Patent ID: 8561698

Claim:
An apparatus, comprising: a downhole tool configured for conveyance within a wellbore extending into a subterranean formation, the downhole tool comprising: a sample chamber configured to store a formation fluid sample and comprising a piston defining a first chamber and a second chamber, wherein the first chamber comprises an injection fluid having a first pressure, and wherein the second chamber is in selective fluid communication with a fluid source having a second pressure that is greater than the first pressure; a flow line configured to provide fluid communication between the formation and the first chamber; and a valve system disposed within the sample chamber and in fluid communication with the flow line between the first chamber and the formation and comprising: a first valve configured to regulate flow of the injection fluid from the first chamber to the formation in response to selective fluid communication between the fluid source and the second chamber; and a second valve disposed in parallel with the first valve and configured to permit the injection fluid to flow into the first chamber; wherein the valve system is disposed within a separate portion of the sample chamber from the first chamber and the second chamber, and wherein movement of the piston directs the injection fluid through a fluid port into the separate portion.