Application 

SHMU junk sub retrieves metal debris and broken bit/mill dressing from a well. 

Design

The junk sub consists of a body with tool joints as per GOST R 50864-96 at the ends. It has a watercourse in the body for fluid circulation. The body goes with a dismountable cover that also has ports to drain fluid when pulling out of hole.

High-rate upflow, created by circulation in annular space, lift the cuttings until they reaches the upper end of the cover. With drop in flow rate, caused by increased annular space, the cuttings get into flow swirling and deposit in a chamber between the body and the cover of the junk sub.

Install gravity-type junk sub above the bit, mill or core catcher. The junk sub is activated by circulation only.
To increase integral capacity of the junk sub cover, use two junk subs.