Patent ID: 6439307
Filing Date: 2002-08-27
Classification: E21B

Abstract:
An apparatus for controlling pressure on a pressurized sample of formation fluid collected downhole in a well, comprising:a housing having a hollow interior; a piston within said housing interior for defining a fluid sample chamber, wherein said piston is moveable within said housing interior to selectively change said fluid sample chamber volume; a pump for delivering a sample volume of formation fluid into said fluid sample chamber by displacement of said piston in a first direction; and, a valve that is operatively responsive to movement of said piston in said first direction for admitting pressurized wellbore fluid against said piston to bias movement of said piston in a second direction wherein said second direction piston movement pressurizes the fluid sample within said fluid sample chamber so that the formation fluid sample remains pressurized when the fluid sample is moved to the well surface.