Method and apparatus for balanced pressure sampling

摘要

A method of sampling fluid from a rock formation penetrated by a borehole includes positioning a downhole tool having a flow line in the borehole, establishing an inlet port through which fluid passes from a first point in the formation into the flow line, establishing an outlet port through which fluid passes from the flow line into a second point in the formation, and passing fluid between the formation and the flow line through the inlet and outlet ports.