Wellhead Retrieval System Saves USD 600,000 in Single-Run Offshore P&A Operation

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.