CN114057934B - Dispersing agent for drilling fluid and preparation method thereof - Google Patents
Dispersing agent for drilling fluid and preparation method thereof Download PDFInfo
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- CN114057934B CN114057934B CN202111462287.6A CN202111462287A CN114057934B CN 114057934 B CN114057934 B CN 114057934B CN 202111462287 A CN202111462287 A CN 202111462287A CN 114057934 B CN114057934 B CN 114057934B
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
- C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
- C08F220/52—Amides or imides
- C08F220/54—Amides, e.g. N,N-dimethylacrylamide or N-isopropylacrylamide
- C08F220/58—Amides, e.g. N,N-dimethylacrylamide or N-isopropylacrylamide containing oxygen in addition to the carbonamido oxygen, e.g. N-methylolacrylamide, N-(meth)acryloylmorpholine
- C08F220/585—Amides, e.g. N,N-dimethylacrylamide or N-isopropylacrylamide containing oxygen in addition to the carbonamido oxygen, e.g. N-methylolacrylamide, N-(meth)acryloylmorpholine and containing other heteroatoms, e.g. 2-acrylamido-2-methylpropane sulfonic acid [AMPS]
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K8/00—Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
- C09K8/02—Well-drilling compositions
- C09K8/03—Specific additives for general use in well-drilling compositions
- C09K8/035—Organic additives
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K8/00—Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
- C09K8/02—Well-drilling compositions
- C09K8/04—Aqueous well-drilling compositions
- C09K8/14—Clay-containing compositions
- C09K8/18—Clay-containing compositions characterised by the organic compounds
- C09K8/22—Synthetic organic compounds
- C09K8/24—Polymers
Abstract
The invention provides a dispersant for drilling fluid and a preparation method thereof, wherein the dispersant is prepared by polymerizing dimethyl acrylamide, 2-acrylamide-2-methylpropanesulfonic acid, p-tert-butyl styrene, a chain transfer agent, a chelating agent, an initiator and the like. The dispersant prepared by the invention has good temperature resistance.
Description
Technical Field
The invention relates to a dispersing agent for well drilling and a preparation method thereof, in particular to the technical field of synthesis of a treating agent for an oil field drilling fluid.
Background
In the drilling process of deep wells and ultra-deep wells, the formation temperature is higher, and sometimes in order to balance the formation pressure, a weighted drilling fluid needs to be used to meet the requirements of engineering and geology. Because the ultra-high density drilling fluid has high solid phase content, the weighting material and the drill cuttings are subjected to high shear rate action and drill bit grinding for a long time in a high-temperature and high-pressure environment, so that fine particles in the drilling fluid are increased, the rheological property is difficult to control, and the mechanical drilling speed is reduced. In order to solve the problems, domestic researchers often improve the rheological property of the drilling fluid by adding a dispersing agent into the drilling fluid. Because the common dispersing agent has limited temperature resistance and limited dispersion effect on the barite, the rheological property of the ultra-high density drilling fluid still cannot meet the field requirement. Patent CN103045185A provides a dispersant for ultra-high density drilling fluid and a preparation method thereof, which is polymerized by carboxyl monomer, sulfo monomer and organic amine monomer, and has good dispersing effect on barite, but the temperature resistance (120 ℃) is not enough.
The invention provides a copolymer dispersant suitable for a high-temperature bottom layer of high-density drilling fluid, and the high-temperature rheological property is improved.
Disclosure of Invention
One of the purposes of the invention is to provide a dispersing agent for well drilling, which can realize the dispersion of particles in the drilling fluid and can effectively improve the slurry preparation performance, the high-temperature rheological property and the sedimentation stability of mud.
The dispersant of the invention has the following general structural unit:
wherein x is 500-1000, y is 200-800, and z is 100-500.
