"Because of high oil prices, oil companies have excessive earnings that go beyond reasonable levels of profitability," Angel Rodriguez, a Venezuelan parliamentarian, told ABN, the country's state news agency.
"One way to distribute them to our people, who are the owners of the oil, is to create this tax."
The tax will apply to both international and national companies, including PDVSA, Venezuela's state oil company.
Thursday's move will give Chavez new funds to shore up popularity among the nation's poor majority, who have backed him for almost a decade but are increasingly critical of his government for food shortages and rampant crime.
Lawmakers could give the bill final approval next week.
PDVSA took control of part of Venezuela's oil field last year as part of the nationalisation programme, pushing out ExxonMobil and the Conoco oil giants in the process.
The showdown led Exxon to seek court injunctions for up to $12 billion in compensation, a move Chavez described as "legal terrorism" and threatened to retaliate by halting oil sales to the US.
A London court last month threw out one of the orders.