A boron-resistant salt-resistant polymer suspension emulsion and a preparation method thereof

Abstract

The application discloses a kind of anti-boron salt-tolerant polymer suspending emulsion and preparation method thereof, it is related to suspending emulsion technical field.The anti-boron salt-tolerant polymer suspending emulsion is prepared in the application, first 1,3-bis (dimethylamino) -2-propanol is reacted with oxalyl chloride mono allyl ester to obtain double bond modified tertiary amine;Amphoteric monomer is prepared by reacting double bond modified tertiary amine with propylsulfonic acid lactone;Hydrophobic monomer is prepared by reacting double bond modified tertiary amine with 1-bromodecane;Modified polyacrylamide is prepared by copolymerizing acrylamide, maleic acid, amphoteric monomer and hydrophobic monomer;The anti-boron salt-tolerant polymer suspending emulsion is prepared by mixing modified polyacrylamide, slurry soil, polyacrylonitrile ammonium salt, organosilicon alcohol, emulsified paraffin, anti-boron agent and water.The anti-boron salt-tolerant polymer suspending emulsion prepared by the application has the advantages of salt resistance, temperature resistance, good filtration loss reduction performance and anti-boron.

Description

Technical Field

[0001] This invention relates to the field of suspension emulsion technology, specifically to a boron-resistant and salt-tolerant polymer suspension emulsion and its preparation method. Background Technology

[0002] As is well known, oil development operations have now entered a stage of exploring for oil in deeper waters, deeper formations, and more complex geological formations. The challenges are increasing, placing higher demands and challenges on drilling, completion, workover, production, and oilfield waste treatment technologies. Drilling fluid, as the lifeblood of drilling, plays an indispensable role in oil development operations, carrying drill cuttings, stabilizing the wellbore, cooling the drill bit, and reducing drag and lubricating. However, a key challenge facing drilling fluid technology is ensuring wellbore stability. Wellbore instability during development operations can have many adverse effects, significantly hindering the normal progress of drilling projects.

[0003] Statistics show that among the many factors causing wellbore instability, most wellbore collapses are related to shale instability. Nearly 75% of the formations encountered during drilling are shale and mudstone; therefore, wellbore stability problems during drilling are sometimes referred to as shale and mudstone stability problems. Shale and mudstone are fine-grained rocks with very small pores, high clay content, and are generally saturated with formation water, resulting in extremely low permeability. These characteristics determine that shale and mudstone have a significant impact on wellbore stability.

[0004] Suspension emulsion drilling fluid is formulated with environmentally friendly positively charged cationic emulsion polymers, emulsified paraffin wax, organosilicone alcohols, and other auxiliary agents. Through charge neutralization and the bridging effect of long-chain polymers, this drilling fluid significantly reduces the specific surface area and negative charge of clay, thereby essentially eliminating the water sensitivity of the clay. This effectively inhibits the expansion, dispersion, and migration of clay particles, stabilizing the clay. Combined with the synergistic effect of emulsified paraffin wax forming a low-permeability shielding zone near the wellbore, it reduces the potential damage to the oil reservoir caused by filtrate and harmful solid phases entering the reservoir, preventing wellbore collapse and protecting the oil and gas layer.

[0005] Amphoteric polyelectrolytes or polyampholytes are polymers with both positively and negatively charged groups on their molecular chains. Due to the simultaneous presence of positive and negative charges on the polymer chains after ionization, amphoteric polyelectrolytes exhibit excellent solubility, salt resistance, acid and alkali resistance, cross-linking properties, and adsorption characteristics, making them widely used in the oil extraction field. Due to the special structure of zwitterionic polymers, they can be used in combination with both anionic and cationic polymers. As drilling fluid treatment agents, zwitterionic polymers not only reduce filtration loss, viscosity, and flocculate, but also possess strong inhibitory capabilities. Therefore, using suspension emulsions with amphoteric polyelectrolytes in drilling fluids can effectively improve wellbore stability. Furthermore, in high-salt environments such as deep seas, salt deposits, and high-salinity formation water, it is also necessary for the suspension emulsions to possess salt resistance to avoid demulsification failure caused by high salt concentrations. Summary of the Invention

[0006] The purpose of this invention is to provide a boron-resistant and salt-tolerant polymer suspension emulsion and its preparation method, so as to solve the problems existing in the prior art.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0008] A boron-resistant and salt-tolerant polymer suspension emulsion, wherein the boron-resistant and salt-tolerant polymer suspension emulsion is prepared by mixing modified polyacrylamide, mortar clay, polyacrylonitrile ammonium salt, organosilicone alcohol, emulsified paraffin wax, boron inhibitor, and water;

[0009] The modified polyacrylamide is prepared by copolymerizing acrylamide, maleic acid, amphoteric monomers, and hydrophobic monomers.

[0010] The amphoteric monomer is prepared by reacting a double-bonded modified tertiary amine with propanesulfonate lactone.