Further, the dispersing agent is prepared by mixing and copolymerizing the following components in proportion:
dimethylacrylamide: 5 to 25 percent of
2-acrylamido-2-methylpropanesulfonic acid: 5 to 15 percent
P-tert-butylstyrene: 2-10% SO 3 H
Chain transfer agent: 0.5 to 5 percent
Chelating agent: 0.02% -0.05%
Cosolvent: 0 to 3 percent
Initiator: 0.3 to 0.5 percent
Solubilizer: 5-8% and the balance of deionized water;
the content is mass percent based on the total mass of the dispersant.
The chain transfer agent is one of sodium formate and sodium hypophosphite.
The chelating agent is one of 2 sodium ethylene diamine tetraacetic acid, sodium tripolyphosphate and sodium citrate.
The cosolvent is one of urea and thiourea.
The initiator is a redox system consisting of ammonium persulfate and sodium bisulfite, and the components comprise 0.001-0.006 percent of ammonium persulfate and 0.001-0.003 percent of ammonium bisulfite by taking the total mass of the dispersant as the reference.
The solubilizer is N, N-dimethylformamide.
The invention also aims to provide a preparation method of the dispersing agent for drilling, which introduces p-tert butyl styrene on the basis of dimethylacrylamide and sodium 2-acrylamide-2-methylpropanesulfonate to improve the dispersibility and the temperature resistance, and the preparation method of the dispersing agent comprises the following steps:
step 1, preparing dimethylacrylamide, 2-acrylamido-2-methylpropanesulfonic acid sodium salt, p-tert-butylstyrene, an auxiliary agent, a solubilizer and deionized water into a uniform solution according to a proportion;
step 2, adjusting the pH value to obtain a solution with pH = 4.0-8.0;
step 3, filling nitrogen into the solution obtained in the step 2 for 20-40 min;
step 4, adding an initiator into the solution obtained in the step 3, and carrying out polymerization reaction for 2-5 hours to obtain a polymer solution;
and 5, insulating the polymer solution to prepare the dispersing agent.
The auxiliary agents in the step 1 are a chain transfer agent, a chelating agent, a cosolvent and an initiator;
in the step 1, the polymerization monomer, the auxiliary agent and the solubilizer are in percentage by mass:
dimethylacrylamide: 5 to 25 percent;
2-acrylamido-2-methylpropanesulfonic acid: 5 to 15 percent;
p-tert-butylstyrene: 2 to 10 percent;
chain transfer agent: 0.5% -5%;
chelating agent: 0.02% -0.05%;
cosolvent: 0 to 3 percent;
initiator: 0.3 to 0.5 percent
Solubilizer: 5-8% and the balance of deionized water;
in step 2, the pH is adjusted by using a common base such as sodium hydroxide.
In the step 5, the heat preservation is carried out after the temperature is firstly raised to 80 ℃ and then is kept for 2 hours.
Has the advantages that:
1. the dispersing agent has good dispersing performance (room temperature curing for 24 hours) of 50 percent in the fresh water-based slurry;
2. the dispersing performance (aging at 220 ℃ for 24 hours) of the dispersing agent in the fresh water base slurry is 50 percent, and the temperature-resistant dispersing performance is good;
3. the dispersing performance (curing for 24 hours at room temperature) of the dispersing agent in the saline-based slurry is 50 percent;
4. the dispersing agent has good dispersing performance (aging for 24 hours at 220 ℃) in saline water-based slurry of 50 percent and good salt resistance.
The above data demonstrate that the temperature resistance and dispersion of the dispersant can be improved by introducing various functional monomers, particularly p-tert-butyl benzene, onto the dispersant polymer monomer.
The specific implementation mode is as follows:
the present invention and its effects are further described below with reference to examples.
The dispersants obtained according to the experimental procedure described above were evaluated according to the following examples, as follows:
the preparation examples of the dispersants are as follows:
the following contents are mass percentages.
