The Reverse Cut and Thread Method is recommended in case a logging tool containing a radioactive source is stuck and has to be fished.
After this point the procedure deviates from the Cut and Thread Method.
- The weak point will not be broken when the fish has been latched into the overshot.
- The cable and drillpipe will be pulled out together and the cable has to be cut whenever a stand of drillpipe has been disconnected.
- This method implies an additional safety factor since the fish remains connected to the cable while pulling out with the drillpipe.
The following procedure should be adhered to whilst POOH.
1. POOH the drillpipe slowly without rotating, if all indications show that the tool is latched on.
Note: Since the drill string and cable are of the same length, give sufficient slack on the cable in order not to over-stretch the cable during the following procedures.
2. Clamp a cable hanger on the cable between the disconnected pipes when the first stand of drillpipe has been pulled out and disconnected.
3. Slak down the cable until the cable hanger rests on the drillpipe box hanging in the slips.
Note: Due to the slack imposed on the cable, the spear and overshot assembly will be located further down the string and cannot be used as a cable cut point. Hence, CUT the cable above the hanger and PULL it out of the stand hanging in the derrick.
4. POOH and disconnect the next stand of drillpipe. Clamp another cable hanger on the cable between the disconnected pipes.
5. Lower down the disconnected stand with the cable inside until the cable hanger rests on the drill pipe box below.
6. Cut the cable above the cable hanger and pull the cable out of the stand hanging in the derrick.
7. Continue with the above outlined procedure until the fish has been recovered at surface.