[0011] The hydrophobic monomer is prepared by reacting a double-bonded modified tertiary amine with 1-bromodecane;

[0012] The double-bond modified tertiary amine is prepared by reacting 1,3-bis(dimethylamino)-2-propanol with oxalyl chloride monoallyl ester.

[0013] As an optimization, the mortar mix is ​​bentonite.

[0014] As an optimization, the boron inhibitor is one or a mixture of several of the following: gypsum, potassium carbonate, mirabilite, potassium chloride, oxidized asphalt, sulfonated asphalt, cationic modified asphalt, emulsified asphalt, trichloromethylsilane, fluorine-silicon and its modified preparations, ethylene oxide-propylene oxide copolymer, propylene oxide-polystyrene copolymer, polyvinyl alcohol, polyacrylamide, potassium humate, and humic silicate.

[0015] A method for preparing a boron-resistant and salt-tolerant polymer suspension emulsion includes the following preparation steps:

[0016] (1) Mix 1,3-bis(dimethylamino)-2-propanol and chloroform, add triethylamine dropwise, add hydroquinone, stir, add 30wt% chloroform solution of oxaloyl chloride monoallyl ester dropwise in an ice water bath, react for 10-12h, heat, continue to react for 10-12h, add sodium acetate, continue to react for 20-24h, filter, evaporate the filtrate to dryness, extract, wash, concentrate and purify to obtain double bond modified tertiary amine;

[0017] (2) Mix double bond modified tertiary amine, hydroquinone and acetone, add 40wt% propanesulfonate lactone acetone solution, heat to react, filter, wash and dry to obtain amphoteric monomer;

[0018] (3) Mix double bond modified tertiary amine, 1-bromodecane, hydroquinone, potassium iodide and acetonitrile, heat and react, rotary evaporate, recrystallize and freeze dry to obtain hydrophobic monomer;

[0019] (4) Mix acrylamide, maleic acid, emulsifier and pure water, adjust pH, add amphoteric monomer, hydrophobic monomer and initiator under nitrogen atmosphere, heat to react, cool naturally, cut, wash, dry, granulate and grind, sieve to obtain modified polyacrylamide.

[0020] (5) The formula according to the mass components is as follows: 3%~5% of the mortar soil; 0.5%~0.8% of the polyacrylonitrile ammonium salt; 1%~1.5% of the organosilicone alcohol; 2%~3% of the emulsified paraffin wax; 0.3%~0.4% of the modified polyacrylamide; 0.5%~2% of the boron inhibitor; the remainder is water. The mortar soil is first pre-hydrated in 10 times its mass of water for 24 hours, and then the polyacrylonitrile ammonium salt, organosilicone alcohol, emulsified paraffin wax, modified polyacrylamide, boron inhibitor and the remaining water are added. The mixture is stirred at 800~1000 rpm for 2~3 hours at room temperature to obtain a boron-resistant and salt-resistant polymer suspension emulsion.

[0021] As an optimization, the double-bond modified tertiary amine in step (1) is prepared by mixing 3-4 parts of 1,3-bis(dimethylamino)-2-propanol and 15-20 parts of chloroform by mass, adding 2.28-3.04 parts of triethylamine dropwise at 7-8 ml / min at room temperature and 200-300 r / min, followed by 0.016-0.018 parts of hydroquinone. The mixture is stirred at 200-300 r / min for 20-30 min at room temperature, then transferred to an ice-water bath and heated at 200-300 r / min. Add 10.67-14.22 parts of a 30wt% oxaloyl chloride monoallyl ester solution in chloroform at a rate of 2-3 ml / min at 00 r / min. React at 200-300 r / min for 10-12 h at room temperature. Heat to 35-40 °C and continue the reaction for 10-12 h. Add 1-1.2 parts of sodium acetate and continue the reaction for 20-24 h. Filter under vacuum, evaporate the filtrate to dryness, dissolve in dichloromethane, wash and extract with saturated sodium chloride aqueous solution, and concentrate and purify the organic phase to obtain the final product.

[0022] As an optimization, the amphoteric monomer in step (2) is prepared by mixing 3-4 parts of double-bond modified tertiary amine, 0.01-0.012 parts of hydroquinone, and 25-30 parts of acetone by mass. At room temperature, at 200-300 r / min, 7.8-10.4 parts of 40wt% propanesulfonic acid lactone acetone solution are added dropwise at 3-5 ml / min. The mixture is reacted at 50-55℃ and 300-400 r / min for 18-20 h. After filtration, the mixture is washed 3-4 times with a 1:1 volume ratio of acetone and diethyl ether mixed solution and dried under vacuum at 50-60℃ for 8-10 h.

