Abstract: The present invention relates to an extraction, analysis and measuring method and system intended for constituents carried along by a well fluid during drilling operations. The system comprises in combination: draw-off means (4) for taking a volume of the fluid, extraction means (3) for extracting in vapour form the constituents contained in the fluid, comprising a space placed under underpressure, a transport line (14), sampling means (27) comprising a sampling loop allowing to take a determined amount of the vapors circulating in the line, distribution means (40) that inject the amount into analysis and measuring means (31), control means (33) for controlling the temperature of the sampling means so as to prevent condensation of said amount of vapors.

Abstract: The fluids to be studied are placed in a chamber (13) of variable volume delimited by a piston (5) that can be moved by hydraulic device (24) in a cavity of a body (1). An endoscope (18) allowing to view the inside of the chamber and notably to see the orifices of two diametrically opposite pipes (14, 15) that communicate the cell with the outside is placed behind a transparent porthole (8) closing the end of the chamber opposite the piston. The body (1) can swivel about a pin (26), which allows achievement of equilibrium and also to draw off a particular phase of a stratified multiphase fluid by placing the orifice of one of pipes (14, 15) within this phase. A pressure detector (19) is included in the wall of the piston so as to decrease practically any dead volume likely to distort the measurements. A single body can contain two cells placed side by side, at least one having a transparent wall. The device can be used for studying fluids, notably petroleum fluids.