International Snubbing Case History #3
Objective: Drilling rig drilled into over pressurized zone, requiring snubbing unit to snub out drill string, and snub in liner.
Well Information: 3800, 7-10 mPa, depending on well kill fluid density. Could not kill well.
Procedure: Prepped unit for job, install 3 ½ handling equipment. Rig in riser spools, rig up snubbing unit, screw into hang off sub, conduct pressure test. Snub in to bottom, circulate, set tubing bridge plug due to floats not holding. Snub out 3 ½ drill pipe, 4 ¾ drill collars, heavyweight, jars, and BHA. Snub in BHA, and 4 ½ liner to bottom. Tag obstruction around 3400m, pull same back out, snub in tools and 3 ½ drill pipe, perform tasks, snub out same and snub in 4 ½ liner, set, and rig out snubbing equipment.
Time on location: 30 days (standby while waiting on auxiliary equipment)