The Watermelon Mills are designed with many functions in mind. The primary function of the mills is to elongate casing windows during a whipstock operation. They can also be used to remove obstructions in casing. In open hole, they can be used to ream through key seats.
These type mills are often run above section mills so any bird nesting of cuttings accumulating at the top of the window can be milled away to ensure that the section mill can be pulled out of the hole.
Most of the mills have a standard drillpipe or drill collar connection to eliminate cross-overs.
All Watermelon Mill have standard pin up API Reg connections. The connection will be dependent on the mill OD.