What does the term 'dead oil' describe?

• A. Oil with dissolved gas
• B. Oil with no dissolved gas
• C. Oil that is fully saturated with oil
• D. Oil that contains gas in solution

Answer: (D)

Dead oil refers to crude oil that has no dissolved gas in it. In reservoir fluids, gas can be dissolved in oil at high pressure, making the oil “live” or gas-saturated. When the pressure drops and the gas comes out of solution, the oil loses its dissolved gas and becomes dead oil. So the term describes oil without dissolved gas. Descriptions that talk about dissolved gas or gas in solution describe live oil, not dead oil, and a statement about being fully saturated with oil isn’t the standard way to describe this.