阅读说明：本技术 一种双重缓速乳化自生酸及制备方法 (Double-retarding emulsifying self-generated acid and preparation method thereof ) 是由 贾文峰 王旭 蒋廷学 姚奕明 魏娟明 吴峙颖 于 2018-06-26 设计创作，主要内容包括：本发明公开了一种双重缓速乳化自生酸及制备方法。所述乳化自生酸包括以体积份数计的以下组分：自生酸60～80份；油相20～40份；其中,以油相总量为100重量份计,所述油相中包含有3～5重量份乳化剂。制备方法包括：自生酸按所述用量,在1000r/min～3000r/min高速搅拌下,滴加入油相,搅拌10～30min,形成均匀乳液,制得所述双重缓速乳化自生酸。本发明的乳化自生酸的乳液结合自生酸与乳化酸的优点,可以在200℃具有良好的稳定性,可以满足超高温碳酸盐岩储层酸压/酸化施工,具有良好的推广应用前景。(The invention discloses a double slow-speed emulsification self-generated acid and a preparation method thereof. The emulsified self-generated acid comprises the following components in parts by volume: 60-80 parts of self-generated acid; 20-40 parts of an oil phase; wherein the total weight of the oil phase is 100 parts by weight, and the oil phase contains 3-5 parts by weight of emulsifier. The preparation method comprises the following steps: dropwise adding the oil phase into the self-generated acid according to the using amount under the high-speed stirring of 1000 r/min-3000 r/min, and stirring for 10-30 min to form uniform emulsion, thereby preparing the double slow-speed emulsified self-generated acid. The emulsion of the emulsified authigenic acid combines the advantages of authigenic acid and emulsified acid, has good stability at 200 ℃, can meet the requirement of acid fracturing/acidizing construction of an ultrahigh-temperature carbonate rock reservoir, and has good popularization and application prospects.)

1. The double slow-speed emulsification authigenic acid is characterized by comprising the following components in parts by volume:

60-80 parts of self-generated acid;

20-40 parts of an oil phase;

wherein the total weight of the oil phase is 100 parts by weight, and the oil phase contains 3-5 parts by weight of emulsifier.

2. The dual retarded emulsified autogenous acid as claimed in claim 1 wherein:

the method comprises the following steps of (1) counting by volume parts:

65-75 parts of self-generated acid;

25-35 parts of an oil phase;

the total weight of the oil phase is 100 parts by weight, and the oil phase contains 3.5-4.5 parts by weight of an emulsifier.

3. The dual retarded emulsified autogenous acid as claimed in claim 1 wherein:

the self-generated acid comprises: chloroacetate, corrosion inhibitor, iron ion stabilizer and water;

the components are calculated by weight portion:

4. the dual retarded emulsified autogenous acid as claimed in claim 1 wherein:

the authigenic acid comprises authigenic acid A and authigenic acid B;

the authigenic acid A comprises: polyaldehyde, water, sodium hydroxide, a corrosion inhibitor and an iron ion stabilizer;

the components are calculated by weight portion:

the authigenic acid B is an ammonium chloride aqueous solution, and comprises the following components in parts by weight:

100 parts by weight of ammonium chloride;

30-60 parts of water.

5. The dual retarded emulsified autogenous acid as claimed in claim 4 wherein:

the mass ratio of the authigenic acid A to the authigenic acid B is 1: 1-2: 1.

6. The dual retarded emulsified autogenous acid as claimed in any one of claims 3 to 5 wherein:

the iron ion stabilizer is at least one selected from citric acid, ethylenediamine tetraacetic acid and ascorbic acid;

the corrosion inhibitor is at least one of imidazoline corrosion inhibitors and Mannich base corrosion inhibitors.

7. The dual retarded emulsified autogenous acid as claimed in claim 1 wherein:

the oil phase is one or a combination of diesel oil, kerosene, white oil and crude oil;

the emulsifier is one or a combination of sorbitan fatty acid ester, sorbitan sesquioleate, self-sorbitan fatty acid ester, alkylphenol polyoxyethylene, dodecylamine, tetradecylamine and hexadecylamine.

8. A process for the preparation of a double retarded emulsified autogenous acid as claimed in any one of claims 1 to 7, which comprises:

dropwise adding the oil phase into the self-generated acid according to the using amount under the high-speed stirring of 1000 r/min-3000 r/min, and stirring for 10-30 min to form uniform emulsion, thereby preparing the double slow-speed emulsified self-generated acid.