Example 1
54.0g of dimethylacrylamide (solids, 98% content), 80.0g of sodium 2-acrylamido-2-methylpropanesulfonate (45% aqueous solution), 7.2g of p-t-butylstyrene, 1.8g of sodium hypophosphite, 21g of dimethylformamide, 1.0g of edta-2 sodium (1%) aqueous solution were added to 162.7g of deionized water. Adjusting the pH value to be =6.8, introducing nitrogen to remove oxygen for 40 minutes, controlling the initiation temperature to be 30 ℃, adding 0.9g of initiator ammonium persulfate (2%) aqueous solution and 0.3g of initiator sodium bisulfite (2%) aqueous solution, reacting for 5 hours, heating to 80 ℃, preserving heat, and continuing to react for 2 hours to obtain a product A.
Example 2
54.0g of dimethylacrylamide (solid, content 98%), 80.0g of sodium 2-acrylamido-2-methylpropanesulfonate (45% aqueous solution), 8.5g of p-tert-butylstyrene, and 2.2g of sodium hypophosphite; 22g of dimethylformamide, 1.0g of an aqueous solution of edta-2 sodium (1%), and 160g of deionized water were added. Adjusting the pH =7, introducing nitrogen to remove oxygen for 40 minutes, controlling the initiation temperature at 30 ℃, adding 1g of an aqueous solution of initiator ammonium persulfate (2%) and 0.4g of an aqueous solution of sodium bisulfite (2%), reacting for 5 hours, heating to 80 ℃, preserving heat, and continuing to react for 2 hours to obtain a product B.
Example 3
50g of dimethylacrylamide (solid, content 98%), 80.0g of sodium 2-acrylamido-2-methylpropanesulfonate (45% aqueous solution), 8.0g of p-tert-butylstyrene, and 2.1g of sodium hypophosphite; dimethylformamide (20g), aqueous solution of eda-2 sodium (1%) (1.0 g), and deionized water (162 g) were added. Adjusting the pH to be =7, introducing nitrogen to remove oxygen for 40 minutes, controlling the initiation temperature to be 30 ℃, adding 0.9g of initiating agent ammonium persulfate (2%) aqueous solution and 0.4g of sodium bisulfite (2%) aqueous solution, reacting for 5 hours, heating to 80 ℃, preserving heat, and continuing to react for 2 hours to obtain a product C.
Example 4
50g of dimethylacrylamide (solid, content 98%), 80.0g of sodium 2-acrylamido-2-methylpropanesulfonate (45% aqueous solution), 7.0g of p-tert-butylstyrene and 2.4g of sodium hypophosphite; dimethylformamide (18g), sodium edta-2 (1%) in water (1%) 1.0 g), and deionized water (162 g) was added. Adjusting the pH =7, introducing nitrogen to remove oxygen for 40 minutes, controlling the initiation temperature at 30 ℃, adding 0.9g of initiator ammonium persulfate (2%) aqueous solution and 0.3g of sodium bisulfite (2%) aqueous solution, reacting for 5 hours, heating to 80 ℃, preserving the temperature, and continuing to react for 2 hours to obtain a product D.
Example 5
45g of dimethylacrylamide (solid, content 98%), 80.0g of sodium 2-acrylamido-2-methylpropanesulfonate (45% aqueous solution), 6.5g of p-tert-butylstyrene, and 5.2g of sodium formate; dimethylformamide (18g), edta-2 sodium (1%) aqueous solution (1.0 g), and deionized water (150 g) were added. Adjusting the pH =7, introducing nitrogen to remove oxygen for 40 minutes, controlling the initiation temperature at 30 ℃, adding 0.9g of initiator ammonium persulfate (2%) aqueous solution and 0.3g of sodium bisulfite (2%) aqueous solution, reacting for 5 hours, heating to 80 ℃, preserving the temperature, and continuing to react for 2 hours to obtain a product E.
