It is a petroleum based reverse mortgage.
The Chavez/Maduro government has used up everything else of value in the country.
Reverse mortgages can be a good deal for those near end of life.
Not so much for the heir left after their passing.
The Chinese are nobodies fools. Undoubtedly this deal includes employing Chinese exploration companies using Chinese workers and Venezuelan oil contracted at 40$ per barrel for seven years out.
If all goes well then more goodies like Chinese bases to annoy the USA