Patent ID: 8109157

Claim:
A downhole apparatus for characterizing fluids withdrawn from a formation, comprising: a primary flowline for conveying the fluids therein, the primary flowline comprising a first end for allowing the fluids to enter and a second end for allowing the fluids to exit; a bypass flowline in fluid communication with the primary flowline, the bypass flowline comprising a first port for allowing the fluids to enter and a second port for allowing the fluids to exit, and the first and second ports of the bypass flowline being separated; a fluid control system interconnecting the primary flowline and the bypass flowline, the fluid control system having a single valve assembly with a first position interconnecting the first end of the primary flowline with the second end of the primary flowline, such that the fluids flow directly in the primary flowline, and a second position interconnecting the first end of the primary flowline with the first port of the bypass flowline, and interconnecting the second end of the primary flowline with the second port of the bypass flowline, such that the fluids flow, via the bypass flowline, in the primary flowline; and a circulation pump for circulating the fluids in the closed loop of the circulation flowline, wherein the first position of the fluid control system forms a circulation flowline to capture and to circulate the fluids in a closed loop.