What is weight of a barrel of oil?

Answer 1

The weight of a barrel of oil will depend on its density. A barrel contains 42 gallons and density is typically measured in units of API gravity. Units can be a bit confusing in this case.

We need to convert from API density to pounds per gallon. Crude oil can typically vary from 15 to 45 deg API although I have worked with oils as low as 8 and as high as 50.

Let us consider oil gravity of 30 deg API, as all other densities are calculated in the same way.

Specific Gravity = 141.5/(131.5 + 30) = 0.876

The specific gravity is the density of the oil relative to water.

Now, to convert this to pounds per gallon, we must multiply the answer by 8.34 (density of water is 8.33 pounds per gallon):

8.34 x 0.876 = 7.30 pounds/gallon.

Since there are 42 gallons in a barrel, we must multiply this answer by 42:

42 x 7.30 = 307 pounds.

To summarize, a) convert API to specific density b) convert specific density to pounds per gallon and c) multiply gallons in one barrel by the pounds per gallon.