Oil commodity futures and the spot market are used more for investing/trading/speculating I believe. I guess if you did buy a barrel of oil on the spot market or the futures market, you could have it delivered by whoever sold it (can you imagine how much that would cost!). If you do buy an oil future, technically the person selling it has to deliver it.
The vast majority of international oil is sold in contracts at negotiated prices and not through the spot/futures market, as that oil is bought, delivered, and refined for products.