The word is ASSAY. Oil types are assayed to determine API and constituent yields.
Venezuela has oil near the north shoreline and they have quietly been increasing production and are up to about 500Kbpd. Iran hauls it and markets it. The Chinese have built them a state of the art refinery so Venezuela generally has plenty of fuel.
The big reserves quoted for Ven are in the Orinoco river areas. It is very low API. Very thick and heavy. Essentially more difficult to process than even Canada’s oil sands.
US policy towards Venezuela has destroyed any possible relationship with them forever. They will always be more interested in their proven friends, Russia and China.
They elect the Chavez and Maduro types because the poor get bribed. So what? US subgroups get bribed too. Venezuela chooses the govt they have and the US has insulted and abused them to the point no other choice will ever happen.
So . . . eventually the US will have to try to liberate those barrels of crude, and then steal them.
Venezuela has the largest total hydrocarbon system on the planet. It is primarily ultra heavy oil and asphalitic heavy oils in sands,sandstones and marls. Total hydrocarbons in place is estimated at 1.2 trillion bbl oil equivalent. Of that 30% is believed to be technically recoverable by any means regardless of economics. The economically recoverable is less obviously. Heavy oils can be cracked with additional hydrogen to smaller C=C,X-Files chains with diesel and kerosene being in the hydrocrackers range with the right catalysts half could be in the diesel range. So yes Venezuela is the King of the hydrocarbon resources especially when diesel is the desired product. There is a reason the Gulf Coast refineries are set up to receive and process sour heavy crudes be them from.Saudi or Venezuela both produce more diesel per bbl than WTI which makes napthas and LPG plus condensate.