ctile gismu

x₁ is a quantity of petroleum/oil from source x₂.

In notes:

grasu: x₁ is a quantity of/is made of/contains grease/fat/oil from source x₂.
ctilytergu'i: x₁ is an oil lamp using petroleum-based products, illuminating x₂ with light x₁.
gaznatu: x₁ is a quantity of natural gas, a mixture of methane with smaller amounts of ethane, propane, butane, other gaseous hydrocarbons and petroleum deposits