CN112480889B - Preparation method of retarder for slag cementing fluid - Google Patents

Abstract

The invention relates to a preparation method of a retarder for slag cementing fluid, comprising: (1) mixing sodium styrene sulfonate, maleic acid and methacryloyloxyethyltrimethylammonium chloride in a reaction vessel Mix, dissolve in deionized water, adjust the pH value of the reaction solution to 7~8; pass nitrogen to remove oxygen, add initiator potassium persulfate when the temperature rises to 70 °C; cool, purify and dry the product to obtain component A; ( 2) Spread the natural vermiculite on the disk, put it in a microwave oven, and treat it under high fire for 1 min, then add it to hydrochloric acid, and stir it in a water bath at 70°C to obtain acid-modified vermiculite powder, namely component B (3) mixing sodium tartrate and citric acid to obtain C component; (4) mixing A component, B component and C component with a mass ratio of 3:1:1. The invention is reliable in principle and simple in operation, and the prepared retarder can effectively control the thickening time of slag cementing fluid without affecting its settlement stability, and can be widely used in cementing engineering supported by slag cementing material.

Description

A kind of preparation method of retarder for slag cementing fluid

technical field

The invention relates to a method for preparing a retarder for cementing fluid in the field of oilfield chemistry, in particular to a method for preparing a retarder for cementing slag cementing materials, which can effectively control the thickening time of the slag cementing fluid, And can improve the settlement stability of slag cementing fluid.

Background technique

Traditional cementing means that when the drilling operation reaches a certain well depth, the casing string is run in the drilled wellbore, and then the cement slurry is injected into the annulus between the casing and the well wall to reach a predetermined position, and make it in the predetermined position. The process of rapidly setting and hardening within a short period of time to form a high-quality, complete cement sheath with good interlayer isolation ability. In recent years, with the increase in the difficulty of oilfield exploration and development and the complexity of underground mining, the difficulty of cementing has gradually increased. Traditional cement slurry cementing technology has problems such as easy formation loss, slow strength development, high density and easy leakage. Therefore, cementitious material slag with hydraulic properties similar to cement has attracted extensive attention from relevant researchers due to its strong activity, high early strength, high replacement efficiency, and low cost, and slag cementing fluid technology has also emerged as the times require. .

Slag cementing fluid is a new type of well cementing fluid prepared from slag as inorganic cementitious material. Sodium hydroxide, sodium carbonate, sodium silicate and their complexes are used as activators. Ethyl cellulose and the like are suspending agents. The slag cementing fluid can replace the cement slurry, fill the annular space between the casing and the casing or the formation, support the casing after solidification and hardening, strengthen the well wall, effectively seal the oil, gas and water layers, and is used to solve the problem of low-pressure leaky formations, long The cementing operation in the sealing section improves the sealing and filling operations of non-target layers such as simplified well structure.

Slag cementing fluid retarder, as one of the three most important admixtures, plays an important role in delaying the solidification time and maintaining the pumpable state of the slurry, and is a key link to ensure smooth cementing construction and cementing quality. The retarders currently used for cement slurry are often not suitable for slag cementing fluids, and it is imminent to develop a retarder suitable for slag cementing fluids.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a preparation method of a retarder for slag cementing fluid, the method is reliable in principle, easy to operate, and the prepared retarder solves the problems of poor settlement stability, excessive dispersion, and reduced consistency of the current slag cementing fluid. It can effectively control and adjust the thickening time of slag cementing fluid without affecting its settlement stability, and can be widely used in cementing projects supported by slag cementing material cementing technology.

In order to achieve the above technical purpose, the present invention adopts the following technical solutions.

A preparation method of a retarder for slag cementing fluid, comprising the following steps in sequence:

(1) Preparation of component A of retarder:

1) In the reaction vessel, mix sodium styrene sulfonate SSS, maleic acid MA, and methacryloyloxyethyltrimethylammonium chloride DMC in a mass ratio of 10~8:7~5:3~1 Mix, dissolve in deionized water, and adjust the pH of the reaction solution to 7~8 with sodium hydroxide;

2) Pour nitrogen into the reaction vessel to remove oxygen for 10 minutes, and when the temperature of the reaction system rises to 70°C, slowly add the initiator potassium persulfate, and the quality of potassium persulfate is 1.0~3.0% of the total monomer mass;

3) After the reaction is carried out for 4 hours, the viscous liquid product is cooled to room temperature, purified, dried and pulverized with acetone to obtain component A of the retarder;

(2) Preparation of component B of retarder:

