Natural gas is not propane.
Natural gas is formed in pockets in the earth's crust and may or may not include crude
oil in the pocket although cude
oil pockets almost always have natural gas in them.
Propane is in a few grades here in the US ranging from what we called "sewer gas" (low grade) to blends like MAPP (propane and acytaline). When we bought propane at the welding shop it's price follows crude
oil because it's made from crude oil. You have to jet stoves, torches, engines, water heaters to one gas or the other. they don't burn the same.
Got to home depot up north everythings jetted to natural gas, down south propane. (I used to repair gas welding equipment in my teens) You'll see about 20% more power from natural gas than propane it's a much hotter burn.