AN ACCURATE CUT IN SIX MINUTES

Background

An operator in Nigeria needed to re-complete a well to boost production rates. The operator’s third-party fishing company required a clean, smooth top to the tubing stub to allow milling and further retrieval. Prior to the cut, the 4.5” tubing was punched to allow circulation, and the well was eventually killed with a 9 ppg kill brine. Welltec® engaged the client about using a non-ballistic approach for the cut and proposed the Well Cutter®, a mechanical cutter able to cut tubing under compression, in neutral, and in tension.

OPERATION

The job began with extensive planning carried out by the operations team. A systems integration test demonstrated the 238 Well Cutter’s ability to cut both 3.5” and 4.5” tubing on the surface.

A Well Tractor® 218 was used to convey the Well Cutter® 238 through parts of the tubing. Upon reaching the location between the two punched holes in the tubing at approximately 9666 ft and correlating the location, the cutting blades were engaged. The Well Cutter® cut the 4-1/2” tubing successfully in under six minutes with the tubing under compression. The client then successfully retrieved the tubing to surface.

ACHIEVEMENTS

The client was extremely impressed with the Well Cutter’s performance for a number of reasons, including the tool’s ability to cut the 4.5” tubing under compression without using the rig to put the tubing in tension and Welltec’s skill at accurately correlating the cut between the two punched holes at the client’s specified depth. Additionally, the fast cut left a smooth, bevelled surface, making it easier to fish the tubing and re-complete the well. Furthermore, running this operation on e-line with a mechanical cutter reduced the HSE risks logistical issues associated with explosive and chemical cutters.

WELL TYPE:  PRODUCER
PRESSURE: 4200 PSI at 9705ft
MAXIMUM DEPTH: 21,850 ft MD
TEMPERATURE: 190°F at 9705 ft

 

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