Boot baskets are run above the mills to collect the larger pieces of debris. Rotary shoes, generally, are run with washpipe in applications where only the material between the tubular being washed-over and the ID of the casing or formation need to be removed. Applications include sanded-up tubing and an open hole where the formation has fallen in.
Washover shoes are used to mill over packers that allow for minimum material removal in order to free the packer.
With both mills and shoes, we recommend running jars and drill collars to prevent sticking.
The METAL MUNCHER™ junk mill is for milling stationary obstructions. The junk mill uses patented technology as the lead cutting structure backed up by SUPERLOY™ tungsten carbide. If the METAL MUNCHER inserts become damaged, the mill will perform like a standard junk mill until a new row of inserts is exposed. The mills have been used to mill cemented tubing at rates sometimes exceeding 30 ft/hr. Cemented drill collars and drillpipe have been milled faster than they could be washed over and recovered.
The Piranha™ mill is for milling cemented pipe in situations where there are large amounts of junk in the hole, which requires a mill with a longer life. Ideal for milling tubing and can be dressed for open or cased hole. The SUPERLOY dressed mill has an offset center to prevent coring. The deep-V design offers maximum fluid circulation and holds a large amount of tungsten carbide dressing.
Rotary shoes are used on the bottom of washpipe in washover or milling operations. The specific application will dictate the shoe type best suited for the job. They are made from heat-treated alloy steel and dressed with SUPERLOY, METAL MUNCHER, or Opti-Cut™ cutters.
Conebuster™ mill is used for milling bit cones or other objects. Dressed with SUPERLOY on the OD, the mill has a slightly concave bottom to keep fish centered under the mill for greater effectiveness in open hole or cased hole.
String and watermelon mills elongate casing windows during a whipstock operation. They can be used to remove tight spots, restrictions, or doglegs in casing. These mills often are run above section mills so any birdnesting of cuttings can be broken up and circulated to ensure the section mill can be pulled out of the well. Most models have a standard drillpipe or drill collar connection to eliminate crossovers. They can be inserted into the workstring at any point and can be dressed rough or smooth OD.
The SUPERLOY™ junk mill, which is used for milling debris where milling inserts are considered too aggressive, does not require pulling off of the fish to make a connection.