Pesca Pubblicazione scientifica Milling PosiSet Plugs with Coiled Tubing to Remove Zonal Isolation FILONE TECNOLOGICO TEMA produzione e cattura RIASSUNTO As part of the old time reservoir strategy to develope the Cusiana field in Colombia, several mechanical plug-back tools (MPBT) were set on Electric Line to isolate the deeper production reservoirs specially for water shut-off. After setting, the anchoring system keeps the tool in place while cement was placed also on Electric Line on top to provide higher differential pressure isolation between reservoirs.In the recent years and once the shallower production reservoir was depleted as previously planned, it was necessary to remove the isolation to comply with the updated reservoir strategy to produce the lower reservoirs. Coiled Tubing interventions were planned instead of a Workover rig for cost optimization purposes in order to mill the cement and those mechanical plug-back tools and reestablish access and production.At the beginning there were not many case histories of MPBT milling worldwide and several difficulties were observed in the first attempts. Milling time was high and not all interventions were as successful as expected. However a robust learning curve was created during the years allowing the current removal of MPBT plugs without major difficulty in terms of 2 to 3 hours. Tools used and operational procedure represents the key points of the strategy implemented. DATA Data di pubblicazione: 25/03/2014 AUTORI HESTER J GIL C TORRES M ENTE DI AFFERENZA EQUION ENERGIA RIVISTA SPE/ICoTA Coiled Tubing and Well Intervention Conference and Exhibition, 25-26 March, The Woodlands, Texas, USA