[0023] As an optimization, the hydrophobic monomer in step (3) is prepared by mixing 5-6 parts of double bond modified tertiary amine, 10.27-12.33 parts of 1-bromodecane, 0.015-0.017 parts of hydroquinone, 0.3-0.4 parts of potassium iodide, and 25-30 parts of acetonitrile by mass, reacting at 40-45℃ and 300-400 r / min for 20-24 h, removing the solvent by rotary evaporation, dissolving in ethanol, recrystallizing with methyl tert-butyl ether, and then freeze-drying.

[0024] As an optimization, the modified polyacrylamide in step (4) is prepared by mixing 8-10 parts acrylamide, 1.63-2.04 parts maleic acid, 1.5-1.6 parts emulsifier, and 20-25 parts pure water by mass, adjusting the pH to 7-8, adding 5-6.26 parts amphoteric monomer, 2.46-3.08 parts hydrophobic monomer, and 0.015-0.016 parts initiator under a nitrogen atmosphere, reacting at 75-80℃ and 300-400r / min for 10-12h, naturally cooling to room temperature, cutting into small pieces, washing with anhydrous ethanol 4-5 times, vacuum drying at 60-65℃ for 8-10h, granulating and grinding with a high-speed pulverizer, and passing through a 120-mesh sieve.

[0025] As an optimization, the type of emulsifier in step (4) is OP-10.

[0026] As an optimization, the initiator in step (4) is one of azobisisobutyramidine hydrochloride and azobisisobutyronitrile.

[0027] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0028] In preparing the boron-resistant and salt-tolerant polymer suspension emulsion, the present invention first reacts 1,3-bis(dimethylamino)-2-propanol with oxaloyl chloride monoallyl ester to obtain a double-bond modified tertiary amine; reacts the double-bond modified tertiary amine with propanesulfonate lactone to obtain an amphoteric monomer; reacts the double-bond modified tertiary amine with 1-bromodecane to obtain a hydrophobic monomer; copolymerizes acrylamide, maleic acid, the amphoteric monomer, and the hydrophobic monomer to obtain modified polyacrylamide; and mixes the modified polyacrylamide, mortar, polyacrylonitrile ammonium salt, organosilicone alcohol, emulsified paraffin wax, and boron inhibitor with water to obtain the boron-resistant and salt-tolerant polymer suspension emulsion.

[0029] First, 1,3-bis(dimethylamino)-2-propanol was reacted with oxalyl chloride monoallyl ester to prepare a compound with a bis-tertiary amine structure and a double bond. The bis-tertiary amine structure facilitates the subsequent introduction of a dicationic structure, greatly improving the cation coverage. At the same time, the introduced double bond allows it to effectively participate in the copolymerization of polyacrylamide. In addition, the two adjacent acyl groups in oxalyl chloride monoallyl ester have good hydrogen bonding, which effectively improves the performance of reducing filtration loss.

[0030] Secondly, propanesulfonic acid lactone undergoes a ring-opening reaction with the tertiary amine group on the double-bond modified tertiary amine to form an amphoteric betaine structure, while also introducing sulfonic acid groups. Due to its structure, the sulfonic acid group has good salt resistance, and its amphoteric structure with both cationic and anionic properties exhibits a significant "anti-polyelectrolyte effect," which also effectively improves salt resistance. 1-Bromodecane undergoes a quaternization reaction with the double-bond modified tertiary amine to form a quaternary ammonium cation, while also introducing a long carbon chain. The hydrophobic monomer with the long carbon chain gives it some of the properties of an emulsifier, and the hydrophobic association effect gives the resulting suspension emulsion good stability and greatly improves the filtration loss reduction effect.

[0031] Finally, the modified polyacrylamide formed by copolymerizing acrylamide, maleic acid, amphoteric monomers, and hydrophobic monomers has an amphoteric structure and a low content of long carbon chain structure, which improves salt resistance and filtration loss reduction. The prepared modified polyacrylamide is mixed with grouting soil, polyacrylonitrile ammonium salt, organosilicone alcohol, emulsified paraffin wax, boron inhibitor, and pure water to form a suspension emulsion system. This system has good application prospects in drilling fluids. Detailed Implementation

[0032] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0033] Information on some of the raw materials used in all the following examples and comparative examples is as follows:

[0034] The mortar mix was made of bentonite, purchased from Dongzheng Chemical Co., Ltd. in Shangnan County, Shaanxi Province.

[0035] Ammonium polyacrylonitrile salt: Model NH4-HPAN, purchased from Dongzheng Chemical Co., Ltd., Shangnan County, Shaanxi Province;

[0036] Organosilanol: Model DS-302, purchased from Henan Longxiang Petroleum Additives Co., Ltd.;

[0037] Emulsified paraffin wax: Model RHJ-1, purchased from Henan Longxiang Petroleum Additives Co., Ltd.;

[0038] Emulsifier: OP-10;

[0039] Initiator: Azobisisobutyramidine hydrochloride;

[0040] Boron inhibitor: potassium carbonate.

