Abstract: A method includes conveying a wireline toolstring into a wellbore to perform a downhole operation, wherein the wireline toolstring has a single packer disposed thereon. The method also includes positioning the wireline toolstring in the wellbore adjacent a zone of interest, wherein the zone of interest has a barrier is located at one end of the zone of interest and the wireline toolstring is positioned such that the single packer is located adjacent the zone of interest such that the zone of interest is between the single packer and the barrier. The method can also include setting the single packer and performing a wellbore operation.

Abstract: A method of evaluating a fluid from a subterranean formation drawn into a downhole tool positioned in a wellbore penetrating the subterranean formation is provided. This method involves drawing fluid from a formation into a flowline, measuring at least one property of the fluid in the flowline and detecting stabilization of the property or properties of the fluid in the flowline. An electrochemical sensor for measuring contents of a fluid or gas at high pressure and/or high temperature may be used.

Abstract: A method of evaluating a fluid from a subterranean formation drawn into a downhole tool positioned in a wellbore penetrating the subterranean formation is provided. This method involves drawing fluid from a formation into a flowline, measuring at least one property of the fluid in the flowline and detecting stabilization of the property or properties of the fluid in the flowline. An electrochemical sensor for measuring contents of a fluid or gas at high pressure and/or high temperature may be used.