A decompression and injection-stimulation gemini surfactant system for oil fields and a preparing method thereof

Abstract

A decompression and injection-stimulation gemini surfactant system for oil fields and a preparing method thereof are provided. The system is a mixed system consisting of a heterogemini amphoteric surfactant as a main component, a nonionic amphoteric gemini surfactant as an auxiliary agent, an anionic surfactant and water. Compared with products in the prior art, the system has a wide spectrum anda wide adaption range; the system has a wide application concentration range, and the interfacial tension of the system can still be 10<-3> mN / m with a low application concentration (0.1%); the systemhas good wettability, high permeability, high oil washing efficiency, and good salt resistance, and is free of precipitate and turbid phenomena in an aqueous solution having a salt content of 100,000ppm (with the content of calcium and magnesium ions being 5,000 ppm); the system is resistant to high temperature and wide in application temperature range; the system is neutral, free of organochlorine and free of alkali and does not cause harm to stratums; and the system can greatly reduce water injection pressure for a water injection well and increase the water injection efficiency.

Description

technical field [0001] The invention provides a Gemini surfactant system for reducing pressure and increasing injection for water injection wells in the petroleum industry and a preparation method thereof. Specifically, it is a broad-spectrum, salt-resistant, temperature-resistant, organic chlorine-free, alkali-free, no damage to the formation, suitable for all oil fields such as carbonates and sandstones, including small fault block oil fields, low permeability oil fields, Gemini surfactant system for pressure-reducing and injection-increasing in ultra-low permeability oilfields and its preparation method. Background technique [0002] In the middle and later stages of oilfield exploitation, many wells were acidified many times but the measures were not effective. Some wells were acidified and fractured. Reservoirs cause great damage, resulting in reduced water injection capacity. During the water injection process, there will be problems such as high water injection press...

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Problems solved by technology

[0002] In the middle and later stages of oilfield exploitation, many wells were acidified many times but the measures were not effective. Some wells were acidified and fractured. Reservoirs cause great damage, resulting in reduced water injection capacity. During the water injection process, there will be problems such as high water injection pressure, failure to inject, and insufficient injection.

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