[0041] Example 1: A method for preparing a boron-resistant and salt-tolerant polymer suspension emulsion, the method comprising the following preparation steps:

[0042] (1) By mass fraction, 3 parts of 1,3-bis(dimethylamino)-2-propanol and 15 parts of chloroform were mixed evenly. At room temperature, 200 r / min was added dropwise at 7 ml / min, followed by 0.016 parts of hydroquinone. The mixture was stirred at room temperature at 200 r / min for 30 min. Then, it was transferred to an ice-water bath and 10.67 parts of 30 wt% chloroform solution of oxaloyl chloride monoallyl ester was added dropwise at 2 ml / min. The mixture was reacted at room temperature at 200 r / min for 12 h. The mixture was then heated to 35 °C and reacted for another 12 h. 1 part of sodium acetate was added and the mixture was reacted for another 24 h. The mixture was filtered, the filtrate was evaporated to dryness, dissolved in dichloromethane, washed and extracted with saturated sodium chloride aqueous solution, and the organic phase was concentrated and purified to obtain double bond modified tertiary amine.

[0043] (2) By mass fraction, 3 parts of double bond modified tertiary amine, 0.01 parts of hydroquinone and 25 parts of acetone were mixed evenly. At room temperature, 7.8 parts of 40wt% propanesulfonic acid lactone acetone solution were added dropwise at 3ml / min at 200r / min. The reaction was carried out at 50℃ and 300r / min for 20h. The mixture was filtered and washed three times with a 1:1 volume ratio of acetone and diethyl ether mixed solution. The mixture was then dried under vacuum at 50℃ for 10h to obtain the amphoteric monomer.

[0044] (3) By mass fraction, 5 parts of double bond modified tertiary amine, 10.27 parts of 1-bromodecane, 0.015 parts of hydroquinone, 0.3 parts of potassium iodide, and 25 parts of acetonitrile were mixed evenly and reacted at 40℃ and 300r / min for 24h. The solvent was removed by rotary evaporation, dissolved in ethanol, recrystallized with methyl tert-butyl ether, and then freeze-dried to obtain the hydrophobic monomer.

[0045] (4) By mass, 8 parts acrylamide, 1.63 parts maleic acid, 1.5 parts emulsifier and 20 parts pure water are mixed evenly, the pH is adjusted to 7, and under nitrogen atmosphere, 5 parts amphoteric monomer, 2.46 parts hydrophobic monomer and 0.015 parts initiator are added. The mixture is reacted at 75℃ and 300r / min for 12h, cooled naturally to room temperature, cut into pieces, washed 4 times with anhydrous ethanol, vacuum dried at 60℃ for 10h, granulated and ground with a high-speed pulverizer, and passed through a 120-mesh sieve to obtain modified polyacrylamide.

[0046] (5) The formula according to the mass components is as follows: 3% of the mortar soil; 0.8% of the polyacrylonitrile ammonium salt; 1% of the organosilicone alcohol; 3% of the emulsified paraffin wax; 0.3% of the modified polyacrylamide; 0.5% of the boron inhibitor; and the balance is water. The mortar soil is pre-hydrated in 10 times its mass of water for 24 hours. Then, the polyacrylonitrile ammonium salt, organosilicone alcohol, emulsified paraffin wax, modified polyacrylamide, boron inhibitor and the remaining water are added. The mixture is stirred at 800 rpm for 3 hours at room temperature to obtain a boron-resistant and salt-resistant polymer suspension emulsion.

[0047] Example 2: A method for preparing a boron-resistant and salt-tolerant polymer suspension emulsion, the method comprising the following preparation steps:

[0048] (1) By mass fraction, 3.5 parts of 1,3-bis(dimethylamino)-2-propanol and 18 parts of chloroform were mixed evenly. At room temperature, 2.66 parts of triethylamine were added dropwise at 7.5 ml / min at 250 r / min. Then, 0.017 parts of hydroquinone were added. The mixture was stirred at room temperature at 250 r / min for 25 min. Then, it was transferred to an ice-water bath. At 250 r / min, 12.44 parts of 30 wt% oxaloyl chloride monoallyl chloroform solution were added dropwise at 2.5 ml / min. The mixture was reacted at room temperature at 250 r / min for 11 h. The mixture was heated to 38 °C and the reaction was continued for 11 h. Then, 1.1 parts of sodium acetate were added and the reaction was continued for 22 h. The mixture was filtered, the filtrate was evaporated to dryness, dissolved in dichloromethane, washed and extracted with saturated sodium chloride aqueous solution, and the organic phase was concentrated and purified to obtain double bond modified tertiary amine.

[0049] (2) By mass fraction, 3.5 parts of double bond modified tertiary amine, 0.011 parts of hydroquinone and 28 parts of acetone were mixed evenly. At room temperature, 9.1 parts of 40wt% propanesulfonic acid lactone acetone solution were added dropwise at 4ml / min at 250r / min. The reaction was carried out at 52℃ and 350r / min for 19h. The mixture was filtered and washed three times with a 1:1 volume ratio of acetone and diethyl ether mixed solution. The mixture was then dried under vacuum at 55℃ for 9h to obtain the amphoteric monomer.

