First Successful Mechanical Cutter Cut Tubing Under Compression Including Three Different Types of Control Lines

Abstract

AbstractOne of O&G operator in Indonesia is scheduled to have a re-entry and drilling campaign at their deepwater field. The re-entry program objectives were to cut 5-1/2", 17#, 13Cr-L80 tubing and POOH existing upper completion prior P&A operation. Due to the well condition the chosen cut depth was at high inclination and multiple control lines need to be severed. A cutter with new design machining arm shaped like tiger claw was chosen to perform the cut. This operation was an outstanding achievement and the first time for deepwater in the region.A conventional way of tubing cut is putting the tubing in tension to prevent cutting blades got pinched and increase the chance of successful cut. However, the challenge for tubing cutting at this well was not only to cut the multiple control lines but also tubing hanger was not preferred to be unlatched prior tubing cut. The mechanical cutter should be able to cut under compression and also reach control lines with total OD of 6.916". Mechanical cutter with new design tiger claw blade was chosen due to its ability to cut the tubing under compression and also the blade arms could expand increases the cutting range to 7.2" guaranteeing continuation cutting beyond tubular OD through the multiple control lines.As this will be the first time in Indonesia, a SIT was performed in two conditions, under compression and neutral, with results confirming the cutter was able to cut tubing and multiple control lines. The cutter was deployed using e-line with tractor conveyance due to high degree inclination and positioned 1m below the tubing coupling to ensure the control lines were still in tension as it was close to the cable clamp.The new machining arm technology produces a grinding effect to cut through the tubing and as it expanded reaching the control lines, the blades keep grinding the tubing body and scored the control lines. After 129mins effective cutting time and confirmed with the circulation from annulus to tubing, it was decided to stop and POOH the cutter. When the cutter at the surface, it was measured that the blade had expanded, and operation continued to unlatch tubing hanger and POOH upper completion. The tubing was cut with a clean and smooth surface with control lines sheared at cutting depth.With the newly designed cutting elements, enabling a safe and efficient cutting operation. This solution eliminates the risks of unlatching the TH and put tubing in tension, the cost of rig time and ensuring no interruption to the well program. Operational details, including job planning and lessons learned will be discussed in the paper