CN116120911A - Cross-linking agent emulsion for seawater-based fracturing fluid and preparation method thereof - Google Patents

Abstract

The invention provides a crosslinking agent emulsion for seawater-based fracturing fluid. The raw materials include: 1-10 parts by weight of a boron compound, 1-5 parts by weight of a zirconium compound, 1-10 parts by weight of an alcohol amine compound, and 1 part by weight of a polyhydroxy carboxylic acid. ~10 parts by weight, 10-25 parts by weight of water-soluble vinyl monomer, 15-35 parts by weight of white oil, 1-5 parts by weight of surfactant, 10-20 parts by weight of water, 0.01-0.1 parts by weight of reducing agent, oxidizing agent 0.01-0.1 parts by weight, phase inversion agent 0.1-0.5 parts by weight. The cross-linking agent is a water-in-oil type emulsion, and acrylamide and acrylic acid copolymer in the water phase form bridging sites with organoboron-zirconium to improve the stability of the emulsion; the water-in-oil type cross-linking agent emulsion slowly releases in seawater and has The cross-linking agent at the cross-linking site can achieve a longer delayed cross-linking time in a weak alkali (pH ≤ 10) environment, meeting the fracturing needs of offshore deep wells.

Description

A kind of cross-linking agent emulsion for seawater-based fracturing fluid and preparation method thereof

technical field

The invention belongs to the technical field of chemical preparation, and in particular relates to a crosslinking agent emulsion for seawater-based fracturing fluid and a preparation method thereof.

Background technique

Fracturing technology is the main technology to increase the output of low-permeability oil and gas reservoirs, coalbed methane, and shale gas. During fracturing construction, it is necessary to control the crosslinking time of fracturing fluid. If the fracturing fluid crosslinks too quickly, it will The frictional resistance in the pumping process of the fracturing fluid is increased, which seriously affects the normal operation of the construction.

The vegetable gum fracturing fluid mainly composed of hydroxypropyl guar gum is still the most important fracturing fluid in the development of oil and gas fields at home and abroad. Most of the vegetable gum fracturing fluids use organic boron zirconium crosslinking agent The problem of delayed cross-linking of vegetable gum fracturing fluid has been greatly improved. By adjusting the pH of the fracturing fluid to delay the crosslinking time, it overcomes the shortcomings of inorganic boron crosslinking fracturing fluid such as poor temperature resistance, rapid crosslinking, small application range, and high construction friction. However, seawater has high concentrations of hypervalent cations, such as magnesium and calcium ions. The widely used organoboron-zirconium crosslinking agent needs to be crosslinked in an alkaline environment. In order to achieve a longer delayed crosslinking time, the crosslinking reaction needs to be carried out in a strong alkali (pH>10) environment, but in a strong alkali Under the environment, magnesium ions and calcium ions will form hydroxide precipitates, resulting in a decrease in the pH value of the system, which is not conducive to the cross-linking reaction. Therefore, traditional organoboron-zirconium is only suitable for shallow offshore wells. For deep offshore wells, a crosslinking agent that can achieve a longer delayed crosslinking time in a weak alkali (pH ≤ 10) environment is needed.

Zhang Rusheng et al. (Zhang Rusheng, Zheng Chenggang, Liu Changyin, et al. A water-in-oil type cross-linking agent emulsion and its preparation method:, CN104232057A[P].2014.) studied and synthesized a kind of oil that can be cross-linked in a weak alkaline environment The water-in-type cross-linking agent emulsion has a longer delay time than the borax aqueous solution, but it can only reach 1.5min at most, which cannot meet the needs of ultra-deep wells.

Contents of the invention

The technical problem to be solved by the present invention is to provide a cross-linking agent emulsion for seawater-based fracturing fluid and a preparation method thereof, in which a cross-linking agent with a cross-linking site is slowly released in seawater through a water-in-oil emulsion, which can be used in In weak alkali (pH ≤ 10) environment, a longer delayed crosslinking time can be achieved, which meets the fracturing needs of offshore deep wells.