[0050] (3) By mass fraction, 5.5 parts of double bond modified tertiary amine, 11.3 parts of 1-bromodecane, 0.016 parts of hydroquinone, 0.35 parts of potassium iodide and 28 parts of acetonitrile were mixed evenly and reacted at 42℃ and 350r / min for 22h. The solvent was removed by rotary evaporation, dissolved in ethanol and recrystallized with methyl tert-butyl ether, and then freeze-dried to obtain the hydrophobic monomer.

[0051] (4) According to the mass fraction, 9 parts acrylamide, 1.84 parts maleic acid, 1.55 parts emulsifier and 22 parts pure water are mixed evenly, and the pH is adjusted to 7.5. Under the nitrogen atmosphere, 5.63 parts amphoteric monomer, 2.77 parts hydrophobic monomer and 0.0155 parts initiator are added. The mixture is reacted at 78℃ and 350r / min for 11h. After naturally cooling to room temperature, it is cut into pieces, washed 4 times with anhydrous ethanol, and vacuum dried at 60℃ for 9h. It is then granulated and ground with a high-speed pulverizer and passed through a 120-mesh sieve to obtain modified polyacrylamide.

[0052] (5) The formula according to the mass components is as follows: 4% of the mortar soil; 0.6% of the polyacrylonitrile ammonium salt; 1.2% of the organosilicone alcohol; 2.5% of the emulsified paraffin wax; 0.35% of the modified polyacrylamide; 1.2% of the boron inhibitor; and the balance is water. The mortar soil is pre-hydrated in 10 times its mass of water for 24 hours. Then, the polyacrylonitrile ammonium salt, organosilicone alcohol, emulsified paraffin wax, modified polyacrylamide, boron inhibitor and the remaining water are added. The mixture is stirred at 900 rpm for 2.5 hours at room temperature to obtain a boron-resistant and salt-resistant polymer suspension emulsion.

[0053] Example 3: A method for preparing a boron-resistant and salt-tolerant polymer suspension emulsion, the method comprising the following preparation steps:

[0054] (1) By mass fraction, 4 parts of 1,3-bis(dimethylamino)-2-propanol and 20 parts of chloroform were mixed evenly. At room temperature, 300 r / min was used to add 3.04 parts of triethylamine at 8 ml / min, and then 0.018 parts of hydroquinone were added. At room temperature, the mixture was stirred at 300 r / min for 20 min. Then it was transferred to an ice-water bath and 14.22 parts of 30 wt% chloroform solution of oxaloyl chloride monoallyl ester was added at 3 ml / min. The mixture was reacted at room temperature at 300 r / min for 10 h. The mixture was heated to 40 °C and the reaction was continued for 10 h. 1.2 parts of sodium acetate were added and the reaction was continued for 20 h. The mixture was filtered, the filtrate was evaporated to dryness, dissolved in dichloromethane, washed and extracted with saturated sodium chloride aqueous solution, and the organic phase was concentrated and purified to obtain double bond modified tertiary amine.

[0055] (2) By mass fraction, 4 parts of double bond modified tertiary amine, 0.012 parts of hydroquinone and 30 parts of acetone were mixed evenly. At room temperature, 10.4 parts of 40wt% propanesulfonic acid lactone acetone solution were added dropwise at 5 ml / min at 300 r / min. The reaction was carried out at 55℃ and 400 r / min for 18 h. The mixture was filtered and washed 4 times with a 1:1 volume ratio of acetone and diethyl ether mixed solution. The mixture was then dried under vacuum at 60℃ for 8 h to obtain the amphoteric monomer.

[0056] (3) By mass fraction, 6 parts of double bond modified tertiary amine, 12.33 parts of 1-bromodecane, 0.017 parts of hydroquinone, 0.4 parts of potassium iodide, and 30 parts of acetonitrile were mixed evenly and reacted at 45°C and 400 r / min for 20 h. The solvent was removed by rotary evaporation, dissolved in ethanol, recrystallized with methyl tert-butyl ether, and then freeze-dried to obtain the hydrophobic monomer.

[0057] (4) By mass, 10 parts acrylamide, 2.04 parts maleic acid, 1.6 parts emulsifier and 25 parts pure water are mixed evenly, the pH is adjusted to 8, and 6.26 parts amphoteric monomer, 3.08 parts hydrophobic monomer and 0.016 parts initiator are added under nitrogen atmosphere. The mixture is reacted at 80℃ and 400r / min for 10h. After cooling naturally to room temperature, it is cut into pieces, washed 5 times with anhydrous ethanol, dried under vacuum at 65℃ for 8h, granulated and ground with a high-speed pulverizer, and passed through a 120-mesh sieve to obtain modified polyacrylamide.

