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...

Examples

Embodiment 1

[0029] This embodiment provides a CO 2 The corrosion inhibitor and scale remover for oil flooding is composed of the following substances by weight percentage: benzoic acid thioureido imidazoline 18%, benzoic acid phosphate ester thioureido imidazoline 2%, isopropanol 11%, acetic acid 8%, Sodium polyepoxysuccinate 13%, OP-10 6%, quinoline quaternary ammonium salt 14%, sodium polystyrene sulfonate 7%, disodium edetate 8%, sodium diethylenetriaminepentaacetate 12%, N-dodecylmethylene bis-secondary ammonium salt 2%, and the balance is water.

[0030] Wherein, the benzoic acid phosphate thioureido imidazoline is prepared by reacting equimolar amounts of benzoic acid thioureido imidazoline and dimethyl phosphite in ethanol.

[0031] The preparation method of benzoic acid thioureidoimidazoline comprises the following steps:

[0032] Step 1) Take n (benzoic acid): n (tetraethylenepentamine) = 1:1.2 as raw material, use xylene as water carrier, react at 170°C for 3h for the first de...

Embodiment 2

[0040] This embodiment provides a CO 2 The corrosion inhibitor and scale remover for oil flooding is composed of the following substances by weight percentage: benzoic acid thioureido imidazoline 17%, benzoic acid phosphate ester thioureido imidazoline 1%, isopropanol 9%, acetic acid 7%, Sodium polyepoxysuccinate 11%, OP-10 3%, quinoline quaternary ammonium salt 12%, sodium polystyrene sulfonate 3%, disodium edetate 5%, sodium diethylenetriaminepentaacetate 11%, N-dodecylmethylene bis-secondary ammonium salt 2%, and the balance is water.

[0041] Wherein, the preparation method of benzoic acid thioureido imidazoline, benzoic acid phosphate ester thioureido imidazoline, and quinoline quaternary ammonium salt is the same as in Example 1. See Example 1 for the preparation method of the corrosion inhibitor and scale remover.

[0042] Through the synergistic effect of the above components, not only CO 2 Corrosion has a good corrosion inhibition effect; and it has a good scale in...

Embodiment 3

[0044] This embodiment provides a CO 2 The corrosion inhibitor and scale remover for oil flooding is composed of the following substances in weight percent: benzoic acid thioureido imidazoline 21%, benzoic acid phosphate ester thioureido imidazoline 3%, isopropanol 13%, acetic acid 11%, Sodium polyepoxysuccinate 15%, OP-10 7%, quinoline quaternary ammonium salt 16%, sodium polystyrene sulfonate 7%, disodium edetate 9%, sodium diethylenetriaminepentaacetate 15%, N-dodecylmethylene bis-secondary ammonium salt 6%, the balance is water.

[0045] Wherein, the preparation method of benzoic acid thioureido imidazoline, benzoic acid phosphate ester thioureido imidazoline, and quinoline quaternary ammonium salt is the same as in Example 1. See Example 1 for the preparation method of the corrosion inhibitor and scale remover.

[0046] The corrosion inhibitor and scale remover is aimed at low permeability oil reservoirs with high salinity and high scaling tendency 2 It was developed f...

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...

Examples

Embodiment 1

[0029] This embodiment provides a CO 2 The corrosion inhibitor and scale remover for oil flooding is composed of the following substances by weight percentage: benzoic acid thioureido imidazoline 18%, benzoic acid phosphate ester thioureido imidazoline 2%, isopropanol 11%, acetic acid 8%, Sodium polyepoxysuccinate 13%, OP-10 6%, quinoline quaternary ammonium salt 14%, sodium polystyrene sulfonate 7%, disodium edetate 8%, sodium diethylenetriaminepentaacetate 12%, N-dodecylmethylene bis-secondary ammonium salt 2%, and the balance is water.

[0030] Wherein, the benzoic acid phosphate thioureido imidazoline is prepared by reacting equimolar amounts of benzoic acid thioureido imidazoline and dimethyl phosphite in ethanol.

[0031] The preparation method of benzoic acid thioureidoimidazoline comprises the following steps:

[0032] Step 1) Take n (benzoic acid): n (tetraethylenepentamine) = 1:1.2 as raw material, use xylene as water carrier, react at 170°C for 3h for the first de...

Embodiment 2

[0040] This embodiment provides a CO 2 The corrosion inhibitor and scale remover for oil flooding is composed of the following substances by weight percentage: benzoic acid thioureido imidazoline 17%, benzoic acid phosphate ester thioureido imidazoline 1%, isopropanol 9%, acetic acid 7%, Sodium polyepoxysuccinate 11%, OP-10 3%, quinoline quaternary ammonium salt 12%, sodium polystyrene sulfonate 3%, disodium edetate 5%, sodium diethylenetriaminepentaacetate 11%, N-dodecylmethylene bis-secondary ammonium salt 2%, and the balance is water.

[0041] Wherein, the preparation method of benzoic acid thioureido imidazoline, benzoic acid phosphate ester thioureido imidazoline, and quinoline quaternary ammonium salt is the same as in Example 1. See Example 1 for the preparation method of the corrosion inhibitor and scale remover.

[0042] Through the synergistic effect of the above components, not only CO 2 Corrosion has a good corrosion inhibition effect; and it has a good scale in...

Embodiment 3

[0044] This embodiment provides a CO 2 The corrosion inhibitor and scale remover for oil flooding is composed of the following substances in weight percent: benzoic acid thioureido imidazoline 21%, benzoic acid phosphate ester thioureido imidazoline 3%, isopropanol 13%, acetic acid 11%, Sodium polyepoxysuccinate 15%, OP-10 7%, quinoline quaternary ammonium salt 16%, sodium polystyrene sulfonate 7%, disodium edetate 9%, sodium diethylenetriaminepentaacetate 15%, N-dodecylmethylene bis-secondary ammonium salt 6%, the balance is water.

[0045] Wherein, the preparation method of benzoic acid thioureido imidazoline, benzoic acid phosphate ester thioureido imidazoline, and quinoline quaternary ammonium salt is the same as in Example 1. See Example 1 for the preparation method of the corrosion inhibitor and scale remover.

[0046] The corrosion inhibitor and scale remover is aimed at low permeability oil reservoirs with high salinity and high scaling tendency 2 It was developed f...