What is meant by oil recovery?

Oil recovery refers to the process of extracting and recovering oil from underground reservoirs. This can involve various techniques such as primary recovery (natural pressure and pumping), secondary recovery (water or gas injection to push oil to the surface), and enhanced oil recovery (using advanced methods such as chemical injection, thermal methods, or microbial processes to extract more oil from the reservoir). The goal of oil recovery is to maximize the amount of oil that can be extracted from a reservoir.

Oil recovery refers to the process of extracting oil from oil-bearing formations such as reservoirs. It involves various techniques and technologies used to maximize the amount of oil recovered from these formations. Oil recovery methods can be broadly classified into two main categories:

1. Primary Oil Recovery: This is the initial stage of oil recovery where natural pressure from the reservoir forces oil to flow into the wellbore. Primary recovery methods utilize existing reservoir energy, such as gas pressure or water drive, to produce oil. It typically recovers about 10-20% of the original oil in place (OOIP).

2. Secondary Oil Recovery (Enhanced Oil Recovery, EOR): When primary recovery methods become less effective, secondary recovery techniques are employed to improve oil production rates and increase oil recovery factors. EOR techniques involve injecting fluids or gases into the reservoir to maintain or increase reservoir pressure, improve fluid flow, or alter the properties of the reservoir fluids. Common EOR methods include:

- Waterflooding: Injection of water into the reservoir to displace oil towards production wells.
- Gas Injection: Injection of gases like carbon dioxide (CO2) or natural gas to reduce oil viscosity, improve flow, and extract more oil.
- Chemical Enhanced Oil Recovery (CEOR): Injection of chemicals like polymers or surfactants to change the properties of reservoir fluids, reduce oil viscosity, or improve sweep efficiency.
- Thermal Enhanced Oil Recovery (TEOR): Application of heat to the reservoir using techniques like steam injection or in-situ combustion to reduce oil viscosity and enhance flow.

Oil recovery is crucial for meeting energy demands and maximizing the extraction of valuable resources from oil reservoirs. By utilizing advanced technologies and innovative techniques, the oil and gas industry aims to improve oil recovery factors and enhance the efficiency of production operations.