High-tension risk mitigation to improve safety, efficiency,
reliability, and sticking avoidance
Withstanding the intense peak shock loads generated downhole called for
the combination of a strong weakpoint, high-tension logging unit, and
ultrahigh-strength cable. The XR-Perf expanded-range wireline perforating
system provides these robust capabilities by integrating the latest
industry-leading cables, units, and perforating accessories to streamline
perforating logistics while avoiding conventional reliance on pipe
To address the expected high pull and shock, TuffLINE 18000
torque-balanced composite wireline cable was specified. Encapsulation of the
cable armor in polymer prevents rotation, effectively permanently fixing the
ends of the cable to raise the ends-free breaking strength to 27,000 lbf. A
high-tension offshore logging unit using TuffLINE 18000 cable can provide
instantaneous pull of up to 18,000 lbf for stick prevention and mitigation
without a capstan. Multiple high-tension operations can be conducted, including
cycling and jarring, without compromising the integrity of the cable or having
to interrupt operations to balance the torque of the cable's inner and outer
Coupling the high-tension unit and TuffLINE cable with the strongest
possible weakpoint specifically designed for the operation enables the
conveyance of heavy gun strings while still providing the option to release in
the event of a stuck gun situation.
Thirty hours of deepwater rig time saved with TuffLINE cable
The interval to be perforated was from 5,625 to 5,665 m in a
9.9-lbm/galUS borehole fluid and 9,500-psi hydrostatic pressure environment.
Schlumberger engineers used proprietary modeling to accurately calculate the
maximum payload and number of guns to be conveyed per trip by the XR-Perf
system for perforating the 40-m interval without compromising safety or service
The field crew completed the entire operation including rig-up and
rig-down and three perforating runs in a total operating time of only 18 h.
This saved the operator approximately 30 h of rig time, which is worth USD 1
million in this deepwater environment.
In addition to greater efficiency, this first perforating job with the
XR-Perf system and TuffLINE 18000 cable for the operator also reduced risk.
TuffLINE cable's high stretch coefficient significantly lessened the amount of
shock transferred to the weakpoint in comparison with conventional 7-48
high-strength cable, improving shock mitigation and reducing the likelihood of
an unintentional pull-off as a result of gun shock.