The original plan was to pull the bridge plug free and then releasing it in a 9-5/8” OD section. This would allow production around the released plug. But a caliper run showed a restriction in the liner 985 ft (300 m) above the plug, preventing the use of a pulling tool or the standard equalizing prong recommended by the plug supplier. Having confirmed that the bridge plug could not be pulled, the team adjusted the strategy and decided to equalize and produce through the plug. Welltec® designed a custom prong, which could pass the restriction and enable production through the plug equalizing ports. Despite applying 33,000 lbs downward force to the sleeve, it would not stay open. The team then decided to mill through the plug to create contact with the lower zone. Welltec delivered a tailored solution consisting of a 1” OD, 4.3 ft (1.3 m) long drill bit fitted on the Well Miller®. The toolstring was designed to penetrate the entire bridge plug and to mill through the plug’s bullnose. The operation was performed from a Riserless Light Well Intervention (RLWI) vessel.
This operation was a world’s first and successfully reestablished communication with the lower zone. After the intervention, oil production increased significantly (200 Sm3/d), while gas and water rates decreased. This case is a testament to the benefits of strong cooperation between operator and service provider in developing tools and methods to achieve better oil recovery and successful interventions by pushing the limits of what can be done on e-line. The ability of Welltec to think creatively, adapt and react quickly in facing this unexpected situation offshore saved valuable time as the operator avoided having to mobilize rig and CT equipment or drill pipe to mill through the restriction.