CN-121991661-A - Oil well cement gas channeling preventing agent and preparation method thereof

Abstract

The invention discloses an oil well cement gas channeling preventive and a preparation method thereof, and relates to the technical field of oil and gas field well cementation engineering. The gas channeling preventive agent consists of an inorganic nano siliceous material and an organic polymer synthetic material, wherein the weight ratio of the inorganic nano siliceous material to the organic polymer synthetic material is (7.5-20), the inorganic nano siliceous material comprises anhydrous sodium silicate, white carbon black and ethylenediamine tetraacetic acid, the organic polymer synthetic material comprises N, N-dimethylacrylamide, acrylic acid and an initiator, the weight ratio of the anhydrous sodium silicate, the white carbon black and the ethylenediamine tetraacetic acid in the inorganic nano siliceous material is (10-20), the weight ratio of the anhydrous sodium silicate, the white carbon black and the ethylenediamine tetraacetic acid is (1-3), the weight ratio of the N, N-dimethylacrylamide, the acrylic acid and the initiator is (5-10), and the weight ratio of the N, N-dimethylacrylamide, the acrylic acid and the initiator is (2-5) in the organic polymer synthetic material is (0.5-1). The high temperature resistance of the gas channeling preventive agent can reach 240 ℃, the static gelation transition time is less than or equal to 10min, and the gas channeling preventive agent has good high temperature resistance and gas channeling preventive capability.

Inventors

• LIU XIAOLI
• CHEN NING
• CHEN XIAORONG
• TANG KAI
• WANG WENBIN
• WAN XIANGCHEN
• MIN JIANGBEN
• ZHANG JIAN
• GAO GUOCHENG
• LI ZHIHONG

Assignees

• 中国石油天然气集团有限公司
• 中国石油集团川庆钻探工程有限公司

Dates

Publication Date

20260508

Application Date

20241106

Claims (13)

1. 1. The oil well cement gas channeling preventive agent is characterized by comprising an inorganic nano siliceous material and an organic polymer synthetic material, wherein the weight ratio of the inorganic nano siliceous material to the organic polymer synthetic material is (10-25) (7.5-20), the inorganic nano siliceous material comprises anhydrous sodium silicate, white carbon black and ethylenediamine tetraacetic acid, the organic polymer synthetic material comprises N, N-dimethylacrylamide, acrylic acid and an initiator, the weight ratio of the anhydrous sodium silicate, the white carbon black and the ethylenediamine tetraacetic acid in the inorganic nano siliceous material is (10-20) (1-3) (1-2), and the weight ratio of the N, N-dimethylacrylamide, the acrylic acid and the initiator in the organic polymer synthetic material is (5-10) (2-5) (0.5-2).
2. 2. The oil well cement gas channeling preventive agent according to claim 1, wherein the initiator is ammonium persulfate, and the effective content of ammonium sulfate is not less than 98%.
3. 3. The oil well cement gas channeling preventive agent according to claim 2, wherein the weight ratio of anhydrous sodium silicate, white carbon black and ethylenediamine tetraacetic acid in the inorganic nano siliceous material is (12-18): (1.5-2.5): (1.1-1.6).
4. 4. A gas channeling preventive agent for oil well cement according to claim 2 or 3, wherein the weight ratio of N, N-dimethylacrylamide, acrylic acid and initiator in said organic polymer composite material is (6-8): 3-4): 0.6-0.9.
5. 5. The oil well cement gas channeling preventive agent according to claim 1, wherein the weight ratio of anhydrous sodium silicate, white carbon black and ethylenediamine tetraacetic acid in the inorganic nano siliceous material is 18:2:1.5.
6. 6. The oil well cement gas channeling preventive agent according to claim 1, wherein the weight ratio of N, N-dimethylacrylamide, acrylic acid and initiator in the organic polymer composite material is 7:3.5:0.8.
7. 7. The oil well cement gas channeling preventive agent according to claim 1, wherein the silica content of the anhydrous sodium silicate is not less than 45%.
8. 8. The gas channeling preventive agent for oil well cement according to claim 1, wherein the white carbon black has a density of 2.5-2.6 g/cm3, a particle diameter of 80-95nm and a silica content of 90% or more.
9. 9. The oil well cement gas channeling preventive agent according to claim 1, wherein the ethylene diamine tetraacetic acid density is 1.56 g/cm3.
10. 10. The preparation method of the oil well cement gas channeling preventive agent is characterized by comprising the following steps of weighing 100 parts by weight of distilled water, adding 0.5-2 parts by weight of ethylenediamine tetraacetic acid, mixing in a beaker, adding a mixture of anhydrous sodium silicate and white carbon black with the mass ratio of 10-20 parts by weight into the beaker, and stirring while heating in a water bath to obtain a suspended emulsion siliceous solution; preparing a monomer mixed solution, which comprises the steps of weighing 100 parts by weight of distilled water, adding 5-10 parts by weight of N, N-dimethylacrylamide and 2-5 parts by weight of acrylic acid, and uniformly stirring to prepare the monomer mixed solution; Gradually adding the suspended emulsion siliceous solution into the monomer mixed solution, adding 0.5-1 weight part of initiator, heating in water bath, stirring, and reacting at constant temperature for 2-3 hours to obtain the high temperature resistant oil well cement gas channeling inhibitor.
11. 11. The method for preparing the oil well cement gas channeling preventive agent according to claim 11, wherein the water bath heating means water bath heating to 65 ℃.
12. 12. The method for preparing an oil well cement gas channeling preventive agent according to claim 11, wherein the stirring while heating in the water bath is stirring at a rotation speed of 200-400r/min by a magnetic stirrer.
13. 13. The method for preparing an oil well cement gas channeling preventive agent according to claim 11, wherein the constant temperature condition is specifically that the temperature is maintained within a range of 65.+ -. 2 ℃.

