Recover wellhead in deepwater P&A operation
During a P&A operation offshore Western Australia, Woodside
Petroleum needed to complete a wellhead recovery operation in deep water. The
company wanted to save a trip by leaving the wear bushing in place.
Deploy ProLATCH wellhead retrieval system to simplify the
operation
Schlumberger used the ProLATCH system for the deepwater operation. The
system does not require weight to be slacked off into a marine swivel, thereby
reducing the bowing effect in the workstring. Additionally, the risk of fatigue
failure is minimized because the string stays straighter, eliminating rotating
bending fatigue. The ProLATCH system simplifies the mechanical P&A
operation and eliminates the need for future service by avoiding seal bores as
well as catching wellheads and casing hangars.
The system comprises a rotating spear configured for 9 5/8-in casing
hanger and wear bushing, a hydraulic pipe cutter, and nonrotating stabilizers
placed above and below the pipe cutter. The workstring can be easily removed
from the wellhead at any time, and no overpull is required.
Saved USD 600,000
Woodside recovered the wellhead and saved a trip by running the rotating
spear configured to pass the wear bushing. The 13 3/8-in and 20-in strings were
severed in 1.5 hours of cutting operations, and the wellhead rotated,
confirming that both strings had been severed below the mudline. Overpull in
the wellhead confirmed that the casing strings and guide base were free. The
entire operation was completed in approximately 13.5 hours, saving USD
600,000.
