the computer 120 the temperature measuring device 62 may be used to measure the fluid temperature in the annulus 146 at this time as the operation of the invention may be conducted in a dynamic manner the temperature of the fluid drawn through the t head connector 80 is effectively the temperature of the fluid in annulus 146 the fluid temperature determined by temperature measuring device 62 is reported to the computer 120 the valve 68 is then placed in the closed position preventing further fluid communication between the annulus 146 and the piston fore chamber 22 the piston 16 is moved away from the closed valve 68 causing an effective axial expansion of the piston fore chamber 22 with the result being a partial vacuum in the piston fore chamber 22 there is no practical resistance to the movement of the piston 16 as the tube 92 is in fluid communication with the after chamber 24 the piston 16 is then driven toward the closed valve 68 driving of the piston 16 compresses the fluid in the piston fore chamber 22 thereby forming a compressed fluid having a greater pressure and temperature than the fluid in the annulus 146 typically it is desirable that the pressure of the compressed fluid in the piston fore chamber 22.