5. Flow Assurance Challenges
• Uninsulated flowline
• Pigging operations unavailable
• Water injection tree
– Limited chemical injection points
• Assumed similar fluid characteristics to offset well
– No down-hole samples obtained
5
10. Bullhead Operation
• Pumped 1000 gals of Xylene down flowline from platform
• Impermeable paraffin blockage formed
Subsea
Flowline
Pressure
Boarding
Pressure
Time Period Shown: 5 Months
10
14. Snubbing Unit
• Advantages
– Rotation capability
– Circulation
– Direct solvent
application to blockage
– Proven industry method
• Risks
– Flexible flowline integrity
– Maneuverability of
curvature in flowline
14
15. Flowline Curvature Risk - Mitigation
15
• Torque and drag modeling shows snubbing unit
capable of operating through bend in flowline.
• Provided parameters while running in hole with work
string.
16. Solvent Selection
• Solvent Selection:
– Diesel
• HSE
• Disposal
• Cost Effective
– Effectiveness of diesel circulation in question at
lower temperatures
16
17. Mechanical Remediation
• Pipe in pipe modeling
completed
– Significant heat loss
expected
• Removal of paraffin
using 3” O.D. brass
nozzle
17
