Carbon dioxide response self-thickening intelligent fluid based on supramolecular self-assembly

Abstract

The invention discloses a carbon dioxide response self-thickening intelligent fluid based on supramolecular self-assembly. The carbon dioxide response self-thickening intelligent fluid comprises a Gemini surfactant, a single-chain amide molecule with a tertiary amine head group and water; the Gemini surfactant and the single-chain amide molecule with the tertiary amine head group are self-assembled to form a vesicle structure which is dispersed in water; and the hydrophilic head group is arranged outside, and the hydrophobic tail part is arranged inside. The preparation method of the carbon dioxide response self-thickening intelligent fluid is simple, and the injection viscosity is low. The fluid is converted into gel after encountering carbon dioxide, and the viscosity is greatly increased. The problem that when the recovery ratio is increased through carbon dioxide gas drive of a low-permeability reservoir, gas flows along a local high-permeability channel, and consequently the swept volume is greatly reduced is effectively solved.

Description

technical field [0001] The invention relates to the technical field of oil and gas field development, in particular to a carbon dioxide-responsive self-thickening intelligent fluid based on supramolecular self-assembly and its preparation and application. Background technique [0002] Carbon dioxide flooding is the second largest enhanced oil recovery technology in the world, and it is one of the main methods to enhance the recovery of low-permeability reservoirs. Carbon dioxide flooding enhanced oil recovery technology has been widely valued by countries all over the world due to its advantages such as wide application range, high oil displacement efficiency and low cost. [0003] However, in field applications, gas channeling caused by various factors such as reservoir heterogeneity severely restricts the gas sweep volume, making it difficult for carbon dioxide flooding to achieve the experimental results of indoor oil flooding. [0004] Aiming at the problem of gas chann...

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Problems solved by technology

[0005] However, the existing technical schemes have the following problems: the water-gas alternating injection method is a technology for enhancing recovery by combining two traditional technologies of water flooding and gas flooding, but the completion cost is high, the process is complicated, and it cannot adapt to strong heterogeneity. quality conditions; the gel sealing channeling method is to use high molecular polymer cross-linking as a gel to realize the sealing of local hypertonic strips, but the high molecular weight involved in this method is large (10-15 million), low-permeable oil The injection ability is not good under reservoir conditions, and the formed cross-linked gel will cause permanent damage to the reservoir; the chemical precipitation method uses the precipitate generated by the reaction of chemical reagents and carbonates to block the channel of carbon dioxide gas channeling, but the chemical The controllability of the precipitation reaction is weak; the challenge of CO2 foam sealing is that the generated foam strength is not high, and it is difficult to control the foaming under the reservoir conditions; the CO2 thickening technology is a technology that directly thickens the CO2 gas. The research on the method is not thorough enough, and there are problems such as high configuration cost and difficult configuration process

However, the synthesis process of the two responsive materials mentioned by researchers such as Jessop and Feng is complicated and costly, making it difficult to realize industrial scale application.

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