Sterling Energy, an oil and gas exploration and production company, has provided an update on operations in the Sangaw North block in Kurdistan.

The company holds a 53.33% working interest in the block and is its operator.

The recent operations have been conducted to remove the hydrocarbon gas, containing about 0.5% hydrogen sulphide that had entered the well bore and to retrieve the drill pipe that had parted at a depth of approximately 850m.

The gas influx has been contained, removed from the wellbore, and flared, and the drilling fluid in the well bore has been replaced with heavier fluid to control the higher formation pressure encountered at the base of the well.

The drill pipe in the well bore has been adversely affected by the hydrogen sulphide within the gas, with the steel becoming brittle and prone to fracturing.

Consequently, operations to retrieve the drill pipe have been challenging with drill pipe being recovered in lengths of between 1m and 120m, and operations being required to clean smaller pieces from the well bore, the company said.

The top of the drill pipe remaining in the well is at approximately 1,670m, about 220m below the bottom of the existing casing.

Recent operations indicate that the structural integrity of the drill pipe is improving with depth.

Based on the increasing rate of recovery, the company plans to continue retrieving drill pipe to reach the bottom hole assembly.

If the rate of drill pipe recovery does not remain sufficiently high, the company may proceed to abandon the existing wellbore at a depth in the open hole above the remaining drill pipe, sidetrack at this depth to a new well bore and re-drill the remaining section to the planned casing point.