9. The method of claim 8, wherein the double retarded emulsified acid is prepared by:

dropwise adding the authigenic acid A into the oil phase, and stirring and mixing uniformly at a high speed; and dropwise adding the authigenic acid B into the oil phase, stirring at a high speed, uniformly mixing, and mixing the two to obtain the double slow-speed emulsification authigenic acid.

Technical Field

The invention relates to the field of acid fracturing production increase of carbonate reservoirs, in particular to a double-retarding emulsification self-generated acid and a preparation method thereof.

Background

With the continuous deepening of the exploration and development of carbonate reservoirs, in order to meet the requirement of deep acidification, the performance requirement of an acid liquor system is higher and higher, and a novel high-temperature-resistant retarded acid liquor system needs to be developed urgently.

Autogenous acids, also known as latent acids, refer to acid precursors that form reactive acids in situ by chemical reaction under formation conditions, and different autogenous acid systems can produce HCl and HF or a mixture of both. The use of the self-acid-generating system in high-temperature stratum can not only avoid the problems of rapid inactivation of acid liquor at high temperature, shortening of effective length of acid corrosion cracks and the like, but also prevent corrosion of pipelines and equipment, but most of the self-acid-generating systems have the problems of poor temperature resistance, large filtration loss, poor flow conductivity and the like. The emulsified acid is an acid-in-oil emulsion formed by mixing an oil phase and an acid phase, and has the advantages of good retarding performance, small filtration loss, low corrosion rate and the like.

Chinese patent CN102899012A discloses a self-generated acid, a preparation method and application thereof, wherein the self-generated acid comprises paraformaldehyde, ammonium chloride and water, hydrochloric acid can be slowly generated by mixing the self-generated acid at room temperature, the acid is rapidly generated under the heating condition, the problems of serious filtration loss, poor temperature resistance and poor etching form exist, the self-generated acid cannot be used in a high-temperature deep well, and the self-generated acid does not have double retarding effects. When the self-generated acid meets formation water, the acid liquor can be quickly diluted, and a good acidification effect cannot be achieved.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a double slow-speed emulsification authigenic acid and a preparation method thereof. The acid liquor system of the invention integrates the advantages of the self-generated acid and the emulsified acid into a whole and has excellent performance. Under the condition of a high-temperature carbonate reservoir, hydrochloric acid is gradually generated and is gradually released along with the destruction of the emulsion, so that the emulsion is a novel dual retarded acid system, and the emulsion has good temperature resistance and deep penetration performance.

One of the objects of the present invention is to provide a dual retarded emulsifying autogenous acid.

The emulsified self-generated acid comprises the following components in parts by volume:

60-80 parts of authigenic acid, preferably 65-75 parts;

20-40 parts of an oil phase, preferably 25-35 parts;

wherein the total using amount of the oil phase is 100 parts by weight, the oil phase comprises 3-5 parts by weight of emulsifier, preferably 3.5-4.5 parts by weight.

Wherein, the self-generating acid can be selected from all self-generating acids in the prior art, and in the invention, the following self-generating acids can be preferably selected:

the self-generated acid comprises: chloroacetate, corrosion inhibitor, iron ion stabilizer and water;

the components are calculated by weight portion:

preferably, the authigenic acid includes authigenic acid a and authigenic acid B;

the authigenic acid A comprises: polyaldehyde, water, sodium hydroxide, a corrosion inhibitor and an iron ion stabilizer;

the components are calculated by weight portion:

the authigenic acid B is an ammonium chloride aqueous solution, and comprises the following components in parts by weight:

100 parts by weight of ammonium chloride;

30-60 parts of water.

The mass ratio of the authigenic acid A to the authigenic acid B is 1: 1-2: 1.

the iron ion stabilizer may be any iron ion stabilizer commonly used in the art, such as: at least one selected from citric acid, ethylenediamine tetraacetic acid and ascorbic acid; the dosage of the compound is conventional, the technical personnel can adjust the compound according to the actual situation, and 0.5-1.5 parts by weight is preferred in the invention.

