12.25″ guidelines for tripping, making connections and back reaming

Making connection

• Wipe the full stand once by pumping out and reaming back down
• Wipe the bottom single once by pumping out and reaming back down
• The driller must nominate a responsible person to control the mud pumps (e.g DD, Toolpusher, AD). This person will be responsible for shutting down the pumps quickly in the event of a pack-off.

Tripping

• The Drilling Supervisor will be on the rig floor from start of the trip out of hole until the string is in cased hole.
• Prior to starting the trip (during circulating bottoms up) check the following:
  • Record up-weight, down-weight, rotating weight and off bottom torque.
  • Have a single of drill pipe available in the V door.
  • List of tight spots/intervals encountered during connections and previous trips
  • BHA schematic with measurements between stabilizers and bit
• Upon encountering tight hole:
  • Go down and re-establish up-weight, down-weight, rotating weight and off bottom torque.
  • Apply overpull – starting with 20klbs – mark the pipe – go down – check the down drag – if negligible increase in down-drag then proceed by trying greater overpull.
  • Apply 30klbs overpull – mark the pipe – go down – check the down drag – if negligible increase in down-drag then proceed by trying greater overpull.
  • Apply 40klbs overpull – mark the pipe – go down – check the down drag – if negligible increase in down-drag then proceed by trying greater overpull.
  • Continue applying the above technique using 10klb increments up to a maximum of the weight of the BHA.
  • If on any overpull attempt, the down drag indicates that the pipe is becoming jammed, then make several attempts with less overpull.
  • If after several attempts there is no further progress (as seen from marks on the pipe) then go down, circulate clean – then try again.
  • If still no success to pass, then go down again and commence back-reaming procedures. Do not attempt to pump out of the hole as this may cause hydraulic compaction whereas rotation may disperse the blockage.
• Do not make wiper trips unless hole conditions – such as unmanageable increase in torque or drag – dictate.
• If during a trip, the crew have to change tour, ensure that the Tool Pusher on tour is at the brakes until a full handover is done between the drillers.

Back-reaming

• Back-reaming should be used as the last resort and with the same flow rate that was used during drilling.
• Back-ream for 5m maximum, circulate cuttings clear of the BHA, then try to pull through the obstruction again using the above procedure – without pumps or rotation.
• During back-reaming the driller must nominate a responsible person to control the mud pumps (e.g DD, Toolpusher, KPO Drilling Supervisor). This person will be responsible for shutting down the pumps quickly in the event of a pack-off.
• In the event of a pack-off:- stop the pumps – go down with the pipe (maintaining rotation) – re-establish circulation – circulate clean.
• Attempt to pull through obstruction again without pumps or rotation.
• Repeat the above process – with patience. The objective is to POOH with the absolute minimum of back-reaming.