Nano oil displacement agent based on destroying oil-rock interaction as well as preparation method and application of nano oil displacement agent

Abstract

The invention discloses a nano oil displacement agent based on destroying oil-rock interaction. The nano oil displacement agent comprises the following components in percentage by weight: 10-30% of an aldehyde group-containing reducing agent, 8-15% of an amino silane coupling agent, 0.01-0.1% of a pH regulator and the balance of water. According to the nanometer oil displacement agent based on destroying the oil-rock interaction, the reaction is controlled through the aldehyde group-containing reducing agent, the reaction process is milder, the particle size of nanoparticles in the obtained product is small (1-8 nm), the uniformity is high, the dispersion stability is high, in addition, multiple functional groups exist on the surface, further modification is facilitated, and the oil displacement effect is good. The surfactant prepared by the method can be better matched with a micro-nano pore throat of a low-permeability / ultra-low-permeability oil reservoir, an oil film on the wall surface of a pore throat structure can be more easily stripped, the oil displacement effect of the surfactant is better than that of a common surfactant and nano silicon dioxide, and the surfactant is suitable for industrial popularization and application.

Description

technical field [0001] The invention relates to the technical field of oilfield development, in particular to a nanometer oil-displacing agent based on destroying oil-rock interaction and a preparation method and application thereof. Background technique [0002] In recent years, the newly proven low-permeability / ultra-low permeability reserves in China are extremely abundant, which has become an important replacement force for conventional oil resources. Low-permeability / ultra-low permeability reservoirs are characterized by well-developed micro-nano-scale pore throats, small pore throats, and low porosity. More than 80% of movable crude oil is stored in pores of 0.01-10.0 μm. Therefore, depending on the low degree of natural energy recovery, it is difficult to supplement the formation energy, and the formation energy must be supplemented by water injection. However, due to the small matrix pore throat and large specific surface area of ​​this low-permeability / ultra-low pe...

AI Technical Summary

Problems solved by technology

However, existing nano-SiO 2 The reaction process is generally uncontrollable, which leads to easy agglomeration in the growth process, relatively large particle size (15nm), poor uniformity, poor dispersion and stability, and easy self-accumulation and settlement to block the reservoir. Nanopore throats have poor adaptability and are not easy to peel off the oil film on the rock surface, resulting in low oil recovery; at the same time, the surface of traditional nano-SiO2 is coated with a large number of single hydroxyl groups, and the particles are easy to agglomerate due to the hydrogen bond of hydroxyl groups, which destroys the oil displacement performance; , a single surface group makes the chemical modification of particles single and complex, which seriously limits its development and application

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