Description

Oil well cement gas channeling preventing agent and preparation method thereof Technical Field The invention relates to the technical field of oil-gas field well cementation engineering, in particular to an oil well cement gas channeling preventive and a preparation method thereof. Background Along with the continuous deep pushing of the oil and gas exploration targets of the long-distance oilfield towards the edge of the basin (wherein the designed well depth of the post-exploration 1 well is 6630 m/the well depth of the completion 6321m, the well depth of the completion 6535m of the completion 1 well and the bottom temperature of the well is 214 ℃), the well cementation construction faces the problem of high-temperature gas channeling, the technical aspect mainly comprises the step of adding latex into cement paste to achieve the purpose of gas channeling prevention, and the action mechanism of the latex gas channeling prevention agent mainly comprises the mixing of polymer latex and cement, so that pores in a cement system can be effectively blocked, and a film structure is formed to prevent gas channeling. However, the latex system has strong sensitivity, poor high temperature resistance and stability, narrow application conditions and large influence on the early compressive strength of the cement stone (about 5MPa is reduced in the strength of 1.85-1.92g/cm < 3 > of the conventional density cement slurry system for 24 hours). The invention discloses a high-temperature gas channeling-preventing polymer, a preparation method and application thereof, which are disclosed in China patent literature with publication number of CN115725017A and publication date of 2023 and 3, wherein the high-temperature gas channeling-preventing self-assembled polymer developed by the invention can improve the high-temperature stability of the polymer, prevent gas channeling, have better thixotropic property and gas channeling-preventing capability, can form a space grid gel structure after being added into well cementing slurry, improve the pore resistance of the slurry, and effectively prevent the slurry stability deterioration caused by additive failure in a high-temperature environment. However, according to the technical scheme, on one hand, the high-temperature resistance reaches 150 ℃, the stability is poor in a basin edge deep exploratory well, the problem of high-temperature well cementation gas channeling cannot be effectively solved, and on the other hand, the gelation transition time is still longer, and the gas channeling prevention performance still needs to be further improved. Disclosure of Invention In order to overcome the defects and shortcomings in the prior art, the invention provides an oil well cement gas channeling preventive agent and a preparation method thereof, which solve the problem of cement loop interlayer channeling caused by high-temperature gas well loop air channeling, improve the efficiency of reservoir reconstruction measures and improve the recovery ratio of an oil and gas field. In order to solve the problems in the prior art, the invention is realized by the following technical scheme: the oil well cement gas channeling preventing agent consists of inorganic nano siliceous material and organic polymer composite material in the weight ratio of (10-25) to (7.5-20), anhydrous sodium silicate, white carbon black and ethylenediamine tetraacetic acid, and the organic polymer composite material consists of N, N-dimethyl acrylamide, acrylic acid and initiator, wherein the inorganic nano siliceous material has the weight ratio of (10-20) to (1-3) to (1-2), and the organic polymer composite material has the weight ratio of (5-10) to (2-5) to (0.5-1) to (N, N-dimethyl acrylamide, acrylic acid and initiator. The initiator is ammonium persulfate, wherein the effective content of ammonium sulfate is more than or equal to 98%. The weight ratio of anhydrous sodium silicate, white carbon black and ethylenediamine tetraacetic acid in the inorganic nano siliceous material is (12-19) (1.5-2.5) (1.1-1.6). In the organic polymer composite material, the weight ratio of N, N-dimethylacrylamide, acrylic acid and an initiator is (6-8): 3-4): 0.6-0.9. The weight ratio of anhydrous sodium silicate, white carbon black and ethylenediamine tetraacetic acid in the inorganic nano siliceous material is 18:2:1.5. In the organic polymer composite material, the weight ratio of N, N-dimethylacrylamide, acrylic acid and an initiator is 7:3.5:0.8. The silicon dioxide content of the anhydrous sodium silicate is more than or equal to 45 percent. The density of the white carbon black is 2.5-2.6 g/cm <3 >, the particle size is 80-95nm, and the silicon dioxide content is more than or equal to 90%. The density of the ethylenediamine tetraacetic acid is 1.56 g/cm3. The preparation method of the oil well cement gas channeling preventive agent comprises the following steps: The preparation method comprises the steps of weighing 100