Blowout Preventer (BOP) and Choke & Kill (C&K) manifold gate valves are critical parts in a Drilling Pressure Control System. A poor functioning gate valve, or one that doesn’t seal correctly, will need to be rectified, resulting in drilling delays and high costs. And, if a gate valve fails, it can cause significant safety issues. All this makes your choice of gate valve lubricant essential to the smooth running of your operations.
What to look for in a gate valve lubricant
BOP and C&K valves have a slab gate that generates a full metal-to-metal seal between the gate and downstream seat. This seal is energised by the bore pressure acting on the upstream side.
In this environment, the primary function of the valve lubricant is to protect the internal gate valve components during service, so the metal-to-metal seal remains true whenever the valve is closed. The valve lubricant also provides protection to the threaded stem of a manually operated gate valve and lubricates the stem-gate and gate-seat contacts to ensure smooth, low-torque valve functioning.
To provide this protection long term, you should choose a valve lubricant with the following properties:
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Adhesiveness, viscosity and density
It may seem obvious, but the most important requirement of any valve lubricant is that it remains inside the valve cavity. If the valve lubricant doesn’t have the required adhesiveness, viscosity and density, it may be displaced during operation, leaving the valve cavity & internal components unprotected.
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Resilience to fluids and high temperatures
As liquids can displace a lubricant from the valve cavity, your valve lubricant must be resilient to drilling fluids, muds and any hydrocarbons that could circulate through your pressure control system. It should also be thermally stable at your system’s maximum operating temperature to ensure that it doesn’t melt, soften or harden during operation.
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Sealing characteristics
If your gate-seat components’ seal faces are damaged, your valve lubricant can help the compromised valve gain a full pressure seal with zero LOR (Leak Off Test). This means your lubricant must have good sealing characteristics.
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Proven long-term performance
If you need to repair or replace a gate valve, you will have to pause drilling operations – which usually comes at a high cost. Therefore, gate valve lubricants must continue to perform for long periods. This makes long-term performance essential – so you should always choose a gate valve lubricant with a proven track record and significant testing behind it.
Why many operators choose Valve Lubricant 601
After the Deepwater Horizon accident in 2010, revised regulations were brought in that required drillers in the Gulf of Mexico to pressure test BOP and C&K manifold valves more frequently. Many gate valves didn’t pass these pressure tests – and several drillers introduced Valve Lubricant 601 to mitigate the problem.
But the lubricant’s track record goes back much further. The earliest full technical evaluation of Valve Lubricant 601 was completed in 1995 on a subsea BOP pod on a HT/HP well in the North Sea. Lower inner and outer killsafe valves were chosen for the evaluation – with Valve Lubricant 601 used in some valves and a competitor product in others.
After four months in operation, the valves were opened and assessed. The competitor product had almost completely disappeared, however, Valve Lubricant 601 was still there, and the valves continued to perform well. As the report stated: “There was obviously a marked difference in the lifespan of the lubrication between these two products.”
Is Valve Lubricant 601 the right product for you? Find out more here.
Left to right: Choke & kill manifold, BOP and standpipe manifold. There are gate valves on all 3 assemblies. The standpipe manifold is part of the mud system. (Note: not all mud-style gate valves have grease ports.)