A process for facile separation of lighter hydrocarbon fractions from the heavier fractions of hydrocarbon oil feedstocks is disclosed, which utilizes novel sparging and reverse distillation techniques. The present invention can be utilized for the facile “topping” of crude oil extracted on-site. Moreover, while heavier hydrocarbon fractions may be shipped to refineries for further processing, this invention will also prove useful for quick separation of light fractions produced by cracking processes off-site.