Coretrax was approached to provide a solution for a well abandonment where annular cement had been confirmed, meaning that the completion did not need to be fully recovered. Aside from the associated rig time when recovering the completion, the cost of disposing completion tubing is estimated at around £250,000 – more should there be NORM contamination present. By removing the need to recover the full completion, significant time and costs can be saved.
Solution
Taking into account the workscope, Coretrax identified that the best solution for our customer would be to use a CX-Tubing Hanger. The CX-Tubing Hanger is easily set with left hand rotation and can hang 400,000lbs tubing weight beneath, making it the optimum solution for this application. Additionally, Coretrax suggested including an isolation facility in the tubing hanger assembly so that it could also be used as a base for cement for an environmental barrier. As this solution provided cost and time savings, Coretrax was awarded the work and it was successfully completed in Q1 2017 and has continued to be used in the UK sector since.
Operation
The upper completion was recovered to the safety valve and was pulled to surface. The tubing hanger and tubing crossover was then installed and run to depth on drillpipe before the hanger were set as per procedure and tagged to confirm depth. A ball was dropped from surface to isolate the lower string and cement was then displaced on top of the hanger, providing a one trip abandonment system delivering further cost savings to our customer.
Achievements
This equipment saved 18 hours rig time facilitating an effective and efficient well abandonment.
Key Benefits
- Huge reduction in the completion disposal costs.
- Cement can be displaced immediately after disconnecting from the hanger, effectively providing a one trip abandonment solution.
