中文
Oil recovery technology refers to the efficiency of extracting oil from oil fields. The evolution of this technology is crucial to the development of the oil industry. Over time, oil recovery technology has undergone many innovations that have not only improved the efficiency of oil extraction but also had profound impacts on the environment, economy, and energy policy.
In the field of hydrocarbon production, oil recovery is a key process whose purpose is to extract as much oil and gas as possible from hydrocarbon-rich reservoirs. As the life cycle of an oil well progresses, the production rate tend to change. In order to maintain and extend the production capacity of the well, additional stimulation of the formation is often required. Depending on the age of the well, the formation characteristics and the operating costs, a variety of technologies and techniques are used at different stages. There are three main categories of oil recovery technologies: primary oil recovery, secondary oil recovery, and tertiary oil recovery (also known as enhanced oil recovery, EOR).
Primary oil recovery mainly relies on the reservoir's own pressure to drive oil to the wellhead. When the reservoir pressure drops and cannot maintain sufficient production rate, secondary oil recovery usually begins. This stage mainly involves increasing reservoir pressure through water or gas injection, thereby continuing to push oil to the wellhead. Tertiary oil recovery, or enhanced oil recovery, is a more complex technology that involves using chemicals, heat or gas injection to further increase the recovery of oil. These technologies can more effectively displace the remaining crude oil in the reservoir, significantly improving overall oil recovery efficiency.
● Gas injection: Injecting gas into an oil reservoir to change the pressure and fluid properties of the reservoir, thereby promoting the flow and production of crude oil.
● Steam injection: Also known as thermal oil recovery, it heats the reservoir by injecting high-temperature steam to reduce the viscosity of the oil, making it easier to flow. It is particularly suitable for high-viscosity or heavy oil reservoirs.
● Chemical injection: By injecting chemicals (such as surfactants, polymers and alkalis), the physical and chemical properties of crude oil can be changed, thereby improving the fluidity of crude oil, reducing interfacial tension and improving recovery efficiency.
● CO2 injection: This is a special gas injection method that, by injecting carbon dioxide, it can not only reduce the viscosity of the oil, but also improve the recovery rate by increasing the reservoir pressure and reducing the remaining crude oil saturation. In addition, this method also has certain environmental benefits because the CO2 can be sequestered underground.
● Plasma Pulse Technology: This is a newer technology that generates high-energy plasma pulses to stimulate the reservoir, create fractures, increase permeability, and thus enhance the flow of crude oil. Although this technology is still in the experimental stage, it shows potential for improving recovery in specific reservoir types.
Each EOR technology has its own specific applicable conditions and cost-benefit analysis, and it is usually necessary to select the most appropriate method based on the geological conditions of the specific reservoir, the properties of the crude oil and economic factors. The application of EOR technology can significantly improve the economic benefits of oil fields and extend the production life of oil fields, which is of great significance to the sustainable development of global oil resources.
Date: 05 Jul 2024