Dynamic Under/Overbalance: A Review of the Current Practices in Block 15

Completion with anchored guns instead of killing techniques have been used extensively in Ecuador since 2008, completing 111 works to date only in Block 15. During this process several continuous improvement practices as well as new completion techniques were implemented including: Job design improvements: Well integrity analysisPenetration and Flow profile analysis on a foot by foot basisOptimization of the current designs by comparing dynamic under/over balance pressure recording with the simulation resultsPost audit of the calculated vs actual productivity Operational improvements: No fluid loss control used in workover operationsUp to two days of early production due to control fluid does not go into formation.Cost reduction since no special control fluid is used when perforating with static/dynamic underbalance and anchored guns.Minimal fluid loss control when perforating with anchored guns (small overbalanced perforating).New dual concentric completion architecture with anchored guns on the lower sands.The use of anchored guns in reentry wells with 5 ½" casing.Rig time saving when running anchored guns in monobore completionNew perforating procedure in monobore completion by activating anchored guns when ESP is running in hole, then pump is placed to the designed depth, this new operational sequence helped to prevent ESP damage due to high pressure is needed to activate firing head during workover operations when a low pressure reservoir is perforated. Productivity improvements: Significant reduction in both perforating and completion skins using static and dynamic underbalance. This paper shows different case studies of completion and perforating designs that enabled to reduce skin as well as completion time in Block 15. A new completion procedure using anchored guns with dual concentric completion is also described.