Fishing with Junk Subs
Junk subs are constructed with rib guides which are welded to the main body. These guides assist in preventing the cup from becoming crushed and guide the tool. Junk subs are available in various lengths.
Guidelines
The following guidelines shall be used when running junk subs:
- The mud stream agitates the junk and causes it to rise as drilling or milling proceeds.
- The annular clearance is small at the bottom of the sub (resulting in high annular flow rates which lifts the junk off bottom) and larger above . . .