Fusible Plug Loop Using Instrument Gas

[amustha1407]

Hi,

We are designing an unmanned remote wellhead platform. Due to economic reason and remoteness we are having trouble to place instrument air compressor on the platform and hence plan to use instrument gas.

On such case, is it OK if we pressurized the fusible plug loop with instrument gas? It seemed counter-intuitive as when the plug melt the inst gas will feed into the fire, hence may make the fire worst. However, when i checked some of other unmanned remote platform design, it seem that this design is common.

Would like to seek for all of your opinion on this. What are the consideration, and do you think it is wise to design so?

Thanks!

 

[LittleInch]

I've seen this done before on remote wellpads where the only source of "power" for instruments, held open actuated valves etc is a small tap off the top of the gas line from the well.

In this instance yes it seems a bad idea, but the volume of the gas in the fusible loop and its feed rate is minute, so if there is a fire a small spurt of gas will be negligible if it makes the system trip the wing valve.

The alternative is a nitrogen bottle but if the wellpad is remote enough these often mysteriously disappear.... and your well pad is shut in as well!

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[amustha1407]

LittleInch, Thank you for your guidance. This helps