a co 2 Corrosion inhibitor and scale remover for oil displacement, preparation method and application method

Abstract

The present invention provides a CO 2 Corrosion inhibitor and scale remover for oil flooding, preparation method and use method, composed of the following substances in weight percentage: benzoic acid thioureido imidazoline 17-21%, benzoic acid phosphate ester thioureido imidazoline 1-3%, Isopropanol 9‑13%, acetic acid 7‑11%, polyepoxysuccinate sodium 11‑15%, OP‑10 3‑7%, quinoline quaternary ammonium salt 12‑16%, polystyrene sulfonate sodium 3-7%, disodium edetate 5-9%, sodium diethylenetriaminepentaacetate 11-15%, N-dodecylmethylene bis-secondary ammonium salt 2-6%, the balance is water. To overcome the existing corrosion inhibitors and scale inhibitors usually have a single corrosion and anti-corrosion effect and scale inhibition effect, while effectively preventing the occurrence of scaling in oilfield water, it can also effectively inhibit corrosion, especially for The barium-strontium scale formed by the formation water with high barium-strontium ions has better scale removal effect.

Description

technical field [0001] The invention belongs to the technical field of oilfield water treatment, in particular to a CO 2 Corrosion inhibitor and scale remover for oil displacement, preparation method and application method. Background technique [0002] At present, more than 70% of my country's newly discovered and discovered undeveloped crude oil reserves are low-permeability oil fields and hard-to-recover reserves. Such oil fields are difficult to develop economically and effectively, and the oil recovery rate is low. Field practice at home and abroad proves that CO 2 Oil flooding can greatly increase the recovery rate of low-permeability oilfields and the production rate of hard-to-recover reserves. Miscible oil flooding can increase oil recovery by more than 10%, and immiscible oil flooding can increase oil recovery by more than 7%. [0003] CO 2 Water injection is used for development before flooding, since the formation water is CaCl 2 Water type, high average sali...

AI Technical Summary

Problems solved by technology

[0005] At present, the application of corrosion inhibitors and scale inhibitors in oilfields can slow down the formation of downhole oilfield scale, but corrosion inhibitors and scale inhibitors only have anti-corrosion and anti-scale effects. The efficiency is limited. The scale accumulated in long-term production will aggravate the under-scale corrosion of the pipe string, which seriously affects the service life of the pipe string and the production efficiency of the oil field.