the outer packer having a bore therethrough; an inner packer disposed in the bore of the outer packer and forming an annulus therebetween, the inner packer being extendable beyond an outer surface of the outer packer for sealingly engaging a second portion of the wellbore within the first portion of the wellbore; a first inlet in the probe body fluidly communicating with the annulus and for admitting one of virgin fluid, contaminated fluid and combinations thereof into the downhole tool; a flow line fluidly coupled to the first inlet and including a filter for filtering particles from the fluid, the filter comprising a cleaning device associated therewith; a second inlet in the probe body fluidly communicating with the inner packer for admitting virgin fluid into the downhole tool; and a flow line fluidly coupled to the second inlet and including a filter for filtering particles from the fluid, the filter comprising a cleaning device associated therewith; wherein a sampling tube is operatively connected to the inner packer; and further comprising a piston disposed within the sampling tube, wherein the piston comprises an axial passageway therein and one or more perforations in a sidewall thereof for conducting virgin fluid admitted to the sampling tube to the axial passageway, the axial passageway fluidly communicating with the second inlet in the probe body.