The technical scheme adopted in the present invention:

A crosslinking agent emulsion for seawater-based fracturing fluid, the parts by mass of each raw material component are as follows: 1-10 parts by weight of boron compound, 1-5 parts by weight of zirconium compound, 1-10 parts by weight of alcohol amine compound, polyhydroxy 1-10 parts by weight of carboxylic acid, 10-25 parts by weight of water-soluble vinyl monomer, 15-35 parts by weight of white oil, 1-5 parts by weight of surfactant, 10-20 parts by weight of water, and 0.01-0.1 parts by weight of reducing agent parts by weight, 0.01-0.1 parts by weight of oxidizing agent, and 0.1-0.5 parts by weight of phase inversion agent.

The boron compound is boric acid or borax, and the zirconium compound is zirconium oxychloride or zirconium tetrachloride.

The alcohol amine compound is at least one selected from monoethanolamine, diethanolamine and triethanolamine.

The polyhydroxy carboxylic acid is at least one of gluconic acid and lactic acid.

The water-soluble vinyl monomer is at least one selected from acrylamide, acrylic acid and 2-acrylamide-2-methylpropanesulfonic acid.

The reducing agent is selected from at least one of sodium bisulfite, ferrous sulfate and tetramethylethylenediamine, and the oxidizing agent is selected from at least one of ammonium persulfate and potassium persulfate.

The surfactant is at least one of nonylphenol polyoxyethylene ether and dodecylphenol polyoxyethylene ether.

The phase inversion agent is at least one of sorbitan fatty acid esters S-40, S-60, and S-80.

A method for using a high-temperature-resistant organic zirconium crosslinking agent for seawater-based fracturing fluid, comprising the following steps:

Step 1. Add boron compound, zirconium compound, alcohol amine compound, polyhydroxy carboxylic acid and water into a three-necked flask, heat up to 65-90°C and react for 3-6 hours;

Step 2. Cool down to room temperature, transfer to a beaker, add water-soluble vinyl monomer, dissolve and stir evenly, add reducing agent, and obtain a solution for later use;

Step 3, adding white oil and surfactant to a four-necked flask, and adding the solution obtained in step 2 under high-speed stirring;

Step 4, heating up to 15-40°C, adding an oxidizing agent, and reacting for 3-6 hours;

Step 5, adding phase inversion agent.

Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

(1) a kind of seawater-based fracturing fluid cross-linking agent emulsion provided by the invention and preparation method thereof,

Acrylamide and acrylic acid copolymers in the water phase form bridging sites with organic boron zirconium to improve the stability of the emulsion. TDZ5-WS centrifuge is used for centrifugation at a speed of 3000 rpm, and the centrifugal rotation is 30 minutes without stratification.

(2) A cross-linking agent emulsion for seawater-based fracturing fluid provided by the present invention and a preparation method thereof, the water-in-oil type cross-linking agent emulsion slowly releases a cross-linking agent with a cross-linking site in seawater, and can be used in weak In an alkaline (pH≤10) environment, a longer delayed crosslinking time can be achieved, which meets the fracturing needs of deep offshore wells.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

A cross-linking agent emulsion for seawater-based fracturing fluid provided by the invention, the mass parts of each raw material component are as follows:

1-10 parts by weight of boron compound, 1-5 parts by weight of zirconium compound, 1-10 parts by weight of alcohol amine compound, 1-10 parts by weight of polyhydroxy carboxylic acid, 10-25 parts by weight of water-soluble vinyl monomer, 15 parts by weight of white oil ~35 parts by weight, 1-5 parts by weight of surfactant, 10-20 parts by weight of water, 0.01-0.1 parts by weight of reducing agent, 0.01-0.1 part by weight of oxidizing agent, and 0.1-0.5 parts by weight of phase inversion agent.

The boron compound is boric acid or borax, and the zirconium compound is zirconium oxychloride or zirconium tetrachloride.

The alcohol amine compound is at least one of monoethanolamine, diethanolamine and triethanolamine.

The polyhydroxy carboxylic acid is at least one of gluconic acid and lactic acid.

The water-soluble vinyl monomer is at least one of acrylamide, acrylic acid and 2-acrylamide-2-methylpropanesulfonic acid.

The surfactant is at least one of nonylphenol polyoxyethylene ether and dodecylphenol polyoxyethylene ether.

The reducing agent is at least one of sodium bisulfite, ferrous sulfate and tetramethylethylenediamine, and the oxidizing agent is at least one of ammonium persulfate and potassium persulfate.

The phase inversion agent is at least one of sorbitan fatty acid esters S-40, S-60, and S-80.