1) Using natural vermiculite (VER) as the raw material, evenly spread it on the disk, place it in a microwave oven, and treat it for 1 min under the condition of microwave high fire to obtain microwave-expanded vermiculite;

2) Take a certain amount of microwave-expanded vermiculite powder, add it to a 2mol/L hydrochloric acid solution at a solid-liquid mass ratio of 1:20~25, and stir at 70°C in a water bath for 2h;

3) Washing, suction filtration, drying, and grinding to 200 mesh to obtain acid-modified vermiculite powder, namely component B of retarder;

(3), preparation of retarder C component:

Mix sodium tartrate and citric acid in a mass ratio of 20~80:80~20 to obtain component C of the retarder;

(4) Preparation of retarder:

The A component, the B component and the C component are mixed in a mass ratio of 3:1:1 to obtain a retarder for slag cementing fluid.

The above substances are available in the market.

The appearance of the retarder for slag cementing fluid prepared by the invention is white powder and tasteless. The retarder has good solubility in water and good retardation effect, can significantly prolong the thickening time of the cementing fluid, and maintain good settlement stability.

Compared with the prior art, the beneficial effects obtained by the present invention are as follows:

1. The present invention adopts the free radical aqueous solution polymerization mode and uses the potassium persulfate of inorganic peroxides as the initiator, the operation process is simple and easy, the success rate of synthesizing the polymer is high, and a certain conversion rate can be guaranteed.

2. Introducing macromolecules and non-degradable functional monomers, the temperature resistance of the obtained polymer is significantly improved, and the thickening time of the cementing fluid can be effectively prolonged.

3. The new monomer used enables the polymer to undergo intermolecular or intramolecular association at a certain temperature. Due to the high SSS content in the polymer molecule, the strong hydrophilicity of the polymer molecular chain is ensured, and the compatibility and stability are improved. .

4. The vermiculite used in the present invention, a natural, non-toxic mineral, is composed of a large number of layers with certain structural units, and will expand under the action of high temperature. The microwave modification method did not destroy the vermiculite structure, but dredged the pores between the vermiculite layers. With the increase of the distance between the vermiculite layers, the adsorption performance of the expanded vermiculite improved, so that the vermiculite could better interact with the vermiculite. Other powder adsorption, while having good water absorption and stable chemical properties.

5. In the present invention, acidification of vermiculite is to dissolve the tetrahedral cations and octahedral cations in the vermiculite structure with strong inorganic acid, so as to achieve the purpose of increasing the specific surface area of vermiculite, improving the layer charge and increasing the surface active functional groups. The acidified vermiculite has better compatibility and can be better combined with the organic matrix.

6. The retarder of the present invention adopts the combination of three components, which makes up for the shortcomings of the original retarder with single material and lack of performance.

7. The retarder of the present invention is specially used for controlling the retarding effect of slag cementing fluid for well cementing, and fills the defects and deficiencies of the prior art.

Description of drawings

Figure 1 shows the thickening curve of retarder for slag cementing fluid at 70°C.

Fig. 2 is the thickening curve diagram of retarder for slag cementing fluid at 80°C.

Fig. 3 is the thickening curve diagram of retarder for slag cementing fluid at 90°C.

Detailed ways

The present invention will be further described below with reference to the accompanying drawings and embodiments.

Example 1

Retarder preparation process:

(1) Preparation of component A:

1) In the reaction vessel, mix sodium styrene sulfonate SSS, maleic acid MA, and methacryloyloxyethyltrimethylammonium chloride DMC in a mass ratio of 10:7:3, and dissolve them in deionized water. In water, the pH value of the reaction solution is adjusted with sodium hydroxide to be 7~8;

2) Pour nitrogen into the reaction vessel for 10 minutes to remove oxygen, and when the temperature of the reaction system rises to 70°C, slowly add initiator potassium persulfate, and the quality of potassium persulfate is 1.0% of the total monomer mass;

3) After the reaction is carried out for 4 hours, the viscous liquid product is cooled to room temperature, purified with acetone, dried and pulverized to obtain the retarder component A;

(2) Preparation of component B:

1) Using natural vermiculite (VER) as the raw material, evenly spread it on the disk, place it in a microwave oven, and treat it for 1 min under the condition of microwave high fire to obtain microwave-expanded vermiculite;

2) Take a certain amount of microwave-expanded vermiculite powder, add it to an acid solution of 2mol/L hydrochloric acid at a solid-to-liquid ratio of 1:20, and stir magnetically for 2h at 70°C in a water bath;

3) After stirring, let it stand in the natural environment for 2 hours, wash it, filter it with suction, and then put it in a drying oven at 105 °C for 24 hours, and then grind it to 200 mesh to obtain acid-modified vermiculite powder, which is a retarder. component B;

(3) Preparation of component C:

Sodium tartrate and citric acid are mixed in a ratio of 20:80 to obtain retarder component C;

(4) Preparation of retarder:

The components A, B and C are mixed in a ratio of 3:1:1 to obtain a retarder for slag cementing fluid.

