Graded retarded cross-linked emulsified acid and preparation method thereof

Abstract

The invention discloses a graded retarded cross-linked emulsified acid which comprises a cross-linked acid and an emulsified acid, wherein the content of the cross-linking acid is 50-80 parts by volume, preferably 55-75 parts by volume, the content of the emulsified acid is 20-50 parts by volume, preferably 25-45 parts by volume, the cross-linking acid comprises a cross-linking acid base solutionand a cross-linking agent, the content of the cross-linking acid base solution in the cross-linking acid is 94.8 to 107 parts by weight, preferably 101.5 to 104.5 parts by weight, the content of the cross-linking agent is 0.6 to 1.5 parts by weight, preferably 0.8 to 1.2 parts by weight, the emulsified acid comprises an oil phase and an acid phase, the content of the oil phase is 20-40 parts by volume, preferably 25-35 parts by volume, and the content of the acid phase is 60-80 parts by volume, preferably 65-75 parts by volume. The graded retarded cross-linked emulsified acid is a novel acid liquid system, has the advantages of high apparent viscosity, low filtration loss, good temperature stability, good retarding effect and the like, meets the acid fracturing application of high-temperature reservoirs, and is simple in preparation method and worthy of popularization and application.

Description

technical field

[0001] The invention relates to a graded slow-speed cross-linked emulsified acid and a preparation method thereof, belonging to the field of acid fracturing stimulation of carbonate rock reservoirs. Background technique

[0002] Ground cross-linked acid and emulsified acid are the most commonly used retarded acid systems for low-permeability, fracture-vuggy, and fractured carbonate reservoirs and acid fracturing. The ground cross-linking acid refers to adding a thickener (or gelling agent) to the acid (such as hydrochloric acid) to increase the viscosity of the acid solution, and then adding a cross-linking agent to form an adjustable hanging jelly acid system, thereby reducing the transmission and diffusion of H+ rate, reduce fluid loss, prolong acid action distance, and improve the effect of acid fracturing. Emulsified acid is an acid-in-oil emulsion formed by mixing oil phase and acid phase. It has the advantages of good retarding performance, small filtr...

Examples

Embodiment 1

[0055] 1) prepare the emulsified acid phase by the following components by weight: get 97.0 parts of 15% hydrochloric acid aqueous solution, under the rotating speed of 500r / min, add 1.0 parts of iron ion stabilizer ethylenediaminetetraacetic acid (Tianjin Guangfu Chemical Reagent Factory) and 2.0 parts of imidazoline corrosion inhibitor, stir evenly;

[0056] 2) The oil phase was prepared according to the following components by weight: 2.0 parts of dipolyhydroxystearate and 0.5 part of hexadecylamine were heated and dissolved in diesel oil, stirred evenly, and cooled to room temperature;

[0057] 3) Prepare the emulsified acid according to the following components by volume: under the condition of stirring speed of 1500r / min, slowly add the prepared acid phase into the oil phase, the volume ratio of the acid phase and the oil phase is 70:30, drop Continue to stir for 20 minutes after adding to obtain emulsified acid system;

[0058] 4) Prepare the cross-linked acid base sol...

Embodiment 2

[0062] 1) Prepare the emulsified acid phase according to the following components by weight: take 96.5 parts of 15% hydrochloric acid aqueous solution, at 500r / min rotating speed, add 1.2 parts of iron ion stabilizer citric acid (commercially available) and 2.3 parts of quinoline quaternary ammonium salt Class corrosion inhibitor (commercially available), stir evenly;

[0063] 2) The oil phase was prepared according to the following components by weight: 2.0 parts of sorbitan sesquioleate and 0.5 parts of polyoxyethylene octylphenol ether-10 were heated and dissolved in diesel oil, stirred evenly, and cooled to room temperature;

[0064] 3) Prepare the emulsified acid according to the following components by volume: under the condition of stirring speed of 2000r / min, slowly add the prepared acid phase into the oil phase, the volume ratio of the acid phase and the oil phase is 65:35, drop Continue to stir for 15 minutes after adding to obtain emulsified acid system;

[0065] 4...