[0058] (5) The formula according to the mass components is as follows: 5% of the mortar soil; 0.5% of the polyacrylonitrile ammonium salt; 1.5% of the organosilicone alcohol; 2% of the emulsified paraffin wax; 0.4% of the modified polyacrylamide; 2% of the boron inhibitor; and the balance is water. The mortar soil is pre-hydrated in 10 times its mass of water for 24 hours. Then, the polyacrylonitrile ammonium salt, organosilicone alcohol, emulsified paraffin wax, modified polyacrylamide, boron inhibitor and the remaining water are added. The mixture is stirred at 1000 rpm for 2 hours at room temperature to obtain a boron-resistant and salt-resistant polymer suspension emulsion.

[0059] Comparative Example 1:

[0060] The difference between the preparation method of the boron-resistant and salt-resistant polymer suspension emulsion of Comparative Example 1 and Example 2 lies in the different step (1). Step (1) is modified as follows: 3.5 parts by mass of 1,3-bis(dimethylamino)-2-propanol and 18 parts by mass of chloroform are mixed evenly. At room temperature, 2.66 parts by mass of triethylamine are added dropwise at 7.5 ml / min at 250 r / min, followed by 0.017 parts by mass of hydroquinone. The mixture is stirred at room temperature at 250 r / min for 25 min. Then, transfer the solution to an ice-water bath and add 12.44 parts of a 30wt% acryloyl chloride solution in chloroform at a rate of 2.5 ml / min at 250 rpm. React at room temperature and 250 rpm for 11 h, then heat to 38°C and continue the reaction for another 11 h. Add 1.1 parts of sodium acetate and continue the reaction for 22 h. Filter the solution, evaporate the filtrate to dryness, dissolve it in dichloromethane, wash and extract with a saturated sodium chloride aqueous solution, concentrate and purify the organic phase to obtain the double-bond modified tertiary amine. The remaining steps are the same as in Example 2.

[0061] Comparative Example 2:

[0062] The preparation method of the boron-resistant and salt-resistant polymer suspension emulsion in Comparative Example 2 differs from that in Example 2 in that step (2) is omitted, and step (4) is modified as follows: 9 parts by mass of acrylamide, 1.84 parts by mass of maleic acid, 1.55 parts by mass of emulsifier, and 22 parts by mass of pure water are mixed evenly, the pH is adjusted to 7.5, and under a nitrogen atmosphere, 2.77 parts by mass of hydrophobic monomer and 0.0155 parts by mass of initiator are added. The mixture is reacted at 78°C and 350 r / min for 11 h, naturally cooled to room temperature, cut into small pieces, washed four times with anhydrous ethanol, vacuum dried at 60°C for 9 h, granulated and ground using a high-speed pulverizer, and passed through a 120-mesh sieve to obtain modified polyacrylamide. The remaining steps are the same as in Example 2.

[0063] Comparative Example 3:

[0064] The preparation method of the boron-resistant and salt-resistant polymer suspension emulsion in Comparative Example 3 differs from that in Example 2 in that step (3) is omitted, and step (4) is modified as follows: 9 parts by mass of acrylamide, 1.84 parts by mass of maleic acid, 1.55 parts by mass of emulsifier, and 22 parts by mass of pure water are mixed evenly, the pH is adjusted to 7.5, and under a nitrogen atmosphere, 5.63 parts by mass of amphoteric monomer and 0.0155 parts by mass of initiator are added. The mixture is reacted at 78°C and 350 r / min for 11 h, naturally cooled to room temperature, cut into small pieces, washed four times with anhydrous ethanol, vacuum dried at 60°C for 9 h, granulated and ground using a high-speed pulverizer, and passed through a 120-mesh sieve to obtain modified polyacrylamide. The remaining steps are the same as in Example 2.

[0065] Comparative Example 4:

[0066] The preparation method of the boron-resistant and salt-resistant polymer suspension emulsion in Comparative Example 4 differs from that in Example 2 in that step (2) is omitted, and step (4) is modified as follows: 9 parts by mass of acrylamide, 1.55 parts by mass of emulsifier, and 22 parts by mass of pure water are mixed evenly, the pH is adjusted to 7.5, and under a nitrogen atmosphere, 2.46 parts by mass of methacryloyloxyethyltrimethylammonium chloride, 2.77 parts by mass of hydrophobic monomer, and 0.0155 parts by mass of initiator are added. The mixture is reacted at 78°C and 350 r / min for 11 h, naturally cooled to room temperature, cut into small pieces, washed four times with anhydrous ethanol, vacuum dried at 60°C for 9 h, granulated and ground using a high-speed pulverizer, and passed through a 120-mesh sieve to obtain modified polyacrylamide. The remaining steps are the same as in Example 2.

