阅读说明：本技术 一种螯合交联共聚包被剂及其制备方法 (Chelating cross-linking copolymerization coating agent and preparation method thereof ) 是由 葛富文 滕军 向金锋 许振波 许现西 李鹏 岳昌 于 2019-11-16 设计创作，主要内容包括：本发明公开了一种螯合交联共聚包被剂及其制备方法,所述螯合交联共聚包被剂由如下重量百分比的原料制成：丙烯酸25-35%、丙烯酰胺30-40%、氧化钙7-12%、硼砂3-8%、氢氧化钠10-20%、氨水5-10%和引发剂0.03-0.1%。本发明所得螯合交联共聚包被剂粘度高,分子量大,抗高温,使用过程用量小、携沙性能好。(The invention discloses a chelating cross-linking copolymerization coating agent and a preparation method thereof, wherein the chelating cross-linking copolymerization coating agent is prepared from the following raw materials in percentage by weight: 25-35% of acrylic acid, 30-40% of acrylamide, 7-12% of calcium oxide, 3-8% of borax, 10-20% of sodium hydroxide, 5-10% of ammonia water and 0.03-0.1% of initiator. The chelating cross-linking copolymerization coating agent obtained by the invention has high viscosity, large molecular weight, high temperature resistance, small using amount in the using process and good sand carrying performance.)

1. The chelating crosslinking copolymerization coating agent is characterized by being prepared from the following raw materials in percentage by weight:

25-35% of acrylic acid, 30-40% of acrylamide, 7-12% of calcium oxide, 3-8% of borax, 10-20% of sodium hydroxide, 5-10% of ammonia water and 0.03-0.1% of initiator.

2. The chelating cross-linking copolymerization coating agent as claimed in claim 1, wherein the mass concentration of the ammonia water is 25-30%.

3. The chelating cross-linking copolymerization coating agent as claimed in claim 1, wherein the initiator is ammonium persulfate and/or sodium bisulfite.

4. The chelating cross-linking copolymerization coating agent as claimed in claim 3, wherein the initiator is ammonium persulfate and sodium bisulfite.

5. A method for preparing the chelating cross-linking co-coating agent as set forth in any one of claims 1 to 4, characterized by comprising the steps of:

(1) adding sodium hydroxide aqueous solution into acrylic acid for neutralization reaction;

(2) preparing acrylamide into an acrylamide aqueous solution, then adding the acrylamide aqueous solution into the solution obtained in the step (1), then adding calcium oxide and borax, and stirring for 1-2 hours;

(3) adding ammonia water into the solution obtained in the step (2), adjusting the pH value to 8.8-9.5, and finally adding an initiator to carry out polymerization reaction;

(4) after polymerization, granulating, drying, crushing and packaging to obtain the product.

6. The method for preparing a chelating cross-linking co-coating agent as claimed in claim 5, wherein the mass concentration of the aqueous solution of sodium hydroxide in step (1) is 20-40%.

7. The method for preparing the chelating cross-linking copolymerization coating agent as claimed in claim 5, wherein the mass concentration of the acrylamide aqueous solution in the step (2) is 35-45%.

8. The method for preparing a chelating cross-linking copolymerization coating agent as claimed in claim 5, wherein the mass concentration of the ammonia water in the step (3) is 25-30%.

9. The method for preparing a chelating cross-linking co-coating agent as claimed in claim 5, wherein the polymerization reaction in step (3) is carried out at a temperature of 25-35 ℃ for 0.5-1 h.

Technical Field

The invention belongs to the technical field of drilling, and particularly relates to a chelating cross-linking copolymerization coating agent and a preparation method thereof.

Background

In order to solve the problem of mud performance in the deep well drilling process, the prior art adopts a zwitterionic polymer coating agent technology which is formed by linear polymerization of acrylic acid and acrylamide under the condition of sodium hydroxide or sodium carbonate, and the prior zwitterionic polymer coating agent technology can only achieve the following effects: (1) under the condition of room temperature, the slurry viscosity (namely 1 percent apparent viscosity is between 30 and 35mPa & s) of the product is not enough, and the carrying process of the drill cuttings in the drilling process is not facilitated; (2) because the product has no chelating crosslinking, the product is a straight chain formed by polymerization, the molecular weight is between 400-500, the product does not resist shearing in mud with the temperature of more than or equal to 110 ℃, and the viscosity is rapidly reduced; (3) the temperature resistance can only reach below 110 ℃. Therefore, the existing common acrylic acid and acrylamide copolymer can not meet the performances of viscosity increasing, coating and fluid loss reduction in deep wells and high-temperature wells, especially in the process of drilling stratums at the temperature of more than 150 ℃ and higher, so that the development of the high-temperature-resistant coating agent for drilling is of great significance with the continuous development of drilling technology and the continuous improvement of drilling depth.

