What term describes the total oil initially in place before production begins?

• A. Oil in place
• B. Reserves
• C. Recoverable oil
• D. Oil on surface

Answer: (A)

Oil in place (often called Original Oil In Place) is the total amount of oil that exists in the reservoir rock before production starts. It’s a static estimate based on the rock properties and the volume of pore space filled with oil, representing all the oil present, regardless of whether it can be recovered with current methods or economics. Reserves are the portion of that oil that can be produced profitably with today’s technology and prices. Recoverable oil is the subset of oil in place that can actually be recovered, given the chosen recovery methods and economic conditions. Oil on surface isn’t a standard measure of the reservoir’s initial oil inventory.