[0067] Test Example 1:

[0068] Salt and temperature resistance tests: The apparent viscosity, temperature-resistant viscosity retention rate, and salt-resistant viscosity retention rate of the prepared boron-resistant and salt-resistant polymer suspension emulsion were tested to evaluate its temperature and salt resistance properties. The specific test methods are as follows:

[0069] Apparent viscosity: 500 ml of the prepared boron-resistant and salt-tolerant polymer suspension emulsion was measured in a beaker and its viscosity at room temperature and a shear rate of 170 s⁻¹ was determined using a ZNND six-speed rotational viscometer. -1 The apparent viscosity of each sample was measured in parallel five times, and the average value was recorded.

[0070] Temperature resistance: The prepared boron-resistant and salt-resistant polymer suspension emulsion was heated at 90℃ for 2 hours, and its temperature resistance at a shear rate of 170 s⁻¹ was measured using a ZNND six-speed rotational viscometer. -1 The viscosity was measured and the viscosity retention rate was calculated and recorded as the temperature-resistant viscosity retention rate. Each group was tested in parallel for 5 times, and the average value was recorded.

[0071] Salt tolerance: A standard saline solution with a mineralization of 85000 mg / L was prepared by mixing 5.5% sodium chloride, 2.0% potassium chloride, 0.45% magnesium chloride, and 0.55% calcium chloride. The water in step (5) was replaced with the standard saline solution to prepare the sample. The saline solution was used to measure the salt tolerance at room temperature and a shear rate of 170 s⁻¹. -1 The viscosity was measured and the viscosity retention rate was calculated and recorded as the salt-resistant viscosity retention rate. Each group was tested in parallel for 5 times, and the average value was recorded.

[0072] The results are shown in Table 1.

[0073] Table 1

[0074] Apparent viscosity / mPa·s Temperature resistance viscosity retention Salt resistance viscosity retention Example 1 38.5 90.71% 126.39% Example 2 39.4 91.94% 127.29% Example 3 38.8 90.88% 125.44% Comparative Example 1 37.3 89.37% 121.57% Comparative Example 2 30.1 76.24% 73.24% Comparative Example 3 31.6 83.49% 114.68% Comparative Example 4 33.7 69.32% 44.89%

[0075] A comparison of the experimental data from Examples 1-3 and Comparative Examples 1-4 in Table 1 reveals that the boron-resistant and salt-tolerant polymer suspension emulsion prepared in this invention exhibits excellent salt and temperature resistance.

[0076] Comparing the data in the table, Comparative Example 2 shows that the addition of the amphoteric monomer increased the apparent viscosity, and its anti-polyelectrolyte effect played a role. Under high salt concentration, the viscosity did not decrease but increased, demonstrating good salt resistance. Furthermore, the amphoteric monomers self-associated with each other through electrostatic forces, effectively improving the temperature resistance. Comparative Example 3 shows that the addition of long carbon chains in the hydrophobic monomer resulted in better emulsification due to the increased lipophilicity, improving both temperature and salt resistance. Comparative Example 4 shows that the sulfonic acid group and the carboxyl group provided by maleic acid have a good synergistic effect with the quaternary ammonium cation. In the case of only cations, it does not have the anti-polyelectrolyte effect, and both temperature and salt resistance are significantly reduced.

[0077] Test Example 2:

[0078] Filtration loss reduction performance test: Refer to SY / T 5621-1993 to test the room temperature medium pressure filtration loss of the prepared boron-resistant and salt-resistant polymer suspension emulsion. Each group was tested in parallel for 5 times, and the average value was recorded.

[0079] The results are shown in Table 2.

[0080] Table 2

[0081] Filtration loss at room temperature / ml Filtration loss at room temperature / ml Example 1 4.1 Comparative Example 1 8.4 Example 2 3.9 Comparative Example 2 14.5 Example 3 4.2 Comparative Example 3 6.9 Comparative Example 4 7.8

[0082] A comparison of the experimental data from Examples 1-3 and Comparative Examples 1-4 in Table 2 reveals that the boron-resistant and salt-tolerant polymer suspension emulsion prepared in this invention exhibits excellent filtration loss reduction performance.

[0083] Comparing the data in the table, Comparative Example 1 shows that the addition of oxaloyl chloride monoallyl ester has better hydrogen bonding and complexation capabilities, exhibiting better performance than acryloyl chloride and effectively improving filtration loss reduction. Comparative Example 2 shows that the amphoteric monomer not only binds to clay through hydrogen bonds but also adheres to the clay surface through electrostatic adsorption. Anions such as carboxyl and sulfonic acid groups prevent free water molecules from contacting clay particles through hydration, effectively improving filtration loss reduction. Comparative Example 3 shows that the introduction of hydrophobic monomers also improves filtration loss reduction. The hydrophobic effect of the long carbon chain allows it to prevent free water from penetrating clay particles through hydrophobic association within a small area, thereby reducing filtration loss. Comparative Example 4 shows that the filtration loss reduction performance is insufficient when only cationic monomers are present. It needs to work synergistically with anions such as sulfonic acid and carboxyl groups to exert the effect of its amphoteric polymer and better improve the filtration loss reduction effect.