A kind of preparation method of crosslinking agent emulsion for seawater-based fracturing fluid provided by the invention comprises the following steps:

Step 1. Add boron compound, zirconium compound, alcohol amine compound, polyhydroxy carboxylic acid and water into a three-necked flask, heat up to 65-90°C and react for 3-6 hours;

Step 2. Cool down to room temperature, transfer to a beaker, add water-soluble vinyl monomer, dissolve and stir evenly, add reducing agent, and obtain a solution for later use;

Step 3, adding white oil and surfactant to a four-necked flask, and adding the solution obtained in step 2 under high-speed stirring;

Step 4, heating up to 15-40°C, adding an oxidizing agent, and reacting for 3-6 hours;

Step 5, adding phase inversion agent.

specific:

Example 1

A kind of preparation method of crosslinking agent emulsion for seawater-based fracturing fluid provided by the invention comprises the following steps:

Step 101. Add 5 grams of borax, 1 gram of zirconium oxychloride, 7 grams of triethanolamine, 5 grams of gluconic acid and 15 grams of water into a three-necked flask, and raise the temperature to 85° C. for 4 hours;

Step 102, cool down to room temperature, transfer to a beaker, add 23 g of acrylamide and 2 g of acrylic acid, dissolve and stir evenly, add 0.01 g of tetramethylethylenediamine to obtain a solution for later use;

Step 103, adding 30 grams of white oil and 3 grams of tx-10 into a four-necked flask, and adding the obtained solution under high-speed stirring;

Step 104, raise the temperature to 30°C, add 0.01 g of ammonium persulfate, react for 4 hours, add 0.5 g of S-80, and obtain a cross-linking agent emulsion for seawater-based fracturing fluid. The test delay crosslinking time is 5min.

Comparative example 1

Synthesis of aqueous solution type organic boron zirconium crosslinking agent:

Add 5 grams of borax, 1 gram of zirconium oxychloride, 7 grams of triethanolamine, 5 grams of gluconic acid and 15 grams of water into a three-necked flask, raise the temperature to 85° C. and react for 4 hours to obtain an aqueous solution-type organic boron-zirconium crosslinking agent. The test delay cross-linking time is 20s.

Example 2

A kind of preparation method of crosslinking agent emulsion for seawater-based fracturing fluid provided by the invention comprises the following steps:

Step 201. Add 1 gram of borax, 5 grams of zirconium oxychloride, 1 gram of triethanolamine, 1 gram of gluconic acid and 20 grams of water into a three-necked flask, and raise the temperature to 85° C. for 4 hours;

Step 202, cool down to room temperature, transfer to a beaker, add 9 grams of acrylamide and 1 gram of acrylic acid, dissolve and stir evenly, add 0.1 gram of tetramethylethylenediamine, and obtain a solution for later use;

Step 203, adding 35 grams of white oil and 1 gram of tx-10 into a four-necked flask, and adding the obtained solution under high-speed stirring;

Step 204, raise the temperature to 30° C., add 0.1 g of ammonium persulfate, react for 4 hours, and add 0.1 g of S-80. A cross-linking agent emulsion for seawater-based fracturing fluid was obtained. The test delayed cross-linking time is 4min.

Comparative example 2

Synthesis of aqueous solution type organic boron zirconium crosslinking agent:

Add 1 gram of borax, 5 grams of zirconium oxychloride, 1 gram of triethanolamine, 1 gram of gluconic acid and 20 grams of water into a three-necked flask, and raise the temperature to 85° C. for 4 hours. An aqueous solution type organic boron zirconium crosslinking agent was obtained. The test delay cross-linking time is 25s.

Example 3

A kind of preparation method of crosslinking agent emulsion for seawater-based fracturing fluid provided by the invention comprises the following steps:

Step 301. Add 10 grams of borax, 2.5 grams of zirconium oxychloride, 5 grams of triethanolamine, 5 grams of gluconic acid and 10 grams of water into a three-necked flask, and heat up to 85°C for 4 hours;

Step 302, cool down to room temperature, transfer to a beaker, add 15.5 g of acrylamide and 1.5 g of acrylic acid, dissolve and stir evenly, add 0.05 g of tetramethylethylenediamine to obtain a solution for later use;

Step 303, adding 25 grams of white oil and 2.5 grams of tx-10 into a four-necked flask, and adding the obtained solution under high-speed stirring;

Step 304, raise the temperature to 30° C., add 0.05 g of ammonium persulfate, react for 4 hours, and add 0.25 g of S-80. A cross-linking agent emulsion for seawater-based fracturing fluid was obtained. The test delayed cross-linking time is 4min.

