Water and gas sampler probes are used to take a discrete sample of well fluid at a particular depth and to return it uncontaminated to the surface.
Principle of Measurement:
Water sampler: The water sampler includes a chamber incorporating motor-actuated valves at the top and base. While the probe is being lowered into the borehole, the valves are held open, allowing well fluid to flow freely through the chamber. At the desired depth, the motor is activated under surface control, closing the valves to seal the chamber and contents ready for retrieval.
Gas sampler: The gas sampler is designed to retrieve uncontaminated samples of well fluids comprising or containing gas whilst maintaining the original well pressure. The probes contain a sealed sample chamber with a moveable piston and motor-actuated valve. Prior to logging, the piston is withdrawn manually and locked into position, leaving a partial vacuum within the sample chamber. For sampling, the valve is opened under surface control, allowing the well fluid to enter the chamber. The valve is then closed, enclosing the sample under ambient pressure. At the surface, the fluid can be transferred while still under pressure to a suitable container for analysis.