The Chinese patent application with publication number CN103613705A discloses a preparation method of nonionic polyacrylamide, which comprises the following steps: firstly, preparing acrylamide into an aqueous solution with a certain concentration, adding an aqueous solution of sodium acrylate, and uniformly mixing; then adding an oxidant, a chain transfer agent and a reducing agent into the solution, uniformly mixing, and initiating polymerization at 10-15 ℃; and after polymerization, granulating, drying, crushing and sieving to obtain the finished product of the nonionic polyacrylamide. The preparation method of the nonionic polyacrylamide provided by the invention has the advantages of simple process, no need of thermal insulation hydrolysis, reaction completion by introducing a small amount of sodium acrylate and acrylamide for copolymerization, avoidance of ammonia gas generation and environmental pollution, and low consumption and environmental protection. However, the addition amount of the sodium acrylate in the patent is small, the acrylic acid mainly plays a role in increasing the solubility and the hydrolysis degree of acrylamide and cannot play a role in improving the viscosity of the product, and the polyacrylamide synthesized by the patent has a small copolymer content, is suitable for water treatment and is not suitable for a fluid loss additive or a tackifier for well drilling.

The Chinese patent application with publication number CN109456443A discloses a functional polyacrylamide and a preparation method thereof, which comprises 120-50 parts of surfactant, 210-30 parts of surfactant, 100 parts of acrylamide, 50-100 parts of acrylic acid, 5-15 parts of AMPS, 0.01-0.5 part of oxidant and 0.01-0.5 part of reducer. The functional polyacrylamide is synthesized by polymerizing acrylamide and a surfactant, and compared with a common oil extraction polymer, the functional polyacrylamide obtained by the invention has the advantages of higher dissolution speed, better viscosity stability, salt resistance and emulsibility, and greatly improved oil displacement effect. However, the acrylic acid in the patent is low in consumption, is only used for producing polyacrylamide for oil recovery, plays a role in oil displacement in the tertiary oil recovery process, and is not suitable for the drilling process, particularly in complex salt and high-temperature mud.

Disclosure of Invention

In order to overcome the defects, the invention aims to provide a chelating crosslinking copolymerization coating agent and a preparation method thereof, wherein the chelating crosslinking copolymerization coating agent has the advantages of large molecular weight, high viscosity, high temperature resistance, small using amount in the using process and good sand carrying performance.

In order to achieve the purpose, the invention adopts the following technical scheme:

a chelating cross-linking copolymerization coating agent is prepared from the following raw materials in percentage by weight:

25-35% of acrylic acid, 30-40% of acrylamide, 7-12% of calcium oxide, 3-8% of borax, 10-20% of sodium hydroxide, 5-10% of ammonia water and 0.03-0.1% of initiator.

Preferably, the mass concentration of the ammonia water is 25-30%.

Preferably, the initiator is ammonium persulfate and/or sodium bisulfite.

Preferably, the initiator is ammonium persulfate and sodium bisulfite.

A preparation method of a chelating cross-linking copolymerization coating agent comprises the following steps:

(1) adding sodium hydroxide aqueous solution into acrylic acid for neutralization reaction;

(2) preparing acrylamide into an acrylamide aqueous solution, then adding the acrylamide aqueous solution into the solution obtained in the step (1), then adding calcium oxide and borax, and stirring for 1-2 hours;

(3) adding ammonia water into the solution obtained in the step (2), adjusting the pH value to 8.8-9.5, and finally adding an initiator to carry out polymerization reaction;

(4) after polymerization, granulating, drying, crushing and packaging to obtain the product.

Preferably, the mass concentration of the sodium hydroxide aqueous solution in the step (1) is 20-40%.

Preferably, the mass concentration of the acrylamide aqueous solution in the step (2) is 35-45%.

Preferably, the mass concentration of the ammonia water in the step (3) is 25-30%.

Preferably, the temperature of the polymerization reaction in the step (3) is 25-35 ℃ and the time is 0.5-1 h.

Detailed Description

The invention will be further illustrated with reference to some specific examples.