The prepared retarder (named H1) was added to the slag cementing fluid formula, and the experiment was carried out under the thickening conditions of temperature 70℃ and pressure 25MPa to verify the retardation performance of the retarder.

Slag cementing fluid formula: 150 parts of slag + 12 parts of activator + 2 parts of suspension stabilizer + 3 parts of retarder + 100 parts of water.

Note: The above slag is titanium extraction tailings, the activator is sodium hydroxide, and the suspension stabilizer is sodium carboxymethyl cellulose.

As shown in Figure 1, the thickening time of slag cementing fluid has been significantly prolonged under high temperature and high pressure environment, which can meet the requirements of oil and gas well cementing site construction for cementing fluid pumping time, and the thickening curve shows that the slow The addition of the coagulant does not appear abnormal "bulging" and "core wrapping" phenomena under the conditions of high temperature and high pressure, and the consistency of the cement slurry is maintained at a relatively stable value, indicating that the retarder can maintain the stability of the settlement of the slag cementing fluid. Sex has a good effect.

Example 2

Retarder preparation process:

(1) Preparation of component A:

1) In the reaction vessel, mix sodium styrene sulfonate SSS, maleic acid MA, and methacryloyloxyethyltrimethylammonium chloride DMC in a mass ratio of 9:6:2, and dissolve them in deionized water. In water, the pH value of the reaction solution is adjusted with sodium hydroxide to be 7~8;

2) Pour nitrogen into the reaction vessel for 10 minutes to remove oxygen, and when the temperature of the reaction system rises to 70°C, slowly add the initiator potassium persulfate, and the quality of potassium persulfate is 2.0% of the total monomer mass;

3) After the reaction is carried out for 4 hours, the viscous liquid product is cooled to room temperature, purified with acetone, dried and pulverized to obtain the retarder component A;

(2) Preparation of component B:

1) Using natural vermiculite (VER) as the raw material, evenly spread it on the disk, place it in a microwave oven, and treat it for 1 min under the condition of microwave high fire to obtain microwave-expanded vermiculite;

2) Take a certain amount of microwave-expanded vermiculite powder, add it to an acid solution of 2mol/L hydrochloric acid at a solid-to-liquid ratio of 1:23, and stir magnetically for 2h at 70°C in a water bath;

3) After stirring, let it stand in the natural environment for 2 hours, wash it, filter it with suction, and then put it in a drying oven at 105 °C for 24 hours, and grind it to 200 mesh to obtain acid-modified vermiculite powder, namely the retarder group. point B;

(3) Preparation of component C:

Sodium tartrate and citric acid are mixed in a ratio of 50:50 to obtain retarder component C;

(4) Preparation of retarder:

The components A, B and C are mixed in a ratio of 3:1:1 to obtain a retarder for slag cementing fluid.

The prepared retarder (named H2) was added to the slag cementing fluid formula, and the experiment was carried out under the thickening conditions of temperature 80℃ and pressure 30MPa to verify the retardation performance of the retarder.

Slag cementing fluid formula: 120 parts of slag + 10 parts of activator + 1.5 parts of suspension stabilizer + 4 parts of retarder + 100 parts of water.

Note: The above slag is titanium extraction tailings, the activator is sodium hydroxide, and the suspension stabilizer is sodium carboxymethyl cellulose.

As shown in Figure 2, the thickening time of slag cementing fluid has been significantly prolonged under high temperature and high pressure environment, which can meet the requirements of oil and gas well cementing site construction for cementing fluid pumping time. The addition of the coagulant does not appear abnormal "bulging" and "core wrapping" phenomena under the conditions of high temperature and high pressure, and the consistency of the cement slurry is maintained at a relatively stable value, indicating that the retarder can maintain the stability of the settlement of the slag cementing fluid. Sex has a good effect.

