Robust gauge system
With the drillstem test string, Schlumberger ran a reliable WellWatcher
permanent gauge system consisting of three quartz pressure and temperature
gaugesrated for 25,000-psi and 425 degFdeployed using one dual and
one single solid gauge mandrel and welded Intellitite electrical dry-mate
connectors. The proven reliability of the welded connector technology used in
this system was considered a key advantage over wireline-deployed gauge options
to acquire this data.
The electrical signal was routed through the SenTREE high-pressure
subsea well control system on the seafloor. At the surface, the pressure and
temperature information was monitored by Chevron and Schlumberger personnel in
real time during well test operations. This real-time surface readout was
critical to the safety and efficiency of this well test.
Uninterrupted data stream
The Schlumberger gauge system transmitted critical downhole annulus and
flow-stream bottomhole pressure and temperature information uninterrupted for
48.5 days. The well test averaged 6,000 bbl/d of oil.
The system facilitated onsite transient analysis of the downhole flowing
and buildup data, allowed engineered execution of the well test, maximized well
test flow rates while minimizing the risk of excessive drawdowns, minimized the
rig time required to fulfill the objectives, and supplied invaluable assistance
to drillstem test specialists.
The Schlumberger gauge system transmitted critical downhole annulus and flow-stream bottomhole pressure and temperature information uninterrupted for 48.5 days.