The corrosion inhibitor may be a high temperature corrosion inhibitor commonly used in the art, such as: at least one of imidazoline corrosion inhibitor and Mannich base corrosion inhibitor. The dosage of the compound is conventional, the technical personnel can adjust the compound according to the actual situation, and 0.5-1.5 parts by weight is preferred in the invention.

The oil phase is oil capable of dissolving emulsifier, such as one or combination of diesel oil, kerosene, white oil and crude oil;

the emulsifier is commonly used in the art for emulsifying acids such as: sorbitan fatty acid ester, sorbitan sesquioleate, self-sorbitan fatty acid ester, alkylphenol ethoxylates, dodecylamine, tetradecylamine and hexadecylamine.

The invention also aims to provide a preparation method of the double slow-speed emulsification authigenic acid.

The method comprises the following steps:

and dripping the oil phase into the self-generated acid under the condition of telling stirring at 1000 r/min-3000 r/min according to the dosage, and stirring for 10-30 min to form uniform emulsion, thus obtaining the double slow-speed emulsification self-generated acid.

Preferably:

dropwise adding the authigenic acid A into the oil phase, and stirring and mixing uniformly at a high speed; and dropwise adding the authigenic acid B into the oil phase, stirring at a high speed, uniformly mixing, and mixing the two to obtain the double slow-speed emulsification authigenic acid.

Of these, the oil phase is preferably used in an amount of 1:1 ratio, i.e., 1/2 oil phase is mixed with the authigenic acid A and 1/2 oil phase is mixed with the authigenic acid B.

The following technical scheme can be specifically adopted:

the preparation steps of the oil phase are as follows:

1) measuring an oil phase with a certain volume, adding a certain amount of high-efficiency emulsifier, heating and stirring until the oil phase is completely dissolved;

2) the oil mixture was cooled to room temperature for use.

The preparation steps of the authigenic acid parent body B are as follows:

measuring a certain mass of water, weighing a certain mass of B salt, adding the salt into the water, and stirring until the salt is dissolved.

The emulsified acid generating system is prepared as follows:

slowly dripping the authigenic acid parent substance A into the oil phase, and stirring at a high speed during and after the addition so as to uniformly mix the authigenic acid parent substance A and the oil phase and form uniform emulsion. Then adding the autogenous acid parent body B by the same method to form uniform emulsion, mixing the two emulsions according to the required proportion before acid fracturing construction, and pumping the two emulsions into the stratum; alternatively, a and B are mixed and then emulsified together to form an emulsion and finally pumped into the formation.

The invention integrates the excellent performances of emulsified acid and self-generated acid, and utilizes the binary synergistic effect to obtain a novel acid solution system. Emulsifying parent substance A, B of authigenic acid into diesel oil/crude oil respectively by using emulsifier to form stable emulsion, and mixing according to proportion before entering a well to form a novel emulsified authigenic acid system or emulsifying mixture A and B to form emulsion.

The emulsified autogenous acid is an emulsion formed by mixing an oil phase and the autogenous acid, after the emulsion is injected into a stratum, the emulsion has high viscosity and can be used for fracturing seams, the emulsion is gradually broken under the conditions of high temperature and rock friction, the parent body of the autogenous acid is released and gradually reacts to generate H⁺Reacting with the rock. The self-generated acid parent substance is controlled to release and gradually react to generate H⁺So as to achieve the purposes of deep acid fracturing and non-uniform etching. By adjusting the type of the emulsifier, the emulsion emulsifying the self-generated acid matrix can have good stability at 200 ℃, and can meet the acid fracturing/acidizing construction of an ultrahigh-temperature carbonate rock reservoir. The emulsified self-generated acid combines the advantages of the self-generated acid and the emulsified acid, is a novel programmed controlled-release dual-slow acid system, and has good popularization and application prospects.

Compared with the conventional acid liquid system, the emulsified self-generating acid system obtained by the technical scheme of the invention has the characteristics of better retarding performance, temperature resistance, high flow conductivity and the like, and has a good acidification effect after being injected into a stratum.

Detailed Description

The technical scheme and technical effects of the present invention are further described below with reference to specific embodiments. The examples described below are only preferred embodiments of the present invention, and it will be apparent to those skilled in the art that several modifications and variations can be made to the technical solution of the present invention without departing from the principle of the invention, and those related improvements and modifications are also within the protective scope of the present invention.