Example 6
40g of dimethylacrylamide (solid, content 98%), 75.0g of sodium 2-acrylamido-2-methylpropanesulfonate (45% aqueous solution), 8g of p-tert-butylstyrene, and 5.5g of sodium formate; dimethylformamide 22g, 1.0g of an aqueous solution of edta-2 sodium (1%), and 150g of deionized water were added. Adjusting the pH to be =7, introducing nitrogen to remove oxygen for 40 minutes, controlling the initiation temperature to be 30 ℃, adding 0.9g of initiating agent ammonium persulfate (2%) aqueous solution and 0.3g of sodium bisulfite (2%) aqueous solution, reacting for 5 hours, heating to 80 ℃, preserving heat, and continuing to react for 2 hours to obtain a product F.
The viscosity of the stock solution obtained in the above example was measured by a brookfield viscometer, and the results were as follows (test conditions, room temperature, S61# spindle, 10 rpm)
| Number of | A | B | C | D | E | F |
| Viscosity (mpa.s) | 428.0 | 282．0 | 251.6 | 242.2 | 216.0 | 231.0 |
Evaluation method of dispersant polymer:
evaluation of mud performance:
preparing base slurry:
1) Fresh water-based slurry: adding 1g of sodium carbonate and 20g of bentonite into 1L of water, stirring at a high speed for 2h by a Wuyi mixing and blending device, and standing and maintaining at room temperature for 24h to obtain 2% freshwater base slurry.
2) Saline water-based slurry: adding 10% sodium chloride into 2% fresh water base pulp, stirring at high speed for 5 min, and standing at room temperature for 24 hr to obtain saline water base pulp.
Performance test method
And (3) measuring the dispersion rate: adding the synthesized dispersant into the prepared base slurry, stirring at a high speed for 5 min, standing and maintaining at room temperature for 24h or rolling and aging at a certain temperature for 16 h, stirring at a high speed at room temperature for 5 min, and measuring the rheological property of the slurry by using a six-speed rotary viscometer.
The dispersion ratio of the dispersant was calculated as follows:
dispersion ratio = (phi) 0 － φ 1 ）/φ 0 X 100% of formula (I), phi 0 ，φ 1 The shear rate of the slurry in the viscometer is 100S before and after the dispersant is added -1 The reading of time.
The results of the tests on the samples obtained in the examples according to the test method described above are as follows:
dispersibility in fresh water-based slurries:
the dispersant was added to the base slurry, and then the rheological properties of the base slurry after aging at room temperature and at 220 ℃ for 24 hours were measured, and the results are shown in tables-1 and-2. (the amount is calculated by mass percent of the base slurry)
TABLE-1 Dispersion Performance of dispersant in fresh water based slurries (Room temperature curing 24 hours)
| Dispersant number | A | B | C | D | E | F |
| Apparent viscosity/(mPa. S) | 121 | 116 | 112 | 110 | 114 | 115 |
| Plastic viscosity/(mPa. S) | 72 | 79 | 80 | 85 | 83 | 86 |
| Dynamic shear force/Pa | 12 | 10 | 8 | 8 | 9 | 8 |
| Percent dispersion/%) | 34.3 | 43.6 | 49.2 | 48.4 | 50.1 | 49.2 |
TABLE-2 Dispersion Performance of dispersants in fresh water based slurries (aging at 220 ℃ C. For 24 hours)
| Dispersant number | A | B | C | D | E | F |
| Apparent viscosity/(mPa. S) | 118 | 110 | 109 | 113 | 110 | 108 |
| Plastic viscosity/(mPa. S) | 70 | 75 | 82 | 86 | 82 | 84 |
| Dynamic shear force/Pa | 11 | 8 | 7 | 8 | 6 | 6 |
| Percent dispersion/%) | 28.3 | 44.7 | 51.5 | 49.3 | 48.6 | 51.2 |
As can be seen from tables-1 and 2 above, the rigid structure of tert-butylbenzene in the polymer can improve the temperature resistance of the polymer.
