In the oil and gas industry, drilling companies utilize several techniques to extract oil beneath the land and achieve maximum mineral production results. Although they try to extract the maximum possible oil beneath the earth’s surface, some amount of oil is left to be extracted, mostly due to reservoir complexities. Therefore, enhanced oil recovery (EOR) techniques are used to extract the remaining oil.
Here you will find detailed information that will assist you in understanding the EOR technique and its potential benefits for achieving maximum oil extraction.
What is Enhanced Oil Recovery?
The enhanced oil recovery technique is utilized to extract the maximum possible amount of oil from the oil reserves after they have gone through the primary and secondary extraction stages. Enhanced oil recovery is also referred to as tertiary recovery.
Executing the EOR method on oil reserves delivers more oil that helps improve production ultimately supporting the state’s economy to grow. In EOR technique chemical composition of oil is altered to achieve smoother extraction.
With this method 30% to 60% of oil from the reservoir can be extracted than 20% to 40% with primary and secondary recovery processes. According to the US energy department, carbon dioxide and water can be injected in the EOR technique.
There are three crucial injection methods that are highly preferred in EOR: Thermal Injection, Gas Injection, and Chemical Injection. In some cases, more speculative and advanced EOR is needed to be executed; such an EOR technique is titled Quaternary Recovery.
What are the Three Major Methods of EOR?
Below are three major injection methods that are mainly preferred in Enhanced Oil Recovery techniques.
- Gas Injection
Gas injection is the most common method utilized in EOR which is also called miscible flooding. Miscible flooding comprises various miscible gasses that are injected into the oil reservoir to extract oil. With the help of these gasses the interfacial tension between oil and gas is minimized, which helps enhance oil displacement, maintaining sufficient reservoir pressure.
The gasses used in these methods are natural gas, CO2 and nitrogen. In order to attain improved miscible displacement carbon dioxide is prioritized as this gas is affordable than Liquid Petroleum Gas and helps reduce the oil viscosity.
The carbon dioxide oil displacement depends upon phase actions of the gas and oil mixture which relies on appropriate pressure, temperature and composition of crude oil.
- Thermal Injection
In this method the heat is applied to oil reservoirs to reduce the oil viscosity and vapourize some portion of the oil ultimately minimizing mobility ratio. The reduced oil viscosity helps take out the oil easily.
Immense heat in oil formation results in lower surface tension, improving the permeability of the oil. The heated oil also gets vaporized and later condensed, enhancing oil quality.
Combustion, steam flooding, and cyclic steam injection methods can be utilized to heat the oil formation. The thermal injection method primarily helps increase the displacement efficiency and sweep efficiency.
- Chemical Injection
In chemical injection methods, various chemicals are used in EOR to help extract maximum oil from reservoirs. The chemicals are mostly preferred as dilute solutions that minimize the surface tension and concurrently reduce the mobility ratio.
The polymers, surfactants, or alkaline are highly preferred as a dilute solution to inject into the reservoir. This results in production of soap that may reduce interfacial tension, improving oil quality.
In some cases, water-soluble polymers are considered a dilute solution for injection. The injection of such polymer increases the water viscosity, resulting in a maximum amount of oil to be recovered.
Chemical injection process is utilized in limited areas only as it holds maximum chemical cost and their adsorption and loss onto the rock of oil containing reservoir.
To sum up, EOR is an effective technique that allows companies to extract more oil from subterranean sources. In addition to improving industry efficiency, this also increases the lifespan of oil fields, guaranteeing access to this vital resource for a longer period of time.
The Oil and gas industries are now focusing on the latest Enhanced Oil Recovery techniques to extract maximum oil from reservoirs. This article has covered the three most preferred and essential methods that enhance the Enhanced Oil Recovery Techniques and deliver maximum oil production while supporting the state’s economic landscape.
