Page 129 - Well Control for Completions and Interventions

Completion Equipment 121

Figure 3.27 Chemical injection mandrel. Illustration courtesy of TCOt group.

3.14 DOWNHOLE PRESSURE AND TEMPERATURE
GAUGES

Downhole pressure gauges can be a valuable source of data for res-
ervoir engineers, and are widely used in offshore wells, especially subsea
wells. Having accurate and up-to-date reservoir pressure data can be
invaluable if preparations need to be made to kill a well in advance of a
workover. Accurate pressure data can also reduce the risk of overpressure
during interventions where fluid is pumped into the well, for example,
scale inhibitor squeezing or stimulation treatments.
A basic quartz gauge will provide continuous surface monitoring
of pressure and temperature at gauge depth. The gauge is mounted in
1
a mandrel that is run with the completion. A /4v hollow steel control
line containing an insulated electrical conductor is attached to the
gauge and clamped to the outside of the tubing as the completion is
run. After the completion has been landed, the cable is fed through
the tubing hanger and exits the wellhead using electrical penetrators
(Fig. 3.28).

Figure 3.28 Gauge mandrel. Image courtesy of Omega.