OPTIMIZING WELL INTERVENTION
Real-time force monitoring
improves CT drillout efficiency
Interactive tubing force analysis models,
real-time data overlays reduce stuck pipe, NPT
BY JESSICA STUMP, TRAVIS THOMAS AND COLT ABLES, NOV
Considerable progress has been made in
advancing methods and procedures for
well intervention operations with coiled
tubing (CT). However, stuck-tubing events
are still common in post-fracturing drill-
outs. Most analysis happens after these
incidents have occurred, despite technol-
ogy allowing for real-time viewing and
engineering analysis of these operations.
Between 2005 and 2010, horizontal
drillouts became common in the Barnett
and Haynesville shale plays. The indus-
try rapidly standardized the operational
procedures for horizontal plug-and-perf
operations. The main standard operating
procedures (SOPs) transferred over were
weight checks to determine that CT was
safe and free. However, CT technology
used to analyze the operations in real time
did not follow suit at the same pace.
CT modeling software and data acquisi-
tion systems (DAS) were used specifically
to track string fatigue and record data for
post-job analysis. Most field operations
directly transferred vertical well SOPs to
horizontal well applications. As horizon-
tal well interventions became common,
each operation was pre-modeled with a
tubing force analysis (TFA). However, the
TFA was used to determine if the CT could
reach total depth (TD) but was not shared
with field operations.
Engineering tools like force monitors
have been available since 2014. However,
their use in North American operations
have been limited because multiple short-
cycle downturns removed engineering
resources from the field. The online migra-
tion capabilities of these engineering tools
have improved as the well site trans-
formed from largely remote to a data-
connected environment. The connection
of the subject matter expertise, which has
moved out of the field and into the office,
has allowed the most informed resources
to access critical operational data and
provide real-time engineering feedback
without ever having to be at the well site.
NOV’s CTES Cerberus intervention mod-
eling software for planning and perform-
ing CT operations now features cloud con-
nectivity to provide field operators, man-
agement and engineers with real-time
access to the same data. This enables
quick and inclusive operational decisions
to be made before potential issues occur.
Interactive TFA models in the software,
combined with real-time data overlays,
improve the efficiency of post-fracturing
intervention of horizontal wells with CT
and prevent problems currently analyzed
only after operations have been negative-
ly affected. Operational efficiencies can
be achieved with the following proactive
real-time engineering approaches:
• Use Cerberus to:
• Create a digital twin of the CT string
for calculating fatigue;
• Create a digital twin of a wellbore so
expected variables, such as dynamic
friction, pressures and temperature,
can be considered when applying cal-
culations in the TFA; and
• Create an Orpheus Force project (TFA)
to generate the expected weight ver-
sus depth;
• Run the Orpheus project to determine
the coefficient of friction (CoF) reduction
needed to reach plug back TD;
• Using historic basin data, determine the
acceptable deviations from the modeled
run in hole (RIH) and pull out of hole
(POOH) weights to ensure there is an
agreed-upon stopping point;
• Upload the Orpheus TFA into the CTES
Figure 1 (left): The TFA shows that during RIH (blue), the model
and weight indicators are good, but the friction increases
before the 0.30 lockup depth, indicating an underperforming
ERT. Figure 2 (above): The post-job TFA shows that after POOH
(green) began, the CT pulled heavy and became stuck. After
five days of circulating, the CT was freed and returned to the
surface. 42
M AY/J U N E 202 2 • D R I L L I N G C O N T R AC T O R