During start-up, the well became unstable and ceased flowing. Well performance during subsequent opening trials and build-ups indicated that a plug must have been established, initially between the bottom-hole gauge and the shallowest fractured zone. The top plug moved further up the well during the repeated opening trials. The blocking of the well resulted in plugging of surface bleed lines on the flow line and surface equipment. A hard and impermeable plug was tagged at approximately 92m MD RKB. BHP data suggests that there is still plugging material between the down hole gauge and the uppermost perforation.
The solution was to perform a wellbore cleanout using Coiled Tubing, accompanied by a FourPhase 5K DualFlow unit allowing safe removal of fracturing proppants. Minimal real estate and and deck load limitations were critical, therefore a 5K DualFlow next generation hydrocyclone desander (2m X 2m X 3.2m) was mobilized.
The DualFlow 5K unit uses next generation solid removal technology that was developed and engineered by FourPhase and is the leading solids removal solution on the market. The DualFlow is used in surface applications where solids might be present during production or intervention cleanup applications.
The wellbore cleanout and separation of solids from Oil Based Mud was a great operational success. The DualFlow unit showed good capacity and separation abilities on oil based mud. A total of 1074 kg of solids was separated throughout the operation.