Coiled Tubing Scale Milling on a Subsea Well

CHALLENGE

A caliper run had shown an increasing trend of thickening scale from circa 7500ft to the logging BHA hold up depth. Due to the quantity of scale present, coiled tubing was mobilised to provide access to the reservoir and to allow for further perforations to be added and thus increase well production.
 

SOLUTION

Altus Intervention mobilised a coiled tubing and pumping package along with an extensive range of thru tubing options at short notice.  Heavy lifts were mobilised the same day as the request was received from the client and all required equipment was offshore five days later. 

RESULTS

The operation was successfully completed with the following key achievements:

• Well objectives completed with minimal downtime  
• 2193ft of hard scale (calcium carbonate) milled over four runs creating 3.8” ID access to reservoir
• 3 x cal acid treatments pumped to soften scale
• 97,000 running feet of coil performed
• Access was gained for the perforating BHA to be run