[0084] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a boron-resistant and salt-tolerant polymer suspension emulsion, characterized in that, The preparation steps include the following: (1) Mix 3-4 parts of 1,3-bis(dimethylamino)-2-propanol and 15-20 parts of chloroform evenly at room temperature, add 2.28-3.04 parts of triethylamine dropwise at 7-8 ml / min at 200-300 r / min, then add 0.016-0.018 parts of hydroquinone, stir at 200-300 r / min for 20-30 min at room temperature, and then transfer to an ice water bath. At a speed of 200-300 rpm, 10.67-14.22 parts of a chloroform solution of 30 wt% oxaloyl chloride monoallyl ester were added dropwise at a rate of 2-3 ml / min. The reaction was carried out at room temperature at 200-300 rpm for 10-12 h. The temperature was then raised to 35-40 °C and the reaction was continued for another 10-12 h. 1-1.2 parts of sodium acetate were added and the reaction was continued for another 20-24 h. The mixture was then filtered and purified to obtain a double-bond modified tertiary amine. (2) By mass fraction, 3-4 parts of double bond modified tertiary amine, 0.01-0.012 parts of hydroquinone, and 25-30 parts of acetone are mixed evenly. At room temperature, 7.8-10.4 parts of 40wt% propanesulfonic acid lactone acetone solution are added dropwise at 3-5 ml / min at 200-300 r / min. The mixture is reacted at 50-55℃ and 300-400 r / min for 18-20 h. After filtration, the mixture is washed 3-4 times with a 1:1 volume ratio of acetone and diethyl ether mixed solution. The mixture is then vacuum dried at 50-60℃ for 8-10 h to obtain the amphoteric monomer. (3) By mass fraction, 5-6 parts of double bond modified tertiary amine, 10.27-12.33 parts of 1-bromodecane, 0.015-0.017 parts of hydroquinone, 0.3-0.4 parts of potassium iodide, and 25-30 parts of acetonitrile are mixed evenly and reacted at 40-45℃ and 300-400r / min for 20-24h. The solvent is removed by rotary evaporation, dissolved in ethanol, recrystallized with methyl tert-butyl ether, and then freeze-dried to obtain the hydrophobic monomer. (4) Mix acrylamide, maleic acid, emulsifier and pure water, adjust pH, add amphoteric monomer, hydrophobic monomer and initiator under nitrogen atmosphere, heat to react, cool naturally, cut, wash, dry, granulate and grind, sieve to obtain modified polyacrylamide. (5) The formula based on mass components is as follows: 3%~5% of the mortar soil; 0.5%~0.8% of the polyacrylonitrile ammonium salt; Organosilicon alcohol, 1%~1.5%; emulsified paraffin wax, 2%~3%; modified polyacrylamide, 0.3%~0.4%; boron inhibitor, 0.5%~2%; balance is water; the prepared soil is first pre-hydrated in 10 times its weight of water for 24 hours, then polyacrylonitrile ammonium salt, organosilicon alcohol, emulsified paraffin wax, modified polyacrylamide, boron inhibitor and the remaining water are added, and stirred at 800~1000 rpm for 2~3 hours at room temperature to obtain a boron-resistant and salt-resistant polymer suspension emulsion; The boron inhibitor mentioned in step (5) is potassium carbonate.

2. The method for preparing a boron-resistant and salt-tolerant polymer suspension emulsion according to claim 1, characterized in that, The modified polyacrylamide in step (4) is prepared by mixing 8-10 parts acrylamide, 1.63-2.04 parts maleic acid, 1.5-1.6 parts emulsifier, and 20-25 parts pure water by mass, adjusting the pH to 7-8, adding 5-6.26 parts amphoteric monomer, 2.46-3.08 parts hydrophobic monomer, and 0.015-0.016 parts initiator under a nitrogen atmosphere, reacting at 75-80℃ and 300-400r / min for 10-12h, naturally cooling to room temperature, cutting into small pieces, washing with anhydrous ethanol 4-5 times, vacuum drying at 60-65℃ for 8-10h, granulating and grinding with a high-speed pulverizer, and passing through a 120-mesh sieve.

3. The method for preparing a boron-resistant and salt-tolerant polymer suspension emulsion according to claim 1, characterized in that, The emulsifier used in step (4) is OP-10.

4. The method for preparing a boron-resistant and salt-tolerant polymer suspension emulsion according to claim 1, characterized in that, The initiator in step (4) is one of azobisisobutyramidine hydrochloride and azobisisobutyronitrile.

5. The method for preparing a boron-resistant and salt-tolerant polymer suspension emulsion according to claim 1, characterized in that, The mortar used in step (5) is bentonite.

6. A boron-resistant and salt-resistant polymer suspension emulsion prepared by the method according to any one of claims 1 to 5.