Primary recovery refers to the initial phase of oil production that relies on natural reservoir pressure to bring crude oil to the surface. This method typically recovers 10-20% of original oil in place before reservoir pressure declines and production rates fall. Primary recovery represents the lowest-cost production phase but has limited ultimate recovery rates.

Primary recovery economics depend on reservoir characteristics, oil quality, and natural drive mechanisms including water drive, gas expansion, or gravity drainage. Understanding primary recovery helps assess oil field economics, production profiles, and the timing for enhanced recovery methods. Primary recovery costs are typically the lowest in field development.

Real-world example: A new oil field produces 50,000 barrels per day initially through primary recovery at $25 per barrel operating costs, but production will decline over 10-15 years as reservoir pressure depletes, requiring secondary or tertiary recovery methods.