Welltec Performs World’s First Milling of Bridge Plugs on Wireline
Welltec is the first company in the world that has been able to mill out permanent bridge plugs on electric wireline. To date, two jobs have been carried out for two different operators that are both major players in the North Sea.
The world premiere took place in June 2007 offshore UK where the Well Miller was used to remove a 3.71” O.D. cast iron bridge plug at 15,000 ft. The well was a gas producer that was experiencing a high water-cut and a low bottom hole pressure of 2000 psi, which threatened gas production. To shut off the water, a bridge plug was installed. However, it was accidently set 80 ft high in the well. In order to mill out the prematurely set plug, the Well Miller was considered the best solution and was combined with the Well Tractor to provide weight on bit (WOB).
This was a unique operation where all milled material was recovered from the well and the challenges of controlling rate and milling penetration were overcome. Total operational time from rig up to rig down was 67 hours but the actual milling time was nine hours. The production enhancement quickly paid for the operation as oil rate increased from 0 to 60 bopd and water rate was reduced to 0 bwpd.
Almost one year later, Welltec was summoned to an offshore oil producer in Norway to remove another permanent bridge plug from the tubing. It was decided to attempt to mill out the 3.25” plug on electric wireline to regain production from the well. Building on the experience gained since the first job, Welltec had further refined the milling technology and performed this job with hydraulically provided WOB.
The offshore operation was successfully completed in three days to the operator’s complete satisfaction. Following the intervention, the client stated: “The solution adopted by Welltec to remove the plug has been innovative. The success of the milling operation is quite an achievement and has pushed the limits for what is possible to achieve using electric wireline and tractor technology.”
To read more about these two ground-breaking jobs, please go to case histories:
UK operation: Milling of Cast-Iron Bridge Plug
Norway operation: Another Successful Milling and Removal of permanent Bridge Plug on Wireline
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