FISHING AND IT`S IMPORTANCE IN OIL FIELD INDUSTRY EPISODE 2
WE STOPPED LAST ARTICLE AT THE JUNK RECOVERY TOOLS, THIS ARTICLE I WILL TRY TO EXPLAIN ONE OR MORE TOOL AND THE PROBER USAGE OR/AND ITS CASE.
We explained last article that we have to ask a specific questions to gather data about the fish to work and to choose your best prober tool for each situation.
This means we have to evaluate the case first.
Junk or Debris Evaluation
Any debris or junk in the borehole must be evaluated before any successful fishing Attempt can be made. Consider the following before proceeding with a fishing job.
• What is the junk size, weight, and condition?
• Is the junk magnetic?
• Pick it up or mill it up?
Fishing magnets are primarily used to pick up bit cones, but they can pick up All types of small objects with magnetic properties.
Magnets should be run on pipe Instead of wire line because of the capability to circulate and rotate. It is necessary to Wash the top of
the fish sufficiently so that enough surface area will make contact With the magnetic pole plate. Run a boot basket directly above the
magnet to catch Any loose bearings or small pieces of junk.
Fishing magnet runs on wire line are usually made inside the casing with clear fluid in the hole.
The OD of the magnet should be 1/4- to 1/2-in. less than hole size
Procedure run Magnet:
1. Trip in hole with the magnet and stop about 30-ft. from bottom.
2. Circulate and ream to the bottom a couple times to rake any loose junk off the wall and top of the fish.
3. Circulate at a good rate a couple inches off the fish to clean off any cuttings.
4. Rotate a couple rounds while slacking off to help roll the fish into the face of the
5. Stop rotating and set 3,000 to 4,000 pounds of weight down on the junk, then shut the pump off.
6. Pull out of the hole slowly without rotating. The guide should prevent the fish from being rubbed off while pulling out of the hole.
Run the magnet more than once if the volume of junk in the hole warrants.
WHILE RUNNING THE MAGNET BE CAREFULL DON`T ROTATE TOO MATCH AS MAGNET IS NOT A DRILLING TOOL.
We mentioned before that we RIH (run in hole) with our BHA (bottom hole assembly) including the BOOT BASKET to fill it with junk.
• Is used to recover small objects.
• Run in conjunction with a bit or mill
• The bit or mill will break up the junk into small pieces which will be carried up the hole by fluid circulation.
• Turbulence in the annulus will cause the junk to drop off in the cup of the boot basket.
• Boot baskets can be useful when drilling up drillable material.
How to work on the BOOT BASKETS to load them with junk ? ,
– Pump at high flow rate while slaking off rapidly with work string.
– Tag on bottom.
– Shut-off the pump for minute while slowly raising the work string.
As the flow changes from turbulent to laminar, the junk will drop off into the boot basket cup.