A unit of volume used in the energy industry, equal to one million barrels of oil. One megabarrel equals 42 million U. S. gallons, which is about 158.987 megaliters (ML)
Russ Rowlett (Director), How Many? A Dictionary of Units of Measurement, Center for Mathematics and Science Education University of North Carolina, USA 2005. http://www.unc.edu/~rowlett/units/dictA.html, (Unit of Meas and Covr Factors - Amer) {608}