Oil displacement method using anion-cation complex surfactant

Abstract

The invention relates to a method of displacing oil by anionic-cationic composite surfactant and mainly solves the problems that the prior method of displacing oil by surfactant is low in oil displacement efficiency in tertiary oil recovery and an oil displacement system containing inorganic base is harmful to stratums and oil wells, corrosive to equipment and pipelines and difficult for demulsification. According to the technical scheme, crude oil is allowed to contact with oil-displacing agent, and the oil-displacing agent comprises, by weight percent, 0.01-5.0% of anionic-cationic composite surfactant, 0.01-3.0% of polymer, and 92.0-99.98% of injected water. The problems are solved well. The method is applicable to tertiary oil recovery for oil fields.

Description

technical field

[0001] The invention relates to an oil displacement method using anion and cation compound surfactants. Background technique

[0002] With the increase of the world's energy demand, the rational development and utilization of oil has attracted great attention, and the requirements for the amount and efficiency of oil extraction are also getting higher and higher. Realizing the efficient exploitation of oil and gas resources not only has practical significance for increasing crude oil production, but also has important strategic significance. Conventional oil recovery methods (primary and secondary methods) generally only produce 1 / 3 of the crude oil geological reserves, and about 2 / 3 of the crude oil has not been recovered. Therefore, in the case of increasingly tight energy sources, enhanced oil recovery It has become a major topic in oil exploration research. Tertiary oil recovery technology is an effective method to increase oil recovery, which can be di...

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