Mill stuck metal centralizer and retrieve toolstring
When a 6-in-long slickline fluted centralizer jammed in a nipple profile above the subsea safety valve of an injector well in the Irish Sea, Eni UK needed to have it milled out to access and retrieve the toolstring. Access to the fish was tight, in 4.79-ID tubing with a minimum restriction to 4.26 in.
A conventional bit hardfaced with tungsten carbide was deployed. However, it was highly inefficient, removing only 60% of the centralizer after 400 operating hours.