Comparative example 3

Synthesis of aqueous solution type organic boron zirconium crosslinking agent:

Add 10 grams of borax, 2.5 grams of zirconium oxychloride, 5 grams of triethanolamine, 5 grams of gluconic acid and 10 grams of water into a three-necked flask, and raise the temperature to 85°C for 4 hours. An aqueous solution type organic boron zirconium crosslinking agent was obtained. The test delay cross-linking time is 30s.

It will be apparent to those skilled in the art that the invention is not limited to the details of the above-described exemplary embodiments, but that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Accordingly, the embodiments should be regarded in all points of view as exemplary and not restrictive, the scope of the invention being defined by the appended claims rather than the foregoing description, and it is therefore intended that the scope of the invention be defined by the appended claims rather than by the foregoing description. All changes within the meaning and range of equivalents of the elements are embraced in the present invention.

In addition, it should be understood that although this specification is described according to implementation modes, not each implementation mode only includes an independent technical solution, and this description in the specification is only for clarity, and those skilled in the art should take the specification as a whole , the technical solutions in the various embodiments can also be properly combined to form other implementations that can be understood by those skilled in the art.

Claims (9)

1. A crosslinking agent emulsion for seawater-based fracturing fluid, characterized in that, the mass parts of each raw material component are as follows: 1-10 parts by weight of boron compound, 1-5 parts by weight of zirconium compound, 1-5 parts by weight of alcohol amine compound 10 parts by weight, 1-10 parts by weight of polyhydroxy carboxylic acid, 10-25 parts by weight of water-soluble vinyl monomer, 15-35 parts by weight of white oil, 1-5 parts by weight of surfactant, 10-20 parts by weight of water, The reducing agent is 0.01-0.1 parts by weight, the oxidizing agent is 0.01-0.1 parts by weight, and the phase inversion agent is 0.1-0.5 parts by weight. 2. The crosslinking agent emulsion for seawater-based fracturing fluid according to claim 1, wherein the boron compound is boric acid or borax, and the zirconium compound is zirconium oxychloride or zirconium tetrachloride. 3. The cross-linking agent emulsion for seawater-based fracturing fluid according to claim 1, wherein the alcohol amine compound is selected from at least one of monoethanolamine, diethanolamine and triethanolamine. 4. The cross-linking agent emulsion for seawater-based fracturing fluid according to claim 1, wherein the polyhydroxy carboxylic acid is at least one of gluconic acid and lactic acid. 5. The cross-linking agent emulsion for seawater-based fracturing fluid according to claim 1, wherein the water-soluble vinyl monomer is selected from the group consisting of acrylamide, acrylic acid and 2-acrylamide-2-methylpropanesulfonate at least one of the acids. 6. seawater-based fracturing fluid cross-linking agent emulsion according to claim 1, is characterized in that, described reducing agent is selected from at least one of sodium bisulfite, ferrous sulfate and tetramethylethylenediamine, The oxidizing agent is at least one selected from ammonium persulfate and potassium persulfate. 7. seawater-based fracturing fluid crosslinking agent emulsion according to claim 1, is characterized in that, described tensio-active agent is at least one of nonylphenol polyoxyethylene ether, dodecylphenol polyoxyethylene ether kind. 8. The cross-linking agent emulsion for seawater-based fracturing fluid according to claim 1, wherein the phase inversion agent is a sorbitan fatty acid ester S-40, S-60, S-80 at least one. 9. prepare the method for cross-linking agent emulsion for sea-based fracturing fluid as described in any one of claim 1-9, it is characterized in that, comprise the steps: Step (1), adding boron compound, zirconium compound, alcoholamine compound, polyhydroxy carboxylic acid and water into a three-necked flask, raising the temperature to 65-90°C for 3-6 hours; Step (2), cool down to room temperature, transfer to a beaker, add a water-soluble vinyl monomer, dissolve and stir evenly, add a reducing agent, and obtain a solution for later use; Step (3), adding white oil and surfactant to a four-necked flask, and adding the solution obtained in step (2) under high-speed stirring; Step (4), heating up to 15-40°C, adding an oxidizing agent, and reacting for 3-6 hours; Step (5), adding phase inversion agent.