Cleaning barium sulfate scale from SSSV
On a platform in the UK North Sea, routine integrity testing of Subsurface Safety Valves (SSSV’s) indicated that one specific valve was faulty. It was established that the failure to operate was due to a buildup of barium sulfate scale, which is an extremely hard compound to remove.
Traditionally, the operator would remove barium sulfate scale using coil tubing; however, a large crew and equipment footprint was not feasible for this intervention. With the prospect of having the well closed in for a prolonged period caused the operator to look for an innovative alternative.
Based on previous experience gained using Welltec® to recover sand from another well, an intervention was planned using the Well Tractor® combined with the Well Cleaner® Wishbone Honer, a rotating brush to clean the valve recess.
Upon the second run, the scale was removed; the valve was tested and returned to full functionality.
• Significant cost-saving due to applying wireline service.
• Quicker rig-up and run times.
• Well downtime reduced by 14 days.
• Avoided the use