Freeze and Hot Tap Case History #35

Objective: Hot Tap and freeze 3 ½” tubing to relieve trapped pressure below plug.

Well Information: Sweet well, 4600kPa on well.

Procedure: Safety and JHA meeting with crew and company rep. Rig up and pressure test Hot tap drill, proceed to drill ½” hole to gain access to ID of 3 ½ tubing. Install cribbing and ice and start to cool pipe for 1 hr. Inject 60 L of freeze medium (GEL) into string and freeze. Preform positive (17,000 kPa) and negative (0 kPa) pressure test on plug, both passed. Remove top joint, install TSI and put 5000 kPa topside pressure to cushion plug when defrosting. Well secured, Rig out and off location.

Time on location: 14 hours