Terms that everyone should understand (PG, I assume you're going to put the together the post w/definitions, right?)
  • EOR (enhanced oil recovery)
  • E&P (exploration and production)
  • URR (ultimately recoverable reserves)
  • OOIP (original oil in place)
  • LNG (liquified natural gas)
  • GTL (gas to liquids conversion)
  • CTL (coal to liquids conversion)
  • BOE (barrels of oil equivalent)
  • BBLs (barrels of usually oil)
  • MBPD (million barrels per day == MMb/d
  • GB (gigabarrels = billion barrels = Bbo
  • RP ratio (reserves/production = years)
  • Qt (the estimated URR from a Hubbert Lineariation)
  • TCF (trillion cubic feet -- dry natural gas)
  • MMx (million x)
  • IEA (International Energy Agency in Paris)
  • CERA (Cambridge Energy Research Associates (Daniel Yergin
  • EIA (Energy Information Admistration (DOE)
  • DOE (Department of Energy
  • NGLs (natural gas liquids eg. condensates)
  • USGS (US Geological Service)
  • IOC (international oil company eg. British Petroleum, ExxonMobil)
  • NOC (national oil company eg. Saudi Aramco)
  • OPEC (organization of petroleum exporting countries)
  • FSU (former Soviet Union)
Well, that should get us started... that's enough for now, already tired...

And a few others...

  • WTF (what the fuck)
  • SHTF (shit hits the fan
  • AFAIK (as far as I know)
  • EBAAN (esteemed and beloved Ali Al-Naimi)
I've seen people here use IIRC as an acronym. Can anyone tell me what that means please?
If I recall correctly.
Dave,

You forgot FUBAR and SNAFU.

Also, not an acronym but "klick" is military slang for kilometer, and also kilometer per hour.  I used this in my Geology class once and got a roomful of blank stares.

"How far is it to base?"
"10 klicks."
"How fast we going?"
"120 klicks." in Germany after all :) "Be there in five minutes"

As long as you're doing colloquial acronyms as well as topical ones, I suggest:
  • IMHO (In My Humble Opinion)
  • IM<HO (In My less than Humble Opinion)</li>
  • 2LoT (2nd Law of Thermodynamics)
  • TANSTAAFL (There Ain't No Such Thing As A Free Lunch, h/t Robt. A. Heinlein)