U.S. oil companies could be “up and running” in Venezuela’s oil sector within 18 months, U.S. President Donald Trump told NBC News days after U.S. forces extracted Nicolas Maduro out of the country holding the world’s largest proven oil reserves. “A tremendous amount of money will have to be spent, and the oil companies will spend it, and then they’ll get reimbursed by us or through revenue,” President Trump told NBC News in an interview. Regarding the 18-month timeline during which U.S. companies…