4 Troubleshooting
4.1 Low Dogleg Workflow
Low doglegs can occur due to Insufficient pressure drop across the pads, insufficient pad force, high
RPM, stick-slip, formation effects (Soft or unconsolidated formations or strong formation push), jamming,
bit selection, BHA design or tool failure.
When troubleshooting low dogleg, the following steps should be taken:
• Check Realtime Diagnostics (if available). PROPEFF should match PRDS_b. If not, jamming
or stick-slip could be reducing the Control Unit’s ability to hold a steady toolface. Don’t rely on
LTRPM (lower torquer RPM) alone as this may not flag.
• Reduce RPM. Attempt to get as close to 100 as possible but be careful not to allow stick-slip to
initiate, which will further reduce DLS response.
• Increase Pad Pressure. Exceeding the recommended range for X6 or Orbit increases the
likelihood of damage to the tool and should not be done without management approval.
• Reduce ROP. This is particularly helpful in fast-drilling formations. Reduce ROP to ~50% of
maximum attainable ROP
4.2 Anti-Jamming Procedure
The nature and size of the debris/ particles causing jamming events are different and require differing
steps to address the problems. Primary failure causes are:
1. Jamming of the impeller relative to the collar. Typically caused by large scale debris such as stator
rubber from motors, plastic tie wraps and other foreign items.
2. Jamming of the magnet housing relative to the torquer body. Typically these events are caused by
fine grade material dropping out of the mud system as the fluid passes across the torquer assembly.
Failures have been found due to LCM, barite, clay / shale and metal filings.
3. Blockage of the bias unit filter assembly. Typically due to LCM material. Failures of this nature are
rare as the filter is designed to be self-cleaning, however problems may occur depending on the pill
mixture being pumped
When it is confirmed that the PowerDrive tool is jammed and the tool has lost its directional function, the
following anti-jam attempts can be tried at the rig site. The steps are independent and repeatable by
itself and shall not be all performed at one time. An evaluation of the result after each attempt must be
done before moving to the next step:
1. Pump the tool at maximum flow (within the operating range of the tool) for 15 minutes.
2. Attempt to turn on the tool by bringing the flow up as fast as possible up to maximum drilling flow.
3. Pump a low vis sweep immediately followed by a high vis sweep. Sweeps can range from 20-30bbl
depending on hole conditions.
• Low Vis Sweep includes the following:
o Drop Vis 15-20 seconds
o For OBM – Dilute with Diesel
• High Vis Sweep includes the following:
o Increase Vis 10-20 seconds
o 5-10 Sacks of PURE Non-Metallic Graphite ***Check for metal with a magnet***
o Mud Weight should stay the same as the MW in the Tanks.
4. Pump water pill off bottom to dissolve any un-mixed additive.
5. Before you pump the Hi/Low vis pills, confirm with the mud engineer that no additional weighting
agents have been used. This may require adjustment of the flow rate to avoid over pressuring the
seals.
6. Attempt to turn on the tool by bringing the flow up as fast as possible up to maximum drilling flow.
7. Attempt to turn on the tool using conventional techniques like recycling the pumps, surging the drill
pipe etc.
8. Start at minimum flow and keep increasing the flow rate in five equal increments up to reaching
maximum drilling flow
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