consultants company (emphasize on design engineers, and others except the offshore team itself) like technip, ranhill, aker hardly have their staffs go offshore. Just do design consultations and paper works on pc in office.

Not sure this would help or not.
I think Mechmar in glenmarie has oil-fired boilers.. the titan series. think they have twin furnace with rotary cup or pressure jet.
not sure abt these ->
arenajaya in bandar putera klang - ldo/fo hot water boiler
george kent puchong
advance boilers teluk panglima garang
vickers hoskins meru

Pre-cooling the feed gas via a small auxiliary refrigeration cycle is another known way of increasing the efficiency of the nitrogen cycle, and this has been found to be the case for the cLNG process also, especially in applications with high ambient temperatures. The auxiliary refrigeration system is relatively small. Conventional chiller packages with "ozone-friendly" Freon refrigerants are used rather than a propane system. This maintains the safety philosophy for offshore applications. By adding the cold expander, and by optimizing the temperature levels and load split between the warm and cold expander duties, a much closer matching of the heating and cooling curves between the feed gas and nitrogen refrigerant can be obtained hence higher thermodynamic efficiency.

That's quite peculiar.. that you said no company will hire you if you leave your current company. Why you don't apply first and see how it goes, rather saying leaving your company to look for another job? That's a much better way to find out about that.
I cannot answer your question but what I can say is if you're planning to apply for PE that's going to sting I guess since your branch of degree is not the same as your branch of work. Correct me if I'm wrong!

There you already list what you need to know/understand for that position. Maybe for blasting you could learn the difference between SA2.5 SA3, rest of the swedish,RA, nace codes etc. Insulation purpose to conserve heat or protect people, which material rockwool GRP etc for which purpose, how they decide the thickness of insulation etc. I think CINI handbook could be used for guidelines.also pickling and passivation process etc. Just throwing out ideas what could be asked. Goodluck btw.