Vertical VR Tool Intervention, Beryl Alpha A44
Petroleum Technology Company (PTC) successfully removed a stuck two-way check valve from the tubing hanger profile using the new long reach VR Lubricator Tool. The VR Lubricator Tool was deployed in collaboration with Apache North Sea LTD as the first vertical intervention performed using the PTC tool. Apache avoided a time consuming and costly intervention.
In 1989, well A44 on the Beryl Alpha platform was completed. By 1996, the tubing had collapsed and the well was killed. A Cameron H2, 5 1/8" – two way check valve, was then installed in the tubing hanger thread profile. The valve installed needed to be removed to accommodate a workover after 18 years in operation. Attempts to remove the valve in August 2014 were unsuccessful. The standard Lubricator tool traditionally used for tubing hanger valve operations is substantial by dimensions providing poor torque capability.
PTC 1380 Telescopic VR Lubricator tools was deployed in cooperation with Apache North Sea LTD as it was suitable for the long stroke length and the torque required for the Beryl wellheads. The VR Lubricator Tool has capability of torqueing up to 1500Nm (1106 lbf.ft) and at a stroke length of 1380mm, whilst only requiring a free stack up height of just 856mm. The required storke was 1981mm so an extension rod was attached to increase the stroke length by 711mm. Torque can be apllied from the back of the lubricator using a standard torque wrench. The VR Lubricator Tool is fully sealed off, telescopic to reduce the length and manufactured in Titanium to minimize the weight. The pistons are exctended and retracted by using a hand pump only. Ensuring that the operation is carried out effectively, easily and safely.
Figure 1| The standard VR Lubricator Tool traditionally used for tubing hanger valve operations is substansial by dimensions and providing poor torque capability.
Figure 2| VR Lubricator Tool during the site integration test before initial deployment. The tool proved to be capable for providing required torque and extention for the task at hand.
Figure 3| 1380 VR Lubricator Tool rig up required for deployment.
Figure 4| VR Tool during operation on site. Pressure testing through the VR Tool flange proves the integrity of the VR Lubricator Tool.
The 1380 VR Lubricator Sysstem package was deployed and rigged up according to the planed 2 days of operation. Two PTC field service engineers with assistance from rig personnel safely operated the VR lubricator Tool and removed the plug at a torque of 300Nm. Actual operational time was just 8 hours. A crane was used to land the crossover spool, VR Flange and Lubricator Tool on top of the swab valve. Even when high winds stopped the ability of crane ops, the assembly was broken down safely in parts after successfully retrieving the valve. Due to the low weights of single components the short length and lightweight of the VR Lubricator Tool enabled rigging down manually with a chain block.
The valve removed showed no sign of thread sealant, corrosion, or damaged as shown in figure5. Previous attempts to remove the valve was clearly caused by the lack of required torque capabilities form the standard tool. PTC VR Lubricator Tools provide substantially more torque than standard industry tools of today. The tools allows for torque to be efficiently and easily applied through telescopic pistons by hydraulic power, thereby ensuring maximal torque on the check valve.
Figure 5 | Successfully removed valve.
The final alterantive involved milling the seized valve. The HSE logistics and implications involved in a milling operation are far greater than the case is by using PTC's solution. The PTC 1380 VR Lubricator Tool based solution was more efficient and cost effective. The cost of a milling opeartion would have been significantly higher.