Page 24 - Geochemistry of Oil Field Waters

SAMPLING AT THE FLOW LINE 13

sample should be analyzed immediately. If this is not possible, cool or freeze
the sample.

Sampling at the flow line
Another method of obtaining a sample for analyses for dissolved gases is
to place a sampling device in a flow line. Fig. 2.3 illustrates such a device.

I
Valve -
container

Pipe line

f Rubber -

Valve

tube

Fig. 2.3. Flow-line sampler.

The device is connected to the flow line, and water is allowed to flow into
and through the container, which is held above the flow line, until 10 or
more volumes of water have flowed through. The lower valve on the sample
container is closed and the container removed. If any bubbles are present in
the sample, the sample is discarded and a new one is obtained.