P&A Application in Norway North Sea April 2017
Well Abandonment with Wel-lok™ TS
Two separate wells had previously been abandoned by setting bridge plugs and dump bailing cement inside a liner to isolate the producing zone. The wells continued to build gas pressure at surface through the production tubing up to 1,200 psi.
1: Issues to overcome
Traditional methods of setting bridge plugs and spotting cement on top does not generate a gas tight seal. In order to continue with the abandonment of the well, the operator needed to ensure the producing zone was properly isolated and there was not pressure in the production tubing string.
Wel-lok™ TS tools were set inside the liner of each well.
An initial pressure test of 4,000 psi was performed, followed by a successful 24-hour negative pressure test which resulted in no bubbles or gas pressure at surface. Further, each of these wells underwent a 1-year monitoring period prior to resuming the well abandonment, resulting in no bubbles or gas pressure build up over this period.