Deep Oil Sampling
The STO RMNTK 153-39.2-002-2003 standard is observed in performing of
such an operation.
The optimum mode of operation of a well (more often through a small
diameter choke) is chosen for correct determination of a sampling point in
a flowing well in order to rise pressure at the sampling point than it is
in gas saturated oil. Prior to sampling, the pressure, temperature and
fluid density gradient is recorded along the entire borehole by off-line
manometers and geophysical instrumentation.
A packer for isolation the annular space is used in sampling of wells
with absence of flowability as well as a check valve which closes the inner
space of tubing. Sampling is carried out during registration of fluid level
build-up curves (FLBC) after the check valve closing. Sampling devices
may be run into a well with tubing or after running of tubing on a
geophysical cable in a set of geophysical instrumentation and a check
valve installed above the sampling devices. The operation of devices is
done at the cost of cutting of studs in the control valve mechanism at
reaching of a calculated pressure value or remotely at triggering a pulse
through a geophysical cable.