9 out of 10 SSSVs restored in a single campaign

Challenge

The producing and injecting wells in the client’s offshore field experience severe calcium carbonate (CaCO3) scaling during operation, affecting the functionality of the sub-surface safety valves (SSSV). The client’s usual method of treatment was spotting acid using coiled tubing. The client was looking for a solution that would reduce costs, footprint, and time, while also improving the intervention’s success rate. The SSSV issues ranged from immobile flow tubes to flapper valves stuck open or stuck closed. Based on BlueSpark’s success in clearing scale across SSSVs in other regions, the customer decided to mobilize BLUESPARK® for the multi-well project.

• Offshore
• Depth: 1780 – 3000 ft
• Temperature: 30-50 °C
• Deviation: up to 50 °
• Tubulars: 4.5 – 7 inch

Solution

Remove scale from SSSV to restore functionality using electro-hydraulic pulsing technology.

• When possible, a pre-treatment camera was run to evaluate the extent of scale
• The BLUESPARK® 275 tool was run on third-party E-Line to the treatment interval of each well
• Two pulsing passes were made over an interval of 12 to 20 ft, delivering 3000 pulses in an average operating time of 12.4 hours
• Another camera run was made to determine the effectiveness of the treatment
• The functionality of the flapper valve was tested, including an inflow test

Outcome

• A total of 10 wells had the SSSV treated, consisting of 7 producers and 3 injectors
• The SSSVs of 9 of the wells showed improved functionality and passed the inflow test
• Images from the camera showed cleaning of the surfaces treated (example images at right)
• The client was extremely pleased with the efficiency & outcome of the operation and the value provided by the treatment method. The client continues to add more wells to the project.

Before & After BLUESPARK® -Treatment Above Flow Tube

Before & After BLUESPARK® -Treatment of Flow Tube & Flapper