Venezuelan oil production has declined by about half since Chavez took power. Given the losses they suffered from expropriation, the oil majors aren't particularly keen on returning to Venezuela without stronger guarantees, and oil executives aren't idiot--they understand that Trump is not a reliable partner and that there's a good chance that any deal he strikes with Venezuela will fail to be honored past 2028 (or possibly even before then).

There's also the fact that Venezuelan crude oil is basically among the worst grades of crude oil, the sort of stuff that the refineries don't want to use unless they have no other options. Which also means that as global oil demand hits its maximum (likely within decades), this is also going to be some of the first oil production to be permanently mothballed. With massive necessary investment to get anything running, subpar product, and a very uncertain political situation for the necessary long-term investment, most oil companies are reluctant to invest.

As a result, the only major oil company to have really been contemplating investing in Venezuela is Chevron (which itself appears to be mostly hedging its bets); Trump more recently announced another deal with a supposed major investment in an unnamed operator to extract oil from Venezuela, but without any companies being named, I'm skeptical of how real it is as opposed to merely being a vehicle for graft.

As AnimalMuppet says, if anything does get built, it's on the order of years before anything starts flowing.

I think I heard 3 years at a minimum (don't take that number as gospel, but the order of magnitude is roughly right as a best case). The issue is that Venezuela's oil infrastructure is basically trashed by decades of neglect and mismanagement. It's going to have to be rebuilt, which is billions of dollars and several years.

That's the best case. Worst case (for Venezuelan oil) is that the Republicans lose the House and Senate in November, then the new Congress starts investigating the Venezuela deal, and court cases start flying, and oil companies back out, and the date for the impact of the deal becomes "never".