Example 3

Retarder preparation process:

(1) Preparation of component A:

1) In the reaction vessel, mix sodium styrene sulfonate SSS, maleic acid MA, and methacryloyloxyethyltrimethylammonium chloride DMC in a mass ratio of 8:5:1, and dissolve them in deionized water. In water, the pH value of the reaction solution is adjusted with sodium hydroxide to be 7~8;

2) Pour nitrogen into the reaction vessel for 10 minutes to remove oxygen, and when the temperature of the reaction system rises to 70°C, slowly add initiator potassium persulfate, and the quality of potassium persulfate is 3.0% of the total monomer mass;

3) After the reaction is carried out for 4 hours, the viscous liquid product is cooled to room temperature, purified with acetone, dried and pulverized to obtain the retarder component A;

(2) Preparation of component B:

1) Using natural vermiculite (VER) as the raw material, evenly spread it on the disk, place it in a microwave oven, and treat it for 1 min under the condition of microwave high fire to obtain microwave-expanded vermiculite;

2) Take a certain amount of microwave-expanded vermiculite powder, add it to an acid solution of 2mol/L hydrochloric acid at a solid-to-liquid ratio of 1:25, and stir magnetically for 2h at 70°C in a water bath;

3) After stirring, let it stand in the natural environment for 2 hours, wash it, filter it with suction, and then put it in a drying oven at 105 °C for 24 hours, and grind it to 200 mesh to obtain acid-modified vermiculite powder, namely the retarder group. point B;

(3) Preparation of component C:

Sodium tartrate and citric acid are mixed in a ratio of 80:20 to obtain retarder component C;

(4) Preparation of retarder:

The components A, B and C are mixed in a ratio of 3:1:1 to obtain a retarder for slag cementing fluid.

The prepared retarder (named H3) was added to the slag cementing fluid formula, and the experiment was carried out under the thickening conditions of temperature 90 ℃ and pressure 40 MPa to verify the retarding performance of the retarder.

Slag cementing fluid formula: 150 parts of slag + 10 parts of activator + 2 parts of suspension stabilizer + 6 parts of retarder + 100 parts of water.

Note: The above slag is titanium extraction tailings, the activator is sodium hydroxide, and the suspension stabilizer is sodium carboxymethyl cellulose.

As shown in Figure 3, the thickening time of slag cementing fluid has been significantly prolonged under high temperature and high pressure environment, which can meet the requirements of oil and gas well cementing site construction for cementing fluid pumping time. The addition of the coagulant does not appear abnormal "bulging" and "core wrapping" phenomena under the conditions of high temperature and high pressure, and the consistency of the cement slurry is maintained at a relatively stable value, indicating that the retarder can maintain the stability of the settlement of the slag cementing fluid. Sex has a good effect.

As shown in Figure 1-Figure 3, the thickening time of slag cementing fluid has been significantly prolonged, and the consistency has not decreased significantly, which can meet the construction requirements of the cementing site, and the thickening curve shows that the retarder is suitable for For slag cementing fluid, it can avoid and solve the problems of poor stability and serious settlement.

Claims (1)

1. A preparation method of a retarder for slag cementing fluid sequentially comprises the following steps:

(1) preparing a retarder A component:

1) mixing sodium styrene sulfonate SSS, maleic acid MA and methacryloyloxyethyl trimethyl ammonium chloride DMC in a mass ratio of 10-8: 7-5: 3-1 in a reaction vessel, dissolving in deionized water, and adjusting the pH value of a reaction solution to 7-8 by using sodium hydroxide;

2) introducing nitrogen into the reaction container for 10min to remove oxygen, and slowly adding an initiator potassium persulfate when the temperature of the reaction system rises to 70 ℃, wherein the mass of the potassium persulfate is 1.0-3.0% of the total mass of the monomers;

3) after the reaction is carried out for 4 hours, cooling the viscous liquid product to room temperature, purifying, drying and crushing the viscous liquid product by using acetone to obtain a retarder A component;

(2) preparing a retarder B component:

1) uniformly spreading natural Vermiculite (VER) as a raw material on a magnetic disc, placing the magnetic disc in a microwave oven, and treating for 1 min under the condition of microwave high fire to obtain microwave expanded vermiculite;

2) adding a certain amount of microwave expanded vermiculite powder into 2mol/L hydrochloric acid solution according to the solid-liquid mass ratio of 1: 20-25, and stirring for 2 hours at 70 ℃ in a water bath;

3) washing, filtering, drying, grinding to 200 meshes to obtain acid modified vermiculite powder, namely the retarder B component;

(3) preparing a retarder C component:

mixing sodium tartrate and citric acid in a mass ratio of 20-80: 80-20 to obtain a retarder C component;

(4) preparing a retarder:

and mixing the component A, the component B and the component C in a mass ratio of 3:1:1 to obtain the slag well cementing liquid retarder.

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