Dispersibility in brine-based slurries:
adding 2% of dispersant into saline water base slurry, respectively maintaining for 24 hours and aging for 24 hours, and measuring the rheological properties of the base slurry, as shown in the following table-3/table-4
TABLE-3 Dispersion Performance of dispersant in saline based slurries (Room temperature curing 24 hours)
| Dispersant number | A | B | C | D | E | F |
| Percent dispersion/%) | 35.6 | 43.9 | 50.1 | 49.6 | 48.9 | 51.2 |
TABLE-4 Dispersion Performance of dispersants in saline-based slurries (aging at 220 ℃ C. For 24 hours)
| Dispersant number | A | B | C | D | E | F |
| Degree of dispersion/%) | 23.2 | 38.7 | 51.2 | 50.1 | 49.3 | 50.6 |
As can be seen from the experimental results shown in tables-3 and 4, the temperature resistance effect and the dispersing effect of the dispersing agent can be improved after various functional monomers are introduced into the dispersing agent polymer monomer.
Claims (8)
1. A dispersant for drilling fluid is characterized in that: contains the following structural units of the general formula:
wherein x, y and z are the number of repeating units of each polymerized monomer, x is 500 to 1000, y is 200 to 800, and z is 100 to 500.
2. The dispersant as claimed in claim 1, which is prepared by mixing and copolymerizing the following components in percentage by mass:
initiator, solubilizer and the balance of deionized water.
3. The dispersant of claim 2 wherein the chain transfer agent is one of sodium formate and sodium hypophosphite.
4. The dispersant of claim 2, wherein the chelating agent is one of sodium 2-ethylenediaminetetraacetic acid, sodium tripolyphosphate, and sodium citrate.
5. A dispersant according to claim 2, wherein the co-solvent is one of urea and thiourea.
6. The dispersant of claim 2 wherein the initiator is a combination of ammonium persulfate and sodium bisulfite.
7. The dispersant of claim 2, wherein the solubilizer is N, N-dimethylformamide.
8. A process for the preparation of a dispersant as claimed in any one of claims 1 to 7, characterized by comprising the steps of:
step 1, preparing dimethyl acrylamide, 2-acrylamide-2-methyl sodium propanesulfonate, p-tert butyl styrene, a chain transfer agent, a chelating agent, a cosolvent, an initiator, a solubilizer and deionized water into a uniform solution according to a proportion,
step 2, adjusting the pH value to obtain a solution with the pH value of 4.0-8.0,
step 3, filling nitrogen into the solution in the step 2 for 20-40min,
step 4, adding an initiator into the solution filled with nitrogen in the step 3, carrying out polymerization reaction for 2-5 hours to obtain a polymer solution,
and 5, insulating the polymer solution to prepare the dispersing agent.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103045185A (en) * | 2011-10-17 | 2013-04-17 | 中国石油化工股份有限公司 | Super-high density drilling fluid dispersing agent and preparation method thereof |
| CN108467713A (en) * | 2018-05-30 | 2018-08-31 | 山东得顺源石油科技有限公司 | A kind of drilling fluid low thickening copolymer fluid loss agent and preparation method thereof |
| CN109863185A (en) * | 2016-11-04 | 2019-06-07 | 巴斯夫欧洲公司 | Novel monomeric and polymer |
| CN112111039A (en) * | 2019-06-19 | 2020-12-22 | 中国石油化工股份有限公司 | Dispersing agent, preparation method and application thereof |
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| KR100811212B1 (en) * | 2005-12-16 | 2008-03-07 | 주식회사 그린테크놀로지 | Water-soluble anionic polymer dispersion and method for producing the same |
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103045185A (en) * | 2011-10-17 | 2013-04-17 | 中国石油化工股份有限公司 | Super-high density drilling fluid dispersing agent and preparation method thereof |
| CN109863185A (en) * | 2016-11-04 | 2019-06-07 | 巴斯夫欧洲公司 | Novel monomeric and polymer |
| CN108467713A (en) * | 2018-05-30 | 2018-08-31 | 山东得顺源石油科技有限公司 | A kind of drilling fluid low thickening copolymer fluid loss agent and preparation method thereof |
| CN112111039A (en) * | 2019-06-19 | 2020-12-22 | 中国石油化工股份有限公司 | Dispersing agent, preparation method and application thereof |
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