IMO The whole "Essequibo is venezuelan" is a diversion by Maduro.
In order to the US lift its sanctions against Venezuela, Maduro promissed fair and free elections. The problem is, if that happened he would inevitably lose those elections.
The chavistas are trying to create the poison and at the same time sell the antidote. The goal is to destabilize America's backyard with the intention of getting the Biden administration to make concessions on that promisse of free and fair elections.
I don't believe guyanan oil reserves are the main aspect of this conflict. I mean, even if Venezuela got hold of them, they wouldn't able to do much. Chavez and Maduro turned PDVSA, the state-run oil company, into a shadow of its former self. It's incredibly corrupt and inefficient, I don't see how they would be able to increase production.