Embodiment 3

[0069] 1) Prepare the emulsified acid phase according to the following components by weight: Take 96.0 parts of 20% hydrochloric acid aqueous solution, at 500r / min rotating speed, add 1.5 parts of iron ion stabilizer acetic acid and citric acid 1:1 mixture (commercially available) and 2.5 parts Paraformaldehyde / p-aniline / acetophenone corrosion inhibitor (commercially available), stirred evenly;

[0070] 2) The oil phase was prepared according to the following components by weight: 2.0 parts of sorbitan fatty acid ester and 0.5 part of polyoxyethylene octylphenol ether-10 were heated and dissolved in diesel oil, stirred evenly, and cooled to room temperature;

[0071] 3) Prepare the emulsified acid according to the following components by volume: under the condition of stirring speed of 2500r / min, slowly add the prepared acid phase into the oil phase, the volume ratio of the acid phase and the oil phase is 60:40, drop Continue to stir for 10 minutes after the addition to obtain...

technical field

[0001] The invention relates to a graded slow-speed cross-linked emulsified acid and a preparation method thereof, belonging to the field of acid fracturing stimulation of carbonate rock reservoirs. Background technique

[0002] Ground cross-linked acid and emulsified acid are the most commonly used retarded acid systems for low-permeability, fracture-vuggy, and fractured carbonate reservoirs and acid fracturing. The ground cross-linking acid refers to adding a thickener (or gelling agent) to the acid (such as hydrochloric acid) to increase the viscosity of the acid solution, and then adding a cross-linking agent to form an adjustable hanging jelly acid system, thereby reducing the transmission and diffusion of H+ rate, reduce fluid loss, prolong acid action distance, and improve the effect of acid fracturing. Emulsified acid is an acid-in-oil emulsion formed by mixing oil phase and acid phase. It has the advantages of good retarding performance, small filtr...

Examples

Embodiment 1

[0055] 1) prepare the emulsified acid phase by the following components by weight: get 97.0 parts of 15% hydrochloric acid aqueous solution, under the rotating speed of 500r / min, add 1.0 parts of iron ion stabilizer ethylenediaminetetraacetic acid (Tianjin Guangfu Chemical Reagent Factory) and 2.0 parts of imidazoline corrosion inhibitor, stir evenly;

[0056] 2) The oil phase was prepared according to the following components by weight: 2.0 parts of dipolyhydroxystearate and 0.5 part of hexadecylamine were heated and dissolved in diesel oil, stirred evenly, and cooled to room temperature;

[0057] 3) Prepare the emulsified acid according to the following components by volume: under the condition of stirring speed of 1500r / min, slowly add the prepared acid phase into the oil phase, the volume ratio of the acid phase and the oil phase is 70:30, drop Continue to stir for 20 minutes after adding to obtain emulsified acid system;

[0058] 4) Prepare the cross-linked acid base sol...

Embodiment 2

[0062] 1) Prepare the emulsified acid phase according to the following components by weight: take 96.5 parts of 15% hydrochloric acid aqueous solution, at 500r / min rotating speed, add 1.2 parts of iron ion stabilizer citric acid (commercially available) and 2.3 parts of quinoline quaternary ammonium salt Class corrosion inhibitor (commercially available), stir evenly;

[0063] 2) The oil phase was prepared according to the following components by weight: 2.0 parts of sorbitan sesquioleate and 0.5 parts of polyoxyethylene octylphenol ether-10 were heated and dissolved in diesel oil, stirred evenly, and cooled to room temperature;

[0064] 3) Prepare the emulsified acid according to the following components by volume: under the condition of stirring speed of 2000r / min, slowly add the prepared acid phase into the oil phase, the volume ratio of the acid phase and the oil phase is 65:35, drop Continue to stir for 15 minutes after adding to obtain emulsified acid system;

[0065] 4...

Embodiment 3

[0069] 1) Prepare the emulsified acid phase according to the following components by weight: Take 96.0 parts of 20% hydrochloric acid aqueous solution, at 500r / min rotating speed, add 1.5 parts of iron ion stabilizer acetic acid and citric acid 1:1 mixture (commercially available) and 2.5 parts Paraformaldehyde / p-aniline / acetophenone corrosion inhibitor (commercially available), stirred evenly;

[0070] 2) The oil phase was prepared according to the following components by weight: 2.0 parts of sorbitan fatty acid ester and 0.5 part of polyoxyethylene octylphenol ether-10 were heated and dissolved in diesel oil, stirred evenly, and cooled to room temperature;

[0071] 3) Prepare the emulsified acid according to the following components by volume: under the condition of stirring speed of 2500r / min, slowly add the prepared acid phase into the oil phase, the volume ratio of the acid phase and the oil phase is 60:40, drop Continue to stir for 10 minutes after the addition to obtain...

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