High-temperature high-salt resistant nano emulsion viscosity-reducing agent

Abstract

The invention relates to a high-temperature and high-salt-resistant nano-emulsion viscosity reducer used for heavy oil exploitation and transportation. It uses surfactants, and at the same time adds alkaline additives and nano additives to significantly improve the effect of emulsification and viscosity reduction. The viscosity reducer is composed of non-ionic surfactant, anionic surfactant, modified nano additive, NaOH, accelerator and water. The preparation method is: add 5-7% of OP-10, 2-5% of accelerator, 0.5-2% of modified nano additives at normal temperature and pressure, and stir evenly; then add anionic surfactant 30-45 %, add O1~3% flatly; finally add NaOH 20~30% and water 20~40%, and then stir continuously at a speed of 60~120r / min for 60~90min to obtain this nanoemulsion viscosity reducer product. The viscosity reducer system has good stability and will not coalesce during storage; the formed oil-in-water particles are smaller and more uniform, which improves the seepage capacity; it can greatly reduce interfacial tension and improve oil displacement efficiency, and can be used for heavy oil recovery and delivery fields.

Description

technical field [0001] The invention relates to a high-temperature and high-salt-resistant nano-emulsion viscosity reducer used in the field of petroleum exploitation for the exploitation and transportation of heavy oil. Background technique [0002] At present, although there are many formulations of emulsified viscosity reducers, there are still many problems: ①It is difficult to treat produced fluid sewage; ②Emulsified viscosity reducers have strong selectivity to heavy oil and are not universal; ③Currently However, there are not many emulsified viscosity reducers that can be used in high-temperature and high-salinity reservoir conditions. Even if there are some reports in the literature, most of them are relatively expensive. Therefore, it is an important development direction of emulsification viscosity reduction technology to study cheap salt-resistant and high-temperature-resistant viscosity reducers. In addition, in view of the fact that most of the old oil fields w...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is: in order to overcome the shortcomings of single use of surfactant steam injection, small viscosity reduction range and short cycle, the organic acid in crude oil is used to reduce the amount of surfactant, and the addition of alkaline additives and nano additives , produce a synergistic effect with the emulsifying viscosity reducer to significantly improve the effect of emulsifying viscosity reducing, and provide a high-temperature and high-salt nano-emulsion viscosity reducing agent