Hello Everyone,

I am working as a petroleum engineer in an oil company. During testing of a well, 5 bridge plugs were run for zonal isolation in 5" liner. Specs are as below

ELASTOMERS: 70 HARD NITRILE PACKING ELEMENT
PRESSURE RTG:10,000 PSI
TEMP. RTG: 250 DEG F,
BAKER MODEL N-1
FOR 5" 11.5-20,8 LB/FT CASING).

After completion of testing, 3 plugs were milled easily, but got stuck at fourth one. 3 trips were made with pdc bit and two with the flat bottom mill to mill the 4th plug. Now 5th plug is being milled with the flat bottom mill in 3rd trip but progress is very slow. Two weeks have been consumed in this work. I seek your suggestions and comments for the above told problem. any alternative for zonal isolation or any other technique for milling and pushing them down....